Well, for the ether-video project you would choose a better chip from their DaVinci range, not this small/slow one. The others do 1080p. Why you asked about the lowest from the range? And anyway whats the VGA for? Those chips does not need any VGA stuff there, they are SoC. Everything from ethernet do HDMI. You just add flash, dram and the software.
Daniel James Richard Tyrer wrote: > Ing. Daniel Rozsnyó wrote: >> Hi James, >> >> I think the programmable logic chip (FPGA) would do the PCI "physical >> layer" and either a FIFO for memory writes, or a memory required for VGA >> image buffer (32kB?). > > This list, OHE <[email protected]>, is for a video > adapter connected to Ethernet rather than the motherboard bus so that > wouldn't be needed. For an internal card, I would personally use a > commercial (probably PCIe) bus interface chip since there is no point in > reinventing the wheel -- less power and less expense than using a FPGA. > >> The VGA would be simpler to emulate via FPGA than >> via software, mostly because of timing. And it would require something >> like Spartan 3E-500 (the largest in 208 pin package with normal legs). >> >> I would rather see this chip in place of accelerating video decoding - >> you can put this small FPGA with hardcoded VGA and the let the TI to >> decode video streams into an overlay memory. >> > That is a trade off. Since VGA is not used when a GUI operating system > is running, I see little point in implementing it in hardware when it > would only be used for boot and text console. If VGA was only accessed > with the BIOS interrupts, there would be no problem implementing that > totally in hardware and it would be much faster since the code would run > on the ARM rather than the host processor. > > However, some software or firmware does access VGA directly -- something > that should be looked into: do we still need this? or are text mode BIOS > calls all that is necessary? What do BIOSs use for boot and set up text > mode? For direct hardware access, you do need a chip that can handle > the reads and write to I/O and video RAM addresses. The original VGA > chip was for an AT bus which IIRC was 8MHz (4 [or more] clock cycles) so > speed shouldn't be a large problem for software emulation at 300MHz. :-) > >> The video buffer should reside in that 32bit DDR2.. so it is sure >> enough for Full HD display and decode in parallel, but it will not do >> 60p as VGA requires [60Hz refresh], just 1080i - interlaced [data rate >> equals to 30Hz refresh]. It's a chip designed for digital still cameras, >> so the playable bit-rate would not be too high. >> > Actually, it is a chip designed to do anything which means that it could > do video phone/conferencing too. TI lists one of the uses as DVR. Note > that at the current speed grade, the MPEG-4 decoder will do 1080p only > for movies at 24f/s. IIUC, TV would be as broadcast: 720P or 1080i -- > one thing missing is deinterlace. I presume that they will be producing > faster chips that can do 1080p at faster frame rates although B-R disks > are usually movies which means 24f/s > _______________________________________________ Open-hardware-ethervideo mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-hardware-ethervideo
