Good point. Maybe that's it. An example of my HDV original is 140 MB. Its Cineform intermediate is 644 MB.

On the other hand - if so, how comes turning the preview to "Preview (Auto)" helps getting full playback rate though this does not change the disk throughput?
If I use a fully uncompressed HD version the playback rate is very low but it does not change no matter what the preview size and quality is set to.

Marco

I was surprised at how well the m2t files were playing back on my system as well. Talked to Cineform and they said that the Cineform files are a bit more disk thruput based and don't work the proc as hard as the raw m2t. On my AMD x2 4800 system I'm getting realtime playback (sometimes it drops down a bit, then comes back up) of both m2t and Cineform at 29.97 with the preview set to auto and the video preview window sized to 720 by 540 (half of the 1440 by 1080). This is playing back off of a 4 drive Raptor raid 0 that benches out at around100mbps empty (but it is pretty full right now).

Here is around what I'm getting;

m2t at best/full = 11fps
m2t at preview/auto = 29.97fps
Cineform at best/full = 16.5fps
Cineform at preview/auto = 29.97fps

"with preview set to "Best (Full)" I get 18 to 20 fps for the HDV originals". Boy, that 's better than me - what is your secret :)

I was kind of surprised to get such good performance from the raw m2t - on my old Intel P4 2.4 system - oh man, it was crawling! Anyone else? How about files form the JVC at 720 by 1280 24p? I've done a few test with those (converted from 29.97 Z1 cineform) and I'm getting full 23.976 fps at best/full - looks smashing. Of course these are only a few quick tests.

>> what is your secret :)

Maybe this is because I have a rather clean system. Besides the OS itself , a software DVD player, a burning app, DVD-A and Vegas there is no other software installed. And clean HDDs. Dynamic Ram Preview is set to zero.

Having set the preview to "Preview (Auto)" and the size to 720x540 I also get 25 fps (which is full playback rate for my "PAL" files) both out of the HDV files as well as out of the Cineform intermediates. It only affects the full preview sizes.

Also I noticed that strange behaviour changes in the moment I apply fx/filters. If I use filters/fx the playback of the intermediate is better than HDV playback. Without filter/fx it is vice versa.



Marco

On my system, m2t clips play back much smoother than Cineform because the m2t clips use the GPU on my graphics card. The Cineform clips do not. They have done this ever since I installed the nVidia Purevideo decoder (even though I am using an ATI Radeon card).

Anyway, this is why Adobe has gone with native m2t editing rather than Cineform: because Premier Pro now can make use of a video decoder, and if a decoder like Purevideo is in use, playback of native m25 video is actually smoother because the video decompression is being offloaded to the GPU accelerator on a compatible graphics card.

>> because the m2t clips use the GPU on my graphics card.

Even if you playback them from the Vegas timeline?

Marco

Sigh....more marketing hype.
m2t is a "transport stream." Not designed for editing. Adobe went with native m2t editing not because there is any benefit via GPU, but because they needed the marketing bullet. Editing with both Cineform and m2t in Adobe (or Vegas), the process is much faster and more efficient with Cineform. HDI's are important regardless of the NLE. Apple, Adobe, Canopus, Sony, whatever; it holds true.
As far as your NLE keeping a reasonable framerate with m2t, keep it rolling for a few. Also look at the CPU differences in the load. Additionally, even if you *were* happy with long form .m2t editing, you still aren't properly accessing frames, you're only seeing decoded references to frames, not actual information. Which is the secondary, but equally important need for a DI. I'm amazed every day at people buying into the whole "native HDV editing" bullet point on most every NLE's feature list.

>> the process is much faster and more efficient with Cineform.

Define "process". Regarding the full size playback Cineform intermediates are even slower on my system. Though I see the other advantages of Cineform intermediates I find this behavior bit strange.
Do you have a glue what might be going on on my system? - Or maybe it's not the intermediates which playback poorer but maybe it's the HDV files which play extraordenary fast on my system!?

