I go YUV-RGB -YUV'. On output I see YUV' is messed up 8 bits in YUV gives 8 bits in RGB according to all the equations.
I find I have to right shift 8 bits of the RGB to get proper looking images back out at YUV'. Hence sws_scale is actually doing some scaling. Even though I did not request. So how do I transform formats without invoking some scaling? Are you familiar with the modules that can point me to lines of C code in a specific file where the scaling is happening ? -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Roman Ryltsov Sent: Saturday, January 05, 2013 1:59 PM To: This list is about using libavcodec, libavformat, libavutil, libavdevice and libavfilter. Subject: Re: [Libav-user] change pixel format without scaling data ? // more3 Jim, > I use this many ways. For one instance: > Input is YUV422 > Output Is RGB16 What kind of grayscale alteration do you see? YUV color space has explicit brightness component, while in RGB it is distributed between all three components. That is, converting between these you inevitably apply math to grayscale levels, though you should not get any significant difference going beyond rounding to nearest integer. Roman _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user
