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    Which ProRes 422 to choose in Mpeg Streamclip
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    I am converting everything to Apple Pro Res to start editing in FCP and was just wondering what the difference in the two choices of Pro Res 422 are... should I use the first or second in the list?


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    What are those 2 choices exactly? There's 4 different flavors of ProRes



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    Senior Member RyanT's Avatar
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    It doesn't look like there's any difference at all...There labeled exactly the same.

    But I wonder if there is a difference. Anyone know?


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    Excellent question. I had no idea what the difference was, I had been using ProRes LT for most things.

    I ended up finding the Apple White Paper document which really offered some interesting insights into the process. I'll summarize it here, but the link follows as well if you want to read it yourself (I recommend it).

    Apple Pro Res White Paper

    In general, the higher quality the codec, the better the output will match the source footage. You've actually got five choices:
    1) Apple ProRes 444
    2) Apple ProRes 422 (HQ)
    3) Apple ProRes 422
    4) Apple ProRes 422 (LT)
    5) Apple ProRes Proxy

    The better the name sounds, the better the codec quality. 444 is better than 422. HQ is better than LT is better than Proxy.

    The better the quality, the more chroma and more luma information preserved. 444 has more chroma than the 422. HQ has better luma rendition than LT.



    The better the quality, the higher the bitrate, thus higher filesizes. Lighter files play back easier, take up less space, and are quicker to move.



    Also, the better the codec, the lower the likelihood of first-generational loss.





    So what does this mean in the real world for the 7D. As we all know, the 7D can produce some very pleasing images, but isn't really a performance spec stunner (re: charts, 4:2:0, codec). Because of that, I personally believe that using ProRes 444 is totally unnecessary. And I doubt (nor have I seen in my own very unscientific experiments) a significant difference would exist between HQ, Standard, and LT. I have never used Proxy.

    Apple's suggestion:


    My suggestion: shoot a test scene with macbeth chart or a scene with lots of different colors and gradations. Take the same source file and encode it differently. Watch them. Pixel peep. See if you can really find a difference.


    Note: This is all in regard to the 7D and only the 7D. If you are shooting on a 4K camera or dealing with IMAX footage then this does not apply. Of course, if you are shooting on a 4K camera, I should be asking you questions!
    Last edited by Michael Olsen; 12-14-2009 at 07:55 AM.


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    Senior Member Ryan Farnes's Avatar
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    As far as choosing between 422 (HQ) and 422, I always use 422. Spoke with an Apple rep at a conference doing workshops about codecs and workflows. Apparently he was the go to guy from Apple for the Cohen brothers whenever they had tech issues with Final Cut Studio.

    When I asked about converting Long-GOP EX1 footage to Prores, he specifically stated that 422 (HQ) was unnecessary and the plain 422 was more than sufficient. I imagine that the 7D is in the same boat and you're not dealing with a major digital film or broadcast piece where the extra space is negligible, and you want to preserve every last minuscule detail. For lots of 7D work, I'll be using normal Prores 422. If I ever make a short film where I "spare no cost," I'll go with the 422 (HQ) just to appease my sense of pristine quality all the way.


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    Wow thanks for that, Michael.

    Very informative.


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    H.264 to Apple ProRes: Can quality improve?
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    The thing that is mysterious to me is, what happens when you convert the 7D or 5D footage from H.264 to ProRes. Suddenly the file size is tripled -- if it was a data rate of 8 megabytes per second out of the 5D, it becomes roughly 24 megs/sec. A 300-megabyte file is now about a 1-gigabyte file. Where does all that new data come from? Is Mpeg Streamclip making pixels up as it converts from H.264 to ProRes? You can't get something for nothing can you? ProRes won't look any better than the original footage, will it?


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    Quote Originally Posted by jimbee View Post
    The thing that is mysterious to me is, what happens when you convert the 7D or 5D footage from H.264 to ProRes. Suddenly the file size is tripled -- if it was a data rate of 8 megabytes per second out of the 5D, it becomes roughly 24 megs/sec. A 300-megabyte file is now about a 1-gigabyte file. Where does all that new data come from? Is Mpeg Streamclip making pixels up as it converts from H.264 to ProRes? You can't get something for nothing can you? ProRes won't look any better than the original footage, will it?
    Hi Jimbee,
    I'm going to mess around with the order of your questions a little bit, but will do my best to answer them all.


    Quote Originally Posted by jimbee View Post
    ProRes won't look any better than the original footage, will it?
    Nope. But that's not what it is supposed to do. ProRes is designed as a lossless intermediate format. Lossless meaning there is very little degradation to the quality. Intermediate meaning that it is used more or less only for editing, not capture, delivery, or storage.

    Quote Originally Posted by jimbee View Post
    You can't get something for nothing can you?
    Not here, you can't. ProRes won't make your footage look feel, or sound better. It will, however, make it easier to work with in post.

    Quote Originally Posted by jimbee View Post
    Is Mpeg Streamclip making pixels up as it converts from H.264 to ProRes?
    Nope. Streamclip isn't making your 1080p into 2K or 4K. And it isn't doing anything to correct for the pixel-binning. And while it is encoding at 4:2:2 or 4:4:4, if the information isn't in the source material (4:2:0 for 7D) it won't be there in the ProRes file.

    Quote Originally Posted by jimbee View Post
    Where does all that new data come from?
    H.264 is a very processor heavy codec, requiring a great deal of power. ProRes is designed to be light and easy to run.

    When moving from H.264 to ProRes, Streamclip is sort of uncompressing the files slightly, making them easier for the computer to understand.

    Think of it in terms of English. A sentence of H.264 may read:

    It ws th bst f tms t ws th wrst f tms.

    The computer then has to take the instructions and fill in all the blanks in order to get:

    It was the best of times, it was the worst of times.

    Pro Res, on the other hand, would take care of some of that for the computer. Reading, for example:

    It was th best f tims it was th worst f tims.

    It is still compressed, but larger than the H.264 version. It is easier for the computer to recreate the sentence...or in the real world, the video.

    I'm sure that analogy is flawed (as all are) but it provides the basic idea. In order for the file format to be easier for the computer to read, thus allowing real-time editing and playback, it must be less compressed and therefore larger.


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    Michael.. that was an AMAZING description of why files get larger when converting to ProRes. THANK YOU for that. x100



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    Read somewhere today (think it was Skywalker discussion) that Philip Bloom uses 422 (LT) and that it's "more than sufficient" or words to that effect.


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