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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: filson on June 10, 2003, 09:55:27 PM
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Anyone remember what the minimum spec is for mp3 decoding on the 680x0 family. Was thinking about making me a portable mp3 player for flash media.
already have the source for a mp3 decoder for 680x0 so it shouldn't be to much trouble.
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Why don´t use a hardware mp3 decoder instead?
Here is a link to a similar project: yammp (http://www.myplace.nu/mp3/index2.htm)
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My old 50Mhz 68030 could just about do it, but you'd probably need a 68040.
It would be cheaper and easier to use a specific MP3 decoder chip; you just feed mp3 data in one end and get audio data out the other. You can use any cheap CPU (PIC, for example) to feed it data and check for user input.
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My 25Mhz 68040 has problems trying to play mp3's but it can do it... my 50Mhz 68030 simply can't do it real time.
So I would say the 040 is the lowest spec for mp3 decoding.... but we all know how hot and hungry they are, so you might want to look at a Coldfire... but that's another thread. :-D
ON the other hand, if you know 68K asm, simply rewrite what you have for a CPU much more suited to the mobile environment... it you want to do it cheap, might I suggest a microcontroler and a DSP combo, that would give the best characteristics for an mp3 player.... I suggest you choose a microcontroller which supports Compact Flash so that you can use cheap removable memory cards.
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My 030 @ 40Mhz is about the lowest spec that'll do it real time, but the quality is terrible. As people have pointed out, a hardware decoder would be much better - for a start you wouldn't have to build your own portable computer to run it on!
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My old 040/33MHz could do it but I had to half the bitstream rate. My 060 can do it without skipping any data, but I had then got a Delfina Plus and used it's processor until the thing broke. (left speaker output is dead and I get no response to emails I send to Petsoff asking about a repair)
I wouldn't go with anything below 060 as the 040 may need to sacrafice quality in order to avoid choppy/skippy playback.
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Thanks all for the feedback.
Guess it'll be easier with some yampp, and no Blodline, no Coldfire :-D Think it is a processor to fill the gap between PPC and MC68x that came to late.
Anyways, Thanks.
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The MASplayer can decode MP3's even with a 68000 processor. It has a MPEP decoder chip on it.
Try to buy a MASplayer from Eyetech or build it yourself. You can find it on
http://home.snafu.de/dcr/mpeg_hardware.html
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Hardware decoders are very limited. They don't return decoded data to the Amiga for players, etc. In fact, the effect of one is nothing much more than buying a portable MP3 player and plugging it into your soundcard.
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@KennyR
If you had bothered to read the inital posting you would see that it was a portable player he intended to make.
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If you had bothered to read the inital posting you would see that it was a portable player he intended to make.
I know, I did read it. I was answering you, not him. My point: mpeg hw decoders on an Amiga are too limited.
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Who says I'm a guy? :-)
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filson wrote:
Who says I'm a guy? :-)
Prove that you are not! :-D
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@KennyR
Sorry. It can sometimes be confusing to see who you address when you don't use @.
btw. I think you were answering amiga1260, not me, as it was he (or she?) who mentioned the amiga solution (MASPlayer).
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Prove that you are not!
wanna see my breasts ? :-D :-D
on second thought, they aren't for the public :-)
i can send you a tampong instead :-D :-D :-D
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heck, my 040@25MHz cant do it
its waaay too slow
perhaps if the sample rate was low(half)? i dont know
mono(eg. just the left channel) instead of stereo?
8bit instead of 16bit
perhaps then it would
it seems like it would be ok if it were twice as fast ;-)
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Try to buy a MASplayer from Eyetech or build it yourself. You can find it on http://home.snafu.de/dcr/mpeg_hardware.html
The page has been deleted. But it can be found at:
https://web.archive.org/web/20040808074656/http://cgi.snafu.de/dcr/user-cgi-bin/Website?name=HTML_MAS
FYI ;)
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Eyetech doesn't exist anymore.
But you can get it from Amigkit:
http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=1078
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@freqmax I guess that page still existed about 11 years ago. Nice thread bump ;)
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I believe the new Prisms Megamix board will be able to do this too once software is completed.
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Eyetech doesn't exist anymore.
But you can get it from Amigkit:
http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=1078
Was just about to post that same link LOL :-)
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@freqmax I guess that page still existed about 11 years ago. Nice thread bump ;)
Well I was looking for cards that used a DSP for mp3 decoding to figure out what capacity that would require. And in the process I succeeded to re-locate the page and thought I just drop a notice to help the next person.
All I found where DSP for sound effects and ASIC for direct mp3 decode which doesn't tell anything about DSP based mp3 decoding demands nor ARM based.