>> + if (frame->format == AV_PIX_FMT_YUVA420P || frame->format == >> AV_PIX_FMT_YUVA422P) >> + x /= 2; >> + >> + if (frame->format == AV_PIX_FMT_YUVA420P) >> + y /= 2; > > Why not use the usual subsampling mechanism? (using vsub/hsub etc)
That seemed more complex to me, as this filter just supports those 3 pixel formats anyway. It would involve getting the pixel format description in some init function, calculating and storing the h/vsub values. Is there any benefit to that? Otherwise I think I'd prefer this solution. >> + frame->data[3][frame->linesize[3] * y + x] = >> do_chromakey_pixel(ctx, u, v); > > You might want to check if saving a bunch of dereferencing in the inner > loop helps performance. You mean getting frame->data[3] and frame->linesize[3] before the loop? Shouldn't this be something the compiler optimises for me? Anyway, can easily be changed. >> + if (res = av_frame_make_writable(frame)) >> + return res; > > You have a .needs_writable attribute somewhere for that purpose Didn't know about that attribute. >> +#define FIXNUM(x) ((int) ((x) * (1 << 10) + 0.5)) > > lrint()? These defines were taken from the old colorspace.h, where they got removed from in 7944b0ce94. No idea if lrint optimizes in the same way, but as this is used only once during startup, it shouldn't matter here.
signature.asc
Description: OpenPGP digital signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
