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Old 7th May 2021, 11:13   #2  |  Link
tebasuna51
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Join Date: Feb 2005
Location: Spain
Posts: 6,890
Thanks FranceBB for let we know that audio format supported in mp4 but than can't be played by lav filters (mpc-hc).

Just for add some info, I try to extract using MP4Box:
Quote:
MP4Box -raw 2: IPCM_Sample.MP4
[iso file] Unknown box type rtmd in parent stsd
[IsoMedia] Track 3 type rtmd not natively handled
Exporting PCM s24 SampleRate 48000 2 channels 24 bits per sample
And output a file IPCM_Sample_track2.ipcm

Loaded it in eac3to show:
Quote:
This might be a RAW/PCM file. Trying to figure out the details.
This will probably take a while. Please be patient...
The RAW/PCM file seems to be big endian.
The RAW/PCM file seems to have a bitdepth of 24 bits.
The RAW/PCM file seems to have 2 channels.
RAW/PCM, 2.0 channels, 0:00:10, 24 bits, 2304kbps, 48kHz
Also can be recoded to any format, without the detection, using:
eac3to IPCM.ipcm IPCM.flac -override -2 -24 -big -48000

Of course the audio is bit-identical to the obtained with:
Quote:
ffmpeg.exe -c:a pcm_s24be -i %1 -acodec pcm_s24le -ar 48000 -ac 2 -y out1.wav
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