Thank you for these most interesting measurements. The problems introduced by the removal of the img_convert() function have been discussed quite often in the past month. I believe that these results are a good argument for reintroducing img_convert() again - maybe as suggested without scaling. In most cases scaling isn't necessary - as it is done by SDL or the graphics card. But the colour space conversion is very important ...
So I hope that libav developers will read these lines and start related actions ... -------- Original-Nachricht -------- > Datum: Wed, 9 Sep 2009 20:31:18 +0400 > Von: Andrey Nikitin <[email protected]> > An: [email protected] > Betreff: [libav-user] img_convert() vs sws_scale() > Hi. > > I measured the performance of picture format conversion (no scaling) > on my P2.4GHz and got the following results: > > Dest. pixel format - YUV420P > > img_convert(): > YUV422P - 4.5 sec ~ 2200 fps > YUVJ420P - 6.5 sec ~ 1500 fps > YUVJ422P - 10 sec ~ 1000 fps > YUYV422 - 4.3 sec ~ 2300 fps > > swscale() do not optimize (lgpl) > YUV422P - 96 sec ~ 104 fps > YUVJ420P - 53 sec ~ 188 fps > YUVJ422P - 110 sec ~ 90 fps > YUYV422 - 7.3 sec ~ 1360 fps > > swscale() --enable-gpl > YUV422P - 30 sec ~ 330 fps > YUVJ420P - 26 sec ~ 380 fps > YUVJ422P - 42 sec ~ 230 fps > YUYV422 - 1.82 s ~ 5500 fps > > Conclusions: JPEG's colorspace YUVJ42{0,2}P -> YUV420P and YUYV422 -> > YUV420P > format conversion by sws_scale() even with the MMX/SSE optimization - is > very very slow > instead old removed img_convert() function. > > Is it time to regain img_convert() (without scaler) function in the code? > > -- > Andrey Nikitin > > _______________________________________________ > libav-user mailing list > [email protected] > https://lists.mplayerhq.hu/mailman/listinfo/libav-user -- Neu: GMX Doppel-FLAT mit Internet-Flatrate + Telefon-Flatrate für nur 19,99 Euro/mtl.!* http://portal.gmx.net/de/go/dsl02 _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
