[PD] Re: [GEM-dev] Codecs in Gem (again!) & ffmpeg

IOhannes m zmoelnig zmoelnig at iem.at
Wed Aug 31 09:29:03 CEST 2005

B. Bogart wrote:
> Thanks for the suggestions.
> I'm not sure about using a mpeg for the following reasons:
> #1. was does the interframe compression thing work, in other words how
> does it compare when seeking to a quicktime with photo-jpg codec?
> #2. I'm damn confused about the seeking (see below)

as chris has pointed out, interframe compression can be a crux.
solution a: make each frame a keyframe (should be possible with the 
encoder of your choice)
solution b: don't care about keyframes at all, use an external tool to 
create a TOC of your mpeg, so that the decoder knows where to look for 
keyframes (mpeg3toc of the mpeg3-utils package) and load the toc-file 
into Gem and seek the file.

of course, solution b is more cpu and disk intensive, so you might still 
want to avoid it. it relies on libmpeg3 (imo libmpeg1 is unusable anyhow)


More information about the Pd-list mailing list