alpha_encoder/README

This is the VP8 Alpha Encoder which can produce VP8 videos with alpha channel
from raw AYUV videos.

To convert an avi/vp6a video with alpha into raw ayuv video, use:
  ffmpeg -i <input_file> -f rawvideo -c:v rawvideo -an -pix_fmt yuva420p raw.out

Make sure to note the width and height in the output.

Then, you can encode the raw file with VP8 along with the alpha using:
  ./alpha_encoder -w <width> -h <height> -i raw.out -o vp8alpha.webm

Various supported options can be found by running:
  ./alpha_encoder -?

The design doc of how this works can be found here: http://goo.gl/wCP1y