A question about compression

[Mylenium]

So, my question is: What compression settings are optimal for achieving the best possible end result for final output?


The settings do not matter that much (to a certain extent), the program doing the compression is the decisive factor. Most commercial DVD projects use highend-ish multipass VBR encoding software or even dedicated hardware. The films are often only encoded with 5.5 MBit/ sec. or even less. What tools are you using?

Mylenium

[Kuroyume0161]

I agree with Mylenium.

First, you should always render out frames - not the animation itself. This allows for the most options and avoids needing to restart if there is a crash or power-outage during rendering.

Then you should convert that into animation at the highest quality necessary - uncompressed! This will occupy GBs or even TBs! But remember the adage: Garbage in, garbage out. What you start with should be the best quality and it will (and can) only go down from there - you can't make it 'better' quality.

Then you'll need software that does VBR (variable-bit-rate) encoding/compression. This means that the streaming bit rate and compression vary depending on the frame-frame variances. This helps reduce 'mpeg-iness' while also reducing size with compression.

[tcastudios]

Rendering to a bigger size will also up the compressed result. Then there is more than one pixel per pixel for the codecs to work with.

Cheers
Lennart

[GruvDOne]

I agree with Mylenium.

First, you should always render out frames - not the animation itself. This allows for the most options and avoids needing to restart if there is a crash or power-outage during rendering.



Yes, I agree. I have given that advice myself, and did, of course, renser out a TIFF sequence around my 'Render Garden' consisting of 4 G5 Quads, 3 17" Mac Book Pros (the Core 2 Duo variety, they actually render at a very impressive speed, just barely slower than the Quads, in fact).


Then you should convert that into animation at the highest quality necessary - uncompressed! This will occupy GBs or even TBs! But remember the adage: Garbage in, garbage out. What you start with should be the best quality and it will (and can) only go down from there - you can't make it 'better' quality.

I did that too. Used After Effects for my assembly, and rendered the final output to lossles. End result for 2:46:20? 9.81 GB.

Then you'll need software that does VBR (variable-bit-rate) encoding/compression. This means that the streaming bit rate and compression vary depending on the frame-frame variances. This helps reduce 'mpeg-iness' while also reducing size with compression.

Well, we use the Final Cut Studio, which has Compressor. As I recall, there are VBR algo's in there. I usually don't do much on that end. Historically, I have always put together the animations and handed them off to the Video Editor who assembles and encodes, but I always get that, as you put it, "mpeg-iness" ;) and I am tired of it. So, this year I decided to control the whole process from start to finish, so that if I get a final product that isn't up to par, I have only myself to blame.

Rendering to a bigger size will also up the compressed result. Then there is more than one pixel per pixel for the codecs to work with.

Cheers
Lennart

Yeah, I thought of that, but greatly underestimated the render time. It only took about 30 hours to render. By contrast, last year's project took 2 1/2 weeks. Had I known it was gonna render so fast, I would have definitely upped the resolution, but now it is unfortunately too late in the game.

But thanks guys, I think I got what I was after. I'll give VBR encoding and see where that gets me. Not knowing what to expect, are there settings within such encoding algos that are generally more desirable?

[Joseppi]

Will,

I found the 2-Pass VBR produces much better compression than single pass. The first pass analyzes the data rate, calucating where the data rate is higher, so in the 2nd pass, it knows where it can take datarates from where less is needed to apply it where the quality would normally start to break down.

Sorenson Sqeeze has modifiable presets to make contained web movies among other things. I've only played around a little with Compressor, and that was to make the separate video and audio files for use in DVD Studio Pro. For a standalone compressed file, Squeeze was pretty easy, although Compressor would probably provide more control if it does 2-pass VBR.

Joe

[Tiziano]

I found the 2-Pass VBR produces much better compression than single pass.I'm no Compressor expert but I seem to remember many posts on Apple's FCP board talking about problems with 2-Pass. They recommend 1-Pass. Might have been fixed in the latest FCPStudio update though.

[Joseppi]

I'm no Compressor expert but I seem to remember many posts on Apple's FCP board talking about problems with 2-Pass. They recommend 1-Pass. Might have been fixed in the latest FCPStudio update though.

I should clarify, I had better results with 2-pass for Squeeze. I just did a 1-pass with compressor, I don't use Compressor much and hadn't heard of the 2-pass probs. Thanks for pointing that out.

