On Mon, Aug 11, 2025 at 11:37:55AM +0300, quink wrote: > PR #20212 opened by quink > URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20212 > Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20212.patch > > A set of files begins with the following byte sequence. > > 00000000 4c 41 4d 45 33 2e 31 30 30 aa aa aa aa aa aa aa |LAME3.100.......| > 00000010 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa |................| > * > > It seems they are encoded with lame, but missing header bytes at the > beginning. > > Signed-off-by: Zhao Zhili <zhiliz...@tencent.com> > > > From e24f7b8d0fbc4295b3dfc9832d7b552086f45ff0 Mon Sep 17 00:00:00 2001 > From: Zhao Zhili <zhiliz...@tencent.com> > Date: Mon, 11 Aug 2025 15:23:36 +0800 > Subject: [PATCH] avformat/mp3dec: Workaround mp3 detection failure > > A set of files begins with the following byte sequence. > > 00000000 4c 41 4d 45 33 2e 31 30 30 aa aa aa aa aa aa aa |LAME3.100.......| > 00000010 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa |................| > * > > It seems they are encoded with lame, but missing header bytes at the > beginning. > > Signed-off-by: Zhao Zhili <zhiliz...@tencent.com> > --- > libavformat/mp3dec.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c > index 31eeb68ebb..fd692a9c76 100644 > --- a/libavformat/mp3dec.c > +++ b/libavformat/mp3dec.c > @@ -121,8 +121,11 @@ static int mp3_read_probe(const AVProbeData *p) > // issues with MPEG-files! > if (first_frames>=7) return AVPROBE_SCORE_EXTENSION + 1; > else if (max_frames>200 && p->buf_size < 2*max_framesizes)return > AVPROBE_SCORE_EXTENSION; > - else if (max_frames>=4 && p->buf_size < 2*max_framesizes) return > AVPROBE_SCORE_EXTENSION / 2; > - else if (ff_id3v2_match(buf0, ID3v2_DEFAULT_MAGIC) && > 2*ff_id3v2_tag_len(buf0) >= p->buf_size) > + else if (max_frames>=4 && p->buf_size < 2*max_framesizes) { > + if (!memcmp(p->buf, "LAME3.100", sizeof("LAME3.100") - 1)) > + return AVPROBE_SCORE_EXTENSION - 2; > + return AVPROBE_SCORE_EXTENSION / 2; > + } else if (ff_id3v2_match(buf0, ID3v2_DEFAULT_MAGIC) && > 2*ff_id3v2_tag_len(buf0) >= p->buf_size)
why is this needed ? Naively i would expect that the probe code would detect a mp3 stream like this based on max_frames why does that fail ? as what is teh stream detected instead ? maybe whatever detects it, is wrong instead and can be improved by not missdetecting it thx [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB If the United States is serious about tackling the national security threats related to an insecure 5G network, it needs to rethink the extent to which it values corporate profits and government espionage over security.-Bruce Schneier
signature.asc
Description: PGP signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
