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Apple Compressor settings for H264 streaming video

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Michael Sigmon
Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 1:13:03 pm

I've searched high and low and I can't really find any guidance as far as optimizing the Compressor settings to create an H264 video which will be streamed. Starting with 1080p30 final program exported from FCP, reduced to 640x360 when run through Compressor in the H264 job.

I also would like to know if it's suggested to use any of the filter settings; for instance, somebody suggested to me that brightness and contrast filter should be applied for H264 streaming video.

If this topic has already been covered, I'd appreciate a link to it because I sure couldn't find it after looking for over half an hour. Thanks in advance.


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Craig Seeman
Re: Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 1:23:07 pm

You can't find what you're looking for because it doesn't exist. There's good reason it doesn't exist.

There's no uniform target. Who's your targeted audience and what is their internet connection like?

Settings for talking head interviews would be different than for fast action sports with heavy motion graphics.

Settings targeting a metro area with fast broadband would be different than a rural area with slow broadband.

Settings for an upscale audience with fast connections would be different than public service video targeting economically depressed areas where people can't afford fast connections.

There is a difference between streaming and progressive download as well and, like most people, you may be using the wrong term and the specs may be different.

You, need to learn to evaluate content, make judgement on the desired target and determine what is optimal for that content and that target.

And apparently in your 30 plus minute search for nirvana you didn't look at the sticky on the top of the form on how to get the fastest compression help followed by the capitalized PLEASE READ. In it you might have read the importance of citing your target. That might have clued you in on the missing part of your question.


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Michael Sigmon
Re: Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 1:38:01 pm

Alrighty then...

1) MacBook Pro, OS X 10.6.4 running Compressor 3.0.5
2) The program is 1080p30 XDCAM.
3) Desired output is H264 .mp4 @ 640x360. Previously, I've used MPEG Streamclip to convert the .mov which Compressor outputs, to the .mp4 file wrapper.

The content will be streamed to paying customers, not for progressive download. The subject matter is mostly talking heads, static shot, or audience b-roll, usually in a static shot but occasionally we pan across them. There are also a number of full-screen JPGs in the program; we just dissolve between the talking head and the JPG. The use of these JPGs varies from infrequent to very frequent. There are no motion graphics, no fast moving subjects. There is a bug in the lower right of the screen which has a 30 frame fade up, stays up 5 seconds, then 30 frame fade out. It comes in every 2 to 3 minutes.

I usually use a 15 frame dissolve between the talking head and the JPG, by the way... it looks right for playback in a timeline but perhaps a longer dissolve is better suited to streaming between such drastically different subjects. I'm also wondering if there's a minimum time that a JPG like that should stay on the screen in a streaming video.

I have no idea what kind of server is going to be used to stream these videos, that has not been communicated to me. We are assuming that all customers will have broadband connections, since the programs are between 1 hour and 1.5 hour (some are even longer, but those are few and there won't be any of those going forward).

Hope that helps and thanks for pointing me to the sticky. Previously the client said, 'give us an H264'. I'm taking it upon myself to do better for them than just tossing a file over the wall...


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Craig Seeman
Re: Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 3:01:13 pm

[Michael Sigmon] "3) Desired output is H264 .mp4 @ 640x360. Previously, I've used MPEG Streamclip to convert the .mov which Compressor outputs, to the .mp4 file wrapper."

I assume you're just opening the .mov and Saving As .mp4 otherwise you're compressing the file again. BTW did you know QuickTime Pro can compress to H.264 .mp4 even though Compressor can't. It can also pass through as well. Of course MPEGStreamclip can do batch lists that QTPro can't.

[Michael Sigmon] "I usually use a 15 frame dissolve between the talking head and the JPG, by the way... it looks right for playback in a timeline but perhaps a longer dissolve is better suited to streaming between such drastically different subjects. I'm also wondering if there's a minimum time that a JPG like that should stay on the screen in a streaming video."

Dissolves tend to need higher bit rates since there is change every frame, otherwise the quality falls apart during the transition.

