[FFmpeg-devel] ffmpeg - message requesting help
GeoffC
geoffc at mail.ru
Wed Jun 16 17:05:47 EEST 2021
Hello.
I'm responding to a request for help with ffmpeg that was output in a terminal
error message via mpv media player.
Full details are below but briefly, I'm on MX Linux 19.4 and using mpv/ffmpeg to
play a movie MKV file with TrueHD audio (bitstreamed through an AV Receiver, in
case that's relevant).
Initially the playback works fine, and remains so if left uninterrupted (at
least as far as I've watched it, not the whole movie).
However if I jump directly to a new point in the movie by e.g clicking in the
time bar or skipping to next chapter, then sometimes - but not always - the
audio is lost. The video plays ok from the new point but the audio sometimes
drops out completely.
When this happens, an error message is output to the terminal regarding an
unusual "samples per frame" value as shown in the terminal output below, along
with a request to help by uploading a sample.
I've created a 5-minute sample that I hope is enough, but the
videolanfileuploader seems to require a gitlab ticket number that I don't have
yet - what is the procedure now?.
A web search on the message showed only one result for the message, it was in
the source code of module avformat/spdifenc, specifically a fix for handling of
large TrueHD frames. This is part of a "sanity check" added by anssih and
committed on 20 Feb 2020 (
https://github.com/FFmpeg/FFmpeg/commit/36e156bef02566d70cea46cc5e00b3e5d5ed3286#diff-86f89550175526d713fb8dd01b291190197a0014c46b9d9e40896ceadfa4b562R474
):-
---------
/* sanity check */
if (padding_remaining < 0 || padding_remaining >= MAT_FRAME_SIZE / 2) {
avpriv_request_sample(s, "Unusual frame timing: %"PRIu16" =>
%"PRIu16", %d samples/frame",
ctx->truehd_prev_time, input_timing,
ctx->truehd_samples_per_frame);
padding_remaining = 0;
}
---------
I think (?) I'm safe in saying that the very latest ffmpeg snapshot will not
make a difference in this case.
Details:-
The following terminal output shows 3 jumps to new positions where the audio
failed and the 3 error messages. On my 4th. jump the audio came back.
Interestingly the 3 pairs of numbers are different but the offending value is
always 40.
------------
Terminal output:-
$ mpv --vo=gpu --profile=gpu-hq "/media/vgx/ML1/The Da Vinci Code
(2006)/DaVinciCode.mkv"
(+) Video --vid=1 (*) (h264 1920x1080 23.976fps)
(+) Audio --aid=1 --alang=eng (*) (truehd 6ch 48000Hz)
(+) Subs --sid=1 --slang=eng (*) (f) (hdmv_pgs_subtitle)
ALSA lib conf.c:5014:(snd_config_expand) Unknown parameters
AES0=6,AES1=130,AES2=0,AES3=14
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM
default:AES0=6,AES1=130,AES2=0,AES3=14
AO: [alsa] 192000Hz 7.1 8ch spdif-truehd
VO: [gpu] 1920x1080 yuv420p
AV: 00:10:59 / 02:54:37 (6%) A-V: 0.000 Cache: 0.0s
[ffmpeg] spdif: Unusual frame timing: 6744 => 40915, 40 samples/frame is not
implemented. Update your FFmpeg version to the newest one from Git. If the
problem still occurs, it means that your file has a feature which has not been
implemented.
[ffmpeg] spdif: If you want to help, upload a sample of this file to
https://streams.videolan.org/upload/ and contact the ffmpeg-devel mailing list.
(ffmpeg-devel at ffmpeg.org)
AV: 00:18:08 / 02:54:37 (10%) A-V: 0.000 Cache: 0.0s
[ffmpeg] spdif: Unusual frame timing: 3352 => 35793, 40 samples/frame is not
implemented. Update your FFmpeg version to the newest one from Git. If the
problem still occurs, it means that your file has a feature which has not been
implemented.
[ffmpeg] spdif: If you want to help, upload a sample of this file to
https://streams.videolan.org/upload/ and contact the ffmpeg-devel mailing list.
(ffmpeg-devel at ffmpeg.org)
AV: 00:24:23 / 02:54:37 (13%) A-V: 0.000 Cache: 0.0s
[ffmpeg] spdif: Unusual frame timing: 39704 => 1989, 40 samples/frame is not
implemented. Update your FFmpeg version to the newest one from Git. If the
problem still occurs, it means that your file has a feature which has not been
implemented.
[ffmpeg] spdif: If you want to help, upload a sample of this file to
https://streams.videolan.org/upload/ and contact the ffmpeg-devel mailing list.
(ffmpeg-devel at ffmpeg.org)
(Paused) AV: 00:24:30 / 02:54:37 (14%) A-V: 0.000 Cache: 20s/43MB
Exiting... (Quit)
---------End of terminal output
---------
mpv details:-
mpv 0.32.0 Copyright © 2000-2020 mpv/MPlayer/mplayer2 projects
built on UNKNOWN
ffmpeg library versions:
libavutil 56.22.100 (runtime 56.51.100)
libavcodec 58.35.100 (runtime 58.91.100)
libavformat 58.20.100 (runtime 58.45.100)
libswscale 5.3.100 (runtime 5.7.100)
libavfilter 7.40.101 (runtime 7.85.100)
libswresample 3.3.100 (runtime 3.7.100)
ffmpeg version: 4.3.2-0+deb11u1~mx19+1
------------End of mpv details
------------
ffmpeg details:-
$ ffmpeg
ffmpeg version 4.3.2-0+deb11u1~mx19+1 Copyright (c) 2000-2021 the FFmpeg developers
built with gcc 8 (Debian 8.3.0-6)
configuration: --prefix=/usr --extra-version='0+deb11u1~mx19+1'
--toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu
--incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl
--disable-stripping --enable-avresample --disable-filter=resample
--enable-gnutls --enable-ladspa --enable-libaom --enable-libass
--enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio
--enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig
--enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm
--enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg
--enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq
--enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh
--enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265
--enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2
--enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2
--enable-pocketsphinx --enable-libmfx --enable-libdc1394 --enable-libdrm
--enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264
--enable-shared
libavutil 56. 51.100 / 56. 51.100
libavcodec 58. 91.100 / 58. 91.100
libavformat 58. 45.100 / 58. 45.100
libavdevice 58. 10.100 / 58. 10.100
libavfilter 7. 85.100 / 7. 85.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 7.100 / 5. 7.100
libswresample 3. 7.100 / 3. 7.100
libpostproc 55. 7.100 / 55. 7.100
-------------End of ffmpeg details
Best regards
Geoff
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