2009/7/24 Josh Allmann <[email protected]> > On Thu, Jul 23, 2009 at 3:17 AM, Alessandro Ferrari > <[email protected]> wrote: > > > > Hello dear community, > > in your opinion, I can use ffmpeg > library > > for parsing an encoded h.264 p-frame to extract Macroblocks and Motion > > prediction Vectors Information? My target is to transcoding an h264 > stream > > for reducing bitrate by reduce granularity of the DCT coefficient, and > for > > achieve this i want to first extract information by the original encoded > > stream, decode the stream, and then encoding the stream without > recalculate > > the motion prediction information. > > Thank in advance for your attention. > > Take a look at the MV visualization code in ff_print_debug_info of > mpegvideo.c. > > I'm doing the same thing right now, and it involves a lot of hackery. > You can calculate MVs through motion_val field of avframe, but to be > useful you also need the MB info, which is tucked tucked away in the > mpegenccontext field of h264context, neither of which are available > via the public API (afaik). > > Right now I basically #include h264.h which is really messy. If there > is a better way of doing this I'd like to hear it. > _______________________________________________ > libav-user mailing list > [email protected] > https://lists.mplayerhq.hu/mailman/listinfo/libav-user >
Thanks Josh, your advice will be very useful. If I will find an alternative way for extract this information I post on this thread of mailing list. _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
