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Best way to encode with H.264 HD from FCP

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Shyfty
Best way to encode with H.264 HD from FCP
on Apr 21, 2007 at 8:17:30 am

Hi,

I am trying to encode to a 1280x720p HD video file (for internet download). I am editing in Final Cut Pro. What is the best way for me to encode with H.264 (trying for a high quality compressed file). Straight from FCP or through another intermidiate codec/software? Specifics would be much appreciated!

Kind of new to this...trying to learn the ropes...=)

Trevor


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Rich Rubasch
Re: Best way to encode with H.264 HD from FCP
on Apr 21, 2007 at 5:04:34 pm

This usually depends on how much post-processing you need to do. The compression apps provide a lot more control and allow batching. Straight out of FCP you can determine the size of the image, bitrate etc. Less control of color correction, sharpening etc.

Depends on what you need.

Rich Rubasch
Tilt Media


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Shyfty
Re: Best way to encode with H.264 HD from FCP
on Apr 22, 2007 at 4:34:14 am

Ok can we back up a bit... There is a difference in the applications? Some are compression applications and others are...for encoding? Wouldn't most of the post-processing be completed in FCP?

Anyway, assuming the video is ready to go upon exiting FCP, is there a better way to get a smaller (but equal quality) video file than by encoding with H.264 directly from FCP?

Note: I need a bit rate of >9000mbps (1280x720)to achieve the results I want...seems really high as most information I have read indicates ~6000mbps is all that's needed. Any thoughts here on why I need such high bit rate?

Thanks

Newbie Video editor and encoder


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Craig Seeman
Re: Best way to encode with H.264 HD from FCP
on Apr 23, 2007 at 10:08:07 pm

Make sure your timeline is rendered.
Then Export out of FCP using File/Export/QuickTime Movie.
If you have the hard drive space do it as Self Contained. You can uncheck that and make a "reference" movie if you have to but in some cases you can bump into issues.
Open Compressor and open your movie. Personally I don't like exporting straight from FCP especially so in this case. You do not want to tie up FCP as a compression app.

Unless you expect people to sit through a very long download and/or have a motive to give them a full sized file, you should compress to a web friendly size such as 640x360. You might want to go to Apple's movie trailer site and download a movie and have a look at their frame size and data rate and then alter a Quicktime 7 (H.264)web download preset to match those.

If you're doing this for HD DVD then you might take a look at those presets in Compressor otherwise I'm not sure why you need a data rate anywhere near what you say you need.





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Shyfty
Re: Best way to encode with H.264 HD from FCP
on Apr 24, 2007 at 6:17:11 am

Thanks Craig, I really appreciate your input! Yes the video is for download (anything good is worth waiting for right!) I have gone to the Apple trailer site and noticed that all the 1080p video is at ~8000kbps...the picture quality Apple is getting for ~8000kbps is far greater than I have been able to achieve thus far, that is why I am so confused! To date I have been encoding straight out of FCP or using QT. I will try the work flow you suggested! Any recommendations for settings in Compressor?

Newbie Video editor and encoder


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Danny2007
Re: Best way to encode with H.264 HD from FCP
on Apr 24, 2007 at 9:21:50 am

Remember that Apple usually gets its hands on very high quality source material, much higher than 720p.


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Craig Seeman
Re: Best way to encode with H.264 HD from FCP
on Apr 24, 2007 at 6:53:43 pm

Are you encoding to 720p H.264 or trying to upconvert to 1080p?
Danny2007 is correct about Apple using higher rez sources than 720p.

What is your source for the 720p? Keep in mind if it's HDV it's already been heavily compressed as MPEG2. DVCProHD source might hold up better although I've never had the chance to really test this.



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Shyfty
Re: Best way to encode with H.264 HD from FCP
on Apr 24, 2007 at 8:15:52 pm

I am recording in 1080i on a Sony V1U (HDV). I would ideally like to encode to 1080p, however, the file sizes I was getting (for the quality I like)were quite prohibitive. I am editing the native HDV file in FCP. 720p was an option for me in order to lower my file size...

My goal is a:
1080p/720p Quicktime file (H.264)
1080p/720p Windows Media Player file (WMV HD)- I intend to use Flip4mac WMV Studio Pro HD for this.

Please, I know I can't livestream this and I will be "limiting my audience"...heard it all...this is what I have to accomplish. I just need help! I really need to compress the file as much as I can, but I want playback to be smooth and of a reasonable quality...


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Craig Seeman
Re: Best way to encode with H.264 HD from FCP
on Apr 24, 2007 at 8:53:37 pm

There's no reason I can think of that would prevent you from matching the file size of the 1080p files on Apple's site.

