---
updatedAt: 2026-02-11T11:12:48.000Z
agentTools:
  projectIndex: https://api.encoding.com/llms.txt
---

# Audio Settings

<a name="audiosettings"></a>Encoding.com's API supports a vast amount of codecs via both open source and commercial engines.  For AAC, AC-3, E-AC3, and HE-AACv1 and v2, Dolby's engine is available at no additional cost for licensed content creation by their own engines.

Support for [Dolby Atmos](ref:dmg-atmos) is covered in a distinct section.

```xml
<?xml version="1.0"?>
<query>
    <userid>[UserID]</userid> <!-- required-->
    <userkey>[UserKey]</userkey> <!-- required-->
    <action>addMedia</action> <!-- required-->
    <source>[SourceFile]</source> <!-- required-->
    <format> <!-- required -->
        <output>[output]</output> <!-- required -->
        <audio_codec>[AudioCodec]</audio_codec>
        <audio_bitrate>[BitRate]</audio_bitrate>
        <acbr>[yes|no]</acbr>
        <audio_sample_rate>[SampleRate]</audio_sample_rate>
        <audio_channels_number>[ChannelsNumber]</audio_channels_number>
        <audio_volume>[Volume]</audio_volume>
        <copy_audio_streams>[Audio streams]</copy_audio_streams>
        <audio_sync>[SyncParam]</audio_sync>
        <pan>[Pan]</pan>
        <audio_minrate>[MinBitRate]</audio_minrate>
        <audio_maxrate>[MaxBitRate]</audio_maxrate>
        <audio_bufsize>[BufferSize]</audio_bufsize>
        <loudnorm>[LoudnessNormalization]</loudnorm>
        <loudnorm_range>[NormalizationRange]</loudnorm_range>
        <loudnorm_peak>[NormalizationPeak]</loudnorm_peak>
        <audio_only>[yes|no]</audio_only>
        <aac_signaling_mode>[SignalingMode]</aac_signaling_mode>
        <dolby_cbr>[yes|no]</dolby_cbr>
        <audio_encoder>[auto|dee]</audio_encoder>
        <audio_profile>[AACProfile]</audio_profile>
        <auto_audio_trim>[yes|no]</auto_audio_trim>
        <!-- format params -->
    </format>
</query>
```
```json
{
    "query": {
        "userid": "[UserID]", // required
        "userkey": "[UserKey]", // required
        "action": "[Action]", // required
        "source": "[SourceFile]", // required
        "format": {
            "output": "[output]", // required
            "audio_codec": "[AudioCodec]",
            "audio_bitrate": "[BitRate]",
            "acbr": "[yes|no]",
            "audio_sample_rate": "[SampleRate]",
            "audio_channels_number": "[ChannelsNumber]",
            "audio_volume": "[Volume]",
            "copy_audio_streams": "[Audio streams]",
            "audio_sync": "[SyncParam]",
            "pan": "[Pan]",
            "audio_minrate": "[MinBitRate]",
            "audio_maxrate": "[MaxBitRate]",
            "audio_bufsize": "[BufferSize]",
            "loudnorm": "[LoudnessNormalization]",
            "loudnorm_range": "[NormalizationRange]",
            "loudnorm_peak": "[NormalizationPeak]",
            "audio_only": "[yes|no]",
            "aac_signaling_mode": "[SignalingMode]",
            "dolby_cbr": "[yes|no]",
            "audio_encoder": "[auto|dee]",
            "audio_profile": "[AACProfile]",
            "auto_audio_trim": "[yes|no]"
            // format params
        }
    }
}
```

