I haven't had time to really look in to this yet, but with USB to DVI/HDMI adaptors getting cheaper and cheaper do any of these actually work with Linux? Then secondly are any of those adaptors have drivers that are open source so they can be ported to Pandora?
USB to DVI/HDMI Adaptors
- Thread starter Fueler
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I think something like one of these - these are active video devices powered by USB, not just a connector converter.
I thought we had a thread on this (besides this one), but I couldn't find it. I'd also be interested in getting a USB VGA/DVI out device if there was one confirmed to work. I'm guessing anything that uses OpenGL would lose acceleration, but would probably be fine for older emulators and for general office stuff.
I thought we had a thread on this (besides this one), but I couldn't find it. I'd also be interested in getting a USB VGA/DVI out device if there was one confirmed to work. I'm guessing anything that uses OpenGL would lose acceleration, but would probably be fine for older emulators and for general office stuff.
DisplayLink devices have GPL'd Linux drivers!
once again, i dont think pandora can output video through usb, it especially cant process a video on pandora and one going through usb, nor does hdmi output make any sense as were still struggling with 720p video. hdmi cables arent magic. its like expecting unlimited electricity from plugging a power surge protector into itself
slaeshjag
¯\_(ツ)_/¯
It can output, it just won't be very fast.
You're not being very clear on exactly what you think won't work. I think that it can output video through a USB video device, but it is possible that it could be slow. Some of the reviews for similar devices to the ones that I linked showed that they were slow even on full desktops; a limitation of USB rather than the CPU. I skimmed DisplayLink's press release from a couple years ago, and they claimed that they have an intelligent way of using the USB bus using compression (uh-oh, CPU) and only send what's changed, meaning that it could be fine for simple office tasks like displaying a PowerPoint presentation. Of course, I don't have any experience with these things, and I don't know if the DisplayLink devices actually work any differently than competitor's products.
As far as processing video on the Pandora and on USB, it isn't necessarily a problem. Again it depends on what you mean by "video." I would intend to use it mostly as an extended desktop, but if you mean video as in AVI/MP4/FLV, then you might be right. As far as processing video on both screens, I don't think that itself would be an issue, unless you're watching two movies at once. The CPU would only have to decode the movie once, but then the problem would be whether there is enough bandwidth to send something like 30 FPS through the USB bus, and if there's enough CPU left over to do that after decoding the movie (probably not).
And "hdmi cables aren't magic?" I'd like to believe there's a little bit of magic left in the world.
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Caine
Hardcore Member
It's basically a matter of processing power and bandwidth. I doubt the Pandora has the processing power to decode a video and transmit it in a different encoding over USB as it currently struggles on the decoding part alone (perhaps the DSP can help a bit, but don't expect any miracles). So the USB output will most likely need to be a raw video stream.
Theoretically USB 2.0 has a maximum bandwidth of 480Mbit/s, but in practice you achieve less. For a raw video stream, the bandwidth requirement is a product of the output resolution, bits per pixel and framerate. A 720p video at 32 bits per pixel and 30 frames per second would consume (1280*720*32*30)/1024^2 ~= 843 Mbit. Obviously it is impossible to transmit this over USB without using any video compression. At 640x480 with the same framerate and bits per pixel, only 281 Mbit would be required which seems feasible.
Theoretically USB 2.0 has a maximum bandwidth of 480Mbit/s, but in practice you achieve less. For a raw video stream, the bandwidth requirement is a product of the output resolution, bits per pixel and framerate. A 720p video at 32 bits per pixel and 30 frames per second would consume (1280*720*32*30)/1024^2 ~= 843 Mbit. Obviously it is impossible to transmit this over USB without using any video compression. At 640x480 with the same framerate and bits per pixel, only 281 Mbit would be required which seems feasible.
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These devices if anyone has ever own one... They can't handle video well even with a full blown desktop/laptop PC.. they're good for regular web browsing/word processing and office work, but any type of game or video (even youtube) they don't perform well. USB 2.0 doesn't have the bandwidth for it.. My guess is they could work on the Pandora, but if they can't handle video or games that takes away most of the uses on the Pandora..
the Pandora Wiki has this entry it's a SVGA adapter not an HDMI/DVI:
Tritton see2 usb 2.0 to SVGA adapter: Needs to be integrated with preferences. Currently I must edit xorg.conf and mess with xinerama. Good for presentations, dragging a window is bearable, but hi-res video is slow. Works in Linux without any issues.
the Pandora Wiki has this entry it's a SVGA adapter not an HDMI/DVI:
Tritton see2 usb 2.0 to SVGA adapter: Needs to be integrated with preferences. Currently I must edit xorg.conf and mess with xinerama. Good for presentations, dragging a window is bearable, but hi-res video is slow. Works in Linux without any issues.
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I keep forgetting to check the Wiki! Thanks for the link. Presentations and such would be my primary use case, so it might be worth me picking one up sometime. Playing games would be nice, but that looks to be unlikely.
I can just imagine what an official Pandora 2 feature request page would look like. HDMI, a few lanes of PCI express out...
Here is some information that I know. DVI/HDMI can do 480i and 480p. We do not have to go straight to 1080p. This requires less bandwidth. I'm not sure on this OMAP, but on older OMAP devices there is a single data bus for all the devices and TI's answer for higher resolution video was then to up the transfer rate of the bus, effectively increase the bus bandwidth. I would understand that we would turn off video to the LCD to reduce the bandwidth requirement. I think 480i/p may be possible and that's the reason for this topic. The signal is digital so the picture should be clear as possible. TVs and receivers these days can do up-scaling to 1080p if needed, not this device though.
I would be curious if during the test shown in http://pandorawiki.org/USB_compatibility_list#Video_display_device if the normal video was disabled to reduce bandwidth on the bus.
And yes, I understand that fps even at 480i/p would not be high, maybe 15fps updates. It would be enough for coding, writing documents ect. I would not expect to play games or movies through this.
I would be curious if during the test shown in http://pandorawiki.org/USB_compatibility_list#Video_display_device if the normal video was disabled to reduce bandwidth on the bus.
And yes, I understand that fps even at 480i/p would not be high, maybe 15fps updates. It would be enough for coding, writing documents ect. I would not expect to play games or movies through this.
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CAZMIESTER
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Did the psp not have some program to output video over hdmi before the slim came out?
sukhi2011
Active Member
I found out that when you playing videos in mini it can play videos upto 720p not 1080p,which is really good,so there must be an way get 720p working but 1080p is not likely to work.
