Transcend express card with EX? at DVinfo.net

Tuomas Sebastien · November 27th, 2007, 08:41 AM

Has anyone tried or does anyone have an opportunity to test EX with Transcend express cards

http://www.transcendusa.com/Products...No=0&ModNo=162

Steven Thomas · November 27th, 2007, 09:04 AM

This question has been brought up over-and-over. The answer is NO, not until Sony upgrades the current firmware and offers an approved card list.
http://www.dvinfo.net/conf/showpost....42&postcount=5

Carlos Moreira · November 27th, 2007, 09:12 AM

the main problem is the PMW exceeds the bandwidth on slow motion up to approx. 85 MBit/s continuous on 60 fps / 720p.
Actual cheaper cards may fail then. Maybe they would operate well with the new firmware on 24 - 30 fps. @35 MBit/sec. we´ll see.

But It would be interresting to know if the PMW gererally accepts this chard when connected or just give an error message.

Tuomas Sebastien · November 27th, 2007, 09:43 AM

Does the slowmotion recording actually rise above the 35Mbit/s limit? I've understood that this is the maximum bit rate.

Transcend write rate is 64Mbit/s and read rate 144Mbit/s.

Carlos Moreira · November 27th, 2007, 09:59 AM

look here:

http://ieba.wordpress.com/2007/11/21...wers-revealed/

"Does the
> camcorder then allocate additional bits for each frame to maintain the set
> data rates?

Yes. If you reduce the number of frames, and the data rate is still 35 Mbps, the encoder gives more bits to each 12-frame GOP.

However, if you record bursts of video at 60p, you don’t get less bits per frame. The data going to the card is more than 3x the normal data rate. For instance, if you set the camera to 24p and record at 60p- in essence, overcranking it- then the video bitrate will be 2.5x, the audio will be 2.5x, the error correction, etc, will be that much more. The volume of data going to the card is over 200 Mbps. That’s why we use the SxS cards."

The other question on the cheaper cards is if the given rate is the a real, reliable continuous rate. But I am shure in near future also cheap cards will match the specs, currently maybe not.

Kevin Shaw · November 27th, 2007, 04:33 PM

Quote:

Originally Posted by Carlos Moreira

For instance, if you set the camera to 24p and record at 60p- in essence, overcranking it- then the video bitrate will be 2.5x, the audio will be 2.5x, the error correction, etc, will be that much more. The volume of data going to the card is over 200 Mbps.

I'm curious how it gets to 200 Mbps if the video stream is 35 Mbps x 2.5 = 87.5 and audio is 1.5 Mbps x 4 channels x 2.5 = 15 for a total of just over 100 Mbps. Can there really be that much again in overhead?

Ola Christoffersson · November 28th, 2007, 05:48 AM

Regardless if the cards can cope with overcranking or not I would find it useful to have a few 16 or 32 gig cards for standard speed shooting. How often do you use the speed effects anyway? And you can always switch to your SXS card for that. Also it seems like you get a USB2-card reader with the card! That saves you another wad of cash compared to buying the Sony reader. I´d be really interested in the result if someone with a camera could test this!

/ola

David Heath · November 28th, 2007, 06:01 AM

Quote:

Originally Posted by Ola Christoffersson

Regardless if the cards can cope with overcranking or not I would find it useful to have a few 16 or 32 gig cards for standard speed shooting. How often do you use the speed effects anyway?

Very well said, and true for the large majority. I suspect most people would be happy to have mainly lower priced cards, with maybe one full spec one for overcranking.

I also agree with Kevin - I can see how 2.5x speed alteration may get to around 100Mbs, but 200?

Tuomas Sebastien · November 28th, 2007, 06:09 AM

Quote:

Originally Posted by Ola Christoffersson

Also it seems like you get a USB2-card reader with the card!

I'd also like to see someone testing that card reader with Sony's original SxS card. The Transcend reader is so small that it would be lot better to travel with than sony original.

