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Stereo master soundtrack
17 octobre 2011, par
Mis à jour : Octobre 2011
Langue : English
Type : Audio
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Langue : English
Type : Audio
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Mis à jour : Février 2013
Langue : English
Type : Audio
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Langue : English
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Sur d’autres sites (2141)
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How to calculate vmaf score of multi-resolution webm using ffmpeg ?
13 juillet 2022, par willI’m trying to calculate the
vmaf
of two videos, one isavi
(rawvideo(I420), yuv420p), the other iswebm
(vp8, yuv420p). I uploaded test video and vmaf log here.

But I found that if it’s a multi-resolution webm, the scores obtained with and without fps filter are quite different. Without fps filter the vmaf score is
34.670390
, with fps filter the vmaf score is56.339923
.

If it‘s a single resolution webm, there is no significant difference between the scores obtained with and without fps filter. Without fps filter the vmaf score is
65.527304
, with fps filter the vmaf score is65.480217
.

I use these commands.


without fps filter


ffmpeg \
 -r 15 -i reference.avi \
 -r 15 -i distorted.webm \
 -lavfi "[0:v]setpts=PTS-STARTPTS[reference]; \
 [1:v]scale=1920:1080:flags=bicubic,setpts=PTS-STARTPTS[distorted]; \
 [distorted][reference]libvmaf=log_fmt=json:log_path=vmaf_without_fps.log:model_path=vmaf_v0.6.1.json:n_threads=10:ssim=1:psnr=1" \
 -f null -



ffmpeg version 4.4.1 Copyright (c) 2000-2021 the FFmpeg developers
 built with Apple clang version 12.0.0 (clang-1200.0.32.29)
 configuration: --prefix=/usr/local/Cellar/ffmpeg/4.4.1_3 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-avresample --enable-videotoolbox
 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, avi, from 'reference.avi':
 Metadata:
 software : Lavf58.76.100
 Duration: 00:00:26.13, start: 0.000000, bitrate: 373260 kb/s
 Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1920x1080, 374202 kb/s, 15 fps, 15 tbr, 15 tbn, 15 tbc
Input #1, matroska,webm, from 'distorted.webm':
 Metadata:
 encoder : Chrome
 Duration: N/A, start: 0.000000, bitrate: N/A
 Stream #1:0(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
 Stream #1:1(eng): Video: vp8, yuv420p(progressive), 1920x1080, SAR 1:1 DAR 16:9, 1k tbr, 1k tbn, 1k tbc (default)
 Metadata:
 alpha_mode : 1
Stream mapping:
 Stream #0:0 (rawvideo) -> setpts (graph 0)
 Stream #1:1 (vp8) -> scale (graph 0)
 libvmaf (graph 0) -> Stream #0:0 (wrapped_avframe)
 Stream #1:0 -> #0:1 (opus (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
libvmaf INFO `compute_vmaf()` is deprecated and will be removed in a future libvmaf version
Output #0, null, to 'pipe:':
 Metadata:
 software : Lavf58.76.100
 encoder : Lavf58.76.100
 Stream #0:0: Video: wrapped_avframe, yuv420p(tv, bt470bg/unknown/unknown, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 15 fps, 15 tbn (default)
 Metadata:
 encoder : Lavc58.134.100 wrapped_avframe
 Stream #0:1(eng): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s (default)
 Metadata:
 encoder : Lavc58.134.100 pcm_s16le
[libvmaf @ 0x7feb8a606a80] VMAF score: 58.1203705.87 bitrate=N/A speed= 5.6x 
libvmaf INFO `compute_vmaf()` is deprecated and will be removed in a future libvmaf version
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 0
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 1
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 2
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 3
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 4
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 5
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 6
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 7
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 8
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 9
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 10
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 11
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 12
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 13
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 14
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 15
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 16
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 17
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 18
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 19
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 20
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 21
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 22
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 23
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 24
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 25
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 26
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 27
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 28
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 29
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 30
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 31
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 32
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 33
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 34
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 35
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 36
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 37
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 38
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 39
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 40
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 41
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 42
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 43
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 44
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 45
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 46
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 47
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 48
[null @ 0x7feb8b04da00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49 >= 49
frame= 392 fps= 36 q=-0.0 Lsize=N/A time=00:00:28.73 bitrate=N/A speed= 2.6x 
video:205kB audio:5400kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
[libvmaf @ 0x7feb8c405bc0] VMAF score: 34.670390



