Ah yes, not sure how I missed that. The color appeared ghosted from the bottom half of the screen to the top. If my hand was in the bottom of the frame then a color ghost was in the top half. Which makes sense based on what you just said. For some reason I was thinking they were the same size just packed differently. Now I see my mistake. I guess I shouldn't be coding at 1:00am....
So what I was doing was taking 160 x 240 U and copying it over the what was supposed to be 160 x 120 U and then also over the 160 x 120 V and missing the V altogether. So by going from 4:2:2 to 4:2:0 i'm actually losing half of my color information. I'll need to investigate the encode codec more as I hate to lose color information if I can avoid it. Thanks On Tue, Nov 17, 2009 at 12:57 PM, Bruce Wheaton <[email protected]>wrote: > On Nov 17, 2009, at 9:35 AM, Glen Ruedinger wrote: > > I trying to convert a captured video frame from YUYV to YUV420P, which on >> the surface appears to be a straight forward operation. From my research >> I >> thought the only difference is that the YUYV is a packed format and the >> YUV420P is a planar format. So what I tried to do is create a planar >> buffer, and then move the bytes from the YUYV to the planar buffer. Y >> followed by V and then U >> >> I did get a video image and brightness appears correct (the Y), but the >> colors are incorrect (V and U). >> > > Well, yuv420 is 4:2:0 sampled, and yuvu is 4:2:2. The colors are wrong how? > Did you rescale the U and V to the correct height? > > What that means is, taking for example a 320 x 240 movie, in 4:2:2, you > would have 320 x 240 of Y, and 160 x 240 of U and V. There's lots of info > about the packaging. The yuv420 version (4:2:0) has 320 x 240 of Y, but only > 160 x 120 each of U and V. > > Bruce > > > > >> Any light anyone can shed on the difference that I'm missing would be >> greatly appreciated. >> >> And yes I know I can use libswscale to do the conversion but libswscale is >> GPL'ed and I'm trying to only use LGPL code. >> >> Thanks >> _______________________________________________ >> 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 > _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
