TechnoCat wrote:What is a good way to do a screencap on Windows encoded as WebM?
Hm, always depends what you need and want.
Like thelinx said, you probably want to encode it after you captured it. There are not many applications that give you the option to use your own codec and VP8 editing sounds like it could be painful.
Here's what I have experience with:
There's FRAPS which captures stuff that uses Direct3D/OpenGL. Because the recording is lossless(*) it requires a fast CPU and hard disk for higher resolutions. Since Aero uses Direct3D it can capture the whole desktop. Never used this feature myself, I'm a "classic" guy.
(* It switches to a different colorspace with HD resolutions for performance reasons. It's possible to force RGB though.)
There's also VirtualDub. It has a neat screen capture feature in its "capture AVI" mode. Unlike FRAPS you have to configure everything yourself and learn what all the little options do. Like "Disk I/O" in the capture menu, where the default setting for the buffers is too small for lossless recordings. And because it uses the old audio interface it can't record the audio, unless your driver provides a loopback (stereo mix, what u hear, ...) that can be selected.
You can choose any of the installed VfW codecs on your system that support RGBA.
I can recommend the Ut Video Codec Suite (
latest version /
readme). It's lossless, fully multithreaded, and the compression is ok. Problem is, FFmpeg can't read it. You have to use avisynth or convert it to something like Huffyuv (or use that codec in the first place, if it's fast enough).
Didn't use anything else long enough to recommend it.
I encoded only a few WebM videos with the reference encoder that only accepts raw input. It's available on the
Google Code WebM download site.
You can get a Windows FFmpeg build
here. Sadly, those autobuilds were stopped because he's on vacation and is apparently annoyed with the troll driven development of FFmpeg.
If you're unfamiliar with FFmpeg be warned: It might give you serious head scratching. It's a collection of audio and video encoder/decoders, format muxers/demuxers and some other stuff. Most are included in the actual source code of the project, some are added with libraries. Simple conversion are easy to do, but it's hard to fine tune stuff. Not all options of the encoders are exposed or documented (at least in the standalone exectuable). Maybe someone else has more experience with it.
The following line encodes the input video with VP8 and Vorbis at bitrates of 1 Mbit for video and 128 Kbits for audio:
Code: Select all
ffmpeg.exe -i input.avi -vcodec libvpx -acodec libvorbis -b 1000k -ab 128k output.webm
Should we move to another thread if there are more questions?