JPEGs are the opposite situation as they have no change (unless you're animating them) from frame to frame.

Given the above two types of elements you may need to test and see what the point of compromise is.

[Michael Sigmon] "We are assuming that all customers will have broadband connections"

That cuts a broad swath depending on region. Depending on the content you might be OK in the 800-1200kbps region. Ideally I'd push to the lower number without serious quality cost (that's your judgement call). In some areas "broadband" can be as low as 768kbps or lower. In others, like mine, it's rock bottom and more typically 1500kbps is slow. Keep in mind that some people get significant less than their ISP claims.

I think the place "of change" may be the dissolves and fades. Get rid of them and you might be able to move to lower bit rates if you hit that point. Then again you may not need to. You'll have to test. How the unknown server is serving may also be a factor. If it's streaming rather than HTTP I'd use CBR encode if you have that control in whatever you use as a compression tool. Some tools do that for you with a "streaming" check box.



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Michael Sigmon
Re: Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 3:27:31 pm

Seeman: "I assume you're just opening the .mov and Saving As .mp4"
absolutely.

Seeman: "BTW did you know QuickTime Pro can compress to H.264 .mp4 even though Compressor can't."

Yes, and I've done that before, but it doesn't offer the fine-grained control that Compressor does.

Seeman: "Dissolves tend to need higher bit rates since there is change every frame, otherwise the quality falls apart during the transition."

Agreed... but shouldn't the 2-pass VBR transcode handle this? I guess I don't need to worry about the dissolve length, then.

Seeman: "JPEGs are the opposite situation as they have no change (unless you're animating them) from frame to frame."

No, no animation in the JPEGs, they are static. One issue the client mentioned to me, is that of there being some pixelation as we dissolve from the talking head to the JPG, then the JPG settles out. But... I'm thinking that a proper compression job should eliminate this pixelation issue as we transition between talking head and JPG?

Seeman: "I think the place "of change" may be the dissolves and fades. Get rid of them and you might be able to move to lower bit rates if you hit that point."

No can do. Client vastly prefers the dissolve between speaker and graphic. Very unlikely I can talk them out of that point of view.

Seeman:"How the unknown server is serving may also be a factor. If it's streaming rather than HTTP I'd use CBR encode if you have that control in whatever you use as a compression tool. Some tools do that for you with a "streaming" check box."

1) OK and that touches on a key issue. I can't really test my compression settings without actually streaming it off their server, can I? (feels like a dumb question. I'm going to assume the answer is, 'yes, you must try streaming a test clip off the server you're using and see how it plays back.')

2) Compressor does indeed have a 'streaming' checkbox in the settings, and I've been wondering if I need to check that when setting up a job. Interesting that you recommended CBR encode rather than VBR for a streaming server. Would you mind explaining? Just so I can know what I'm talking about.

By the way, I'm aware that there are better H264 streaming compression tools than Compressor... for now, that's my only option. Down the road I can look into getting something better.

Also... is there any need to use the filters in Compressor? Someone mentioned to me the need to reduce contrast by applying the Brightness and Contrast filter, for instance.

Thanks for the advice.


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Craig Seeman
Re: Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 3:49:33 pm

[Michael Sigmon] "Agreed... but shouldn't the 2-pass VBR transcode handle this? I guess I don't need to worry about the dissolve length, then."

2 Pass VBR is generally not a good idea for streaming. That's the key difference in stream RTSP, RTMP vs HTTP progressive download which is cached on the viewer's side. That's why you really need to know how they're serving the file. Given the long program length, streaming makes sense but you should confirm it and if it's really streaming and not progressive download you'll probably want CBR.

[Michael Sigmon] "No can do. Client vastly prefers the dissolve between speaker and graphic. Very unlikely I can talk them out of that point of view."

Then the quality of the dissolve will be the lead factor in determining the data rate. That data rate may be different for a CBR vs a VBR encode since VBR has room for temporary peaks and then you have to see how the server handles it too. This gets back to the "optimized" target. The answer is, it depends on your specifics.

