[FFmpeg-user] ProRes422 with 8 audio tracks converted to mp4 -- muffles audio 4

Harvey Pikelberger communque at gmail.com
Tue Nov 20 05:28:10 EET 2018


Testing the creation of 8-audio-channel mp4 proxies from ProRes422 sources using ffmpeg.
For some reason audio channel 4 of the mp4 is coming back muffled, like it got drowned in a pool.

Recently tested using DNxHD mxf files -- same audio configuration and everything worked perfectly.
The the ProRes file is the exact same content.

The code:

ffmpeg -i SoundMappingTest-H8Discreet.mov  -map 0 -g 48 -c:v libx264 -profile:v baseline -crf 16 -c:a aac -b:a 256k -vf scale=1280:720 -pix_fmt yuv420p SoundMappingTest-H8Discreet.mp4


The stdout:

ffmpeg version 4.0.2 Copyright (c) 2000-2018 the FFmpeg developers
  built with Apple LLVM version 10.0.0 (clang-1000.10.44.2)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0.2_1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gpl --enable-libmp3lame --enable-libopus --enable-libsnappy --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-chromaprint --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-librsvg --enable-librtmp --enable-librubberband --enable-libsoxr --enable-libssh --enable-libtesseract --enable-libvidstab --enable-libwebp --enable-libzimg --enable-libzmq --enable-opencl --enable-openssl --enable-videotoolbox --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/2.3.0/include/openjpeg-2.3 --enable-nonfree
  libavutil      56. 14.100 / 56. 14.100
  libavcodec     58. 18.100 / 58. 18.100
  libavformat    58. 12.100 / 58. 12.100
  libavdevice    58.  3.100 / 58.  3.100
  libavfilter     7. 16.100 /  7. 16.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  1.100 /  5.  1.100
  libswresample   3.  1.100 /  3.  1.100
  libpostproc    55.  1.100 / 55.  1.100
Guessed Channel Layout for Input Stream #0.1 : 7.1
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'SoundMappingTest-H8Discreet.mov':
  Metadata:
    major_brand     : qt  
    minor_version   : 537199360
    compatible_brands: qt  
    creation_time   : 2018-11-20T03:09:22.000000Z
  Duration: 00:00:36.70, start: 0.000000, bitrate: 115812 kb/s
    Stream #0:0(eng): Video: prores (apcn / 0x6E637061), yuv422p10le(bt709, progressive), 1920x1080, 109439 kb/s, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 24k tbn, 24k tbc (default)
    Metadata:
      creation_time   : 2018-11-20T03:09:22.000000Z
      handler_name    : Apple Alias Data Handler
      encoder         : Apple ProRes 422
      timecode        : 00:00:00:00
    Stream #0:1(eng): Audio: pcm_s16le (lpcm / 0x6D63706C), 48000 Hz, 7.1, s16, 6144 kb/s (default)
    Metadata:
      creation_time   : 2018-11-20T03:09:22.000000Z
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
    Stream #0:2(eng): Data: none (tmcd / 0x64636D74) (default)
    Metadata:
      creation_time   : 2018-11-20T03:09:22.000000Z
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
Stream mapping:
  Stream #0:0 -> #0:0 (prores (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (pcm_s16le (native) -> aac (native))
  Stream #0:2 -> #0:2 (copy)
Press [q] to stop, [?] for help
[libx264 @ 0x7fcaf5819200] using SAR=1/1
[libx264 @ 0x7fcaf5819200] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x7fcaf5819200] profile Constrained Baseline, level 3.1
[libx264 @ 0x7fcaf5819200] 264 - core 152 r2854 e9a5903 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=0 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=48 keyint_min=4 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=16.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[mp4 @ 0x7fcaf5818000] You requested a copy of the original timecode track so timecode metadata are now ignored
Output #0, mp4, to 'SoundMappingTest-H8Discreet.mp4':
  Metadata:
    major_brand     : qt  
    minor_version   : 537199360
    compatible_brands: qt  
    encoder         : Lavf58.12.100
    Stream #0:0(eng): Video: h264 (libx264) (avc1 / 0x31637661), yuv420p(progressive), 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 23.98 fps, 24k tbn, 23.98 tbc (default)
    Metadata:
      creation_time   : 2018-11-20T03:09:22.000000Z
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
      encoder         : Lavc58.18.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 7.1, fltp, 256 kb/s (default)
    Metadata:
      creation_time   : 2018-11-20T03:09:22.000000Z
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
      encoder         : Lavc58.18.100 aac
    Stream #0:2(eng): Data: none (tmcd / 0x64636D74) (default)
    Metadata:
      creation_time   : 2018-11-20T03:09:22.000000Z
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
frame=  880 fps= 56 q=-1.0 Lsize=   20539kB time=00:00:36.71 bitrate=4582.8kbits/s speed=2.34x    
video:19371kB audio:1148kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.096736%
[libx264 @ 0x7fcaf5819200] frame I:25    Avg QP:12.97  size: 76022
[libx264 @ 0x7fcaf5819200] frame P:855   Avg QP:15.71  size: 20976
[libx264 @ 0x7fcaf5819200] mb I  I16..4: 24.5%  0.0% 75.5%
[libx264 @ 0x7fcaf5819200] mb P  I16..4:  8.4%  0.0%  6.3%  P16..4: 47.6% 19.5%  6.0%  0.0%  0.0%    skip:12.2%
[libx264 @ 0x7fcaf5819200] coded y,uvDC,uvAC intra: 43.4% 73.1% 33.9% inter: 18.9% 43.1% 2.0%
[libx264 @ 0x7fcaf5819200] i16 v,h,dc,p: 41% 23% 13% 23%
[libx264 @ 0x7fcaf5819200] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 28% 23% 16%  5%  7%  6%  5%  5%  4%
[libx264 @ 0x7fcaf5819200] i8c dc,h,v,p: 48% 21% 23%  8%
[libx264 @ 0x7fcaf5819200] ref P L0: 68.7% 20.5% 10.8%
[libx264 @ 0x7fcaf5819200] kb/s:4323.39
[aac @ 0x7fcaf581aa00] Qavg: 133.287


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