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Current video compression recommendations - HD/SD



  • Does anyone know of somewhere I can find clear, concise info on current codec/resolution suggestions?  I have been working with Isadora for several years - and compressing DV video at 320x240, Photo-JPEG. But, now I am working with a mix of DV, DSLR video, and HD (from Canon XF100).

    On the "Optimizing for Speed" page it seems to indicate that using HD resolutions is fine - and that 720x480 is fine for SD (is 320x240 an antiquated idea? - although that is what is still recommended in the manual).  And is HDV really best for any HD footage? Also - does Pro-Res really work or is it too heavy? (I tend to do a lot of live mixing).
    Anyway - many questions  - and I feel like I should just know this stuff - but still wondering if there was an easy to digest summary somewhere.
    Thanks!


  • Hi,

    Codecs and resolutions are depending quite a lot on your machine.
    Can you describe it ( OS, CPU, HDDs ) a bit ?
    The 320x240 is I think related to the powerbook g4 times, with a recent machine you can deal with HD ( 1080p ), even multiple files at once depending on your storage speed.
    Best
    Mehdi


  • Hi -

    I am mostly on a Mac tower - 2.8ghz quad-cord intel xeon - with 16gb of RAM - I am stil on 10.6.8\.  But I am also at times working on laptops (of varying quality and power) - from a 2007 MacBook Pro to a new one with a 2.5ghz intel core i5 running OS 10.8.
    I try to run from an internal harddrive when possible -but sometimes am using externals with FW800.
    Does this info help?
    Thanks.


  • Dear Lala,

    First, you're right that the 320 x 240 references are now antiquated. I need to go through this in the manual. But the "Optimizing for Speed" page (starting on page 64 of the current manual, as found in 1.3.0f24 in the Help menu) was updated recently, and that's the advice you should follow.
    Internal hard drive with a Mac Book Pro is not as good even as an external FW 800, because the rotation speed of the internal drive is slow (5400RPM) unless you've special ordered or installed a faster one. A few laptop users I know have replaced the optical (DVD) drive with an SSD. That gives them big storage on the main drive, and super fast storage on the SSD. Increasing your hard drive speed is a critical factor in good performance -- especially when playing "heavy" codecs such as Apple Pro Res which has a bandwidth of 20 megabytes per second.
    In terms of other HD codecs, I'm afraid I haven't done enough testing myself to give a good recommendation. Others here may have more experience. But, in general I've been testing with Apple Pro Res because the quality is very good and the CPU requirements are not very high. Using H264 will give you much smaller files, and thus lower the hard drive band width requirements, but it eats CPU. 
    This topic is always a bit voodoo.... there are pluses and minuses everywhere. Part of it just requires experimentation, and the results on one machine may vary substantially when compared with another.
    Sorry that I cannot provide you with clearer gudance. But I hope that what I've said above helps.
    Best Wishes,
    Mark


  • Hi Mark-

    Thanks so much for your thoughts and for the information.  It is somewhat reassuring that there is no straight answer - at least my confusion and questioning seems justified.
    I am always using external drives when on a laptop - the internals are usually when I use the tower (which I will try to use for more complicated tasks).
    I will do some tests - but since I am mixing sources - I am just having a tricky time settling on a universal, base setting. Looks like I have a lot of exporting to do...
    Thanks,
    Lauren


  • I run off a MBP with 2.66GHZ, 4GB & 5400 rpm internal, and have been converting all my H264 clips to Photo JPEG.  I've found that the increase in output frame rate is well worth the increase in disk space.



  • I am almost a totally green hand on video compression problem. I have only tried to do image compression work using some 3rd party tools. I think there must be some fine tools to help us with that, right?


  • Tech Staff

    I switched the internal drive on my macbook pro to an ssd. The performance difference is huge!

    Cheers,
    Alex


  • In my experience it depends on a lot of factors but here are some things I have found (not just based on isadora). Mac has optimised decompression on the gfx card for pro-ress and h264. This is great if you don't need pixels (meaning you are working on the CPU), if you are using core video much of the video processing will be done on the gfx card, if you use Isadora actors they are using the cpu. I am not sure about inside Isadora but when using the quicktime api there are flags you can set for increased performance, like decode pixels only (for CPU) or decode texture only (for gpu) and also use synchronous seeking (do you just play or do you need to scrub and go backwards).

    If you want HD and can stick to GPU processing then pro-ress is great, not too much decompression and not too big file sizes (h264 can be good too especially if you just play a file). If you are working on the CPU then less compression is better so your photo jpeg codec is still good (pro-ress does perform well here too). Each version of the mac OS has advantages and disadvantages for playback and decoding (although in my experience go for 10.6.8 or 1.8.4+, 10.7 of any release seems to have the worst performance).
    On your main work machine, whatever your resolution, change to an SSD if you can, the performance difference is pretty huge.
    There is no easy answer for all machines and all jobs, but if you know the rules and don't expect and patch that works on your quad core mac pro to work on your 2007 laptop you will be fine.
    Fred

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