Why does 720 H.264 take much LONGER to render than 1280 ProRes?

[TailG8R]

I have an uncompressed master timeline with a 90 minute HD movie @ 1920 X 1080. I just did an export to ProRes 422 HD 1280 X 720 that took about 14 hours.
Now I'm in the process of rendering from 1920 X 1080 down to H.264 @ 720 X 480. For this export it's estimated to take 2 1/2 days! Why is that? Why wouldn't a smaller file export faster?

Should I be exporting using my ProRes file instead of my uncompressed 1920 X 1080 master timeline? Does it make any difference quality wise? If so I'm guessing that it would go a lot faster since the ProRes 422 file is only 39 GB.

[El Heggunte]

{{edit}}

SameSelf's reply is better.

[SameSelf]

ProRes is an intermediate codec for editing purposes that uses light, nearly lossless compression. Judging from the file size of your 90 minute video, you are using the ProRes Proxy setting. H.264 is a delivery codec that is usually used for HD video, and you are downsampling to SD.

So my question would be, what is it you are trying to do?

[TailG8R]

ProRes is an intermediate codec for editing purposes that uses light, nearly lossless compression. Judging from the file size of your 90 minute video, you are using the ProRes Proxy setting. H.264 is a delivery codec that is usually used for HD video, and you are downsampling to SD.

So my question would be, what is it you are trying to do?

Thanks for your help. My ProRes output is intended for Amazon's new Video Direct platform. The smaller file I was hoping would be a good fit for selling my movie as a rental on YouTube.

Using Final Cut Pro's QuickTime conversion I selected H.264 NTSC 720 X 480 (16:9). 12 hours gone by and still have another 2 days of rendering to go!

[SameSelf]

Gotcha. I don't have a Mac or use FCP. But some thoughts:

- H.264 is a fairly demanding encoder, even for modern systems. Maybe it not well threaded on a Mac?
- What sort of resizer are you using in FCP? That can make a big difference in the frames per second of the render speed as well, and may even be the main bottleneck.
- Rendering out of an NLE is generally slower than using x264 (although I have no idea if x264 has been compiled for Mac or not)

But to answer your original question, I don't see anything to be gained from going through a ProRes Proxy intermediate on your way to a final H.264 encode. In fact that may introduce some unacceptable generational losses/artifacts. However, two days is somewhat extreme. As a rule, you should never render to the same drive that the master file is stored on. Did you try rendering to a separate drive?

[TailG8R]

What is a resizer?

The assets in my timeline are spread across 5 drives, not counting my system drive. My destination drive does contain some of my timeline assets.

[Cornucopia]

WTF? What kind of machine are you encoding these things on? (some kind of mac)

With a good machine, a prores encode of a 90min title shouldn't take much longer than 90min - couple of hours max. And h264 should be like 2-6 hours, unless you're doing something strange/wrong.

Scott

[TailG8R]

An old Mac purchased in late 2004. The OS X hasn't been updated since 2008. I'd tell you the version number but I'm in the middle of this friggin' render that won't be done until Friday! Agggghhhh!

[redwudz]

TailG8R, I've moved your thread to our Mac Forum. You should be able to get good answers there.

And welcome to our forums.

[KarMa]

Maybe you could only export to Prores on your old Mac, and if you want to have a more efficient lossy H.264 video, you could encode the Prores video to H.264 on a faster machine (Mac/PC). Assuming you have a better separate computer.

[sophisticles]

An old Mac purchased in late 2004. The OS X hasn't been updated since 2008. I'd tell you the version number but I'm in the middle of this friggin' render that won't be done until Friday! Agggghhhh!

You have a 12 year old Mac and you're trying to encode H264 with it and I'm guessing you're using Apple's H264 codec, what do you expect? Of course the encode is going to take forever.

[Brad]

My ProRes output is intended for Amazon's new Video Direct platform. The smaller file I was hoping would be a good fit for selling my movie as a rental on YouTube.

Unless you're deliberately trying to drive people away from the YouTube rental option toward the Amazon option for financial reasons, upload the highest quality file you can to both.

YouTube supports 4K, so there is no technical or quality reason to limit uploads there to SD. I suspect you should be able to upload the 39GB file faster than 2.5 days, too.

[pandy]

An old Mac purchased in late 2004. The OS X hasn't been updated since 2008. I'd tell you the version number but I'm in the middle of this friggin' render that won't be done until Friday! Agggghhhh!

Then buy cheap PC and finish your work in less than 2 - 4hr... honestly - even NVidia encoder will provide better quality (size vs bitrate) in real time than prores on your current computer. Latest NVidia card should be able even deliver h.265 10 bit 4k in real time and still beat prores in terms size vs encoding time.

[godai]

you need change your dinosaur,

[TailG8R]

As it turns out this thing rendered in "only" a day and a half. Final Cut Pro over estimated the render time to be 3 days.

I'd get a new computer but once I'm done rendering this movie I'm done with this type of work.