Paul Joy · November 28th, 2007, 06:23 AM

Quote:

Originally Posted by Carlos Moreira

The data going to the card is more than 3x the normal data rate. For instance, if you set the camera to 24p and record at 60p- in essence, overcranking it- then the video bitrate will be 2.5x, the audio will be 2.5x, the error correction, etc, will be that much more.

I'm not so sure that's correct. The EX1 does not record audio at all whilst overcranking so that part is certainly wrong.

Paul.

Carlos Moreira · November 28th, 2007, 06:39 AM

Quote:

Originally Posted by Kevin Shaw

I'm curious how it gets to 200 Mbps if the video stream is 35 Mbps x 2.5 = 87.5 and audio is 1.5 Mbps x 4 channels x 2.5 = 15 for a total of just over 100 Mbps. Can there really be that much again in overhead?

I just quoted from the link.

http://ieba.wordpress.com/2007/11/21...wers-revealed/

I also wonder how they get 200 Mbits. And whats up with 4 channel audio - I guess the PMW can record 2 channels audio only ?
Or is there any error correction or failure detection which reads the written data and doubles the needed bandwidth ?

Dave Elston · November 28th, 2007, 07:06 AM

So, if I understand this correctly, the overcrank (60p->24p) forces the camera to record at 2.5x the normal bit rate, ie 87.5Mb/s (as opposed to shooting without overcrank = HQ bitrate of 35Mb/s).
Now, if I tell my NLE to playback the overcranked 60p footage at the 60p rate, I am getting a 2.5x better bit rate (at the cost of space on the SxS obviously).

Does this not seem like a hidden "Ultra-HQ" mode (atleast for 720p60) ?

Using some basic math I suppose the 720p50 "Ultra-HQ" equivalent would come out at 70Mb/s (or 2x HQ bit-rate).

At these rates the MPEG2 long-GOP is going to be very robust!

Please shoot me down if I am overlooking something silly ! ;0)

Carlos Moreira · November 28th, 2007, 07:28 AM

not really - in this higher bandwidth are 2.5 x more frames encoded, so the quality of a single frame will be identical to 24 @35Mbit. You just get more frames.

But this gives firmware Hackers some chances to pimp the encoder to a much higher bandwidth @24/25/30p :D

Dave Elston · November 28th, 2007, 07:36 AM

Hi Carlos,

I'm comparing 'normal' HQ 720p60 to 'overcrank-to-24p' HQ 720p60, so the number of frames per real-time second is the same, you just need to tell your NLE to ignore the 24p playback (flag?).

As you say, this would suggest a firmware (hacked or otherwise) might be possible in the future to enable a higher-than-HQ acquisition (50+Mb/s?) format for the lower frame rates. I wonder if Sony are saving this one for a rainy (Pana-xxx) day? ;0)

It'll be an interesting year ahead!

November 27th, 2007, 08:41 AM	#1
Tuomas Sebastien Regular Crew Join Date: Nov 2007 Location: Finland Posts: 107	Transcend express card with EX? Has anyone tried or does anyone have an opportunity to test EX with Transcend express cards http://www.transcendusa.com/Products...No=0&ModNo=162

November 28th, 2007, 07:06 AM	#12
Dave Elston Regular Crew Join Date: Oct 2004 Location: UK 50i/25p Land Posts: 103	"Ultra-HQ" mode ? 720p60 @87.5Mb/s So, if I understand this correctly, the overcrank (60p->24p) forces the camera to record at 2.5x the normal bit rate, ie 87.5Mb/s (as opposed to shooting without overcrank = HQ bitrate of 35Mb/s). Now, if I tell my NLE to playback the overcranked 60p footage at the 60p rate, I am getting a 2.5x better bit rate (at the cost of space on the SxS obviously). Does this not seem like a hidden "Ultra-HQ" mode (atleast for 720p60) ? Using some basic math I suppose the 720p50 "Ultra-HQ" equivalent would come out at 70Mb/s (or 2x HQ bit-rate). At these rates the MPEG2 long-GOP is going to be very robust! Please shoot me down if I am overlooking something silly ! ;0) __________________ Play to Learn, Learn to Earn, Earn to Play... Dave - Broader Pictures

