From: Jon Dahl <jon@...>
Date: 2007-10-03T23:38:51+09:00
Subject: Re: RVideo - Ruby video transcoding library

Ilmari Heikkinen wrote:
> 
> One API idea:
> RVideo.transcode("filename.mp4", "filename.avi",
>   :resolution => [640,480],
>   :video_codec => 'xvid',
>   :audio_codec => 'mp3')
> 

Thanks for the suggestion. I'd like to do something like that at some 
point, but I'm not exactly sure how.

I spent quite a bit of time thinking about the best way to define a 
command. The problem is that ffmpeg is extremely complex, and a good 
quality transcoding job often involves more than just resolution, codec, 
format, etc. There are literally hundreds of other options that can be 
set that control quality, file size, a/v sync, etc. So I didn't want to 
reduce the power of ffmpeg by controlling the options too much.

So I decided for now to just do the simplest thing possible and pass in 
a command with variable interpolation. This allows you to store recipes 
on your system (in your database, in a yaml config file, etc.), and to 
pass in whatever variables you want.

For now, you can certainly build your own RVideo recipe constructor, 
which does exactly what you're describing. It should just output a 
string, and then pass that string to a RVideo::Transcoder object.
-- 
Posted via http://www.ruby-forum.com/.