with fps filter


ffmpeg \
 -r 15 -i reference.avi \
 -r 15 -i distorted.webm \
 -lavfi "[0:v]setpts=PTS-STARTPTS[reference]; \
 [1:v]fps=fps=15,scale=1920:1080:flags=bicubic,setpts=PTS-STARTPTS[distorted]; \
 [distorted][reference]libvmaf=log_fmt=json:log_path=vmaf_with_fps.log:model_path=vmaf_v0.6.1.json:n_threads=10:ssim=1:psnr=1" \
 -f null -



ffmpeg version 4.4.1 Copyright (c) 2000-2021 the FFmpeg developers
 built with Apple clang version 12.0.0 (clang-1200.0.32.29)
 configuration: --prefix=/usr/local/Cellar/ffmpeg/4.4.1_3 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-avresample --enable-videotoolbox
 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, avi, from 'reference.avi':
 Metadata:
 software : Lavf58.76.100
 Duration: 00:00:26.13, start: 0.000000, bitrate: 373260 kb/s
 Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1920x1080, 374202 kb/s, 15 fps, 15 tbr, 15 tbn, 15 tbc
Input #1, matroska,webm, from 'distorted.webm':
 Metadata:
 encoder : Chrome
 Duration: N/A, start: 0.000000, bitrate: N/A
 Stream #1:0(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
 Stream #1:1(eng): Video: vp8, yuv420p(progressive), 1920x1080, SAR 1:1 DAR 16:9, 1k tbr, 1k tbn, 1k tbc (default)
 Metadata:
 alpha_mode : 1
Stream mapping:
 Stream #0:0 (rawvideo) -> setpts (graph 0)
 Stream #1:1 (vp8) -> fps (graph 0)
 libvmaf (graph 0) -> Stream #0:0 (wrapped_avframe)
 Stream #1:0 -> #0:1 (opus (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
libvmaf INFO `compute_vmaf()` is deprecated and will be removed in a future libvmaf version
Output #0, null, to 'pipe:':
 Metadata:
 software : Lavf58.76.100
 encoder : Lavf58.76.100
 Stream #0:0: Video: wrapped_avframe, yuv420p(tv, bt470bg/unknown/unknown, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 15 fps, 15 tbn (default)
 Metadata:
 encoder : Lavc58.134.100 wrapped_avframe
 Stream #0:1(eng): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s (default)
 Metadata:
 encoder : Lavc58.134.100 pcm_s16le
[libvmaf @ 0x7fdeab00bac0] VMAF score: 58.3160815.27 bitrate=N/A speed=5.08x 
libvmaf INFO `compute_vmaf()` is deprecated and will be removed in a future libvmaf version
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 0
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 1
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 2
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 3
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 4
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 5
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 6
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 7
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 8
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 9
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 10
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 11
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 12
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 13
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 14
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 15
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 16
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 17
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 18
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 19
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 20
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 21
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 22
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 23
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 24
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 25
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 26
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 27
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 28
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 29
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 30
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 31
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 32
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 33
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 34
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 35
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 36
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 37
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 38
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 39
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 40
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 41
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 42
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 43
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 44
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 45
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 46
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 47
[null @ 0x7fdeab84ba00] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 48 >= 48
frame= 391 fps= 36 q=-0.0 Lsize=N/A time=00:00:28.73 bitrate=N/A speed=2.62x 
video:205kB audio:5400kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
[libvmaf @ 0x7fdea9f34a00] VMAF score: 56.339923



I'm curious about what causes such a difference ? And how to calculate vmaf score of multi-resolution webm correctly ?


