Hardware Mpeg2

Been looking at the nvida purevideo decoder, which is great for straight playback of multiple streams, is there any chance of getting vari speed playback or even backwards available? Backwards would be good with avi’s to be honest, but there are work arounds of course!
Anyways just a thought!


varying playback speed and even backwards are not restricted by vvvv. speed -1 should play backwards if the underlying directshow-graph can play backwards.

What codecs support this, I’ve not come across one yet?


me neither. but that is the therie. .what about uncompressed?

a suggestion as to which codecs would be interesting to test:

  • frame-by-frame / lossless codecc
    ** MJPEG (Picvideo, MainConcept,…)
    ** HuffYuv
    **quicktime Animation
    **microsoft RLE
    **Autodesk FLC
    **microsoft DV

*just because I hevn’t seen them & they are promising
**on2 vp7

as newer codecs focus on internet deliverability they are often concerned with bandwith problems rather than seek time, which seems mutually exclusive. I guess old-fashioned codecs like FLC/RLE etc could do the trick here.

Any volunteers to test these codecs?
Your findings would ideally go to the FAQ Codecs. How about an overview table?

Well I’ve tired
DV low cpu use, pause on loop, vari speed, seeks slowly
PicVideo Mjpeg moderate cpu, loops well, seeks well, varispeed
Quicktime Photo Jpeg (with qtime alternative)higher cpu, loops well, seeks well, varispeed
Indeo low cpu, loops well, seeks well, varispeed,
M2v, hardware decompression means very low cpu, loops ok (I think!) doesnt varispeed
So far…

I bet cinepak will do it, ahhhgghhh I hate it I hate it!
If I test some more I’ll update the codecs page!

In order to get M2v files to do varispeed and play backwards, you need to encode it as “all I frames” as it uses interframe compression.
Then, it SHOULD work

and a little addendum from me, too:
in a recent project we found that with DV files, seek speed depends heavily on the length of the clip - worked pretty well with 30 secs test clips, but just dies in a clip >30 minutes. This occured with both QT DV and AVI DV. Did not investigate further into this, just converted all to MJPEG, which worked a little better.

any more tests? for the FAQ Codecs?

jrudolph, have you used all-I-fame M2Vs in vvvv yet? and backwards?
just curious.


I’ve tried I frame mpg2’s, and they dont seek very well, nor play backwards!
I’ve recently work on shows with hippotizers, which are optimised for mpg2 I frame playback using nvidia’s hardware decompressor, and they work very well, so it is possible, just requires extra coding to make it happen (they’re the obly file format hippos will play backwards!)

I’m not sure that vvvv is the source of seeking problem. In the past I’ve tried differents filters for play mpeg2 files. In conclusion for me: seeking and other play backwards behaviour depended more on filters used. which demux filter do you use?

using windows or Moonlight or Nvidia demux filter before decompress provides very differents behaviour.