Hd


Crasherball said:
Chip said:
At this time, however, there is no way to get that video off of the device. Perhaps that will change in the future.
isnt it theoretically possible to have a usb-vga-cable?

Yes, but one does not exist that will display full HD.

I suggest that you look into a BeagleBoard, it has the same processor (and ram?), a single SD card slot, but it has HDMI for output.

I am pretty sure that for the $150 that a beagleboard costs you won't find a better USB display.

I just hope that somebody starts a "Pandora Console" project to port over the firmware of the Pandora to the BeagleBoard so that we can have HDMI/DVI outputs.

Am I wrong or is this the most sensible way to get an Omap3 with HDMI?
 
Last edited by a moderator:
Tom` said:
Snu said:
IceBerg303 said:
to get 720p you need RGB or Y,Pb,Pr over 3 independent shielded channels. You can get 1080p over YPbPr but you lose some color saturation. For 1080p you really need something like DVI or HDMI with many channels to handle the massive bandwidth needed.

Just think, 1280x720 = 921,600 pixels each being 32bit color is 29,491,200 bits at a refresh of 30FPS that is 884,736,000bits (~885Mbit/s)
eh, for one thing, why would it be 32bit? the only 32bit color video ive seen is video with an alpha channel (24bit color, 8bit alpha), which would be completely pointless for just watching. also, uncompressed video is pretty much never used - even in pro video setups we use compressed (typically 25mbit/sec for sd, not entirely sure about hd).

ATSC HDTV streams in the US are 45 MBit/s, and use MPEG-2 compression. While uncompressed video needs a lot more bandwidth than we have, I don't see why it wouldn't be possible to use the DSP to decode the video and have the CPU take care of the USB stuff...probably not easy, but at least possible.


So, We Decompress the file with the DSP, then REcompress the file with the CPU before sending it over the USB cable to some device that then Decompresses the file and converts it to RGB?
Why not just send the compressed file directly over the USB and have it decompressed at the destination?

The Composite Video output does not look very useful to me. Analog TVs die next year. We would be better off if it could be replaced with an HDMI connector.
 
Last edited by a moderator:
DAP said:
So, We Decompress the file with the DSP, then REcompress the file with the CPU before sending it over the USB cable to some device that then Decompresses the file and converts it to RGB?
Why not just send the compressed file directly over the USB and have it decompressed at the destination?

The Composite Video output does not look very useful to me. Analog TVs die next year. We would be better off if it could be replaced with an HDMI connector.
I think that a BeagleBoard is what you are looking for, there is no way to make the Pandora have DVI or HDMI or VGA without a complete redesign to be bigger and more expensive with less battery life.

Get a Beagleboard and run Pandora Firmware on it. = Pandora Console with DVI. Problem solved.
 
Last edited by a moderator:
DAP said:
The Composite Video output does not look very useful to me. Analog TVs die next year.

That's correct. The government are sending a special signal across the air waves which will disable the composite and s-video inputs of EVERY television set in the Uk. They will, overnight, become useless.

They are also passing a bill making it ILLEGAL for companies to produce devices with composite and s-video inputs so you will no longer be able to hook up ANY of your masses of equipment which only outputs a composite or svideo signal.

It's a conspiracy, I tell you. Analog TVs die next year.
 
Last edited by a moderator:
there are a few usb vga cables (actually quite a few) which would work with linux so some of their drivers may work with Pandora
however, i have yet to see a USB Vga cable that would actually be worth buying especially considering the low performance and high price (correct me if i'm wrong, but i'm pretty sure there usually about 80 dollars)
these cables are usually for computers to output to a second monitor for browsing the web and word processing and i'm sure they would fail in terms of quality for output
so even if you did get a 720p/i output from one of them it would most likely not work for videos
i wish they would have added a proprietary connector so that some kind of cable could be later devised but i there were casing and battery life issues with this
 
Ashwin said:
there are a few usb vga cables (actually quite a few) which would work with linux so some of their drivers may work with Pandora
however, i have yet to see a USB Vga cable that would actually be worth buying especially considering the low performance and high price (correct me if i'm wrong, but i'm pretty sure there usually about 80 dollars)
these cables are usually for computers to output to a second monitor for browsing the web and word processing and i'm sure they would fail in terms of quality for output
so even if you did get a 720p/i output from one of them it would most likely not work for videos
i wish they would have added a proprietary connector so that some kind of cable could be later devised but i there were casing and battery life issues with this
To clarify:
  1. They do not have the bandwidth and latency to effectively display moving video.
  2. In order to get effective moving video from a USB port there must be compressed video moving over the USB and being decoded on the external card.
  3. The complexity and expense of this card would rival or surpass the BeagleBoard.
  4. The BeagleBoard uses almost the same hardware as the Pandora while offering HDMI standard and only costs $150.
 
