Thank you very much . You resolved my blunder , I'm more clear about the AVFrame structure now.
One last question: Is there any significant advantage in using the prebuild filters of ffmpeg over manipulating YUV frames by iterating through it? On Wed, Jul 23, 2014 at 7:26 PM, James Darnley <[email protected]> wrote: > On 2014-07-23 15:39, David Varghese wrote: > > Thanks for the reply. > > > > Infact I tried to directly manipulate the YUV frame that I got from > decoder > > . I tried to modify the Y value of every pixels of every frames to 1 , > > expecting to see a much darker video . But I didnt found any changes in > the > > video . > > > > The code snippet is as below, > > > > AVFrame *frame = {*YUV420P frame recieved from ffmpeg decoder*}uint8_t > > *tempPtr = NULL; > > tempPtr = frame->data[0];int j;for(j = 0 ; j < frame->linesize[0] ; j++){ > > *(tempPtr++) = 1;} > > > > Am I doing something seriously wrong? > > You are only processing one line there. You need to be iterating over > the height too. > > > > > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > > -- Thanks and Regards , David Varghese _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