November 28th, 2007, 07:36 AM	#14
Dave Elston Regular Crew Join Date: Oct 2004 Location: UK 50i/25p Land Posts: 103	Hi Carlos, I'm comparing 'normal' HQ 720p60 to 'overcrank-to-24p' HQ 720p60, so the number of frames per real-time second is the same, you just need to tell your NLE to ignore the 24p playback (flag?). As you say, this would suggest a firmware (hacked or otherwise) might be possible in the future to enable a higher-than-HQ acquisition (50+Mb/s?) format for the lower frame rates. I wonder if Sony are saving this one for a rainy (Pana-xxx) day? ;0) It'll be an interesting year ahead! __________________ Play to Learn, Learn to Earn, Earn to Play... Dave - Broader Pictures

November 27th, 2007, 09:04 AM	#2
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	This question has been brought up over-and-over. The answer is NO, not until Sony upgrades the current firmware and offers an approved card list. http://www.dvinfo.net/conf/showpost....42&postcount=5

November 27th, 2007, 09:12 AM	#3
Carlos Moreira Regular Crew Join Date: Nov 2007 Location: Spain, Barcelona Posts: 27	the main problem is the PMW exceeds the bandwidth on slow motion up to approx. 85 MBit/s continuous on 60 fps / 720p. Actual cheaper cards may fail then. Maybe they would operate well with the new firmware on 24 - 30 fps. @35 MBit/sec. we´ll see. But It would be interresting to know if the PMW gererally accepts this chard when connected or just give an error message.

November 27th, 2007, 09:43 AM	#4
Tuomas Sebastien Regular Crew Join Date: Nov 2007 Location: Finland Posts: 107	Does the slowmotion recording actually rise above the 35Mbit/s limit? I've understood that this is the maximum bit rate. Transcend write rate is 64Mbit/s and read rate 144Mbit/s.

November 27th, 2007, 09:59 AM	#5
Carlos Moreira Regular Crew Join Date: Nov 2007 Location: Spain, Barcelona Posts: 27	look here: http://ieba.wordpress.com/2007/11/21...wers-revealed/ "Does the > camcorder then allocate additional bits for each frame to maintain the set > data rates? Yes. If you reduce the number of frames, and the data rate is still 35 Mbps, the encoder gives more bits to each 12-frame GOP. However, if you record bursts of video at 60p, you don’t get less bits per frame. The data going to the card is more than 3x the normal data rate. For instance, if you set the camera to 24p and record at 60p- in essence, overcranking it- then the video bitrate will be 2.5x, the audio will be 2.5x, the error correction, etc, will be that much more. The volume of data going to the card is over 200 Mbps. That’s why we use the SxS cards." The other question on the cheaper cards is if the given rate is the a real, reliable continuous rate. But I am shure in near future also cheap cards will match the specs, currently maybe not.

November 28th, 2007, 05:48 AM	#7
Ola Christoffersson Major Player Join Date: Nov 2007 Location: Stockholm, Sweden Posts: 462	Regardless if the cards can cope with overcranking or not I would find it useful to have a few 16 or 32 gig cards for standard speed shooting. How often do you use the speed effects anyway? And you can always switch to your SXS card for that. Also it seems like you get a USB2-card reader with the card! That saves you another wad of cash compared to buying the Sony reader. I´d be really interested in the result if someone with a camera could test this! /ola

November 28th, 2007, 07:28 AM	#13
Carlos Moreira Regular Crew Join Date: Nov 2007 Location: Spain, Barcelona Posts: 27	not really - in this higher bandwidth are 2.5 x more frames encoded, so the quality of a single frame will be identical to 24 @35Mbit. You just get more frames. But this gives firmware Hackers some chances to pimp the encoder to a much higher bandwidth @24/25/30p :D