Thanks for the great idea. Following your suggestion, I scaled one of the source images to the allocated dest. frame (640x480). It is fast! However, I could only scale the first src image to the left portion of the dest. frame. How can I scale the second src image to the right portion of the dest. frame? sws_scale/sws_getContext only give sizes no location coordinates. Is there a way with which I can specify the coordinates as well?
Thanks again! 2010/3/12 Hendrik Jürgens <[email protected]> > Am 12.03.2010 01:14, schrieb Stefano Sabatini: > > On date Thursday 2010-03-11 14:21:24 -0500, Ke Yu encoded: >> >>> Hi! >>> >>> I've got avframes from two udp multicast video streams. I would like to >>> scale every avframe into half (only x coordinate, e.g., >>> 640x480->320x480) and stitch the two scaled avframes into one avframe >>> with >>> original size (e.g., 640x480). After that, I'll encode the generated >>> avframes into one output video stream. My input video streams have the >>> same >>> encoding context. The frame rate is 30 fps. So I have about 33ms to >>> finish >>> the scaling and stitching. The performance is critical. I plan to use >>> sws_scale to scale the avframe but don't know how to stitch two scaled >>> avframes together. I prefer not to use a third party image lib. >>> >>> Can anyone help me to figure that out? >>> >> >> Try with libavfilter+overlay, integration into main SVN pending. >> >> Regards. >> > > > Hi, > > You can allocate your AVFrame with the target resolution (640x480) and then > let sws_scale the sourceimages directly onto this frame. > > You simply have to modify the data pointers and linepitches of yout AVFrame > before giving them to sws_scale. If you don't need any transparency or some > other fancy image stuff this should be the fastest way. > > > Best regards > Hendrik > > _______________________________________________ > libav-user mailing list > [email protected] > https://lists.mplayerhq.hu/mailman/listinfo/libav-user > _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
