Re: play 624x352 DivX smoothly
 

sorry i forgot to say- thats wut i meant (hi-res is dumb for Video only)

Re: play 624x352 DivX smoothly
 

Got Zod2 too. Even if it is great device I hardly use it now when I have N800 and 770. When playing video I can't stand the 2 pixel white border around the screen. And the 200MHz CPU is slow for some emulation stuff. But it beats tablets in gaming control department :-) Today I'm using it mostly just to play Duke3D.

And BTW 4GB SD (non-SDHC) cards work too with Zodiac. You only need hacked fat32 driver.

Re: play 624x352 DivX smoothly
 

Yes, you are completely right here. MPlayer decodes frames in planar YV12 format to system memory, then when it is time to display the decoded frame, it moves frame data from system memory to framebuffer (*) converting it to YUV420 or YUV422 format in the process (format names according to Epson documentation) and initiates asynchronous DMA transfer of frame data from the framebuffer to LCD controller memory. We don't need to wait for the completion of this transfer, and start decoding the next frame immediately. Anyway, after the next frame is decoded, we can't write next frame data to the framebuffer unless we are sure that the previous transfer to the LCD controller memory is complete at this point. We get a stall here if the graphics bus is not fast enough to complete the transfer in time (and this stall gets higher if tearsync is enabled as we additionally need to wait for the next screen refresh cycle).

The process of copying from system memory to framebuffer with color format conversion is a small gap, where graphics bus is not used (and graphics bus bandwidth is a scarce resource). Fortunately copying is quite fast and does not take too much time, but improvements in this area can help to avoid some framedrops for high resolution movies playback with tearsync enabled (and tearsync is always enabled for video). We could use something like 'page flipping' if we had enough framebuffer memory.

(*) actually framebuffer physically is a region of the system memory too (unless it is that SRAM which is allocated for Xv overlay, which is not used by mplayer anyway).

Re: play 624x352 DivX smoothly
 

Yeah, me too admittedly; The battery's practically gone :(

I did try the hacked fat32 driver but it didn't work for me... do you have a copy of the one you got to work still?
I'd like to try it :)

I got one set to work in my TH55, but that disables the MP3-playback DSP and anything that depends on it, so had to remove it :(
That driver didn't work in the Zod alas... just made it crash a lot ;)

Re: play 624x352 DivX smoothly
 

Try this one http://www.tapland.com/forums/viewtopic.php?t=6455
I got mine from elsewhere so PM me if this doesn't work. Also if card is unreadable it may be better to format the card in PC with usb reader first, I'm not sure Zodiac can format it. But once formatted it works fine.

Re: play 624x352 DivX smoothly
 

I guess you tried to start copying earlier to narrow the gap? It just needs to write to framebuffer data which is already transferred and do not outrun the DMA in progress. Maybe some timestamp when DMA transfer started could help with timing this? But this would need modified kernel anyway (unless the timestamp can be figured out somehow) so we could also preallocate second framebuffer in such kernel too (but this eats memory). Is the timing worth the effort?

Re: play 624x352 DivX smoothly
 

I have my biggest video playback problems when some background process (like the N800 connecting to a nearby open wireless network while the bus is stopped at a red light) tries to draw an info box on the screen in the middle of my 1970s Doctor Who episode. By the way, did you know that in a 1976 episode, Doctor Who hooks his brain up to a giant computer and then chases a villain through a computer-simulated reality... called the Matrix? Hmmm, sounds like prior art, to me.

Re: play 624x352 DivX smoothly
 

Ahh thanks! I'll try it ;)

Although if it works, I think I will have trouble finding a 4GB SD card these days... unless someone's hacked the Treo SDHC driver for Zodiac 2 as well.... :D

Re: play 624x352 DivX smoothly
 

Yes, I thought about it, but that's a bit unportable as the timings depend on memory and graphics bus performance difference (and I don't know how this performance may change depending on various factors, for example frequency scaling). And it does not solve the problem completely. Having two pages in the framebuffer seems like a better option. I considered splitting current framebuffer into two parts, doing software downscaling to fit video frames into each part, and do screen updates with hardware upscaling each of the parts to fullscreen. All of this supposedly could be done with a new framebuffer screen update ioctl (which allows to specify destination x and y coordinates), but it did not work as I expected when I tried it earlier (was its implementation buggy?). I can try to experiment with this trick again on OS2008 firmware.

Kernel modifications are rather hard to deliver to end users. We still even can't use YUV420 color format reliably in mplayer on 770 (for ~2% faster video playback) as there is no way to know beforehand if it will work properly (fixed kernel) or deadlock (original kernel). Also such a small speedup may be not enough to provide motivation for the users to install new kernel.