-
ffmpeg concat doesn't sync to manual frame by frame concatenation
5 juillet 2022, par memoI have hundreds of short (10-120seconds) videos (H264 mp4) with audio (aac). (let's call these 'clips'). All identical video and audio codecs, resolution, framerate, crf, pixel format, sample rate etc.


concat_demux :


If I concat these with ffmpeg concat (demuxer), I get a single nice H264 mp4 with audio perfectly synced to the video (as expected).


cmd_args = ['ffmpeg',
 '-f concat',
 '-safe 0',
 f'-i "{output_filelist_path}"',
 '-c copy',
 '-y',
 '-r 30', # trying this out of desperation
 f'"{output_concat_demux}"'
 ]

cmd = ' '.join(cmd_args)
r = subprocess.call(cmd, shell=True, cwd=args.output_dir)



frame_by_frame :


However, if I manually iterate every frame of every clip video and write the frames to an mp4 using skvideo.io, this video drifts out of sync with the concat_demux version.


input_dict = { '-r':str(fps) } 
output_dict = { '-r':str(fps), '-pix_fmt':'yuv420p', '-vcodec':'libx264', '-crf':'18' }
video_writer = skvideo.io.FFmpegWriter(output_path, inputdict=input_dict, outputdict=output_dict) 

for video_path in video_paths:
 video = skvideo.io.vread(video_path) # read all frames into np.array
 for frame in video:
 video_writer.writeFrame(frame)
video_writer.close()



When I compare these two files in a video editor (e.g. AfterEffects) and step through frame by frame, I can see that with every new clip, the frame_by_frame version slips 1 or 2 frames ahead of the ffmpeg concat_demux version. What is going on ? How can I fix - or at least debug - this ?


On a side note, I do need to concatenate manually frame by frame, as I'm also doing a ton of other stuff (triggering events on clip change, overlaying additional elements etc). And I need to be able to sync a concatenated audio. I was hoping to concatenate the video manually frame by frame and do my post-processing, and then mux with the audio from the ffmpeg concat_demux version. But alas they drift out of sync.



(I've found quite a few posts on SO where the problem is using ffmpeg concat results in videos which are out of sync with the audio. However, this is not my problem. My video created with ffmpeg concat is perfectly in sync with the audio, but it's out of sync with a manually frame-by-frame concatenated video.)



Update - concat_protocol


I've tried using the concat protocol. Now the output of this gives a file where the video is frame synced to the frame_by_frame version, BUT the audio is synced to the audio of the concat_demux version. So its audio is out of sync with the video.


intermediate_paths = []
for p in clip_file_list:
 intermediate_path = os.path.join(args.output_dir, 'intermediate', os.path.basename(p) + '.ts')
 intermediate_paths.append(intermediate_path)
 cmd_args = ['ffmpeg',
 f'-i "{p}"',
 '-c copy -bsf:v h264_mp4toannexb -f mpegts -y',
 f'"{intermediate_path}"'
 ]

 cmd = ' '.join(cmd_args)
 r = subprocess.call(cmd, shell=True, cwd=args.output_dir)


intermediate_paths = '|'.join(intermediate_paths)
cmd_args = ['ffmpeg',
 f'-i "concat:{intermediate_paths}"',
 '-c copy -bsf:a aac_adtstoasc',
 f'"{output_concat_path}"'
 ]

cmd = ' '.join(cmd_args)
r = subprocess.call(cmd, shell=True, cwd=args.output_dir)



I am getting loads of errors like below


corrupt input packet in stream 0
[mp4 @ 0x137e043d0] Non-monotonous DTS in output stream 0:1; previous: 83027966, current: 83027198; changing to 83027967. This may result in incorrect timestamps in the output file.




