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Enough power to decode PCM?

This thread brings up a related question in my mind... what is the least powerful computer that can decode and play MP3 audio in real time, without reducing the sampling rate or downconverting to mono?

Assuming a 44.1 kHz stereo 128 kbps MP3 file as the norm, my Toshiba Pentium-90 laptop can do it without even breaking a sweat.

Same thing with my Cyrix 5x86-133 desktop (which is about on par with a P90 anyway).

MPXPlay for DOS claims to be able to do it on a 486DX4-100.

I was able to do it with MacPlay3 in OS 7.x on an original 60 MHz PowerPC 601 PowerMac, but it clearly put a large load on the CPU.
 
This thread brings up a related question in my mind... what is the least powerful computer that can decode and play MP3 audio in real time, without reducing the sampling rate or downconverting to mono?

Generally, a Pentium. If you don't want to downconvert, you need the dual pipelines (and coding to exploit them) as well as the faster floating-point. But any Pentium should do.

MPXPlay for DOS claims to be able to do it on a 486DX4-100.

Yes, but just barely. Notice you need a 100MHz 486. You only need a 60MHz Pentium.
 
I'm a bit surprised at this, as my original P133 system was sold as a "multimedia" PC and was quite capable of displaying multiple video windows simultaneously (albeit small ones), with sound, with no stuttering. I can only assume from this that AVIs don't need as much processing power?

However, I do remember any attempt at audio playback (using Winamp) being interrupted by accessing the modem.


BG
 
I'm a bit surprised at this, as my original P133 system was sold as a "multimedia" PC and was quite capable of displaying multiple video windows simultaneously (albeit small ones), with sound, with no stuttering. I can only assume from this that AVIs don't need as much processing power?
Early AVI and QuickTime videos used only very simple data compression schemes (like ADPCM for sound) and could be played back even on a 386.

The original MPC1 (Multimedia PC) standard from 1991 required at least a 386SX-16. The MPC2 standard in 1993 increased the requirement to a 486SX-25.

http://www.buildorbuy.net/mpcspecs.html
 
I'm a bit surprised at this, as my original P133 system was sold as a "multimedia" PC and was quite capable of displaying multiple video windows simultaneously (albeit small ones), with sound, with no stuttering. I can only assume from this that AVIs don't need as much processing power?

It depends on the .AVI's CODEC, but some codecs used very little processing power. A 386/40 could play back a 320x240 @ 30fps Cinepak file without any trouble. Some codecs used more horsepower, but I'm sure a Pentium 133 could play at least two 320x240 30fps clips simultaneously regardless of codec (at least, any codec available at that time).
 
Ech. Can you imagine? And what, it wasn't it about 40 times a second the report rate was for 98?

Can you imagine 40 times a second the mouse saying: "EXCUSE ME!!.............the mouse moved this way...........EXCUSE ME!!...............now it moved that way"
 
messages

messages

You think that's bad ?
Hook a registry tracer onto the Windows registry, or hook into some of the WM_ messages that Windows generates.
You'll be amazed that anything gets done at all. (At least I am, at times).
patscc
 
Hmm, at the time, my mouse was a serial port mouse.
PS/2 connectors weren't common on aftermarket build-it-yourself PCs until the ATX form factor began to take over the market in 1997 or so -- a full decade after IBM introduced the PS/2 mouse and keyboard connectors!

If you want to know just how "busy" a mouse makes the CPU while moving, install a cheap ISA sound card with not many filter capacitors on it, then crank up the volume while not playing any sound... you'll hear every pixel the mouse moves as a click or buzz! (The ISA bus has poor grounding; MCA and PCI are much better.)

Even worse, my dad had a Leading Edge 486SLC laptop whose internal PC speaker was so poorly grounded that you could literally hear the machine think -- heavy CPU activity would cause faint but audible noises from the speaker.
 
Had a cheap PCI sound card that did that too.

My old Dell CSx laptop did the same thing, CPU thinking sounds, but not out of the speaker, but out of the northbridge. VERY creepy.
 
My old Dell CSx laptop did the same thing, CPU thinking sounds, but not out of the speaker, but out of the northbridge. VERY creepy.
Flowing current can make noise all by itself. It's the same principle which makes an AC transformer hum and the flyback transformer in a TV set squeal. I have a Sony Walkman which has no built-in speaker, but if you unplug the headphones and turn the volume all the way up, you can hear a faint, tinny rendition of the audio -- the circuitry inside the Walkman itself is making the noise!
 
Flowing current can make noise all by itself. It's the same principle which makes an AC transformer hum and the flyback transformer in a TV set squeal. I have a Sony Walkman which has no built-in speaker, but if you unplug the headphones and turn the volume all the way up, you can hear a faint, tinny rendition of the audio -- the circuitry inside the Walkman itself is making the noise!

Got a walkman that does just that. Flat pager looking thing with a big sliding power switch.
 
Got a walkman that does just that. Flat pager looking thing with a big sliding power switch.
A Sony SRF-42 with AM Stereo? That's mine. No tape.

srf42.jpg
 
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