HDV or 24p?

Aaron Shaw · March 14th, 2005, 10:24 AM

I don't think any special editing software would be needed. All you need is the ability to import the footage and output it in an uncompressed format. If they record 24 real frames per second only then there would be no further processing required.

Barry Green · March 14th, 2005, 03:16 PM

Sounds like "ProHD" will indeed be a new format, sort of like a DVCAM version of DV was a new format, even though the internals were all basically the same.

I don't know if JVC has announced any specs on the GOP or anything else about the 24P option, other than to say that it's still 19mbps. Even if the GOP is the same length, that's still good news, as it means each frame will get more bits allocated to it than would have happened in HDV 720/30p, so more efficient compression and fewer artifacts.

If the GOP is shorter or longer, that's both good and bad. Shorter GOP means easier/more efficient editing, less impact of dropouts, and less impact of variable-resolution imaging on high-motion, high-frequency changes. However, MPEG compression excels at longer-GOP lengths, that's where the efficiency of the MPEG compression really comes into play, and why HDV on the FX1/Z1 can look so great (especially on relatively static shots) at such a tiny bitrate.

The thing to keep in mind is, the GOP in 720p is already a *lot* shorter than it is in 1080i. In Sony's 1080i version of HDV the GOP is 15 frames, but in JVC's 720p implementation it's already a six-frame GOP. So even if the GOP stays the same for ProHD 720/24p, it'll still be much shorter than the GOP in 1080/60i HDV.

Heath McKnight · March 14th, 2005, 09:48 PM

I thought it was still mpeg2-ts, which would require special software, unfortunately. ARGH!

heath

March 14th, 2005, 09:48 PM	#18
Heath McKnight MPS Digital Studios Join Date: Apr 2003 Location: Palm Beach County, Florida Posts: 8,531	I thought it was still mpeg2-ts, which would require special software, unfortunately. ARGH! heath __________________ My Final Cut Pro X blog

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March 14th, 2005, 10:24 AM	#16
Aaron Shaw Major Player Join Date: Jul 2004 Posts: 587	I don't think any special editing software would be needed. All you need is the ability to import the footage and output it in an uncompressed format. If they record 24 real frames per second only then there would be no further processing required.

March 14th, 2005, 03:16 PM	#17
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Sounds like "ProHD" will indeed be a new format, sort of like a DVCAM version of DV was a new format, even though the internals were all basically the same. I don't know if JVC has announced any specs on the GOP or anything else about the 24P option, other than to say that it's still 19mbps. Even if the GOP is the same length, that's still good news, as it means each frame will get more bits allocated to it than would have happened in HDV 720/30p, so more efficient compression and fewer artifacts. If the GOP is shorter or longer, that's both good and bad. Shorter GOP means easier/more efficient editing, less impact of dropouts, and less impact of variable-resolution imaging on high-motion, high-frequency changes. However, MPEG compression excels at longer-GOP lengths, that's where the efficiency of the MPEG compression really comes into play, and why HDV on the FX1/Z1 can look so great (especially on relatively static shots) at such a tiny bitrate. The thing to keep in mind is, the GOP in 720p is already a lot shorter than it is in 1080i. In Sony's 1080i version of HDV the GOP is 15 frames, but in JVC's 720p implementation it's already a six-frame GOP. So even if the GOP stays the same for ProHD 720/24p, it'll still be much shorter than the GOP in 1080/60i HDV.