Marco

One issue that did spring into my mind reading this if what's being said is true then what you're seeing depends on the decoder in the GPU. I'd imagine that might not be used during actual rendering so you could well not get the same result. That may or may not be an issue for you, could be a bit of a worry for things like CC.

So Vegas does benefit from GPU power when playbacking certain kind of video formats?

Marco

I can't say, seems from what others are saying it does. If that's the case it's sure news to me and something that should be verified. Might not be by design though.

The m2t clips only play back more efficiently through Windows Media Player. From Vegas, Cineform clips play back better. That is because Vegas is still using the archaic VFW (video for windows) technology that can't make use of decoder chips.

There are some legitimate reasons to use the Cineform codec over native m2t editing: better looking animations, transitions, color correction etc. But none the less, a video editor such as Vegas or Premier Pro should be able to work with native m2t video when that is what the editor wants to do. I am currently working on a straight ahead hour long training video. I'm not doing color correction, layers or any of the things that make Cineform better. I would LOVE to be able to do a simple single line m2t edit. It would save me HUGE amounts of hard disc space, rendering time, and let me work from an external USB or Firewire hard disk.

It is not hype. It is just another way to work which can in many instances be preferable.

>> The m2t clips only play back more efficiently through Windows Media Player.
>> From Vegas, Cineform clips play back better.

Not sure if you read my first posting. Because that's exactly it: On my system it's the m2t clips which playback more efficiently in the Vegas timeline.

Marco

Wierd. How is the m2t performance during clip crossfades?

What must be going on is that your cpu performance must be better than your hard disc performance. In other words, decompressing the video must be easier on your system than trying to stream three times the amount of Cineform data through your hard disc system.

If I use any kind of fx/filters the Cineform intermediates play better. For example if I reduce Track Level - Cineform files playback more than double as good as .m2t files.

Marco

Yes, sounds logical. But strange is when I change my preview setting to "Preview (Auto)" and use a preview size anywhat up to half HDV resolution I have a better playback of Cineform file (full fps speed).

If bottleneck is the hard disc performance then changing the preview settings should not affect the playback performance I think. If I use Sony YUV intermediates or uncompressed RGB AVIs then it doesn't matter what my preview settings are set to. Performance is always same.

Marco

I go back to the question Spot asked, namely whether the m2t files continue to play faster than the Cineform intermediates, even if you watch for awhile. I have found that for 5-10 seconds the m2t files play OK, but if I watch, without stopping the playback, for a minute or two, things bog down (Vegas 6.0d). This doesn't happen with the CF intermediates.

Good point. I'll test.

Marco

This hint was a good one!

I can't see any performance drop of hdv files even after more than 12 minutes continuous playback, but ...

... what I now recognized is the playback performance of hdv differs a lot dependend on the different shots. I have shots at the beginning of the timeline which only plays with less than 10 fps and I have shots beyond 13 minutes in the timeline which plays with 18 to 20 fps.

Before I only tested one single shot and it seems I had the luck to have had one which played very smooth.

I now will batch render my whole longer sequence to Cineform intermediates to take a look whether these ones will not have differing playback performance.

Marco

O.k. - just tested.

When playbacking lots of files continuously over a longer time in the Vegas timeline the performance of the hdv file differs more than the performance of the Cineform intermediates. Having the preview set to "Best (Full)" the avarage fps of the hdv files is about 14 +/-6. The avarage fps of the Cineform intermediates is about 14 +/-2.

So on my system avarage playback performance of Cineform intermediate and original hdv is roundabout same with more "ups & downs" of the hdv files. Playback performance of Cineform intermediates is more "stable" and much more efficient when filters/fx are used.

Marco

Playback performance of Cineform intermediates is more "stable" and much more efficient when filters/fx are used.

I think you pretty much just gave a definition of the advantages of using the intermediates.