EXPERT ADVICE needed on an idea.

[robbyduffy]

I have little experience with the actual internal goings on of a PC. I've built a few in my time but the specific functions are a mystery to me. It seems that the optional harware in PCs (gfx/sound cards) are there simply to process inputted information then convert it into some kind of output (monitor/speakers). If this is basically all these do then surely one could build a program which runs through the processor and performs the same task, or maybe it could enhance the performance of the devices. It just thought this having just used a PC with no sound card which stops me from playing any AV file in WMP.

I know i'm probably being a complete newbie here but any help please?

btw how do U play just the video in e.g. WMP??

[ripken204]

u want to play audio with no sound card? where would u plug the speakerse into?

and why do u want to only play the video? u could just mute it. and vlc media player will allow u to disable the audio or video track, not sure about wmp since i dont use it.

[nmX.Memnoch]

If this is basically all these do then surely one could build a program which runs through the processor and performs the same task, or maybe it could enhance the performance of the devices.

You would still have to have some sort of output connection.

Doing these tasks in software would be MUCH slower than doing them with hardware acceleration. The devices you mentioned (sound, graphics card, etc) are designed specifically for those tasks and are highly optimized to do just those tasks.

The system CPU could be optimized to handle all of these tasks, but it would make it a much more complex, and therefore MUCH more expensive (more so than having each individual device), piece of hardware.

[Albuquerque]

Sounds like there aren't any old-school folks in here.

Not *that* long ago, video was (for the most part) driven by your processor and/or the PC's BIOS. However, that was also during a time when machines were maxing out at 8-12mhz and used a maximum bus width of sixteen bits to transfer data to a "dumb framebuffer" card. Essentially all the computations were done by the processor, but the video card served only as a memory holding cell for the data being displayed on the screen -- and of course to house the connector.

The problem was usually horrible update speed and horrible compatibility. As GUI-based interfaces (such as Windows) came onto the scene, video card manufacturers began building video coprocessor chips that could accelerate GUI functions such as building windows and clearing the screen. These evolved into "2D accelerators" and began pushing more of the work away from the BIOS and CPU and instead into the dedicated processor(s) on the video card.

And as you can imagine, that evolved over time into 3D accelerators, which began tackling more and bigger issues until where they are today. Why haven't we gone back to CPU assistance? In some smaller cases, certain things are still processed by the CPU even now. But most of those items are "backwards compatible" things that really aren't used anymore and weren't used much to begin with, such as ATI's Truform abilities (which hasn't been video-hardware accelerated since the 8500).

Audio has, interestingly, gone from hardware only, to software optionally, and is now somewhere in the middle. Originally sound hardware was entirely responsible for making sound, but later advances in CPU power without similar advances in sound quality gave developers the ability to generate the sound-card-equivalent of a "dumb buffer" sound card: the CPU (ie windows driver) does most of the work, while the audio chip serves mostly as a buffer and hardware support of source control (mic / line in / CD in / etc).

Later, as more features are added to sound cards (higher quality 24bit / 96khz output, 3D maniupalation of sounds, etc) newer soundcards have given rise to moving the acceleration back onto dedicated processors on the card. But there are still "software driven" audio options, just like there are still "software driven" modems.

Most of it is a performance tradeoff. Video will probably never go back to the CPU, just because we're demanding so much from it these days. Audio will probably straddle the available options for much longer until we get into some serious audo quality upgrades to push more processing to the card; a prime example of which will be apparent with Vista's new "HD Audio" strategy.

Hope that answers your question

[noguru]

But your other question, I did not even know that WMP refuses to play movies when you don't have a sound card . They don't cost a lot anymore, just buy one!

In case you don't want that you can use your PC speaker. See here:

http://www.mdgx.com/newtip23.htm

I hope WMP will accept this. I don't know for sure.

Edited April 14, 2006 by noguru