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-   -   New: Canon PowerShot TX1 -- hybrid HD (https://www.dvinfo.net/forum/photo-hd-video-d-slr-others/87215-new-canon-powershot-tx1-hybrid-hd.html)

Paulo Teixeira February 22nd, 2007 08:12 PM

If those specs are accurate than I do hope Canon will make enough because this thing will fly off the selves. Like Lorry, I believe the bit rate being this high will produce wonderful videos, I mean why wouldn’t it? MJPEG is an intra frame codec and the potential is huge if used properly. Sanyo will obviously have to sell the HD2 at 500 dollars to compete although the HD2 will kill it if you’re inside a house with very little lighting.

http://www.watch.impress.co.jp/av/do...222/canon1.htm

English version.
http://babelfish.altavista.com/babel...2%2Fcanon1.htm

Thomas Smet February 22nd, 2007 08:13 PM

yes mjpeg can be very good and is far superior to mpeg2 but it needs bits to look good.

mpeg-2 works well because it doesn't need to encode redundant information. That is why the size can be so much smaller. With mjpeg it encodes every single frame as a jpeg image so each frame needs lots of bits.

I work with a lot of I frame only HD mpeg2 video (which is pretty much the same as mjpeg) and the lowest I would ever go for 24p 720p is 53mbits/s or maybe even 50 to make it a nice round number. 30p of course needs a little bit more bandwidth to make it look good. 40mbit/s mjpeg is going to be a little on the low side. We will not see the usual macroblock type artifacts but what we will see is more noise and dancing artifacts on high contrast edges.

The compression ratio of this format is about 11:1. Try encoding a jpeg still image at that level and you will see how compressed it is. With motion it gets even worse because as things move slightly each frame gets jpeg compressed in a different way with translates to dancing noise in the image.

jpeg compress a 1280x720 still image that only takes up 0.166 MB and see how it turns out. You could also try to use quicktime photojpeg on a video and figure out what compression level will give you the same datarate and see how that looks.

Kurth Bousman February 22nd, 2007 09:49 PM

I'd say we're gonna need a sample before we know how good or bad it is. It's a great move on canon's part and I hope this will be a developing model line.

Paulo Teixeira February 22nd, 2007 10:05 PM

Assuming the information is accurate, the memory cards would have to be able to write at a speed of around 35 to 40MBPS. So how much money is a memory card of that speed? Anyway, cheep memory cards are definitely out of the question if you want to shoot in HD mode.

I thought the reason that you aren’t able to put the highest bit rate of the JVC HD7 into the memory card was because standard memory cards aren’t fast enough.

Lorry Smyth February 23rd, 2007 01:42 AM

First Still Samples Out!
 
1 Attachment(s)
From the Japanese Canon site:
Stills:
http://cweb.canon.jp/camera/powersho...ata/TX1_l0.jpg
http://cweb.canon.jp/camera/powersho...ata/TX1_l1.jpg

Flash presentation (unfortunately all in Japanese)...
http://cweb.canon.jp/camera/powersho...p/index_f.html

Also, Canon's specs state the use of wave compression (which stands for Wavelet that is by far the best compression/ less artifacts MJPEG compression type) plus 1080i video output playback capability. I think this camera has all the ingredients to become a landmark product.

Jack Jenkins February 23rd, 2007 03:55 AM

I like the retro styling. And I agree if Canon can hit that price point these things will be popular.

Alexander Wrana February 23rd, 2007 05:46 AM

I just saw that it says on the Canon site "Available in April 2007"
http://www.usa.canon.com/consumer/co...&modelid=14903

I guess I'll have to consider this as a rival to the HD2 I wanted buy.

Lorry Smyth February 23rd, 2007 10:27 AM

I wonder on the impossibility of using a wide-angle adapter or filters. If the lens totally retracts in on Power-Off (plus there is an auto cover that goes in front of it), anything you put in front of the lens will hit and get stuck around outer casing of the camera's lens ring as it retracts in and breaks the mechanism... hmmm... troubling design... horrifying thought...