[Michael Sigmon] "1) OK and that touches on a key issue. I can't really test my compression settings without actually streaming it off their server, can I? (feels like a dumb question. I'm going to assume the answer is, 'yes, you must try streaming a test clip off the server you're using and see how it plays back.')"

Actually very smart and very key question. Knowing the server helps. The best is to test though. Better to hand the client one file and test then to have to redo a batch. Even if they can't "name the beast" (the server), they get back to you very quickly with "great" or "crap." If you want an "optimal" rule it's CBR for streaming and VBR for HTTP progressive download.

[Michael Sigmon] "2) Compressor does indeed have a 'streaming' checkbox in the settings, and I've been wondering if I need to check that when setting up a job. Interesting that you recommended CBR encode rather than VBR for a streaming server. Would you mind explaining? Just so I can know what I'm talking about."

Yes, Compressor has "magical" boxes like "streaming." It does not have overt options like CBR vs VBR. This is one reason why I use Telestream Episode. I don't like compression tools that keep things hidden from me. Heck they even dispense with the H.264 .mp4 option that Quicktime Pro has. Apple has created a simple and moderately powerful tool (within its limits) but when you're doing client based compression it can be a big "danger zone." In fact even Apple's H.264 is probably the worst amongst the codec variants. Dicas, MainConcept, x264 are all better. Better means more user controls in the tools that implement them. Better means better quality at comparable bit rates. The dissolves that might be problematic in Compressor might look just fine in Episode or Squeeze at similar settings for example.

[Michael Sigmon] "Interesting that you recommended CBR encode rather than VBR for a streaming server. Would you mind explaining? Just so I can know what I'm talking about."

Variable bit rate allows for peaks for challenging passages with lots of frame to frame change. CBR is constant bit rate. streaming servers prefer the latter as they send the same bits from "moment to moment" for a potentially large base of viewers. VBR would have bit rates "all over the place" depending on where the different viewers are in a given video. The data rate being served would vary, the server load would therefore vary, the user experience would therefore vary. With HTTP, for the individual viewer, as long as the caching is faster than the viewing, all the bits will be there for nice smooth playback.

If Compressor is your only tool at the moment it's important to know the limitations. Of course you do have MPEGStreamclip. It does batch encoding to H.264 .mp4. It can utilize x264 as well. It may not be as easy to use but it may well give you the quality you want in fewer steps and with the control you might want.


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Michael Sigmon
Re: Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 3:55:00 pm

That's all very helpful. I wasn't looking for anyone to tell me exactly what buttons to push, but rather what I need to be evaluating and adjusting for. Thanks so much.

One last question: any idea about the use of filters, specifically adjusting brightness and contrast for a streaming video? I'm going to be asked about that, I need to have some kind of answer as to whether it's necessary or not. It could impact my transcode time, after all.


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Craig Seeman
Re: Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 4:12:07 pm

[Michael Sigmon] "One last question: any idea about the use of filters, specifically adjusting brightness and contrast for a streaming video? I'm going to be asked about that, I need to have some kind of answer as to whether it's necessary or not. It could impact my transcode time, after all."

It depends on your source. There's far too many filters which vary in quality and effectiveness by compression app to go through them.

If your source is interlaced you MUST deinterlace. Compressor Frame Controls is slow so Better is often good enough compared to Best. These days I always shoot progressive. Some people like pushing the contrast and there are various ways to do that. Gamma would be one choice. Some like pushing saturation. If blacks are noisy Black Restore can crush them at the cost of losing detail.



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Michael Sigmon
Re: Apple Compressor settings for H264 streaming video
on Jul 29, 2010 at 4:20:31 pm

fair enough. I always shoot progressive so interlace is not an issue.

Thanks again for your knowledgable responses, you've definitely set me on the right path to figure out the best way to deliver these videos to the client.


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Alex Serban
Re: Apple Compressor settings for H264 streaming video
on May 21, 2012 at 6:26:36 pm

No need for snottiness. It drips all over this site.


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