On Sat, Feb 7, 2015 at 6:05 PM, Cristiano Chieppa <cristiano.chie...@gmail.com> wrote: > I save the raw frames (NALs) in a file (some frames grabbed from a camera) > and I invoke the ffmpeg from the sw - like a batch program - to encode the > raw H264 in MP4. > The conversion works well.
Out of curiosity, how exactly are you doing it? Is the file basically an Annex B stream? > Sometimes, under circumstance that I’m not able to understand, I see that > the generated mp4 video is like “accelerated”: the speed is very fast compare > with the real stream. > Is there a way to invoke ffmpeg and tell him, as a parameter, the timestamp > of each grabbed frames to get the real synchronized video? ffmpeg -r 25 -i input output This is how you force the frame rate. Actually, when you do "ffmpeg -i input -c:v libx264 output.h264", the output file indicates the frame rate when you read it back in with "ffmpeg -i output.h264". And when you force a different frame rate, with for example "ffmpeg -i input -c:v libx264 -r 12 output.h264", this frame rate change is visible when doing "ffmpeg -i output.h264". This is due to the timing information being written into the Sequence Parameter Set (SPS). _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
