60 MB/s SDHC memory card and live full HD video out on GH13!

P

Psyco

Member
Hi!

Wouldn't it be nice to have a very cheap, fast and big SD card in your GH13? And having a live full HD video on an extra screen...?

USB-SDHC.jpg

What about this:

1) take a SD to miniSD card adaptor

2) solder a USB cable to the pins where the miniSD card would normally be

3) plug the card into your GH13 and connect it to a USB port on your laptop

4) start a program that simulates a SDcard on your USB port, save the video stream directly to your harddisc and display the video stream on your monitor


So, here comes the catch: I have no idea if thats possible! :grin:

But maybe some knowes? Vitaly?

The SDcard pins are directly compatible with a USB port - they where desigend to for it. So, in theorie it should be possible to write a program that gives the right "answers" to the camera - make it think there is only a normal SDcard.
The cable would cost less than $10, The speed of USB 2.0 is (up to) 60MB/s - twice as much as the fastest cards, and harddisc space is cheap - did I hear 1TB :cheesy:
From that point on, every up to date laptop can display the video stream in many different ways (full picture, zoom in for easy focus, focus assist by contrast measurement,...)

Just an idea....

Cheers
 
Psyco said:
Hi!

Wouldn't it be nice to have a very cheap, fast and big SD card in your GH13? And having a live full HD video on an extra screen...?

View attachment 25897

What about this:

1) take a SD to miniSD card adaptor

2) solder a USB cable to the pins where the miniSD card would normally be

3) plug the card into your GH13 and connect it to a USB port on your laptop

4) start a program that simulates a SDcard on your USB port, save the video stream directly to your harddisc and display the video stream on your monitor


So, here comes the catch: I have no idea if thats possible! :grin:

But maybe some knowes? Vitaly?

The SDcard pins are directly compatible with a USB port - they where desigend to for it. So, in theorie it should be possible to write a program that gives the right "answers" to the camera - make it think there is only a normal SDcard.
The cable would cost less than $10, The speed of USB 2.0 is (up to) 60MB/s - twice as much as the fastest cards, and harddisc space is cheap - did I hear 1TB :cheesy:
From that point on, every up to date laptop can display the video stream in many different ways (full picture, zoom in for easy focus, focus assist by contrast measurement,...)

Just an idea....

Cheers
Click to expand...

very cool idea. best one I've heard in a while. are their programs that simulate an SD card because I haven't heard of one ?
 
Try it!

Tethering from the SD card slot onto a laptop seems like a good 1st step. Then, find an application like Vitaly suggested a while back to get a live view going.
 
What I know about any camera that the Live stream out is possible through HDMI, SDI, or Firewire.
Even if we make such thing, I don't think that Streaming AVCHD video through USB is possible.
Because I don't know if AVCHD streams.

Well, its my opinion, can't really say what's possible these days.
 
i dont know about the GH13, but i know that a HMC150 insists that the memory card door is closed, so you would have to work around that with a cable hanging off the card
 
HVXguy said:
Have you seen these cards?

http://www.eye.fi/products/prox2

http://support.eye.fi/product-info/...-fi-card-compatible-with-my-camera/panasonic/
Click to expand...


Looks quite nice - but the wireless LAN can't delivere the speed we need with the GH13 (so it would work with an unhacked GH1).

Endless shooting is nice, but the main "feature" of the idea is the higher data rate (60MB/s) and the live view on an external screen.

What I know about any camera that the Live stream out is possible through HDMI, SDI, or Firewire.
Even if we make such thing, I don't think that Streaming AVCHD video through USB is possible.
Because I don't know if AVCHD streams.

Well, its my opinion, can't really say what's possible these days.
Click to expand...

If the application writes the AVCHD data on the harddrive, there shouldn't be a problem by playing it directly from the file. Just use a player that doesn't freak out if some header data is missing (I think VLC will work). So there will be a slight delay of about 1/50 - 1/2 sec. (depending on GOP length) but thats no problem, as I know nobody that can focus in under 1 sec. :grin:

If anybody has some insight on the USB/SD pinout, voltage, protocoll and data flow, please let us know if it is (at least) possible to make this SD<->USB cable without frying my GH13 or USB port.

