Tuesday, November 27, 2012

Been doing some video capturing lately

I've been capturing some S-VHS tapes lately and this gave me a chance to try out the Neat Video plugin which I bought a while ago.  It does quite a good job of cleaning up the noise from these old analog tapes.  I wonder if it could also handle Super8?  Here is just a quick screenshot of my preliminary results.  You can see the difference.

Saturday, November 24, 2012

There may be hope for USB just yet...

In talking with one of the Raspberry Pi guys, I've learned that the USB performance problems I am seeing are related to the FTDI chip I chose to put on the Dexter board.  This means that it is possible that using another vendor's chip may solve this issue.

He says: "Looking at your post I see you were hitting the high CPU issue, which is inevitable with the FTDI serial adaptor. Was this the only issue?

I'm pretty sure that Gordon has a non-FTDI serial apator that doesn't suffer the high CPU effect. I'll try and find out exactly what is was."

What this means is that for rev2 of the Dexter board, the only way to use it with a Raspberry Pi will be to hook into the pins on the pi itself using the same method I used (which is not the most convenient but it works!).  I will probably post the steps I took for this method later, but using a PC to test still works fine so no one should be blocked in their testing :)

For the next (final?) revision of the Dexter PCB, hopefully another USB<->serial chip will surface so that the USB port can be used with the Raspberry Pi.  The good news is that the rev2 Dexter board is still and will be very useful for testing going forward since it works fine with a PC and I still have a lot of firmware code to write for it.

Thursday, November 22, 2012

Dexter's USB port is too slow with the Raspberry Pi

Well, after writing some new code to bypass the /dev/ttyUSB0 path on the Raspberry Pi and instead use the direct method of http://www.intra2net.com/en/developer/libftdi/ , I have sadly observed the same problem exists for both methods; performance goes down the drain and the Pi cannot play the video at the full speed.  So for now, the only method that exists for getting the video playing full speed on the Pi is using the pin headers on the Pi.  This actually works great BUT I am wondering how this solution could possibly work for a consumer version of Dexter.  This will have to be something to think about.

Wednesday, November 21, 2012

Dexter/Raspberry Pi sound issues resolved

After doing some final tests today, I've decided to call sound "finished" on the Raspberry Pi.  It is playing fine now with no stuttering.  Occasional stuttering is still possible if serial communication has random errors; this is still rare though.

Next step is getting the Dexter USB port working without performance penalties on the Raspberry Pi.  After that, then I would say the Pi is ready for people to start testing with Dexter.