On Sun, Nov 16, 2014 at 12:05 AM, Luca Barbato <[email protected]> wrote:
> 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 > Thank you for the prompt reply. For the moment I don't think I would have the know-how to be able to work on the code base… Joan _______________________________________________ libav-api mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-api
