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H264 Bitrate Limit

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Andrei Popa
H264 Bitrate Limit
on Sep 9, 2014 at 11:42:15 am

Hi there,

I have a 720P video that I have to encode in h264 with a bitrate of 12Mbps.

Is this possible?

The max I can get either in Media Encoder or Final Cut (quality settings maxed out) is 5Mbps in MOV format at 10Mbps in MP4 format.

If this is not the limit, how can i get a bitrate of 12Mbps with the H264 codec for a 720P video

Thanks


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Ivan Myles
Re: H264 Bitrate Limit
on Sep 9, 2014 at 1:59:00 pm
Last Edited By Ivan Myles on Sep 9, 2014 at 2:08:52 pm

Are you using presets or custom settings? Please post screen shots of your export settings.

In AME with the H.264 codec use Level 3.2, Target Bitrate 12 Mbps, Maximum bitrate 18-25 Mbps, and 2-Pass VBR encoding. If using the QuickTime H.264 codec in AME or Compressor, set the bitrate to 12,000 kbps, Quality to 100, and Multipass encoding.


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Andrei Popa
Re: H264 Bitrate Limit
on Sep 10, 2014 at 12:53:36 am

Hi Ivan,

I know what you are saying, I managed to do it, but I can't duplicate it...

I did so many variations, and although I saved the good ones (or I thought so), it doesn't seem to work...

I did it as a MOV file.

But now if I select the MOV file and the H264 container, I don't get the level & bitrate options...

And I'm using custom presets, if I select MOV it just gives me PAL and NTSC presets...

Here is a screen shot of how I'm not getting the level and bitrate options...

http://postimg.org/image/819s1v52b/

When I did the proper file, if I remember correctly it was MOV H264 but I was getting the level/bitrate options


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Eric Strand
Re: H264 Bitrate Limit
on Sep 10, 2014 at 1:41:02 pm

At the bottom of the screenshot, where it says Bitrate Settings, check that box and type in 12,000 kbps. I would also set Key Frames every 24 frames.

@ericstrand11


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Andrei Popa
Re: H264 Bitrate Limit
on Sep 10, 2014 at 2:58:53 pm

Ok,

Now I know why I did it and can't duplicate it or presets I saved do not work.

I did what you said, it worked once.

When I tried to do it again it did not work....

Meaning it was a low bitrate (like 3k) although limit said 20k...

So for some reason neither AMC or Compressor seem to "load" the presets, or make the bitrate changes specified in a custom setting...

So the bitrate appears high in the setting, but it's not having any effect with the actual encoding...


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Eric Strand
Re: H264 Bitrate Limit
on Sep 10, 2014 at 3:03:22 pm

That's odd. You're absolutely sure the Limit Date Rate is checked on? Like it's lit up, not greyed out? You're hitting okay when you're done changing the settings and not cancel? Or you're not clicking match source settings before you hit okay?

@ericstrand11


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Andrei Popa
Re: H264 Bitrate Limit
on Sep 10, 2014 at 3:33:49 pm
Last Edited By Andrei Popa on Sep 10, 2014 at 3:35:15 pm

Yep...

I've been losing hour on end trying any possible combination.

There's definitely something wrong with my software.

What I don't understand though is why both AMC and Compressor exhibit the same behavior, if it was only one of them ok, but both... that's extra odd..

I actually tried it on 2 different OSX's (Snow Leopard and Mountain Lion, have 2 drives with 2 systems) and still the same...


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Eric Strand
Re: H264 Bitrate Limit
on Sep 10, 2014 at 4:44:56 pm
Last Edited By Eric Strand on Sep 10, 2014 at 4:45:15 pm

Wow that is really bizarre. Maybe upload a screen capture video of what you're doing? I have not heard of that behavior before. Sorry Andrei

@ericstrand11


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Andrei Popa
Re: H264 Bitrate Limit
on Sep 10, 2014 at 8:55:06 pm
Last Edited By Andrei Popa on Sep 10, 2014 at 8:55:30 pm

It is indeed very bizzare...

I've lost at least 8 hours trying to figure this out...

The thing is, that sometimes it does encode at the proper bitrate, but sometimes it doesn't...

Basically out of at least 2 dozen encodings 3 were correct and the rest not...

I don't think it's the video since, sometimes it encodes it correctly.

Anyway, here is a link to one of the videos, they're all basically the same content wise, this being the shortest one.







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