Broken MPEG Audio decoding

See following thread: https://forum.videolan.org/viewtopic.php?f=35&t=119033

Same issue on desktop with --codec=avcodec Works fine with avplay.

See #11743 (closed)

Do we have libmad in VLC/Android?

The mp3 parser has to be used for this sample (AVSTREAM_PARSE_HEADERS).

Added attachment:

• Young Sherlock Holmes 1985 Dual Audio [Hindi-Eng] YATESH POONIA(00h01m00s-00h01m12s)-002.mkv

Added attachment:

• Young Sherlock Holmes 1985 Dual Audio YATESH POONIA_0013.mkv

The problem happens only when the demux is matroska and the codec is avcodec. (no problems with avformat/avcodec and matroska/mpeg_audio)

Libav reports that the header is missing: ff_mpa_check_header() fails from mpegaudiodec_template.c.

I think the problem come from vlc/modules/demuxer/mkv or libmatroska I don't know.

assigned to @typx

This file broken. The frames coming from track 2 (MP3 audio) are not properly packetized.

The VLC mpeg_audio decoder is buffering data are looking for a proper MP3 frame boundary by itself. See http://git.videolan.org/?p=vlc.git;a=blob;f=modules/codec/mpeg_audio.c;h=936b1fa24d522eca6ef06c9e37f8976e1594177a;hb=HEAD#l231

But the libavcodec MPEG audio decoder assumes the data are properly packetized and since the frames are never starting with 0xFFFE the packets are just discarded.

One solution could be to force a buffering packetizer when feeding MP3 to libavcodec.

changed milestone to %3.0.0

commit 9d5d8ab5 Author: Steve Lhomme robUx4@videolabs.io Date: Wed Feb 25 16:01:08 2015 +0100

MKV: force packetization of MPEG audio frames

Fixes [#11479](https://code.videolan.org/videolan/vlc/-/issues/11479)
The file has some MP3 frames, but the frames are not packetized correctly in the Matroska file (spec violation)

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Original author: robUx4@videolabs.io

added Status::fixed label

closed

Milestone renamed

changed milestone to %3.0 FF

Milestone renamed

mentioned in issue #11743 (closed)