mp4 rendering problem

trojanrobmc wrote on 3/17/2011, 11:02 AM
I'm trying to render many of my HD video files in Vegas Platinum 9.0 to AVC-based .mp4 files, instead of AVC-based .m2t files--obviously, the quality is very similar, despite the fact that .mp4 files are about half the size (which is why I want to do it).

But I'm running into problems doing this. When I try to render longer video files (15 minutes or longer), the final render has problems: when I try to play back the rendered .mp4 file, about 12 or 13 minutes into the video, it gets VERY choppy. This is not the case when I'm rendering those same video files to .m2t (mpeg-2)--that render plays back just fine.

Does anyone have any idea why I'm running into problems when rendering .mp4 files specifically? Again, it's only with LONGER files. Shorter files (3-10 minutes or so) seem to render just fine to .mp4.

BTW, at first I thought it might be a memory problem, but I do have 6GB of memory, and I've watched resource monitor while rendering, and it doesn't even get close to running out.

Thanks for any suggestions :)

Comments

Eugenia wrote on 3/17/2011, 11:39 AM
Playing back the files is a media player problem, not Vegas' (unless you're trying to play them back inside Vegas, which is a bad idea). The fastest decoder today is CoreAVC's, which when coupled with nvidia's CUDA support, can deliver smooth playback using a compatible media player, e.g. WMP, MPC etc.
trojanrobmc wrote on 3/17/2011, 2:12 PM
Thanks for the response. I'm not quite sure I understand. Are you saying I need to download a better decoder (CoreAVC) to work in tandem with WMP? I'm not exactly sure how to do that...I thought that all decoders were already built into WMP. Thank you again.
Eugenia wrote on 3/17/2011, 2:21 PM
There are h.264 decoders and h.264 decoders. Quicktime's sucks for example. It's slow. WMP's is better, but the best one is CoreAVC's. It's fast even without CUDA support, but if you do happen to have an nVidia card, it will literally fly.

Try the trial version, and VLC the way I describe here and then decide for yourself:
http://eugenia.queru.com/2009/07/11/how-to-fast-h-264-decoding-on-your-pc/
trojanrobmc wrote on 3/17/2011, 3:47 PM
I tried the trial version of CoreAVC; I also installed VLC player and tried to run the file in conjunction with that. Neither option worked. I'm almost positive that the problem is not with the playback, it's that for some reason Vegas is not rendering the .mp4 file properly (on longer videos).
Eugenia wrote on 3/17/2011, 5:32 PM
Then either export in WMV, or upgrade to Platinum 10 so you are able to export MP4 using the customizable MainConcept encoder, not the Sony AVC one. Alternatively, you can export in an intermediate codec, e.g. the freeware Lagarith, and then import the generated AVI file on an x264 front-end encoder (e.g. MeGUI or other), and use that utility to export to MP4 rather than doing it through Vegas.
trojanrobmc wrote on 3/18/2011, 7:57 PM
Thanks! That worked...kind of. I was able to render a .mp4 file in MainConcept, but for some reason, when I move the file over to DVD Architect to burn it to a Bluray, it needs to render it AGAIN. The main purpose of me wanting to render in Vegas in .mp4 is so it won't need to be re-rendered just to burn it to Bluray. Are there special settings in MainConcept .mp4 that I need to apply so that it will be all set for bluray?

Thanks again for all your help.
Eugenia wrote on 3/18/2011, 8:22 PM
Sony AVC MP4, Main Concept MP4, and WMV are for PC playback, TV playback via media player, and online uploading only. Not for DVD/BD. For those, you export differently.

For DVD -> DVDA you export with mpeg2 widescreen NTSC for video, and AC3 for audio, and DVDA puts that back together.

For BD->, you export using the Sony AVC template for Blu-Rays, and AC3 for audio.

Alternatively, if you don't want menus, you can burn DVDs and AVCHD disks (if your BD player supports those) directly via the Vegas main menu, no need for DVDA in that case.
trojanrobmc wrote on 3/18/2011, 8:59 PM
Alas, the Sony AVC template is what's giving me problems in Vegas. For some reason, longer files don't render correctly; they get choppy toward the end of the file--whereas shorter files are just fine. I'll probably just need to render longer files through MPEG2 (.m2t) instead. They take up more space on my disk, but at least they work properly.
Thanks
TOG62 wrote on 3/20/2011, 1:34 AM
Alas, the Sony AVC template is what's giving me problems in Vegas. For some reason, longer files don't render correctly; they get choppy toward the end of the file--whereas shorter files are just fine. I'll probably just need to render longer files through MPEG2 (.m2t) instead. They take up more space on my disk, but at least they work properly.

When you say that the files get choppy to you mean when they are just played on the PC, or after they are burnt to disc in DVDA? I would expect the former, but not the latter.
trojanrobmc wrote on 3/23/2011, 10:05 AM
Most files rendered through Vegas as a Sony AVC .mp4 file play fine on the PC, and burn through to a bluray just fine too. But larger files give me problems via playback on WMP, VLC player, etc. I have to be honest with you and say I haven't actually burned those files that are bad yet--that's a good idea to see if the problem is simply with playback on my PC, or with the rendering process itself.

Again though, SONY AVC .mp4 files are the only problem... MainConcept AVC .mp4 files play just fine.