I planning to get one XL-1s, Anyone tell me when Canon release the next Version of XL-1s or XL2?????

Hi Andrew. Do a search and you'll find this question popping up a bit - with opinions from many of the knowledgeable people on this forum.

Cheers
Aaron

Andrew, it most likely won't be until next summer.

Anybody that really does know has probably signed a NDA. Is that correct Chris?

Heh. I signed an NDA, but I really don't know... really!

Of course there will be something to succeed the XL1S, but most likely it won't happen until next year.

Yeah, I think that is a pretty safe bet. One thing I wonder about is if the new system uses HD might it be MPEG? After reading some info on editing MPEG, I can see that might be a problem for standard NLEs.

I still say an HD cam should use a DV-style intra-frame only compression. 1280 x 720 is a little less than 3 times the resolution of DV. So use 90-minute DV tapes for 33-minute HD clips and you're set. Cheap and simple.

PS - A 24p HD cam, 1280x720x24p, should also use 20% less of the tape than at 30p, something the DVX100 doesn't do.

I hope Canon and the other co's are listening. :)

Peter,

this is assuming the MPEG2 stream will have the same bandwidth as the standard DV stream, which is 25MBit/s. Most DVD's have bandwidths of under 10Mbit/s, so if you want the same quality it will be difficult if you don't increase the bandwidth of the final MPEG2 stream over 25Mbit/s...
However, as we can see from the offerings on the market that do MPEG2 on DV media, it is certainly possible, and I am certainly waiting to see what the first prosumer HD camera with removable lenses will be...

Kai.

No, I'm talking about using DV intra-frame compression on HD, just at a higher resolution. Because 720/30p HD has a resolution of about 3 times DV, a 90 minute DV tape would be able to store 30 minutes of HD (perfectly acceptable), with no inter-frame compression, making it easily edited.

720p is less then two times the resolution of DV. DV has a
resolution of 480p [if your camera can do true progressive
capture].

720 x 480 x 30 = 10368000
1280 x 720 x 30 = 27648000

Multiple = 2.67. In DV compression format, 720p would take up 2.67x the space that DV would, or 34 minutes per LP tape for 30p, or 42 minutes for 24p HD. That would make the most sense for pro-sumer HD capture and editing.

Unfortunately, DV holds no possibility for capturing in formats other than NTSC or PAL, so a different compression algorithm is needed, hence the use of MPEG2 over DV. This is no disadvantage however; even though DV is compressed at roughly 5:1, many MPEG2 codecs show better results in terms of artifacts etc than DV at higher compression ratios. Also we may finally be released from 4:1:1 or 4:2:0 in favor of 4:2:2, but this will depend on implementation... It is unlikely that higher res formats (like 720p etc) will be able to be captured using the 25Mbit max at 4:2:2 at an acceptable compression ratio... If anyone has any info on how the current crop of HDV capture, please let us now.

Kai.

"DV holds no possibility for capturing in formats other than NTSC or PAL, so a different compression algorithm is needed,"

Please explain how this could possibly be so. I see no reason, technoloically (and I am a programmer among other things) why the intra-frame compression algorithm would not work at a higher resolution. The fact that DV works equally well for PAL and NTSC shows that it is not dependent on resolution.

And the enormous disadvantage of using MPEG2 is inter-frame compression, which makes frame-accurate editing extremely tedious.

Sorry for not being completely clear; it is simply a matter of standards. The DV format uses JPEG compression, and only allows for those two resolutions _as per the standard_. Of course, if you look at the specs of the standard, one quickly notices how the stream is actually split up into data blocks and control blocks, which is what things like dvbackup (with which you can use your DV cam as a streamer for backing up your computers data) use to write arbitrary data to the DV tape.

The same principle is used on the current crop of HDV cams, so the use the DV standard in a very loosely interpreted way, and write a non-DV video stream (MPEG2) to a DV medium. Of course, if you wanted to, you could also write full HD res material to the DV tape this way, you just wouldn't be able to do it in real time, as the DV tape mechanisms in cameras will only write 25Mbit/s, or roughly 3.5 Mbyte/s (including sound), to the tape (no more, and no less).

So basically you dealing with a situation that yes, you can write any kind of data to a DV tape, but as soon as it's not a DV video stream, it's not standard, which means you can't read it using a normal DV deck/cam. It also means that your bandwidth is limited to 25mbit/s for sound and video, how you split this up is up to whoever develops this non-standard device, but you will therefore have a maximum of 25mbit/s available for your video stream (if you don't record sound), but that is apparently good enough for 720p or 1080i mpeg2.

Kai.

I forgot about the horizontal increase as well... My bad, should
get some more sleep this week. Ehehe.

Anyways, Kai is correct. The STANDARD doesn't allow for anything
else. In theory you could go unlimited with DV compression
algorithm, ofcourse.

What currently is done is that an MPEG2 stream is written inside
the DV structure. Ofcourse devices that don't understand such
a construct (which isn't standard yet) would not read the stream

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.

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

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.

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.