Four NTSC Video Sources --> DM8168 --> Gigabit Ethernet ???

Hi,

Answers inline,

Helmut Forren said:

I just finished my DM6467T product, and now I need to develop a more sophisticated one using the DM8168.  I'm confident the DM8168 will be able to capture four NTSC video sources using four 8-bit wide ports.  But this time, instead of sending the video out one of the DaVinci video ports, I want to send it out over the (local) Ethernet.  I'm not sure if the DaVinci has an "internal pathway" for doing this.  Can I do this?  

There is no internal path way to route captured video to network directly. You have to get the captured video to memory. You can encode it in any of the video encoder format like h.264. After encoding you can send it to network.

Helmut Forren said:

Note also that in parallel I'll be wanting to send video out the video ports nevertheless, using one 8-bit wide port for composite output and one 16-bit wide port for VGA output (with cheap frame rate conversion done by frame repetition).  That leaves me one 8-bit port to whistle "Dixie."

Also you can send video over network and display simultaneously.

Regards,

Hardik Shah

Thanks, Hardik Shah.

I did realize last night that the appropriate way to do this was probably on the ARM, where the image capture loop exists already and frame buffers are available, by opening a socket to the network.  I haven't done socket work in a long time, but I'll be able to figure it out.

I'm also wondering about bandwidth.  My 720 x 480 YUV buffers are 691200 bytes.  At 30 fps that's 166 Mb/s uncompressed.  My DSP is busy already and I would rather spend minimal or none of its horsepower on compression/encoding.    Do you think a 1Gb/s ethernet connection can successfully support this 166 Mb/s stream, when fully packetized, etc?  I have never investigated, but I would hope that IP packetizing and collision avoidance are more efficient than just 17%.   I need a little command overhead, but that shouldn't have an impact.

ON THAT SUBJECT, do you know off hand if I could cheat the h.264/mpeg4 encoding by wrapping headers around the frame but NOT spending the time to do any actual compression?  Doing this would maintain compatibility with possible off-the-shelf ethernet video devices (like PC's), assuming they have the bandwidth to input this [standard definition] uncompressed video.

ALTERNATIVELY, I do have the option of putting TWO DaVinci processors back-to-back.  I assume I could pump my video out one DaVinci's port and into the next DaVinci's port.  Then the second DaVinci's DSP is available to do the video compression and on out to ethernet.  (There are additional optional needs for the second DaVinci, so this wouldn't be as wasteful a use of it as first appears.)

Any comments?  Thanks.

(ref: http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC)