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

[FFmpeg]

#9437: bursts of noise in alac output
---------------------------------------+-----------------------------------
             Reporter:  Nat Goodspeed  |                    Owner:  (none)
                 Type:  defect         |                   Status:  new
             Priority:  normal         |                Component:  avcodec
              Version:  4.3.2          |               Resolution:
             Keywords:  noise output   |               Blocked By:
             Blocking:                 |  Reproduced by developer:  0
Analyzed by developer:  0              |
---------------------------------------+-----------------------------------
Comment (by Nat Goodspeed):

 Replying to [comment:7 Elon Musk]:
 > Try with 4.4 instead.

 It took me a while, but I did retry with ffmpeg 4.4, this one built from
 MacPorts on a newer Mac:
 {{{
 $ ffmpeg -i "Everybody's Weird.ogg" -acodec alac "Everybody's Weird.m4a"
 ffmpeg version 4.4 Copyright (c) 2000-2021 the FFmpeg developers
   built with Apple clang version 12.0.5 (clang-1205.0.22.11)
   configuration: --prefix=/opt/local --enable-swscale --enable-avfilter
 --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-
 libopus --enable-librsvg --enable-libtheora --enable-libopenjpeg --enable-
 libmodplug --enable-libvpx --enable-libsoxr --enable-libspeex --enable-
 libass --enable-libbluray --enable-lzma --enable-gnutls --enable-
 fontconfig --enable-libfreetype --enable-libfribidi --enable-zlib
 --disable-libjack --disable-libopencore-amrnb --disable-libopencore-amrwb
 --disable-libxcb --disable-libxcb-shm --disable-libxcb-xfixes --disable-
 indev=jack --enable-opencl --disable-outdev=xv --enable-audiotoolbox
 --enable-videotoolbox --enable-sdl2 --disable-securetransport
 --mandir=/opt/local/share/man --enable-shared --enable-pthreads
 --cc=/usr/bin/clang --enable-libzimg --enable-libdav1d --arch=x86_64
 --enable-x86asm --enable-libx265 --enable-gpl --enable-postproc --enable-
 libx264 --enable-libxvid
   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
 Input #0, ogg, from 'Famous_Last_Words_-_ODDS14_Everybody's_Weird.ogg':
   Duration: 00:02:02.07, start: 0.000000, bitrate: 122 kb/s
   Stream #0:0: Audio: vorbis, 44100 Hz, stereo, fltp, 128 kb/s
     Metadata:
       title           : Everybody's Weird
       artist          : Famous Last Words
       album           : CDDB info not available
       track           : 14
       genre           : folk
       comment         : Produced using crip v3.7
 (http://bach.dynet.com/crip) on Sun Jun 10 20:19:07 EDT 2007
       sourcemedia     : CD
       discid          : 0d0c5d14
       encoding        : OggEnc v1.0.2 -q 4
       REPLAYGAIN_TRACK_PEAK: 0.91232300
       REPLAYGAIN_TRACK_GAIN: -3.94 dB
     Side data:
       replaygain: track gain - -3.940000, track peak - 0.000021, album
 gain - unknown, album peak - unknown,
 File 'Everybody's Weird.m4a' already exists. Overwrite? [y/N] y
 Stream mapping:
   Stream #0:0 -> #0:0 (vorbis (native) -> alac (native))
 Press [q] to stop, [?] for help
 [alac @ 0x7fd41100be00] encoding as 24 bits-per-sample
 Output #0, ipod, to 'Everybody's Weird.m4a':
   Metadata:
     encoder         : Lavf58.76.100
   Stream #0:0: Audio: alac (alac / 0x63616C61), 44100 Hz, stereo, s32p (24
 bit), 128 kb/s
     Metadata:
       title           : Everybody's Weird
       artist          : Famous Last Words
       album           : CDDB info not available
       track           : 14
       genre           : folk
       comment         : Produced using crip v3.7
 (http://bach.dynet.com/crip) on Sun Jun 10 20:19:07 EDT 2007
       sourcemedia     : CD
       discid          : 0d0c5d14
       encoding        : OggEnc v1.0.2 -q 4
       REPLAYGAIN_TRACK_PEAK: 0.91232300
       REPLAYGAIN_TRACK_GAIN: -3.94 dB
       encoder         : Lavc58.134.100 alac
     Side data:
       replaygain: track gain - -3.940000, track peak - 0.000021, album
 gain - unknown, album peak - unknown,
 size=   21573kB time=00:02:02.04 bitrate=1448.1kbits/s speed= 178x
 video:0kB audio:21566kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 0.032725%
 }}}

 The song is still interrupted by frequent bursts of static. I could post
 the output file, but to me it sounds just like the one I already linked
 above.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9437#comment:8>
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