Matt,

Thanks for the cross-post!
I am curious to know how you know that the Apple/Sanyo iFrame format actually uses i-frame encoding (as opposed to long-GOP encoding). I don’t know for sure at this point, but I’m more inclined to believe that it was more likely to be progressive long-GOP. I wouldn’t be at all surprised if the marketing people at Apple and/or Sanyo didn’t have any idea what i-frame encoding is, or what the HTML IFRAME command or implementation is. I haven’t found any reference to i-frame encoding in any of the Apple or Sanyo specs so far. Have you? I would really like to know for sure.

Allan Tépper

Posted by Allan Tépper  on  10/25  at  06:02 AM

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Thanks. I think that 540p is not enough for the Youtube generation either though. Now that Youtube supports HD, requires a minimum of 720p to re-encode in HD. I don’t think that consumers can be fooled with a non-HD re-encoding for too long.

Posted by Eugenia  on  10/25  at  01:28 PM

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Eugenia _ I found your blog as a result of this article. You’re all right and you do good work. Rock on.

Posted by Jim Hines  on  10/26  at  06:55 AM

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Hey Allan, thanks for asking about the i-frame thing. I’ve gone back and double checked, and now I’m not so certain it’s an i-frame only implementation of MPEG-4. I’ve updated the post accordingly.

Posted by Matt Jeppsen  on  10/26  at  03:44 PM

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Wouldn’t being rid of the long-GOP encoding potentially make the codec better suited for editing and post? I still shudder when I think of my first HDV edit. A music video which took FOREVER and then some. I know today’s machines are more powerful, but especially if it’s geared toward consumers/prosumers, you’d think that the specs shouldn’t have to be too extreme. Any thoughts?

Posted by Bjarkovic  on  10/29  at  06:32 PM

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Bjarkovic,

Yes, it certainly would. However, doing so either means either a higher bit rate or subsampling (throwing away pixels). Please see my article WHEN TO EDIT NATIVE, WHEN HYBRID, WHEN PURE I-FRAME, AND WHY (http://provideocoalition.com/index.php/editingpost/story/when_to_edit_native_when_hybrid_and_when_pure_i_frame_and_why/) for the historical examples about that.

Allan Tépper

Posted by Allan Tépper  on  10/29  at  06:49 PM

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Allan,

Thanks for the link. I actually had an interesting conversation with a Sony rep at IBC a couple of years ago, having unintentionally waded into a debate about codecs. All present agreed that the all codecs are good at one thing. Being kind to the camera or kind to the editing process. The space-friendly long-GOP formats were really handy for the cameras, taking up less space and delivering good images, but were hell on editors. At the same time nobody was really pushing the post production-friendly codecs because they weren’t a viable option in the field. I think ProRes may have changed the way we think about them, even if some people may not like it. If only for having united so many formats, it’s been a godsend for most of us.

Bjarki.

Posted by Bjarkovic  on  10/29  at  07:14 PM

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