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How do I fix mp4 rendering problems

Posted: Sat Jul 02, 2016 1:51 am
by strider2000
I've seen this problem before, but don't know how to solve it. Basically, when I render out to mp4 I occasionally get pixel groups that are not properly rendered. I even have the same problem if I set extra smooth images, NTSC-safe colors and 100% quality :( I can get good output with AVI, but the file size is much larger. Does anyone know how I can fix this. I use the default mp4 setup. I imagine that a different codec might help, but I don't know how to set that up and I don't know how much of a pain that would be.

Since I just ran into a problem with it again, I thought I'd post an example.

I'm highly confident that it has something to do with the colors. Maybe gradient is the worst. If I change the sky to flat light blue, or the hair to brown, things are better, but there are still black speckles :( It's frustrating to spend so much time animating and then have the rendering look messy.

Thanks for any help.

Re: How do I fix mp4 rendering problems

Posted: Sat Jul 02, 2016 3:06 am
by synthsin75
Have you tried without multi-threaded rendering?

Re: How do I fix mp4 rendering problems

Posted: Sat Jul 02, 2016 1:22 pm
by strider2000
Well that was an interesting test. It was interesting to see parts of the animation being rendered, but unfortunately it didn't fix the problem.

Thanks for the idea.

I did find a small help. I noticed that the problem is related to how many frames I render. I'm not talking about a lot though. My entire test animation was only 133 frames. But when I rendered just the problem area, about 20 frames, the problem went away. Not a great fix (who wants to render 20 frames at a time :o)

I thought turning of layer effects might help, but, surprisingly to me, it didn't.

Just Found Something that Works Pretty Well
I did just try something else. I used my Corel Video Studio to input AVI and output MP4. That worked out very well. The result is only 2x the ASP mp4 output, but the quality is much better and it's from 10x to 300x smaller thant the AVI. I love Video Studio! It's the best I've ever seen of easily dealing with all the different video formats. It just seems to work and easy to tweak.

That works, but it's too bad that, as of yet, in some cases, I can't just render straight out of ASP with good quality :(

I'm still interested any any ideas to output better quality with small file size if people have other ideas.

Re: How do I fix mp4 rendering problems

Posted: Sun Jul 03, 2016 4:57 pm
by Greenlaw
How much RAM do you have? Rendering movie files can be limited by RAM since it generally needs to hold all the image and animation data for every frame to write a movie file. File compression during the process. of course, adds to the RAM needs. That said, 122 frames isn't really a lot unless you have a lot of really huge image files and a lot of fx.

FWIW, I typically render to frames and then compile the frames to a movie file in another program (comp or editorial). This is mostly because I usually render for compositing but rendering to frames is my normal workflow regardless. It allows for more flexibility if you need to re-render just a portion of your animation or if you need to manipulate a frame in another program like, say, Photoshop. Also, it won't require as much RAM to render to frames because it only needs to work on and save one frame at a time, and it takes less RAM to render a sequence of pre-rendered frames to a movie file (from another program or ASP.)

BTW, if you really need to output multiple frame ranges of one scene, you can do this with the Batch Renderer. Just duplicate the scene multiple times with the Duplicate Selected button and set different frame ranges for each instance. It's not an ideal way to work but in situations like the one you're seeing, it can sometimes be necessary.

Re: How do I fix mp4 rendering problems

Posted: Sun Jul 24, 2016 5:37 am
by strider2000
Wow, I missed this until just now :o Ok, just clicked the notify my when a reply is posted.

I have 6G RAM. Mainly I'm just looking for simple without sacrificing quality.