[FFmpeg-trac] #9437(avcodec:new): bursts of noise in alac output

[FFmpeg]

#9437: bursts of noise in alac output
---------------------------------------+----------------------------------
             Reporter:  Nat Goodspeed  |                     Type:  defect
               Status:  new            |                 Priority:  normal
            Component:  avcodec        |                  Version:  4.3.2
             Keywords:  noise output   |               Blocked By:
             Blocking:                 |  Reproduced by developer:  0
Analyzed by developer:  0              |
---------------------------------------+----------------------------------
 Summary of the bug:

 Converting a particular 2-minute .ogg file to ALAC as .m4a produces a file
 containing brief bursts of white noise every couple seconds. This seems
 reminiscent of #2497, which was closed as fixed 8 years ago. Also that one
 only complained of a single burst of noise.

 Moreover, although iTunes correctly reports the song duration as 2:02, at
 about 1:12 (after 16 such bursts) iTunes abruptly stops playing.

 The whole point of attempting this conversion is to be able to play my
 nontrivial collection of .ogg files on iTunes, hence it must be a format
 understood by that player. I want to convert to ALAC rather than plain AAC
 since the original .ogg files are already lossy and I don't want to
 degrade the quality in conversion. This is the first song file I've tried,
 but results so far are hardly encouraging.

 How to reproduce:
 {{{
 % ffmpeg -i songfile.ogg -acodec alac songfile.m4a
 ffmpeg is quite recently installed from MacPorts:
 ffmpeg version 4.4 Copyright (c) 2000-2021 the FFmpeg developers
   built with Apple LLVM version 10.0.0 (clang-1000.10.44.4)
   ...
   libavutil      56. 70.100 / 56. 70.100
   libavcodec     58.134.100 / 58.134.100
   libavformat    58. 76.100 / 58. 76.100
   libavdevice    58. 13.100 / 58. 13.100
   libavfilter     7.110.100 /  7.110.100
   libavresample   4.  0.  0 /  4.  0.  0
   libswscale      5.  9.100 /  5.  9.100
   libswresample   3.  9.100 /  3.  9.100
   libpostproc    55.  9.100 / 55.  9.100
 }}}

 I selected Version 4.3.2 in the pulldown since I don't see version 4.4
 there.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9437>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker