On 15/11/14 23:55, Joan Charmant wrote: > Hello > > I have an input stream in GRAY8 color space (also called Y800, Y8 or GREY > elsewhere) that I would like to encode to MJPEG (inside MP4). > > In my understanding there is no technical limitation for an MJPEG encoder > to directly compress GRAY8 samples. The JPEG standard allows it and the > libjpeg-turbo that I considered earlier can take these samples directly. > Since I have samples coming in grayscale, I would have liked to avoid an > unnecessary color space conversion and probable suboptimal compression > speed and ratio. > > However, when I try to open the MJPEG encoder having specified > AV_PIX_FMT_GRAY8 as pixel format, it fails with -1. It works fine when > specifying AV_PIX_FMT_YUV420P, so I did add the extra color conversion as a > workaround for now. > > Am I correct in my understanding that currently the MJPEG encoder does not > support GRAY8 pixel format as input? Or is there something else I need to > do to make it work?
The encoder doesn't list it as supported format and you are right, we should support it. Since it is related to the quite convoluted mpegvideo encoder might be a _bit_ complex to add the support by yourself, but if you want to try feel free to jump on irc and somebody should at least give you some pointers =). lu _______________________________________________ libav-api mailing list libav-api@libav.org https://lists.libav.org/mailman/listinfo/libav-api
