[FFmpeg-trac] #5719(ffmpeg:new): Using -stream_loop is wrong duration output

[FFmpeg]

#5719: Using -stream_loop is wrong duration output
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             Reporter:  nicol       |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  ffmpeg
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Comment (by nicol):

 > `-stream_loop 1` means that the input stream should be used twice in the
 output stream (looped once) and this is what the documentation says:
 https://ffmpeg.org/ffmpeg-all.html#Main-options
 > If your input stream has 25 frames (does it?) then 50 output frames are
 correct or do I misunderstand?

 Yes, sample video is 25 frames, 1 second. Then use `-stream_loop 1`,
 output video is 50 frames(with movie), 2 seconds.

 ffmpeg -f lavfi -i testsrc2=d=1 -f lavfi -i anullsrc=r=48000:cl=stereo
 -shortest -vcodec libx264 -acodec aac sample.mkv

 This command output 50 frames, 2 seconds.
 ffmpeg.exe -stream_loop 1 -i sample.mkv -vcodec copy sample-v-copy.mp4 -y

 This command output 51 frames, 2 seconds.
 ffmpeg.exe -stream_loop 1 -i sample.mkv sample-no-copy.mp4 -y

 But, this command output 50 frames, '''27 seconds'''.
 ffmpeg.exe -v 9 -loglevel 99 -stream_loop 1 -i sample.mkv -c copy
 sample-c-copy.mp4 -y
 frame=   50 fps=0.0 q=-1.0 Lsize=      74kB time=00:00:27.00 bitrate=
 22.3kbits/s speed=3.41e+003x

 Sorry The seconds command, I mistook to wite command.
 output 50 frames, '''27 seconds'''.
 ffmpeg.exe -v 9 -loglevel 99 -stream_loop 1 -i sample.mkv -vcodec copy -an
 sample-v-copy-an.mp4 -y
 frame=   50 fps=0.0 q=-1.0 Lsize=      71kB time=00:00:26.88 bitrate=
 21.8kbits/s speed=1.12e+004x

 '''output 26 secnods''' without movie.
 ffmpeg.exe -v 9 -loglevel 99 -stream_loop 1 -i sample.mkv -acodec copy -vn
 sample-a-copy-vn.mp4 -y
 size=       2kB time=00:00:26.02 bitrate=   0.6kbits/s speed=4.38e+003x

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Ticket URL: <https://trac.ffmpeg.org/ticket/5719#comment:2>
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