Last edited by a moderator:
DAP said:
The Composite Video output does not look very useful to me. Analog TVs die next year. We would be better off if it could be replaced with an HDMI connector.
There's only one digital output, and it's used to drive the LCD. You can't have an unused connector on that as that could cause impedance mismatches and other problems. The only proper way of having a HDMI connector is to remove the LCD completely and replace with a HDMI socket (via suitable transmitter, as done on the Beagle).

It's easier to just buy the Beagle :)
 
Last edited by a moderator:
Squidge said:
DAP said:
The Composite Video output does not look very useful to me. Analog TVs die next year. We would be better off if it could be replaced with an HDMI connector.
There's only one digital output, and it's used to drive the LCD. You can't have an unused connector on that as that could cause impedance mismatches and other problems. The only proper way of having a HDMI connector is to remove the LCD completely and replace with a HDMI socket (via suitable transmitter, as done on the Beagle).

It's easier to just buy the Beagle :)

Not to mention you get an Omap handheld and console for the same money :).

Are there plans to have a version of the Pandora firmware that can run on the BeagleBoard? I assume that most apps will talk to SDL or OpenGL and should be fine with a different display resolution (or indeed the same display resolution, but on HDMI or DVI).

As long as the applications all have USB control support there isn't really a reason it couldn't be the Pandora Console is there?
 
Last edited by a moderator:
Uhm...

So the only way to use a Pandora as a little computer, connected to a VGA monitor is to buy a Beagleboard?

I can understand taking out the SD cards from your Pandora and booting them on the Beagleboard, but what about the stuff on Flash memory?
 
It's a moot problem. The only thing that'll be on the NAND is the basic firmware and OS, most of which probably isn't directly portable to the beagleboard anyway. Different drivers and all that.
 
ashdjones said:
So the only way to use a Pandora as a little computer, connected to a VGA monitor is to buy a Beagleboard?
You could use the USB-to-VGA adapters they were talking about, they just said the quality for moving images (like movies) would probably be low. Several of the Dell LCD monitors we've purchased at work have S-video. You could just use that as well.

What they mean though, is that if you want to connect to a VGA monitor or have spectacular video output, you should consider buying a Beagleboard *instead of* a Pandora.
 
Last edited by a moderator:
Yamara said:
You could use the USB-to-VGA adapters they were talking about, they just said the quality for moving images (like movies) would probably be low. Several of the Dell LCD monitors we've purchased at work have S-video. You could just use that as well.

What they mean though, is that if you want to connect to a VGA monitor or have spectacular video output, you should consider buying a Beagleboard *instead of* a Pandora.
I gather that the Beagleboard only outputs 30fps over HDMI.
 
Last edited by a moderator:
WizardStan said:
It's a moot problem. The only thing that'll be on the NAND is the basic firmware and OS, most of which probably isn't directly portable to the beagleboard anyway. Different drivers and all that.
Well, different input drivers, and a different SD setup, also no wifi/BT or integrated screen.

But the OMAP contains the 3D accelerator, the CPU, the RAM, the NAND (flash), and the USB hardware, as well as the S-Video output, so it can't really be as different as all that.

As far as the "OS" goes, it can probably handle no Wifi or keyboard/controls just fine, it might need a patch.

Basically the games will probably be running on top of SDL or kdrive(X server), so they won't care about the difference unless they need something special, or don't support USB input devices. I hope that all the software supports USB input though.

Edit: Notice the picture lower in this page: http://beagleboard.org/hardware The blue box explains everything in the main chip, all of that should be identical between the Pandora and the Beagleboard, and it is most of the hardware that the Pandora has.

The BeagleBoard uses a DVI/HDMI chip to output in high quality and high resolution, this chip is likely connected across the same wires that the Pandora screen uses, so to implement DVI/VGA/HDMI on the pandora would need a chip with pass-through, and there simply isn't room for any chips. We get to use just about everything the OMAP has, and it simply doesn't have VGA or HDMI onboard the main chip.

There "are" USB video cards, but unless they are working with compressed data they simply can't move enough info to be effective for video content, or gaming for that matter. They are also quite expensive, and pretty bulky, and draw a lot of power. I also doubt they have open drivers, or ARM drivers (If they do I would love to know about it, I like wacky hardware :)). To get a USB video card capable of playing movies or games would probably cost much more than the BeagleBoard, so it makes more sense to just use the BeagleBoard.

(This is just the way I see it, I could be wrong, and if I am I really would like to understand it better, so please post.)
 
