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<p style="margin:0px 0px 1em;padding:0px;border:0px;font-size:15px;clear:both;color:rgb(36,39,41);font-family:arial,"helvetica neue",helvetica,sans-serif">
> I am trying to write a C program that demuxes audio from an MP4 file and write demuxed AVPacket data to a file. But the resulting dump is missing ADTS headers. Any pointers on what is the best way to add ADTS headers.</p>
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> I see that ffmpeg has 'adtsenc.c' file that seems to implement an ADTS muxer:</p>
<pre style="margin-top:0px;margin-bottom:1em;padding:5px;border:0px;font-size:13px;width:auto;max-height:600px;overflow:auto;font-family:consolas,menlo,monaco,"lucida console","liberation mono","dejavu sans mono","bitstream vera sans mono","courier new",monospace,sans-serif;background-color:rgb(239,240,241);word-wrap:normal;color:rgb(36,39,41)"><code style="margin:0px;padding:0px;border:0px;font-family:consolas,menlo,monaco,"lucida console","liberation mono","dejavu sans mono","bitstream vera sans mono","courier new",monospace,sans-serif;white-space:inherit">AVOutputFormat ff_adts_muxer = {
.name = "adts",
.long_name = NULL_IF_CONFIG_SMALL("ADTS AAC (Advanced Audio Coding)"),
.mime_type = "audio/aac",
.extensions = "aac,adts",
.priv_data_size = sizeof(ADTSContext),
.audio_codec = AV_CODEC_ID_AAC,
.video_codec = AV_CODEC_ID_NONE,
.write_header = adts_write_header,
.write_packet = adts_write_packet,
.write_trailer = adts_write_trailer,
.priv_class = &adts_muxer_class,
.flags = AVFMT_NOTIMESTAMPS,
};</code></pre>
<p style="margin:0px 0px 1em;padding:0px;border:0px;clear:both"><font color="#242729" face="arial,helvetica neue,helvetica,sans-serif"><span style="font-size:15px">> Can I use this muxer for my purpose? If yes, any links on how to use it?</span></font></p>
<p style="margin:0px 0px 1em;padding:0px;border:0px;clear:both"><font color="#242729" face="arial,helvetica neue,helvetica,sans-serif"><span style="font-size:15px">> Thanks in advance,</span></font></p>
<p style="margin:0px 0px 1em;padding:0px;border:0px;clear:both"><font color="#242729" face="arial,helvetica neue,helvetica,sans-serif"><span style="font-size:15px">> Malik</span></font></p>
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<div>Malik – Yes, use the adtsenc encoder to add ADTS headers to AAC encoded audio. (if that’s the output media)</div>
<div>See <a href="https://ffmpeg.org/doxygen/2.6/transcode_aac_8c-example.html">https://ffmpeg.org/doxygen/2.6/transcode_aac_8c-example.html</a></div>
<div>For the output format, you can do avformat_alloc_output_context2(&m_format_context, NULL, "adts", NULL)</div>
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