Opened 11 years ago
Closed 14 months ago
#3433 closed defect (wontfix)
using "shortest" results in mismatched audio and video lengths
Reported by: | mjmvisser | Owned by: | |
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Priority: | normal | Component: | ffmpeg |
Version: | git-master | Keywords: | shortest |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
Summary of the bug:
"-shortest" does not add trim/atrim filters, so the length of each output stream will be a multiple of sample size. In the given example, the video is exactly 1s, but the resulting output is 1.02s. If "-t 1.000" is passed instead of "-shortest", the resulting output is exactly 1s.
The difference is that using "-t" adds trim/atrim filters, so the last frame->nb_samples encoded will be truncated to fit the given duration.
How to reproduce:
% ffmpeg -y -probesize 500000 -f image2 -r 25 -i colorbars.%04d.png -i 100Hz_44100Hz_16bit_05sec.wav -shortest -c:v png -c:a pcm_s16le -q:v 1 -2 -f mov colorbars.mov Note that input streams have durations of 5s and 1s. % ffprobe colorbars.mov Note that the output stream has a duration of 1.02s. ffmpeg version N-60960-gf3eef02 built on Feb 28 2014 10:31:20
Attachments (1)
Change History (3)
by , 11 years ago
Attachment: | ffmpeg-ticket-3433.zip added |
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comment:1 by , 11 years ago
I tried forcing the trim filter to be added if shortest=1, and finding & updating it at the same time of->recording_time is set in close_output_stream. No good, this has no effect because filter initialization is done before close_output_stream is called and libavfilter doesn't allow filters to be re-initialized.
comment:2 by , 14 months ago
Resolution: | → wontfix |
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Status: | new → closed |
-shortest cant add filters because it is working also for stream copy.
repro kit