[FFmpeg-devel] [PATCH] Add alphaextract, alphamerge filters

Steven Robertson steven at strobe.cc
Wed Jul 11 07:41:06 CEST 2012


Hi all,

I need to transmit a bunch of frames with a real-valued alpha channel
(not just a static mask) over a relatively slow link, and since the
recipient is on Windows, I'd like the relative simplicity of having
FFmpeg be the only tool that he needs to recover the content. A bit of
searching seems to indicate I'm not the first to want this, so I wrote
up a simple pair of filters to make this possible. From the patch
description:

"These filters are designed for storing and transmitting video sequences
with alpha using higher-efficiency codecs such as x264 which don't
natively support an alpha channel. 'alphaextract' takes an input stream
with an alpha channel and returns a video containing just the alpha
component as a grayscale value; 'alphamerge' takes an RGB or YUV stream
and adds an alpha channel recovered from a second grayscale stream."

Happy to address any review comments.

Thanks,
Steve
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Add-alphaextract-alphamerge-filters.patch
Type: application/octet-stream
Size: 17362 bytes
Desc: not available
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20120710/68fa2c57/attachment.obj>


More information about the ffmpeg-devel mailing list