Unfortunately -debug does not serve my purpose . i need intra-predictions and i should add some lins in ffmpeg coding like fprint () function to save them in a text file.
On 26 June 2012 20:51, Alex Cohn <[email protected]> wrote: > On Tue, Jun 26, 2012 at 12:21 PM, Rouhi Amirhossein2 > <[email protected]> wrote: > > Hi Misha > > Thanks for prompt reply. That would be a very useful code for extracting > key > > frame images. but actually need to extract the intra-prediction modes in > > each key frame of an input video stream. Can you help me to achieve this? > > the input of the program would be an h264 raw video file and the output > > would be a text file that stores intra-prediction modes with related MB > > address and i-frame id. > > > > > > On 26 June 2012 19:12, Misha Penkov <[email protected]> wrote: > >> > >> On 26 June 2012 18:05, Rouhi Amirhossein2 <[email protected]> > wrote: > >> > > >> > Hi > >> > You know that in h264, a methos is used for compression which is > called > >> > intra prediction method. totally we have 9 intra prediction modes > which > >> > showing different direction of top and left side pixels of 4x4 > blocks. I > >> > want to extract such modes in any frame that uses intra prediction > such > >> > as > >> > I-Frames and IDR,s. Do you know how can i achive this purpose? > >> > In JM software i did the same in decoder, do you think it should be > done > >> > in > >> > FFplay as a decoder or it can be done by FFmpeg? > >> > >> AFAIK, H.264 I-frames and keyframes are the same thing. Once you have > >> an AVFrame, you can check its key_frame member. It will be non-zero > >> if it's a keyframe (I-frame). > >> > >> For full code, have a look here: > >> > >> https://github.com/mpenkov/sandpit/blob/master/ffmpeg/keyframes.c > >> > >> Provided that you're using MP4 as the container, you can confirm that > >> the keyframes extracted are indeed I-frames by using the mp4videoinfo > >> utility (http://mpeg4ip.sourceforge.net/documentation/index.php). > >> > >> > Thanks for your expert advice. > >> > Amir > >> > > > -- > > Amir H. Rouhi > > PhD Student/ CSIT RMIT University > > Room: 14-09-04 > > http://raws.adc.rmit.edu.au/~s3288736/blog2/ > > Check ffmpeg -debug options, especially pict and mv: > > -debug <flags> EDVAS print specific debug info > pict .DV.. picture info > mb_type .DV.. macroblock (MB) type > mv .DV.. motion vector > > Regards, > Alex Cohn > _______________________________________________ > Libav-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/libav-user > -- Amir H. Rouhi PhD Student/ CSIT RMIT University Room: 14-09-04 http://raws.adc.rmit.edu.au/~s3288736/blog2/
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