here's the info on the two output files. Input #0 is the ffmpeg concat_demux. Input #1 is the manual frame-by-frame. Note the concat.mp4 has a framerate of 29.94 fps. I'm not sure if this is the problem. I couldn't figure out how to make this 30 (see '-r 30' in the ffmpeg concat command above)


ffmpeg version 5.0.1 Copyright (c) 2000-2022 the FFmpeg developers
 built with Apple clang version 13.1.6 (clang-1316.0.21.2.5)
 configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/5.0.1_2 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-neon
 libavutil 57. 17.100 / 57. 17.100
 libavcodec 59. 18.100 / 59. 18.100
 libavformat 59. 16.100 / 59. 16.100
 libavdevice 59. 4.100 / 59. 4.100
 libavfilter 8. 24.100 / 8. 24.100
 libswscale 6. 4.100 / 6. 4.100
 libswresample 4. 3.100 / 4. 3.100
 libpostproc 56. 3.100 / 56. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'clips_concat.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf59.16.100
 Duration: 00:01:43.22, start: 0.000000, bitrate: 5412 kb/s
 Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 5276 kb/s, 29.94 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'clips_frames.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf59.16.100
 Duration: 00:01:43.00, start: 0.000000, bitrate: 4917 kb/s
 Stream #1:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080, 4914 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]




here's info on first few clips (the manual concat is already 2 frames out of sync with the ffmpeg concat version by the second clip !)


ffmpeg version 5.0.1 Copyright (c) 2000-2022 the FFmpeg developers
 built with Apple clang version 13.1.6 (clang-1316.0.21.2.5)
 configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/5.0.1_2 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-neon
 libavutil 57. 17.100 / 57. 17.100
 libavcodec 59. 18.100 / 59. 18.100
 libavformat 59. 16.100 / 59. 16.100
 libavdevice 59. 4.100 / 59. 4.100
 libavfilter 8. 24.100 / 8. 24.100
 libswscale 6. 4.100 / 6. 4.100
 libswresample 4. 3.100 / 4. 3.100
 libpostproc 56. 3.100 / 56. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'clip_1080px_0.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:05.02, start: 0.000000, bitrate: 3944 kb/s
 Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 3818 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 131 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'clip_1080px_1.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:05.02, start: 0.000000, bitrate: 4557 kb/s
 Stream #1:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 4438 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #1:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]
Input #2, mov,mp4,m4a,3gp,3g2,mj2, from 'clip_1080px_2.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:11.02, start: 0.000000, bitrate: 5447 kb/s
 Stream #2:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 5320 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #2:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]
Input #3, mov,mp4,m4a,3gp,3g2,mj2, from 'clip_1080px_3.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:11.02, start: 0.000000, bitrate: 5978 kb/s
 Stream #3:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 5851 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #3:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]
Input #4, mov,mp4,m4a,3gp,3g2,mj2, from 'clip_1080px_4.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:16.02, start: 0.000000, bitrate: 6570 kb/s
 Stream #4:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 6441 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #4:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]
Input #5, mov,mp4,m4a,3gp,3g2,mj2, from 'clip_1080px_5.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:13.02, start: 0.000000, bitrate: 5069 kb/s
 Stream #5:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 4940 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #5:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]
Input #6, mov,mp4,m4a,3gp,3g2,mj2, from 'clip_1080px_6.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:22.02, start: 0.000000, bitrate: 4775 kb/s
 Stream #6:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 4642 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #6:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]
Input #7, mov,mp4,m4a,3gp,3g2,mj2, from 'clip_1080px_7.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:22.02, start: 0.000000, bitrate: 5402 kb/s
 Stream #7:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1080x1080 [SAR 1:1 DAR 1:1], 5269 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
 Metadata:
 handler_name : VideoHandler
 vendor_id : [0][0][0][0]
 Stream #7:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
 Metadata:
 handler_name : SoundHandler
 vendor_id : [0][0][0][0]



-
avcodec/v4l2_m2m : Check if the file descriptor is valid before closing
28 juin 2022, par Wujian(Chin)