[Ffmpeg-devel] Accepted SoC Apps
Fri May 26 00:02:27 CEST 2006
On Thu, 25 May 2006, Michael Niedermayer wrote:
> things to do for snow:
> * multiple reference frames support
> +number of picture buffers field per keyframe
> +decode frame buffer index (into which decoding happens)
> +display frame buffer index (which frame is outputed)
> +a symbol per block to select the reference frame
> +some changes to the motion estimation code
> +some changes to the mv prediction code
I have a patch for multiref support. Will post once it's cleaned up.
Preliminary results: at high bitrates, it helps just as much as h264's
multiref. At low bitrates, not as much. This might be because I have not
yet modified mv prediction.
> * non translational motion compensation
> +estimate non translational parameters per block by using surrounding
> motion vectors
> +add a ac coded bit per block to switch between translational and non
> translational MC
> +borrow the non translational MC code from libmpcodecs/vf_perspective.c
> +some changes to the encoder to decide between translational and non t.
> * trellis quantization (select quantized coefficient so as to minimize
> the ratedistrortion
> * 4x4 sized block support (we have 16x16 and 8x8 currently)
> * 1/8 pel motion compensation / estimation support (pretty much just
> encoder changes needed which in case of the iterative me should be
> * 1 pass ratecontrol
* Figure out how to optimally use intra. There are cases where enabling
8x8 blocks greatly reduces quality per bitrate, and I think this is mostly
due to trying to encode in intra prediction what could be left to the wavelet.
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