h.264 Encoding Options?

Discussion in 'Digital Video' started by hotwire132002, Aug 26, 2007.

  1. hotwire132002 macrumors 65816

    hotwire132002

    Joined:
    Jan 24, 2004
    Location:
    Cadillac, MI
    #1
    I'm in the process of putting together an HD podcast, and as such, I'm going to need to encode HDV to h.264 regularly.

    I'm currently running on a Dual 2.5Ghz G5 with 2 gigs of RAM, and encoding h.264 is SLOW. It probably took an hour or so to encode 5 minutes of video (HDV to HD h.264).

    I looked at Elgato's turbo.264, but it doesn't seem to support HD encoding.

    I would guess there aren't really any ways to speed up the encoder on my G5 -- right now I close everything out and let Compressor do its thing... but if there are any tricks that might make this run faster, I'd love to hear them =)

    I've been considering a mac pro for quite a while now... and this is one more reason to get it. For anyone who has gone that route, can you tell me what kind of speed increase I might see? Also, when it comes to encoding... what kind of gain is there moving up from the 4-core to the 8-core?

    Thanks for any suggestions -- if there's a faster way to encode, I'd love to hear it!
     
  2. dave@toastmedia macrumors member

    Joined:
    Aug 23, 2007
    #2
    I play games with a single account, this dramatically increases the speed of the game as I can switch off other things, I also know that I have nothing else running except for the game and the system.

    Perhaps this would work for you, granted you will have to forgo using the computer at this given point in time. Switch off a lot of external startup programs including widgets etc for this account and see how it goes.
    killing processes that you know are not being used before starting up compressor will give you a little more ram.

    I have a ppc dual 2500 with 3 gigs of ram ati 9800 xt and never experienced that kind of time frame coming straight out of FCP 5.5.
    I use 2 x 1 gig rams then 2 x 512's as the last gig sticks.

    Compressor 1 & 2 would always fail when trying to open a file.
    background process error or something and the apple page with it listed did not solve it for me, this is why i had to encode with FCP or Quicktime.
    I have not tested compressor just yet now im upgraded to 3.
     
  3. mrgreen4242 macrumors 601

    mrgreen4242

    Joined:
    Feb 10, 2004
    #3
    That seems really slow for some reason. Of course, it's probably about right on for HD video, but have you tried a third party compressor? The new handbrake has some support for HD MPEG2 transport streams, and should (from some reports I've read on the HB forums) work with HDV. FFMPEGX might be able to do something with it as well, if HB doesn't work out.

    Anyways, my point being that Apple's QT encoder is pretty slow for SD material when compared to some of the other solutions out there, so I'd assume the same for HD. Try to integrate some other apps into your workflow and see if you can get the desired results without spending the big bucks!

    As an aside, I'm wondering whether it's accurate to call an HD online video series a Podcast, since there's no iPod that could play it... ;)
     
  4. hotwire132002 thread starter macrumors 65816

    hotwire132002

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    #4
    I'll mess around with some other encoders, and see how it goes...

    Good point about the Podcast terminology, but I just felt that "AppleTVinHDCast" din't flow quite as well :p :D
     
  5. ppc_michael Guest

    ppc_michael

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    Apr 26, 2005
    Location:
    Los Angeles, CA
    #5
    H.264 is a very intense compression. Software-based stuff will be slow for quite some time. There are hardware encoders that I believe encode in real time (a five minute video would encode in five minutes), but they are hella expensive, especially for anything of satisfactory quality.
     
  6. Alican macrumors regular

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    LONDON, UK
    #6
     
  7. yadmonkey macrumors 65816

    yadmonkey

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    Western Spiral
    #7
    I remember this rumor about Apple putting h.264 decoding/encoding chips in future Macs. Somebody in the thread suggested (see below) that new ATI video cards had such a chip - might a card upgrade help you?

     
  8. Alican macrumors regular

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    Apr 16, 2007
    Location:
    LONDON, UK
    #8
    Just as a guide, it's just taken me 5'45" to encode 2 mins of HDV using h264, best quality, single pass, 1440x1080. But this was from FCE using Quicktime conversion which might not be nearly as efficient as Compressor.
     
  9. mrgreen4242 macrumors 601

    mrgreen4242

    Joined:
    Feb 10, 2004
    #9
    Thanks for doing some tests, I'm sure other people beyond the OP appreciate that. Mind trying out Handbrake 0.9? It SHOULD take an HDV transport file without trouble. I'm curious what the difference is between the QT encoder and the open source x264...
     
  10. Alican macrumors regular

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    LONDON, UK
    #10
    Sure will do that later. I do have handbrake 9 but I'm just heading off for work now. Do you mean I should burn an HDV transport file to DVD first?
     
  11. hotwire132002 thread starter macrumors 65816

    hotwire132002

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    #11
    Thanks for testing this!

    I know you're using QuickTime rather than Compressor, but is there still an Export for Apple TV preset? If so, can you try that one and let me know how long it takes?

    Thanks again for taking the time to run these tests, It's greatly appreciated!
     
  12. Alican macrumors regular

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    Apr 16, 2007
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    LONDON, UK
    #12
    Yes I'm sure there's an option for apple tv preset, I think the option came on the last software update.

    I'm at work now, but will be happy to test when I get home
     
  13. hotwire132002 thread starter macrumors 65816

    hotwire132002

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    #13
    Awesome, thanks!
     
  14. Alican macrumors regular

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    Apr 16, 2007
    Location:
    LONDON, UK
    #14
    The encoding of 2 mins of 1080 50i HDV using the apple tv preset took exactly 4 minutes. However, the resulting image was squashed into a 4:3 raster. Given that HDV is native 16:9 I wonder why it wasn't letterboxed.
     
  15. hotwire132002 thread starter macrumors 65816

    hotwire132002

    Joined:
    Jan 24, 2004
    Location:
    Cadillac, MI
    #15
    Although HDV is 16:9, the picture is stored as 1440 x 1080 pixels -- a 4:3 ratio. It's stretched horizontally when played -- to fill 1920 x 1080, a 16:9 format.

    Thanks for your help -- I like the numbers you're getting on that machine! :)
    Now to come up with a few thousand dollars.... ;-)
     
  16. Alican macrumors regular

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    Apr 16, 2007
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    LONDON, UK
    #16
    Yeah it's a shame about the cost but you really do get what you pay for, barring any serious hardware failures, I'm banking on my machine being good for a few years yet.

    Using Istat Pro, the processor usage only showed about 35% max. Hopefully as encoders get more developed, they will use the CPUs more agressively.

    Capturing HDV footage in FCE or Imovie is real time - no lag whatsoever while it transcodes to AIC

    I should have realised about the picture being naturally stretched out on a 16:9 TV
     

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