Op 18 feb 2009, om 22:26 heeft Stas Oskin het volgende geschreven: > Hi. > > I need to extract image from exact position in the video. > > Problem is, that I have media with large GOP value, and when I try to > convert non-key-frame to image (via img_convert()), I get a gray > image. > Converting key-frames works just fine. > > Is there any way that I can convert a non-keyframe to normally looking > image?
It is my understanding that non-keyframes depend on the information provided in the preceding frames up until the first keyframe. If you do not decode these frames, there is no way to decode the frame you actually need. This is why very large GOP sizes are evil.. So in order to get the frame you need, you need to decode all the frames since the last keyframe. I believe this is where the AVSEEK_FLAG_BACKWARD flag comes in. - arjan _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