Thanks
 
Psyco said:
If the application writes the AVCHD data on the harddrive, there shouldn't be a problem by playing it directly from the file. Just use a player that doesn't freak out if some header data is missing (I think VLC will work). So there will be a slight delay of about 1/50 - 1/2 sec. (depending on GOP length) but thats no problem, as I know nobody that can focus in under 1 sec. :grin:

If anybody has some insight on the USB/SD pinout, voltage, protocoll and data flow, please let us know if it is (at least) possible to make this SD<->USB cable without frying my GH13 or USB port.

Thanks
Click to expand...
Again, AVCHD isn't made for Streaming. If that was possible, we could have got Direct Video stream from USB in HMC150.
Even HMC80 has IEEE 1394 but that's for DV output.

One point to consider, the GH1 doesn't write direct video on Card, (and card will convert it into AVCHD!???, that doesn't work that way).
Camera Encodes the video and writes the 'Data File' on card.
If you try to stream that Data to computer, you have to write it first and then play it back.

I don't think Reading while writing is possible, because the Player must decode that data file in a way to Play Video.
It's possible on Web but not in Camera, because "USB/SD pinout, voltage, protocoll and data flow" will make difference I think.
Maybe, Vitalie or Barry will make this to conclusion.
 
I can undertand this would not create some sort of 'live view" out of the GH-1(3) but what I'm thinking this could allow (if it works) is for us to set the highest possible data rate that the PC could allow without getting those pesky "card write errors."

I too have thought about this possiblity many moons ago.
 
Do you think live HDMI or composite out during record is ever going to be a possiblity Vitaliy
 
Vitaliy Kiselev said:
You can safely forget abut this idea.
Click to expand...

And why is that?

The data is writen one GoP after another - so why wouldn't it be possible to play it back? The header data is known, exept the length of file.

VLC is quite resistant to errors in the video files, it does even play unfinished files - something like that should even work on unfinished AVCHD files, as the main data must be writen every GoP.
 
Psyco said:
So, here comes the catch: I have no idea if thats possible! :grin:
Click to expand...

This is obviously possible, just not as simple as you make it soud. But it´s not that difficult either.
Interface and voltages are not compatible between USB and SD (spec), so there needs to be hardware in the middle. Probably the best bet would be a PIC or AVR USB.

But the principle of operation would allow both storage and near real-time monitoring (perhaps with 100ms delay). The hard part would be to achieve the expected high bit rates ove 500Mbps!
 
This is not it. It's a dual device, that can be used as a SD or USB MSD, but not simultaneously.
I have no knowledge of such device already existing, so it would have to be developed on a fast microprocessor:
  • USB3, in order to go beyond the 480Mbps USB2 theoretical speed limit, and much lower real limit
  • FAT32 on SDHC interface

Certainly feasible, but challenging in order to obtain high bit rate. Also, I don't know the delay on GH1 writing to SD after capture. It may be high (few seconds), rendering real-time monitoring somehow useles.
 
You're new here, so you may not know who Vitality is. He is the gentleman known as Tester13, and he is the one who unlocked the GH1 firmware and created the PTool hack.

There are a lot of big brains on this forum and Vitaliy's is one of the biggest. When he says forget it, I take it as read. He's spent more time inside these cameras than most of have shooting with them.

I agree that being able to stream live video from an SD-to-USB dongle would be super cool. I know far, far less about this stuff than Vitaliy, but I know enough to know that this is not happening any time soon, especially with a 4-conductor cable soldered between an SD adapter and a USB plug.

mapombo said:
If you have no constructive thought to offer, do constrain from commenting.
This is actually an interesting idea.
Click to expand...
 
Sorry shaveblog, but the picture is obviously a fake. I just "photoshoped" it to help people to get the idea.

I still think it is possible to get the data in near realtime out of the GH13 through the card slot - but if it is as easy as I depicted it...I don't know. In the end, it would be a small cable with a SDHC-card on one end and a conector to you favourite port on your laptop on the other end.
 
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