File half corrupted after render and how to make renders faster

[Jeff Kay]

What format did you use to render the final output?

[Brendon Sulesky]

H.264

[Brendon Sulesky]

Okay, sorry I wasn’t clear enough. (this is long so brace yourself) I have after effects cs4 and update it whenever it says there is an update. I made the entire project from scratch, no source footage was used, but I did use a mp3 song for sound keys so the smoke would dance. No error messages, just long render time and half corrupted file. This has worked in the past but I have never done a video until now that was longer than 10 seconds. I guess I have installed a few programs since my last animation but I can’t remember which ones, and I doubt any of them would interfere with after effects. I have absolutely no idea what version of quicktime is installed but I have a version installed. I wasn’t running any other software, maybe once or twice opened up My Computer to see how much space I had left on the drive. I have a few third party effects installed like the effects suite, magic bullet suite, keying suite, and trapcode suite from foundry, and video copilots optical flares and twitch. A few other’s I think. My computer is a dell latitude d830, microsoft windows xp professional, version 2002, service pack 3, 32 bit, Intel Core Duo CPU T7500 at 2.20GHz 1.58GHz, 1.99 GB of RAM. Graphics card is mobile intel 965 express chipset family. I had a removable usb external drive which was where I was rendering the file to. I don’t know if I have any third party hardware, and I believe I am not using open-GL features in after effects but I’m not 100% sure. The problem happens only with the final render. I don’t think I have Render Multiple Frames Simultaneously multiprocessing. And lastly the exact sequence of steps I’m taking is creating the animation (I have a few different project files where I practice the techniques and figure out how to do stuff then use it in my main project)then add comp to render queue, choose my render settings, usually I choose H.264 cause that’s the one I’ve had best luck with so far with quality, it is set to lossless and best settings with 256 audio bitrate. I then choose the output, which in this case is the external hard drive cause I only have 3 GB on my dell at the moment due to a lot of pictures I need to delete, and then hit render. A message comes up saying:

The File ‘Fin.’ from the output module ‘Lossless’ does not have the correct file type extension. The recommended extension is ”. The file will render correctly, but the OS will not be able to identify the type of data it contains.

I just hit ok and let it render, cause this message has always come up for every codec I choose and it hasn’t really seemed to cause any problems before. Once done, 17 hours later, I enter my editing software play the video and at a certain point the video is completely gone. That’s about it…

[Cassius Marques]

Does it seem to take the same time to render 1 frame when you ram preview and when you render out?

I’m trying to exclude anything output related.

If you don’t mind sharing the project we can see if is there anything unusual in it. Because there’s no answer to how to speed up rendering in generic projects other than get a faster computer. Anything I say like “turn down motion blur samples in particular” may not be what you wanted your project to look like after all.

[Brendon Sulesky]

I suppose, here is the project file. It shows my render settings too in case that will help.
6223_whymetestrender.aep.zip

[Brendon Sulesky]

Oh and sorry I forgot, yes the preview takes about the same time to render…

[Jeff Kay]

You computer specs seem awfully low to me running AE unfortunately. Especially with only 2GB of ram as AE is particularly RAM intensive. Are you able to successfully do full quality RAM previews?

I also recommend not exporting from AE in H.264. The render queue from AE doesn’t handle most of the lossy codecs as well as other encoders (Media Coder, Compressor, Sorenson). If you can handle a large intermediary file, my preferred method of AE export is to export in RAW. This is the same format that AE uses for its previews and will have to calculate it during the export process anyway (and with lower amounts of RAM I could see AE running short on available RAM during the export which could cause corruption, though that is speculation). For a 3min movie I would expect the intermediary size to not be more than 40GB.

So try this. Export from AE Render Setting: Best Setting and Output Module: Lossless, both of those should be presets (or they are in CS6). If not make sure Render Settings are Best and Full and Output Module is AVI with “none” selected as your video codec (also make sure it exports audio if you want the output from AE to have audio). This render should take significantly less time, though its still likely to be a long render. Once you have that intermediary run it through another encoder to get H.264 or whatever format you need for delivery/further use.

[Cassius Marques]

[Jeff Kay] “…This render should take significantly less time…”

It should take about the same time, not shorter by any significance! He is rendering 5700 frames 1080p 200k visible particles on average, shaded with motion blur… Encoding time will be meaningless.

Though rendering to an lossless format is the way to go…since if you get any corrupted file you can probably patch it up re-rendering from the error onwards.

You gou there a tough thing to render, It was exactly what I thought. You can speed up by lowering particle number or motion blur steps. Though it will look different. My AE estimates 10 hours to render out (12-core). All seems to be fine with the project.

[Brendon Sulesky]

As long as I’ve been using after effects I’ve had almost no problems. The preview is full quality as far as I know. Best settings and lossless are the presets, although I don’t have “none” option in video codec or avi.

[Jeff Kay]

It will actually decrease render time. The raw export is what AE natively uses and (if my understanding is correct) AE will have to calculate this as an intermediary then encode from that to actual exported format. But even if that is not the case, I have tested this many times and can safely say that a raw export is far faster than an export in any other codec, particularly the more compressed lossy codecs such as H.264. Raw export and reencode together might not save time over an AE export of the final codec, but the RAW render time will be less and I’m not impressed with AE’s built in encoder.