Compression

[Antoni Jones]

The DVD format is mpeg2. VOB (Video OBject) files found on DVD’s are in fact mpeg2 files usually containing AC3 (dolby digital) audio. If you intend to create a DVD out of your projects then you could create mpeg2-DVD complaint files by adding your comp to the render queue and clicking on the Lossless property and choosing “mpeg2-dvd” next to the Format drop down box. Doing this creates m2v (mpeg2 Video) and mpa (mpeg audio) or wav if you choose to export the audio as PCM format elementary streams which you can then use in applications like Adobe Encore to create your DVD and include menu’s etc. Encore will then take the finished DVD and convert it to VOBS to burn to DVD using your favorite burning software. If you don’t have encore then google m2v to DVD etc..

-Regards

[Brendan Coots]

You have no options in the matter – DVDs will only work with MPEG2 files. If you are using DVD authoring software (like Adobe Encore or Apple DVD Studio Pro) You should output from After Effects in an uncompressed format (like Quicktime Animation codec, or Windows Media Uncompressed) and bring that file into your DVD authoring program. It will automatically create an MPEG2 and the proper audio files out of your uncompressed video.

The reason for working this way is that After Effects doesn’t output compressed files very well, MPEG2 included. They almost never look as good as they will using the above workflow.

As for how Hollywood makes DVDs, they use MPEG2 files like everyone else, but they have (very) expensive hardware encoders that make the file as crisp and clean as possible while still fitting on the disc. Sonic Solutions is the main company that makes DVD encoding tools like this, if you’re interested.

[Adam Mcewen]

Awesome guys, thanks for your help.

[Roland R. kahlenberg]

Actually, MPEG-1 files are part of the DVD specs – just that no one uses it as there is a strong preference for MPEG-2.

It’s sad that you’re a student asking questions that are integral to digital media content – stuff like these should have been taught. I cover compression and video architectures in all my AE classes. Like I said, they’re integral.

AE’s MPEG-2 output is pretty good. A bitrate setting of 8Mbits for video is pretty awesome.

HTH
Roland Kahlenberg

https://www.broadcastGEMs.com – AE Project Files
https://www.myspace.com/rorkrgbspace

[Brendan Coots]

I can’t remember where, but I saw some comparison tests that were done between After Effect’s compressed output (MPEG2, MPEG4, Sorenson and WMV9) versus using a third party tool on uncompressed files from AE. The difference was very obvious, both in quality and file size. For all of the formats tested AE’s output was always 20-70% (!) larger, and looked much worse in all cases.

So while AE can output MPEG2 files, and they aren’t horrible per se, you will likely always get better results using a compression app instead of AE for those tasks. There’s a free tool I use called SUPER (https://www.erightsoft.com/SUPER.html) which compresses to every format under the sun and does a great job.

[Roland R. kahlenberg]

You’re comparing apples versus oranges. For MPEG-2, AE does a good job when compared to other tools. If it’s 8Mbits for an MPEG-2 file, then the file sizes shouldn’t be different between what AE delivers and the other tools. And less visual difference when you’re doing CBR. I’d stay away from VBR MPEG-2 files unless disc space is going to be an issue.

For Web delivery, AE will be far behind other compression-only-tools.

HTH
Roland Kahlenberg

https://www.broadcastGEMs.com – AE Project Files
https://www.myspace.com/rorkrgbspace

[Brendan Coots]

“For MPEG-2, AE does a good job when compared to other tools. If it’s 8Mbits for an MPEG-2 file, then the file sizes shouldn’t be different between what AE delivers and the other tools. And less visual difference when you’re doing CBR.”

That may be so. I rarely output to anything but uncompressed from AE and prefer using DVD Studio Pro’s MPEG2 encoding, a lesson learned from seeing poor results out of AE one time too many. I should also note that in a recent interview one of Adobe’s own product guys conceded that AE’s compressed output was not up to snuff. I just think it’s safer to use tools designed for compression and let AE do what it’s made for – high quality master files.

I agree that the file size shouldn’t be larger with MPEG2 in particular, but I have noticed quality issues in the final DVDs that weren’t there when DVDSP was allowed to create the MPEG2 instead.

[Roland R. kahlenberg]

[beenyweenies] “I should also note that in a recent interview one of Adobe’s own product guys conceded that AE’s compressed output was not up to snuff.”

If that’s the case, then rendering to ALL compressed formats from AE should be objected to. That is obviously not what this Adobe guy meant. Hence, that is not what we shold be regurgitating.

Not having listened to the original discourse, I would nonetheless suss it out that the topic in question, then, was compressing movies for the Web and not compression in general, which includes the Animation CODEC, Motion JPEGs, etc. Having said that, WMV output from AE is pretty acceptable. No 2-pass VBR and fancy filters but it does a good job for client previews over the Web – good-sized file and pretty good quality.

FWIW, DVD Studio Pro used to have very poor MPEG-2 encoding. It’s gotten better. I kinda like the MPEG-2 encoding in AE7. It does CBR rather well at the 7-8Mbit range. If you’re looking for VBR MPEG-2 solutions then AE will not be a suitable tool.

Best to check it out with the folks at the COW’s Compression Forum. They love this kinda stuff.

Cheers
Roland Kahlenberg

https://www.broadcastGEMs.com – AE Project Files
https://www.myspace.com/rorkrgbspace