| Parameter                   | Description                                                                                                                 | Allowed Value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | Default Value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| :-------------------------- | :-------------------------------------------------------------------------------------------------------------------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **audio\_codec**            | Specify the audio codec                                                                                                     | **mp3**: libmp3lame  <br/>**m4a**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2, eac3, eac3joc  <br/>**flv**: libmp3lame, libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2  <br/>**mp4**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2, ac3, eac3, eac3joc  <br/>**fl9**, **m4v**, **ipod**, **iphone**, **ipad**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2  <br/>**wowza**, **roku\_\***, **kindle\_fire**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2, eac3, eac3joc  <br/>**mov**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2, eac3, eac3joc, pcm\_s24le, pcm\_s24be, pcm\_f32be, pcm\_f32le, dolbye  <br/>**iphone\_stream**, **ipad\_stream**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2  <br/>**wowza\_multibitrate**, **hds**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2, eac3, eac3joc  <br/>**smooth\_streaming**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2, eac3, eac3joc  <br/>**advanced\_hls**, **fmp4\_hls**, **advanced\_dash**, **advanced\_fmp4**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2, ac3, eac3, eac3joc  <br/>**fmp4\_hls**, **advanced\_dash**, **advanced\_fmp4**: libfaac, dolby\_aac, libfdk\_aac, dolby\_heaac, dolby\_heaacv2, ac3, eac3, eac3joc  <br/>**wmv**, **wma**, **zune**: wmav2, libmp3lame  <br/>**wav**: pcm\_s16le, pcm\_s24le, pcm\_s32le  <br/>**ogg**, **webm**: libvorbis  <br/>**android**: libamr\_nb, libfaac, libfdk\_aac  <br/>**mpeg2**: pcm\_s16be, pcm\_s16le, ac3  <br/>**mpeg1**: mp2, copy  <br/>**mpegts**: ac3, eac3, eac3joc, libfaac, libfdk\_aac, libmp3lame, mp2, dolby\_aac, dolby\_heaac, dolby\_heaacv2, copy  <br/>**mpeg\_dash**: libfaac, libfdk\_aac, eac3, eac3joc  <br/>**mxf**: pcm\_s16le, pcm\_s24le, pcm\_s24be, copy  <br/>**dnxhd\_mxf**: pcm\_s16le, pcm\_s24le, copy  <br/>**apple\_prores**: copy, pcm\_s16le, pcm\_s24le, pcm\_s32le, libfaac, libfdk\_aac  <br/>**cablelabs\_mpegts**: ac3, s302m, mp2  <br/>**mainconcept\_mxf**: pcm\_s16le, pcm\_s24le, copy  <br/>**mxf\_op1a**: pcm\_s16le, pcm\_s24le, pcm\_s24be, dolbye, copy  <br/>**mxf\_as11**: copy | **flv, mp3**: libmp3lame  <br/>**fl9, mp4, m4v, ipod, iphone, ipad, wowza, kindle\_fire**: libfaac  <br/>**mov**: libfaac  <br/>**iphone\_stream, ipad\_stream, wowza\_multibitrate, smooth\_streaming, hds**: libfaac  <br/>**advanced\_hls**, **fmp4\_hls**, **advanced\_dash**, **advanced\_fmp4**: libfaac  <br/>**wmv, zune: wmav2<br/>wav**: pcm\_s16le  <br/>**ogg, webm**: libvorbis  <br/>**android**: libamr\_nb  <br/>**mpeg2**: pcm\_s16be  <br/>**mpeg1**: mp2  <br/>**m4a**: libfaac  <br/>**mpeg\_dash**: libfaac  <br/>**mpegts**: ac3  <br/>**mxf**: pcm\_s24le  <br/>**dnxhd\_mxf**: pcm\_s16le  <br/>**apple\_prores**: pcm\_s24le  <br/>**mainconcept\_mxf**: pcm\_s24le  <br/>**mxf\_op1a**: pcm\_s24le  <br/>**mxf\_as11**: copy |
| **audio\_bitrate**          | Specify the audio bitrate.                                                                                                  | Nk – where N is any non-zero integer.  <br/>  <br/>**flv, wmv, mp3, wma, zune**: 32k, 40k, 48k, 56k, 64k, 80k, 96k, 112k, 128k, 144k, 160k, 192k, 224k, 256k, 320k  <br/>**ogg, webm**: 45k,64k, 80k, 96k, 112k, 128k, 160k, 192k, 224k, 256k, 320k, 500k                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | **All**: 64k  <br/>**android**: 12.2k  <br/>**ipod**, **iphone**, **ipad**: 128k                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| **acbr**                    | Enable CBR (Constant bitrate) for audio streams. Only for vorbis (Ogg, Webm).                                               | yes, no                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | no                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| **audio\_sample\_rate**     | Specify the audio sampling frequency (Hz).                                                                                  | **All**: any non-zero integer  <br/>**flv, mp3**: 11025, 22050, 44100  <br/>**ogg, webm**: 16000, 32000, 44100, 22050, 11025, 192000  <br/>**wmv, wma, zune**: 11025, 22050, 32000, 44100, 48000  <br/>**mpeg2**: 44100, 48000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | **All**: none  <br/>**mp4**: 44100  <br/>**android**: 8000  <br/>**flv, mp3, zune, mpeg2**: 44100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| **audio\_channels\_number** | Specify the number of audio channels.                                                                                       | **All**: any non-zero integer  <br/>**android**: 1, 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | **All**: 2  <br/>**android**: 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| **audio\_volume**           | Specify audio volume level as a percentage.                                                                                 | Non-negative integer                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| **copy\_audio\_streams**    | Specify audio streams to be passed to the output.                                                                           | Comma separated non-negative integers, or all or auto                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | auto                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| **audio\_sync**             | Adjusts the audio stream to match the timestamps, in number of samples per second. 1 is special value that means automatic. | positive integer or auto if you want us to handle audio synchronization issues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **pan**                     | Enable the selection and remapping of audio channels.                                                                       | output\_audio\_chanel,input\_audio\_channel:output\_audio\_chanel,input\_audio\_channel  <br/>Example: 0,0:1,1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **audio\_minrate**          | Specify minimum allowed audio bitrate.                                                                                      | N or Nk — where N is any non-zero integer                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **audio\_maxrate**          | Specify the maximum allowed audio bitrate.                                                                                  | N or Nk — where N is any non-zero integer                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **audio\_bufsize**          | Specify rate control buffer size (bits).                                                                                    | N or Nk — where N is any non-zero integer                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **loudnorm**                | Specify the integrated loudness target.                                                                                     | Negative float number from -70.0 to -5.0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **loudnorm\_range**         | Specify the loudness range target.                                                                                          | Positive float number from 1.0 to 20.0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **loudnorm\_peak**          | Specify the maximum true peak.                                                                                              | Float number from -9.0 to 0.0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **audio\_only**             | Use only audio streams in output                                                                                            | yes, no                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | no                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| **aac\_signaling\_mode**    | Audio signaling mode                                                                                                        | sbr-implicit, sbr-explicit-nbc, sbr-explicit-compatible, sbr-and-ps-explicit-nbc, sbr-and-ps-explicit-compatible                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **dolby\_cbr**              | Turn dolby aac/heaac/heaacv2 encode to mp4 container instead of raw audio stream to make an audio CBR output.               | yes, no                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | no                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| **audio\_encoder**          | Select what audio encoder will be used for eac3 audio codec                                                                 | auto, dee                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **audio\_profile**          | AAC audio profile                                                                                                           | aac\_low, aac\_he, aac\_he\_v2, aac\_ld, aac\_eld, mpeg2\_aac\_low                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | *none*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **auto\_audio\_trim**       | Auto trim audio track if it's duration is longer than video duration                                                        | yes, no                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | no                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |

> 🚧 Note
>
> If you specify the **audio\_codec** as 'copy', the options **audio\_channels\_number**, **audio\_sample\_rate**, **audio\_bitrate** will be ignored and their values will be copied from your source file.

> 🚧 Note
>
> **audio\_volume parameter** will not work with \*dolby\_\*\* audio codecs if [audio\_normalization](https://api.encoding.com/reference/dmg-loudness-control) or [input\_dialnorm](https://api.encoding.com/reference/dmg-loudness-control) parameters are set.

> 🚧 Note
>
> **copy\_audio\_streams parameter** is only applicable for mp4, mov, apple\_prores output formats and audio\_codec = copy.

> 👍 EBU Requirements
>
> **loudnorm**: -23\
> **loudnorm\_range**: 1\
> **loudnorm\_peak**: -1
>
> [EBU Guidelines](https://tech.ebu.ch/docs/techreview/trev_297-spikofski_klar.pdf)

> 👍 FCC Requirements
>
> The CALM Act prohibits broadcasters from broadcasting commercials at a louder volume than their accompanying programming.  The information below outlines the US requirements.
>
> **loudnorm**: between -23 and -25 LKFS\
> **loudnorm\_peak**: -2\
> No requirement for range.
>
> [FCC Guidelines](https://www.fcc.gov/document/commercial-advertisement-loudness-mitigation-calm-act)

> ❗️ Note
>
> **Loudnorm** feature not supported by [advanced multibitrate](https://api.encoding.com/reference/advanced-mbr) formats.

> 🚧 Note
>
> **Loudnorm** feature doesn’t affect Dolby audio

> 🚧 For audio\_only parameter
>
> **\<audio\_only />** parameter works only for **mp4** and **mpegts** output formats.

> 🚧 For aac\_signaling\_mode parameter
>
> **\<aac\_signaling\_mode />** parameter works only with **dolby\_heeac** and **dolby\_heeacv2** audio codecs.

> 🚧 For audio\_profile
>
> **\<audio\_profile />** parameter works only with **libfdk\_aac** audio codec.