Paulo Teixeira February 23rd, 2007 11:25 AM

Quote:

Originally Posted by Chris Hurd
This thing is *no* replacement for an HD110 or any other HDV camcorder. It's just a digicam that has an interesting video mode if you ask me. Definitely in the Sanyo HD1/HD2 league... not that there's anything wrong with that...

At least I didn’t use what I originally wanted to say, the HD250, but I figured there would have been too many negative responses.

Realistically, like everybody else I would like to see how this thing holds up against the Sanyo HD2 and dare I say it, the JVC HD1. It won’t give you the colors or the contrast levels of the HD1 but the detail may come close. Its funny but if this thing is good enough then some people may want to use it as a B camera for the HD1 if you have a good editing program.

Besides the price of the Sanyo HD2 going down, this Panasonic camcorder needs to be no more than 250 to 300 dollars http://dvinfo.net/conf/showthread.php?t=86627. Yes you can thank Canon for that. So far they caused the V1u to be a lot cheaper, then the Sony HC5, HC7 and the JVC HD7 to be a lot cheaper and now the Sanyo and the Panasonic digicams will have to fallow suit.

Lorry Smyth February 23rd, 2007 11:34 AM

Quote:

Originally Posted by Paulo Teixeira
...It won’t give you the colors or the contrast levels of the JVC HD1 but the detail may come close...

I hope its much better than the JVC HD1 because I had one for a day before I returned it... color /luminance noise plus ridiculous shadow detail reminded me of of a really sharp good-old VHS camcorder... mortifyingly bad...

Yi Fong Yu February 23rd, 2007 12:05 PM

this rox! viva la HD!

Kurth Bousman February 23rd, 2007 01:22 PM

alittle more info here - still no video samples , but this is probably where they'll appear first .

http://www.canon.co.jp/Imaging/pstx1/index-rtn-e.html

Paulo Teixeira February 23rd, 2007 05:30 PM

I think Canon should do a promo video for this camera like this.
http://www.youtube.com/watch?v=JIZc1XkaUpk

According to Camcorderinfo, the bit rate is confirmed to be around 35MBPS.

David Gurney February 23rd, 2007 05:46 PM

Quote:

Originally Posted by Paulo Teixeira
Assuming the information is accurate, the memory cards would have to be able to write at a speed of around 35 to 40MBPS.

Quote:

According to Camcorderinfo, the bit rate is confirmed to be around 35MBPS.
That's incorrect; you're confusing megabits and megabytes. It's around 40 mbps, so about 5 MBps. In fact, even lower. To quote the article you cited on Camcorderinfo:

"According to Canon, this equates to approximately 4.375MB/sec (megabytes), or approximately 35Mbps (megabits)"

The point is, this is a pretty pitiful data rate for so-called HD. Then again, so far nothing being peddled to the consumer as "HD" is worthy of the moniker.

Paulo Teixeira February 23rd, 2007 06:15 PM

Quote:

Originally Posted by David Gurney
That's incorrect; you're confusing megabits and megabytes. It's around 40 mbps, so about 5 MBps. In fact, even lower. To quote the article you cited on Camcorderinfo:

"According to Canon, this equates to approximately 4.375MB/sec (megabytes), or approximately 35Mbps (megabits)"

The point is, this is a pretty pitiful data rate for so-called HD. Then again, so far nothing being peddled to the consumer as "HD" is worthy of the moniker.

I’m not sure I understand what you’re saying. HDV at 1080i is around 3.6MB/sec in MPEG2. This camera uses 4.375MB/sec in MJPEG. The picture quality may not be as good as the JVC HD1 but it should be better then the Sanyo HD1 and for a 500 dollar camera, that is not pitiful at all.

Besides, I’m sure most people know what I meant when I used 35MBPS. I also use the words 25MBPS when I talk about HDV2.


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