Audio Settings

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 is covered in a distinct section.

<?xml version="1.0"?>
<query>
    <userid><<id>></userid> <!-- required-->
    <userkey><<key>></userkey> <!-- required-->
    <action>addMedia</action>
    <source>[SourceFile]</source>
    <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>
        <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>
{
    "query": {
        "userid": "<<id>>", // required
        "userkey": "<<key>>", // 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]",
            "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
m4a: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2, eac3, eac3joc
flv: libmp3lame, libfaac, dolby_aac, dolby_heaac, dolby_heaacv2
mp4: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2, ac3, eac3, eac3joc
fl9, m4v, ipod, iphone, ipad, psp: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2
wowza, roku_*, kindle_fire: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2, eac3, eac3joc
mov: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2, eac3, eac3joc, pcm_f32be, pcm_f32le
iphone_stream, ipad_stream: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2
wowza_multibitrate, wowza_multibitrate_mp4, roku_hls, hds: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2, eac3, eac3joc
smooth_streaming: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2, eac3, eac3joc
advanced_hls, fmp4_hls, advanced_dash, advanced_fmp4: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2, ac3, eac3, eac3joc
fmp4_hls, advanced_dash, advanced_fmp4: libfaac, dolby_aac, dolby_heaac, dolby_heaacv2, ac3, eac3, eac3joc
live hls stream: libfaac, ac3
wmv, wma, zune: wmav2, libmp3lame
wav: pcm_s16le, pcm_s24le, pcm_s32le
ogg, webm: libvorbis
3gp: libamr_nb
android: libamr_nb, libfaac
mpeg2: pcm_s16be, pcm_s16le, ac3
mpeg1: mp2, copy
mpegts: ac3, eac3, eac3joc, libfaac, libmp3lame, mp2, dolby_aac, dolby_heaac, dolby_heaacv2, copy
mpeg_dash: libfaac, eac3, eac3joc
mxf: pcm_s16le, pcm_s24le, copy
dnxhd_mxf: pcm_s16le, pcm_s24le, copy
apple_prores: pcm_s16le, pcm_s24le, pcm_s32le, libfaac
mainconcept_mxf: pcm_s16le, pcm_s24le, copy

flv, mp3: libmp3lame
fl9, mp4, m4v, ipod, iphone, ipad, psp, wowza, roku_*, kindle_fire: libfaac
mov: libfaac
iphone_stream, ipad_stream, wowza_multibitrate, wowza_multibitrate_mp4, roku_hls, smooth_streaming, hds: libfaac
advanced_hls, fmp4_hls, advanced_dash, advanced_fmp4: libfaac
wmv, zune: wmav2
wav
: pcm_s16le
ogg, webm: libvorbis
3gp, android: libamr_nb
mpeg2: pcm_s16be
mpeg1: mp2
m4a: libfaac
mpeg_dash: libfaac
mpegts: ac3
mxf: pcm_s24le
dnxhd_mxf: pcm_s16le
apple_prores: pcm_s24le
mainconcept_mxf: pcm_s24le

audio_bitrate

Specify the audio bitrate.

Nk – where N is any non-zero integer.

3gp: 4.75k, 5.15k, 5.9k, 6.7k, 7.4k, 7.95k, 10.2k, 12.2k
flv, wmv, mp3, wma, zune: 32k, 40k, 48k, 56k, 64k, 80k, 96k, 112k, 128k, 144k, 160k, 192k, 224k, 256k, 320k
ogg, webm: 45k,64k, 80k, 96k, 112k, 128k, 160k, 192k, 224k, 256k, 320k, 500k

All: 64k
3gp, android: 12.2k
ipod, iphone, ipad, psp: 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
3gp: 8000
flv, mp3: 11025, 22050, 44100
ogg, webm: 16000, 32000, 44100, 22050, 11025, 192000
wmv, wma, zune: 11025, 22050, 32000, 44100, 48000
mpeg2: 44100, 48000

All: none
mp4: 44100
3gp, android: 8000
flv, mp3, zune, mpeg2: 44100

audio_channels_number

Specify the number of audio channels.

All: any non-zero integer
3gp: 1
android: 1, 2

All: 2
3gp, android: 1

audio_volume

Specify audio volume level as a percentage.

Non-negative integer

100

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
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

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 or input_dialnorm parameters are set.

👍

EBU Requirements

loudnorm: -23
loudnorm_range: 1
loudnorm_peak: -1

EBU Guidelines

👍

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

❗️

Note

Loudnorm feature not supported by advanced multibitrate formats.

🚧

Note

Loudnorm feature doesn’t affect Dolby audio

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For audio_only parameter

<audio_only /> parameter works only for mp4 and mpegts output formats.

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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.