Keep in mind your source is interlaced and Flip4Mac's deinterlacing is very simple. I'm sure Apple's sources are all progressive. I don't think Windows Media 9 will look as good as H.264 at the same data rates. On the other hand VC-1 (Windows Media 9 Advanced) should be competitive and will be supported in the next Flip4Mac release. Regarding H.264, Compressor now has very good (and very slow) deinterlacing.

BTW if you are using the Sony V1 why not shoot in 24p or 30p?

Again keep in mind you're coming from heavily compressed MPEG2 (HDV) and that's a CBR encode too (as compared to XDCAM which, while GOP based, is a VBR encode). There probably are other related factors that may have impact on quality I'm not thinking about at the moment.

That said, you should get a pretty good looking encode. If you can put one up and post a link maybe I (we) can have a look at it.

BTW, the Apple full size 1080p movies trailers play in real time (progressive download) for me even though they're around 10mbps. I'd thought I'd mention that, as a result, I'm really a lousy judge of how patient people have to be.



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Shyfty
Re: Best way to encode with H.264 HD from FCP
on Apr 25, 2007 at 1:38:58 am

Great information Craig... we have been debating whether to shoot in 60i vs 24p/30p. Until now I never thought of what the implications would be on compression etc. 30p would be a better way to go, so I dont have to deinterlace?

Based on the limitations of HDV...etc any suggested settings for me to consider in my endeavor? Best to encode with compressor Quicktime movie as opposed to with FCP or Quicktime Pro?

Here are my settings:

Bit rate: 10,000kbps
Key Frames: 5 ----> any recommendations here?
Size: 1920x1080 HD
Output:Progressive
Frame rate: 29.97 fps---> would 30fps
Multi pass


Newbie Video editor and encoder


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Craig Seeman
Re: Best way to encode with H.264 HD from FCP
on Apr 25, 2007 at 2:49:24 pm

Compressor and QuickTime Pro use the same "engine." Compressor gives you more tweaks if needed though.

If your final edit is FX and transition heavy, you might drop it into a DVCProHD or even 8 or 10 bit uncompressed timeline and rerender in FCP. This way the FX and transitions won't suffer an HDV MPEG2 Quality hit before going on to compressing the file in another codec for web use.

For compressing I'd make sure your frame rate is set to "Current."
Generally if you have lots of fast editing, codecs use "natural" key frames (edit points) so use of "forced" keyframes (key frame every x frames or seconds) depends a lot on content.



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shyfty
Re: Best way to encode with H.264 HD from FCP
on Apr 27, 2007 at 2:45:57 pm

Key Frames has me a little confused...I have seen better results for some video with less key frames (i.e every 150 frames) than with more (every 5 frames). Any way of narrowing this down or isa it just trial and error.

Oh how would I rerender a DVCProHD file in FCP? In teresting though because I have noticed that when I encode staright from FCP I get audio lag...not cool!


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Danny2007
Re: Best way to encode with H.264 HD from FCP
on Apr 27, 2007 at 4:10:56 pm

Every 5 frames is 'wrong' (when I saw that you were using that seeting in an earlier post I assumed it was for every 5 seconds) - a general rule of thumb is to set keyframes to be 10 x your frame rate, so at 30fps there should be a keyframe every 300 frames.

Modern codecs are very good at inserting keyframes when there's enough of a 'scene-change' to warrant one.

Inserting more frequent keyframes (especially once every 5 frames) usually just ends up making a much bigger file, with a much higher datarate and without too much improvement in picture quality.



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Craig Seeman
Re: Best way to encode with H.264 HD from FCP
on Apr 27, 2007 at 6:29:21 pm

Danny's correct.

Here' some more info.

Modern codecs will insert keyframes on edit points (scene change). Those are often referred to as "natural" key frames. There's also setting a keyframe rate, often referred to as "forced" key frames.

Those "forced" keyframes can become important if you have shots that go on for a bit without an edit point. The image can gradually look worse as it gets farther away from a keyframe so there can be value to using forced keyframes.

Sometimes you can see keyframe "breathing" though. A sudden visual increase in quality for one frame (the keyframe) which can be more or less obvious depending on codec, frame rate, content.

10x the frame rate for forced keyframes is a good rule of thumb as Danny mentions but what one may chose might depend on content. Something with lots of fast action/motion might warrant more a higher forced keyframe frequency.



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shyfty
Re: Best way to encode with H.264 HD from FCP
on Apr 28, 2007 at 1:55:06 am

Good stuff guys! yeah, I can't wait to try encoding with KF every 300 frames! Will let you know how it goes...


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shyfty
Re: Best way to encode with H.264 HD from FCP
on Apr 29, 2007 at 4:18:55 pm

Not much changed in the picture quality, but the file size did decrease somewhat, which is a good thing. I think I found a sweet spot at keyframes = 150.

Under QT video size settings, what is the difference between these two settings?

HD 1920x1080 16:9 and 1920x1080 HD

Doesn't make much sense...?


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