[FFmpeg-trac] #3327(avformat:new): libavformat fails to detect some mp3 files reliably
FFmpeg
trac at avcodec.org
Mon Jan 27 12:08:13 CET 2014
#3327: libavformat fails to detect some mp3 files reliably
------------------------------------+------------------------------------
Reporter: gjdfgh | Owner:
Type: defect | Status: new
Priority: normal | Component: avformat
Version: git-master | Resolution:
Keywords: mp3 | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
------------------------------------+------------------------------------
Comment (by gjdfgh):
>So you agree that what FFmpeg reports is correct? After all, it does
report the correct file type or do I miss something?
I'm doing this for a video player. I do not want libavformat to
"recognize" random binary files as media files (which it does often with
low probescore/probesize), OTOH I sure want it do detect simple mp3 files.
Usually this works great by requiring at least AVPROBE_SCORE_RETRY+1,
except for some mp3 files.
So yes, I see a problem here.
>Define "reliably": Afaict, for the file in question, FFmpeg succeeds with
auto-detection (which is apparently not trivial, see "other"
applications), I don't find "I am not 100% sure" so bad for mp3 files with
large attachments.
I wouldn't mind feeding a few megabytes of mp3 data to the probe function
in the case of large attachments, but even then it doesn't "work".
No, I do not want to play back ELF files as mp3, which is why I think some
work is needed here.
>*Please* provide such samples!
Uploaded issue3327-libc-2.17.so. It's recognized as mp3, and even decodes
some audio artifacts.
>>Using the file extension instead of the sophisticated probing in
mp3_read_probe would be more reliable.
>This opinion seems to be in strong contrast to what FFmpeg stands for
(since forever) and most people always saw that as one of the largest
advantages over WMP etc.
I generally agree that it's better to determine the file format by content
and not by extension. However, although this is quite a pathological case,
the bad mp3 detection does lead to user complaints. And lowering the
probescore for file detection isn't a solution either, because you get too
many false positives.
(For now I've special cased mp3 in my player, so strictly speaking this is
not an issue for me anymore.)
--
Ticket URL: <https://trac.ffmpeg.org/ticket/3327#comment:7>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list