[PD] gem & cinepak video on linux

B. Bogart ben at ekran.org
Sat Mar 19 16:19:37 CET 2005

Datarate is the real problem here.

If this is what you do visually then spec your HW to do this. Try
putting two clips on one drive (not partition) and the other two on
another. That should double your datarate for disk access. 7200 RPM
drives are faster too, SCSI or SATA... beats old IDE.. check your DMA

You have two problems. Datarate is the first, and loading will be slower
if you can't get the pixels off the drive and onto your texture fast
enough (which means that depending on the resolution your gfx card APG
speed may make a difference.

Second problem is the CPU usage it takes to decode a frame. There are
fast photojpeg decoder libs (with optimization) and on macOS most things
are super fast...

On an old 800MHZ PC with a single drive I could mix two videos at a
time, but there were four videos in the schene, just only two visible at
any given moment. When one was invisible it stopped playing but was
still in the scene.

My videos were photoJPG 256x256 pixels.


justin c. rounds wrote:
> i agree that cinepak looks terrible, but i feel like i'm stuck using it
> because:
> 1. the files are relatively small and they decompress quickly, so i can
> play many of them simultaneously
> 2. i can keyframe every single frame, so i don't get any hiccups
> scrubbing/scratching the video
> so what i'm asking is:
> given that i want to be able to play back many (at least four) video
> files simultaneously while manipulating their playback speeds and
> directions (like scratching records on turntables), what is the best
> codec to use?
> also am i making incorrect assumptions given the capabilities of modern
> hardware? that is, do i really need to keyframe every single frame in
> order to get smooth playback in both directions and at rapidly varying
> speeds? and do i really need to be concerned with having file sizes
> small enough to reside in memory and not streamed from disk?
> _
> j
> chris clepper wrote:
>> On Mar 17, 2005, at 2:53 PM, Tim Blechmann wrote:
>>> hi all ...
>>> i'm currently working with a gem patch to play back videos files encoded
>>> with the cinepak format on linux ...
>> Why on earth are you doing that?  Cinepak is the very first lossy
>> codec developed for quicktime around 1991 and the quality is
>> horrendous.  It's very unlikely that you would encounter any content
>> compressed after 1996/97 in Cinepak as literally every single codec
>> after it is superior.
>>> and what's the prefered (most stable, hq) video codec for linux ...
>> Photo-Jpeg?  Uncompressed 4:2:2?  Anything other than Cinepak!
>>> thanks .... tim
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