There are really good explanations of what goes into this in
"Introduction to Data Compression" by Khalid Sayood. The first few
chapters are written in plain English and are easily understood. The
math gets a little scary (at least for me) after that. It's worth
reading, at least up to the point where your brain starts to sweat. --J.B.
Mark Spano cutandcover@gmail.com [Avid-L2] wrote:
>
>
> Bouke - isn't XAVC interframe compression, and XAVC-I intraframe
> compression? Interframe requires the look forward/backward processes,
> but intraframe means each frame is compressed independently. For
> example, DNxHD 36 is intraframe compression, but MPEG-2 is interframe.
> I would think that intraframe compression would be easier on CPU.
> However, the special case with XAVC-I is that it's H.264, and
> therefore, harder for CPU to decompress. I'm willing to concede here
> on the specifics, just thought all this time it was interframe =
> complex, intraframe = simple.
>
> On Sun, Apr 3, 2016 at 8:49 AM, 'Edit B' bouke@editb.nl
> <mailto:bouke@editb.nl> [Avid-L2] <Avid-L2@yahoogroups.com
> <mailto:Avid-L2@yahoogroups.com>> wrote:
>
>
>
> To be utterly correct, It's slightly more complex than that.
> It's not about the AMOUNT of compression, it's about the KIND of
> compression. Intra frames require to look around more frames to be
> able to decode a given frame. That takes time and math.
> DNxHD 36 is VERY HIGH compression, but still very easy to decode
> since it's I frame only.
> And yes, File size does not say anything about quality unless the
> kind of compression and resolution is the same.
> But even then, on a VBR codec a large file may be worse than a
> small file. Noise free clouds / macro shots are way easier to
> compress than noisy images where everything is in focus.
> Bouke
> VideoToolShed
> van Oldenbarneveltstraat 33
> 6512 AS NIJMEGEN, the Netherlands
> +31 24 3553311 <tel:%2B31%2024%203553311>
>
> ----- Original Message -----
> *From:* David Ross speckydave@gmail.com [Avid-L2]
> <mailto:speckydave@gmail.com+[Avid-L2]>
> *To:* Avid-L2@yahoogroups.com <mailto:Avid-L2@yahoogroups.com>
> ; hartfilms@earthlink.net <mailto:hartfilms@earthlink.net>
> *Sent:* Saturday, April 02, 2016 10:28 PM
> *Subject:* Re: [Avid-L2] Laptop Media Composer for XAVC
> editing - best configuration and workflow
>
> Intra-frame codecs are considerably more compressed than DNx,
> so yes, the files are smaller. The extra compression is what
> makes them more painful to edit with.
>
> D.
>
> Sent from my mobile phone - please excuse spellung.
>
> On 2 Apr 2016 9:11 p.m., "hartfilms@earthlink.net
> <mailto:hartfilms@earthlink.net> [Avid-L2]"
> <Avid-L2@yahoogroups.com <mailto:Avid-L2@yahoogroups.com>> wrote:
> >
> >
>
Posted by: john beck <jb30343@windstream.net>
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