Last edited by a moderator:
Noob linux question:
If you plug an s-video cable into a linux box (ie. pandora), what kind of tinkering do you need to do to have it export video to the TV?

Will programs like mplayer/emulators export to the TV in fullscreen mode without much fuss?
 
Mr Wendal said:
Noob linux question:
If you plug an s-video cable into a linux box (ie. pandora), what kind of tinkering do you need to do to have it export video to the TV?

Will programs like mplayer/emulators export to the TV in fullscreen mode without much fuss?
I think the OS should handle it, and the program probably won't care, or even know, as it is shielded from the hardware by SDL or X, or OpenGL.

I would like to learn more when the Linux Gurus get back :).
 
Last edited by a moderator:
nubie said:
I would like to learn more when the Linux Gurus get back :).
My experience with Linux, nVIDIA graphic cards output via S-Video like any other X screen. Text is often fuzzy but retro gaming is a blast. The Pandora's GPU having access to what looks like two RAMDACs, it will be capable of dual display, which may come in the form of a kdrive config.
 
Last edited by a moderator:
nubie said:
WizardStan said:
It's a moot problem. The only thing that'll be on the NAND is the basic firmware and OS, most of which probably isn't directly portable to the beagleboard anyway. Different drivers and all that.
Well, different input drivers, and a different SD setup, also no wifi/BT or integrated screen.

But the OMAP contains the 3D accelerator, the CPU, the RAM, the NAND (flash), and the USB hardware, as well as the S-Video output, so it can't really be as different as all that.

As far as the "OS" goes, it can probably handle no Wifi or keyboard/controls just fine, it might need a patch.

Basically the games will probably be running on top of SDL or kdrive(X server), so they won't care about the difference unless they need something special, or don't support USB input devices. I hope that all the software supports USB input though.

I was speaking directly to the post previous to mine
QUOTE
I can understand taking out the SD cards from your Pandora and booting them on the Beagleboard, but what about the stuff on Flash memory?

Point I was trying to make was that only thing on the flash is the OS, and I would be surprised if the Pandora OS ran directly on the Beagleboard without any modification at all; close, but at the least the input and output would need to be reconfigured. A direct binary copy of the OS as it is in Pandora's flash memory is not likely to work right on Beagleboard. Hence why I said taking things off the flash is moot. Everything else in your post pertains to the SD card which ashdjones has already agreed is an understandable concept.
 
Last edited by a moderator:
Snu said:
IceBerg303 said:
to get 720p you need RGB or Y,Pb,Pr over 3 independent shielded channels. You can get 1080p over YPbPr but you lose some color saturation. For 1080p you really need something like DVI or HDMI with many channels to handle the massive bandwidth needed.

Just think, 1280x720 = 921,600 pixels each being 32bit color is 29,491,200 bits at a refresh of 30FPS that is 884,736,000bits (~885Mbit/s)
eh, for one thing, why would it be 32bit? the only 32bit color video I've seen is video with an alpha channel (24bit color, 8bit alpha), which would be completely pointless for just watching. also, uncompressed video is pretty much never used - even in pro video setups we use compressed (typically 25mbit/sec for sd, not entirely sure about hd).


Standard TV uses 8bit color(this is per color so 3*8=24bit color), HDTV uses 10 bit, it's easier to use 32bit words. I don't know what if anything the extra 2 bits are used for. 12bit is about where the majority of people can no longer distinguish any differences, tough many people are going to struggle telling differences between 10 and 12. 12bit is still a little impractical since it's much easier and cheaper to build 32bit bus systems not 36bit.

Mpeg2 is used in DVD video and Mpeg4 in HD video as it's less lossy. Newer standards are in the works for lossless compression, but that is still a ways off. Both are variable compression so that more compression occurs when there is less data(not as much color) this can result in color banding. You notice this in higher compression ratios used by xvid and divx to get a 8G dvd shrunk to 700M. This is why you notice it most in black/dark areas not bright multi colored areas.

decoding mkv and h.264 is actually feasible but until I can actually get my hands on a pandora I can not tell you how scaling is going to come into that as you usually do this with the dsp, but since we have GLes we may be able to do something tricky. The problem is that when something is compressed it's bad, you lose quality and it take more cycles to decode it before you can display it. Vorbis which is the better choice is less lossy and less compression still. The best of all would be one of the lossless video codecs. This way you have little processor need for decoding and more to use for scaling. The more you have for scaling the better your scaling algos can be so that you dont get artifacting, color banding, tearing, and other anomalies.
 
Last edited by a moderator:
Hm? Thought vorbis was an audio codec?
:p

---
Lossless video compression? That would need an USB HD, SD cards don't have enough bandwidth...
EDIT: not to mention that only one video would fit per 16GB card...
 
Back
Top