MPEG-2 Decoding

[James Board]

I'm looking for a hardware MPEG-2 decoder for use with a Fedora-based machine. This could either be a card that I plugin to the PCI bus, or an external device that connects via the USB bus. The important characteristics are that the MPEG-2 decoding is done in hardware on the device (not the computer CPU). and is supported by Linux. Does anyone know of such a device?

James

[dann]

there are lots of card with that capability:

http://www.misco.ie/productinformati...ics%20card.htm

but i would check on the ffmpeg site to see if it's supported in any of the media players (unless you don't plan on using a media player?)

[James Board]

The ffmpeg site does not have a "Supported Hardware" page, so it's difficult to tell if it supports that card. Also, ffmpeg does MPEG-2 decoding, the card you linked to does hardware MPEG2-decoding, but it's not clear to me that if I put the two together, that ffmpeg would actually do the decoding on the hardware.

Yes, I plan to use a media player. I'd like to send the output of the decoder to a TV screen and watch videos from there.

James

[JohnVV]

I may be wrong but i was under the impression that my nvidia card did that for the tv out . Process it on card rather that have the cpu do it then send it to the gpu . But this may be the digital to analog conversion ?

[lazlow]

I think what you are going to run into is that the price of a good hardware decoding card is going to be higher than a cpu that will handle the task with ease. A PIII 1ghz is plenty of cpu to handle acting as a video player (what I am using right now). So some of the newer sub $100 low power cpus will handle the task without even breaking a sweat.

[James Board]

A good hardware decoding card should cost about $50. Sigma Designs used to make them (I have two of them), but they only appear to be supported in Microsoft Windows.
Anyone, the price of the hardware decoder is not really an obstacle.

It looks like there are plenty of video cards out there with MPEG decoding hardware, but if I install them on a Linux machine, will there exist drivers for them so that the decoding is done on the card, not the CPU?

James

[JohnVV]

all new ( 2003~4) nvidia cards are supported in fedora9 [ 2000~1 for fedora8] and ati just started shipping a Linux driver on the cd alongside the windows driver

[James Board]

Do those nvidia cards, or ATI cards, have MPEG-2 decoder hardware on them? Checking....

[lazlow]

Why exactly are you so set on hardware decoding? Particularly mpeg-2? The shift is actually away from mpeg2 right now. No clear winner yet, but h.264 would be a strong candidate.

[James Board]

On hardware decoding:

a) The CPU will be busy doing other computationally intensive tasks.

b) When I've experimented with software encoding in the past, the results were not good. Lots of missed frames, and they didn't get the field order correct, etc. If there's a cheap, or mid-range, hardware encoder out there, I'd like to try that first. If not, I'll look into the software decoders.

As far as MPEG-2 is concerned: I have lots of existing MPEG-2 files. I'd rather not convert to another format if it involves re-encoding the video data and lossing further image quality.

[James Board]

How does this sound: Recommend a video card with a TV-out that is fully supported by linux. I'll buy it, try it out with ffplay, for Mplayer. And, if it works well, I will grant you eternal consciousness. Deal?

[lazlow]

Pretty much any of the nvidia cards (that have TV out)IF you use the proprietary drivers(livna is easiest). I have an old 32mb asus 7700 (geoforce2) in my old PIII and it works fine. If you are getting missed frames I would look to your hard drive speeds. If the system accesses a slow drive while you are playing a vid, you are going to see what you are describing. I run mprime on the PIII while I am playing vids(no problem). Also look how lean you are running your memory. If you have other tasks running that are using a lot of memory, you may be dropping your buffers/cache low enough that you are seeing that behavior.

[James Board]

Let me ask a slghlty different question. All I really need is a device that will let me play MPEG-2 files stored on an external USB drive to a TV. A computer isn't really necessary. A DVD player has the basic functionality, but they don't have USB ports for external drives. Right?

Here's the question: Is there any kind of device (DVD player, DVR, other?) that will let me attach an external USB disk drive with some fairly common filesystem type (ext3, or NTFS, etc) that will let me play MPEGs files on that drive to a TV screen?

James

[lazlow]

DVR are (usually) just a specialized distro on specialized hardware. Look at Tivo, it is just a pc running a special distro of Linux.

What you are describing is exactly what I use my PIII for. It is directly attached to my tv (the only monitor it has) and its primary function is to play videos. I use its spare cylces to run mprime. The only big difference between what you are asking and what I am running is that I store my files on a server in the basement. I remotely play then via NFS rather than a direct usb drive. You can build a system like this for very cheap. I think I have about $100 stuck in mine(mostly the Seasonic power supply). If you were willing to spend a little more you could start with one of the 45w X2s and a fan less PSU. These are dead quiet. Since playing videos does not require much of a video card, anything current would work (easily sub $50). Having the videos stored eslewhere (usb or NFS) means you do not need much of a hard drive (maybe run the system off a 1 gig usb stick). The trickiest part is the remote.

[James Board]

This is looking pretty cool:

http://www.hawkee.com/shop/prod/2403848/

It's an INOi Digital Media Player which is a standalone unit that contains a 500 GB disk and connects to your TV amd play video files. It comes with a remote control.

James