31hour render produced a corrupt mp4 file, ouch!

essami wrote on 10/6/2010, 5:35 AM
Hi!

Man I seem to have a lot of questions for the forum lately :)

I have a pretty complex project that has 720p AVCHD files, MOV files and other files too. It's a 1h 15min project and I've graded it with Magic Bullet.

It takes 31 hours to render to a 720p mp4 file. Im rendering with a Mainconcept custom template, 5 000 000 bps constant bitrate, 1280x720, 25fps. I've rendered mutliple portions individually and they all turn out fine. But for the last 31 hours I let it render the whole thing and when I try to open the mp4 file in VLC or any other program it says that it's not a valid file.

The render seems to have completed fine and there is no error messages from Vegas Pro 8.

So before trying again I thought I'd ask for opinions?

Sami

Comments

john_dennis wrote on 10/6/2010, 7:24 AM
I created a template as you described and my brief test worked fine, as yours did. Windows Media Player under Windows 7 played the material. Have you tried the Sony AVC codec? Or, I hate to say it but render the 31 hour project again.
essami wrote on 10/6/2010, 10:05 AM
Thanks John, yeah I think Im gonna try once more. I wonder if the fact that I kept working on my computer and doing a lot of other projects while this was rendering could have had something to do with it.

Sami
TheHappyFriar wrote on 10/6/2010, 11:16 AM
I've never had an issue with doing work while rendering.

But try this idea: make a bunch of regions & render the regions out to AVI or HDV (mpg). Basicly a prerender. I've had issues when there's to much "stuff" & I run out of memory right before the end, killing my file. If you prerender & bring the prerenders in to a new project it uses very little memory as everything is already prerendered, you're just encoding to the format of choice.

If you find an issue with a small part or another, just re-render that region to the same file name & it will autoupdated the "whole" prject.
Xander wrote on 10/6/2010, 12:38 PM
Check to see whether you exceeded some 2GB or 4GB barrier. I know that it can be an issue with some file types. Can't say I have ever rendered a MP4 file that long.

Typically, I render to an avi file (Cineform in my case) which I then use as the master for rendering any other format. This is also a quicker workflow if the project has to be rendered to multiple formats.
essami wrote on 10/6/2010, 1:21 PM
I'm trying to render a "preview" file for the artist whos DVD its going to be. So I need a good looking file but small in size. And I've never had a prob with mp4's before.

But Ill try rendering it in batches, can you automate this if you make regions and render regions to individual files?

Sami
kairosmatt wrote on 10/6/2010, 1:23 PM
tools-scripting-batch render

kairosmatt
kairosmatt wrote on 10/6/2010, 1:26 PM
does vegas smart render MP4s together? Or are you going to just show him smaller files? If you do a 15 minute file you can at least figure out if that gets corrupted too without wasting as much time in render.

I always do what Xander suggested, make a completed cineform file and render from that. If you have lots of hard drive space, you could do uncompressed.

kairosmatt
Former user wrote on 10/6/2010, 4:32 PM
Definitely check to see if your hard-drive is formatted with NTFS. If not, FAT32 is going to balk after a 4GB file. I had the same issue once before rendering to an external drive. When I reformatted for NTFS the problem was solved.
essami wrote on 10/7/2010, 12:52 AM
Yep, all hard drives are formatted NTFS. I dont think its a file size issue, it should come to about what the corrupt file showed as size: 2.3GB

Sami