Thanks a lot, Sergey! I got it.
On Fri, Jul 26, 2013 at 1:56 PM, Sergey Fedorov < [email protected]> wrote: > ‘-r[:stream_specifier] fps (input/output,per-stream)’ > > Set frame rate (Hz value, fraction or abbreviation). > > As an input option, ignore any timestamps stored in the file and > instead generate timestamps assuming constant frame rate fps. > > As an output option, duplicate or drop input frames to achieve > constant output frame rate fps. > > > 2013/7/23 Liang Zhang <[email protected]>: > > Hello, > > > > I'm learning how to use libav to decode the video data into YUV. I try to > > use ffmpeg commend line and also use the example program "demuxing" > which is > > provided in ffmpeg documentation. It surprised me that both resulted in > > different frame number. > > > > I use the following ffmpeg commend line > > > > ffmpeg -y -i sample.mp4 -an -r 24 -pix_fmt rgb24 -vcodec tiff > tif/%06d.tif > > > > to decode one video data file and get, e.g., 1460 frames. > > > > Then, I used the example program "demuxing" > > > > demuxing sample.mp4 out_video out_audio > > > > to decode the same file and I got 1821 frames. > > > > Can someone help me explain why the frame number is different with these > two > > methods? > > > > FYI, I run the program in Ubuntu operating system. > > > > Thanks, > > > > > > > > liang > > > > _______________________________________________ > > Libav-user mailing list > > [email protected] > > http://ffmpeg.org/mailman/listinfo/libav-user > > > _______________________________________________ > Libav-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/libav-user >
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