[FFmpeg-trac] #8464(avformat:closed): `outpoint` directive of `concat` demuxer may be off by 1 frame
FFmpeg
trac at avcodec.org
Mon Jan 13 06:37:50 EET 2020
#8464: `outpoint` directive of `concat` demuxer may be off by 1 frame
-------------------------------------+-------------------------------------
Reporter: gdgsdg123 | Owner:
Type: enhancement | Status: closed
Priority: normal | Component: avformat
Version: git-master | Resolution:
| worksforme
Keywords: concat | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Changes (by gdgsdg123):
* resolution: invalid => worksforme
Comment:
The [http://trac.ffmpeg.org/attachment/ticket/8464/merge.avi
""merge.avi""] also serves as a good example for testing the cutting
accuracy.
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[[BR]]
The file is entirely composed of "Black Screen" frames with only 3
exceptions:
||= Frame Number =||= Presentation Timestamp =||= Duration =||= Content
=||
|| 564|| 87.05|| 0.033333|| Yellow ||
|| 595|| 88.083333|| 0.033334|| Green ||
|| 596|| 88.116667|| N/A|| Red ||
Which resemble all 3 possible outcomes: on point, early, late.
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----
Another thing: possible 0 frame output (null segment) without warning...
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[[BR]]
X.txt:
{{{
file 'merge.avi'
inpoint 87.05
outpoint 87.05
}}}
[[BR]]
{{{
ffmpeg -y -f concat -safe 0 -i "X.txt" -c copy "temp.avi"
}}}
{{{
ffmpeg version git-2020-01-10-3d894db Copyright (c) 2000-2020 the FFmpeg
developers
built with gcc 9.2.1 (GCC) 20191125
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-
fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-
libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg
--enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr
--enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack
--enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2
--enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-
libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc
--enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
--enable-amf
libavutil 56. 38.100 / 56. 38.100
libavcodec 58. 65.103 / 58. 65.103
libavformat 58. 35.101 / 58. 35.101
libavdevice 58. 9.103 / 58. 9.103
libavfilter 7. 70.101 / 7. 70.101
libswscale 5. 6.100 / 5. 6.100
libswresample 3. 6.100 / 3. 6.100
libpostproc 55. 6.100 / 55. 6.100
Input #0, concat, from 'X.txt':
Duration: 00:00:00.00, bitrate: N/A
Stream #0:0: Video: h264 (High 4:4:4 Intra) (H264 / 0x34363248),
gbrp(tv, gbr/unknown/unknown, progressive), 256x144, 60 fps, 30 tbr, 60
tbn, 60 tbc
Output #0, avi, to 'temp.avi':
Metadata:
ISFT : Lavf58.35.101
Stream #0:0: Video: h264 (High 4:4:4 Intra) (H264 / 0x34363248),
gbrp(tv, gbr/unknown/unknown, progressive), 256x144, q=2-31, 60 fps, 30
tbr, 60 tbn, 60 tbc
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame= 0 fps=0.0 q=-1.0 Lsize= 6kB time=00:00:00.00 bitrate=N/A
speed= 0x
video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: unknown
}}}
[[BR]]
[[BR]]
{{{
ffmpeg -ss 87.05 -to 87.05 -i "merge.avi" -an -c copy "to.avi"
}}}
{{{
ffmpeg version git-2020-01-10-3d894db Copyright (c) 2000-2020 the FFmpeg
developers
built with gcc 9.2.1 (GCC) 20191125
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-
fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-
libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg
--enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr
--enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack
--enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2
--enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-
libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc
--enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
--enable-amf
libavutil 56. 38.100 / 56. 38.100
libavcodec 58. 65.103 / 58. 65.103
libavformat 58. 35.101 / 58. 35.101
libavdevice 58. 9.103 / 58. 9.103
libavfilter 7. 70.101 / 7. 70.101
libswscale 5. 6.100 / 5. 6.100
libswresample 3. 6.100 / 3. 6.100
libpostproc 55. 6.100 / 55. 6.100
-to value smaller than -ss; aborting.
}}}
[[BR]]
[[BR]]
The `inpoint`/`-ss`, `outpoint`/`-to` values must be carefully chosen.
[[BR]]
[[BR]]
[[BR]]
[[BR]]
**Off-Topic**
[[BR]]
Is it yet possible to instruct FFmpeg to report the number of frames of
each segment? (when using `concat` demuxer)
--
Ticket URL: <https://trac.ffmpeg.org/ticket/8464#comment:5>
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