Hi, On Thu, Mar 15, 2012 at 4:36 AM, wl2776 <[email protected]> wrote: > Hi all. > I'm wondering what is this function (draw_horizontal_band) for? > The comments say that this function is called by libavcodec decoder to draw > a horizontal band.
Imagine a video codec outputing video frames; instead of getting whole video frames, draw_horiz_band allows you to draw individual macroblock rows just after decoding. This is useful because the data is still in cache, thus having lower load latency, and it decreases the overall decode-display latency. If your image is 16 macroblocks high (i.e. 16x16 = 256 pixels high), draw_horiz_band will be called 16 times per output frame. Note that draw_horiz_band isn't very useful in codecs with delay (e.g. B-frames). Ronald _______________________________________________ libav-api mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-api