Joe

[GruvDOne]

Hmmm, that's interesting and unfortunate news about Compressor. I can't afford to buy Squeeze just now either. Hmmm.....

Well, once I get the final audio from the composer, I'll try doing a pass with each and see which one works out better.

Maybe I'll see if there is a trial of the Sorenson software. If there is, and I can get a 3 min animation crunched with it, I can probably convince the higher-ups to pony up the dough.

Thanks for all the input guys.

-Will

[Tiziano]

Hey Will,
Don't give up on Compressor yet.
I did find some posts on Apple's Compressor forum that suggest the problem is solved with the latest update (free, assuming you have the 2006 version of FCPStudio).

[GruvDOne]

Hey Will,
Don't give up on Compressor yet.
I did find some posts on Apple's Compressor forum that suggest the problem is solved with the latest update (free, assuming you have the 2006 version of FCPStudio).


I do, and that's good news. I do remember the first incarnation of Compressor was far from stable. Hopefully this particular bug has been squashed.

I'll report back the final results when they happen.

Cheers
Will

[marcorabellini]

Also remember that compression is more "art" than "science". A setting that works well for one thing may not work as well for another, similar project later on. If I have the time I test small sections. Although keep in mind that in VBR compression the keyframes are dependent on many other frames around them. I try to do at least 30 second tests.

The key to good compression is available time and lots of patience. I use both Compressor and Squeeze, although I use Compressor mostly for DVDs and Squeeze for all others (WM and QT movies). Both seem to work well for me in these implementations. I think Squeeze is more customizable but I've also got the latest version of that and the Compressor I'm using is the one that came with FCP 4.5 HD. A trick for DVDs is to increase the default data rate, although the default data rate is guarenteed to work on most all DVD players and higher data rates may not. Because 3D animation has a lot less noise in it than video or film the higher data rate can help keep artifacting down.

Also be aware that VBR is, well, variable and that can actually lead to undesirable results for DVD playback.

I used to use Cleaner but that seemed like it became a pariah in the software world and was quitely sold to company after company and never updated for years. I see it finally got an update and is with Autodesk now. I liked it but moved on to Squeeze for newer features.

[ahven]

I have similar stuff under progress. I'm producing a 720 degree rotating product animation for a DVD. I think I'll use subcontractor to make the final DVD because I have no DVD authoring programs. Do you prefer TGA or TIFF for image sequence output? I'm using C4D r 9.6.
Finally I combine the image sequence in Adobe Premiere I think.

[Cityscape]

Hi guys,

I have been using sorenson squeeze for a few years now and have struggled to get the the quality of compression that they get on websites for film trailers.

The Apple sitre is a good example, the clips on there are of such a good quality, does anyone have any idea how they look like they are of un-compressed quality, but are are still of a sall size.

I noticed that the data rates of teh files were upto 2500kb/s which when I compress my video files to they sufer from not having smooth playback. Ive tried using the new H264 but I finf it desaturates the image and loses contrast.

[imashination]

Rendering to a bigger size will also up the compressed result. Then there is more than one pixel per pixel for the codecs to work with.

Cheers
Lennart

Nice idea but unfortunately no compressors work like this. The compression codecs are always fed the final scaled down frames to work with, rendering to a larger size will bring no benefits to the compression.

[tcastudios]

Your right about that the codec itself doesn't work so but never the less to take it to an extreme.
Render a 2000x1000 and scale it down to 200x100 (in post) and run the codec.
Render directly to 200x100 and run the codec.
The difference should be more than noticable.


Cheers
Lennart

[ooo]

If I remember right Nick Woolridge wrote to do the Final compression never from AE or C4D, but beter use QT-Pro. I'm not sure if this applies to all kinds of compression or only for webbased output. He did some tests so you might want to try to find that thread.

OK: found that particular thread again.

http://forums.cgsociety.org/showthread.php?f=47&t=357103&highlight=compression

odo

[Cityscape]

Great I will have a read.... thanks

[marcorabellini]

Always create a render (I use AE and render 100% Animation compressed QTs) at the final size you want. Never depend on compressor software to resize your program. Every piece of compressor software has always sucked at resizing.

I recently did a program and my client needed three final products, a playable DVD, WMV files for play off a computer, and a version for a DV edit. I rendered three sizes out of AE and compressed each individually.

m

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