On Wed, Apr 28, 2010 at 1:45 PM, Ferenc Deak <[email protected]> wrote: > Hi all, > > I have the following situation here: I need to implement a small tool which > cuts the first X (10 or 20, 30, ...) seconds out of a movie clip, and writes > the result in a new file. > > What I do is very similar to the initialization/opening phase from ffplay.c: > > 1. Open the file (av_open_input_file, av_find_stream_info) > 2. Seek to the required position (avformat_seek_file) > 3. Setup the codecs (including check for global headers > 4. Create an output context (AVFormatContext based on AVOutputFormat) > 5. Open the output file (url_fopen) > 6. Write the output header > 7. loop starts: read a packet from the input file (av_read_frame) > 8. modify the packet's time to be zero based (PTS, DTS) > 9. write the packet to the output > 10. go to 7 if we have more packets to read > 11. write_trailer, close the files. > 12. done > > Now, here comes the problem. It has a small "bug" (probably in the logic) : > after the app runs and "cuts" the file it seems that the players don't see > the video stream anymore, so they display the first video frame and after > this only the audio is being played. I have included a small logger, and if > I run my cutter application once more, it sees only the audio frames... In > ffplay I open the file and it plays the audio nicely, the first video frame > is frozen on the screen, but if I click somewhere on the ffplay window > (meaning: seek) it seeks there, starts playing the video only. NO audio > frames are there anymore ... Step 8 is not responsible for this stupid > behavior, it behaves the same way if it's there or not. > > Have you ever seen this behavior? Had anyone of you implemented this cut out > feature? > > Thanks > Ferenc >
I got similar task but totally different problems - i loose the audio :( and the file doubles it's size. If interested my code is at http://sdr.tera-com.com/tmp/sdrlive_src.tar.bz2 and I'm much interested in yours _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
