Canon Xl-2????

Peter Moore · August 21st, 2003, 08:18 AM

I guess my point is that a pro-sumer HDV cam should use a DV-LIKE compression scheme (intra-frame compression only), and use existing DV tapes. So yes, they would not be compatible with playback on existing DV equipment, but then neither are the tapes of JVC's HD10.

If 25 mbps is really a physical limitation on the tape (I still am not sure I see why this would be), then let's have a new tape all together. But MPEG_TS is just not the way to go I think, when you can have reasonable tape sizes and stil have intra-frame only compression.

Zac Stein · August 21st, 2003, 08:37 AM

Sorry to be a bit mislead, but i can see your point of simply increasing the bandwidth allowance of the dv stream writing to the tape at an escalated speed, but wouldn't the real problem be not in the software, but the limitations of the hardware they are willing to 'support' hence financially.

Writing to the tape at a higher bandwidth would mean a complete redesign of many many parts of the camera which i don't think they want to do. They are in it for the money, best way to make money is be able to use as many parts of the old standard there is. Including the huge investments in producing the very tapes these camera's use. I seriously doubt they want to re-tool plants and redesign the heads of the decks and so on and so on.

I think this standard (mpeg-2) was nicely agreed upon because of how much they can still use. I mean thinking about it many many many parts of the old cameras can still be used with no amount of re-tooling. It is more at the front end of the camera, but large portions of it can be retrofitted from existing tooled up production parts.

There is also the added costs of handling more bandwidth in a camera. We might think that the extra $10 they have to spend on solid state memory or whatever they have to place into the camera, and the increased speeds of the dsp chips and so on and so on, is not much, but imagine producing over a million of these cameras and see how much all the r&d, testing and buying of those parts add's to the camera costs.

I see mpeg-2 winning out for now, because it is designed, easily implimented and a neat package for all the companys to clean up after jvc dropped their bomb.

Zac

Peter Moore · August 21st, 2003, 03:41 PM

Yeah I can definitely understand why they did it, it is just disappointing.

I wish the NLEs would start making some DV-like HD codecs so at least we could re-format the footage after it's captured to the computer for intra-frame compression only, and edit it that way.

By the way, isn't 25 Mbps just about the same bandwidth as is used for HDTV broadcasts? That would make sense since DVDs are about 4 Mbps + audio and 1080i is 6 times the video data as DVDs.

Rob Lohman · September 9th, 2003, 08:10 AM

DVD's have a maximum bandwidth of 10.08 mbps (including all
video, audio, subtitles etc.). Maximum for the video part is 9.8 mbps.

September 9th, 2003, 08:10 AM	#19
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	DVD's have a maximum bandwidth of 10.08 mbps (including all video, audio, subtitles etc.). Maximum for the video part is 9.8 mbps. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

August 21st, 2003, 08:18 AM	#16
Peter Moore Trustee Join Date: Oct 2002 Location: Arlington VA Posts: 1,034	I guess my point is that a pro-sumer HDV cam should use a DV-LIKE compression scheme (intra-frame compression only), and use existing DV tapes. So yes, they would not be compatible with playback on existing DV equipment, but then neither are the tapes of JVC's HD10. If 25 mbps is really a physical limitation on the tape (I still am not sure I see why this would be), then let's have a new tape all together. But MPEG_TS is just not the way to go I think, when you can have reasonable tape sizes and stil have intra-frame only compression.

August 21st, 2003, 08:37 AM	#17
Zac Stein Major Player Join Date: Aug 2002 Location: Melbourne, Australia Posts: 730	Sorry to be a bit mislead, but i can see your point of simply increasing the bandwidth allowance of the dv stream writing to the tape at an escalated speed, but wouldn't the real problem be not in the software, but the limitations of the hardware they are willing to 'support' hence financially. Writing to the tape at a higher bandwidth would mean a complete redesign of many many parts of the camera which i don't think they want to do. They are in it for the money, best way to make money is be able to use as many parts of the old standard there is. Including the huge investments in producing the very tapes these camera's use. I seriously doubt they want to re-tool plants and redesign the heads of the decks and so on and so on. I think this standard (mpeg-2) was nicely agreed upon because of how much they can still use. I mean thinking about it many many many parts of the old cameras can still be used with no amount of re-tooling. It is more at the front end of the camera, but large portions of it can be retrofitted from existing tooled up production parts. There is also the added costs of handling more bandwidth in a camera. We might think that the extra $10 they have to spend on solid state memory or whatever they have to place into the camera, and the increased speeds of the dsp chips and so on and so on, is not much, but imagine producing over a million of these cameras and see how much all the r&d, testing and buying of those parts add's to the camera costs. I see mpeg-2 winning out for now, because it is designed, easily implimented and a neat package for all the companys to clean up after jvc dropped their bomb. Zac

August 21st, 2003, 03:41 PM	#18
Peter Moore Trustee Join Date: Oct 2002 Location: Arlington VA Posts: 1,034	Yeah I can definitely understand why they did it, it is just disappointing. I wish the NLEs would start making some DV-like HD codecs so at least we could re-format the footage after it's captured to the computer for intra-frame compression only, and edit it that way. By the way, isn't 25 Mbps just about the same bandwidth as is used for HDTV broadcasts? That would make sense since DVDs are about 4 Mbps + audio and 1080i is 6 times the video data as DVDs.