[HN Gopher] A C64 MP3 Player
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A C64 MP3 Player
Author : ibobev
Score : 65 points
Date : 2023-02-17 10:41 UTC (1 days ago)
(HTM) web link (lyonsden.net)
(TXT) w3m dump (lyonsden.net)
| miohtama wrote:
| Now, only if it could play music from a casette...
| detrites wrote:
| The SID chip has an audio in that lets you use the filter, so
| it should be possible.
| vidarh wrote:
| You can use the tape sense pin as a 1 bit sampler, and toggle
| the volume for playback, so you can do that. Badly.
| xuhu wrote:
| Can a 386SX play an mp3 ? Or any CPU without a FPU for that
| matter ?
| miohtama wrote:
| Even Pentium class CPUs had problems handling MP3s depending on
| the encoding
| pwg wrote:
| Doubtful. Back in the day when my 'work computer' was a Pentium
| (Pentium 200MMX to be exact) playing a MP3 consumed 50% CPU.
| Note, I no longer remember if mpg123 was using MMX instructions
| or not.
|
| Given how much faster a Pentium 200MMX was than any 386 CPU, I
| very much doubt a 386 (even a DX) would have had enough power
| to decode in real time a MP3.
| xuhu wrote:
| Found this (cubic player on a 386DX at 40MHz)
| https://www.youtube.com/watch?v=6Jj97NXgHw4 and I'm wondering
| how much a 32bit ISA is better than a 16bit one for integer
| decoding.
| asveikau wrote:
| I remember using winamp on a Pentium 90 and it was up to the
| job single tasking. I couldn't say the same about the one
| time I tried to encode.
|
| I can't recall what hardware I first used an MMX-optimized
| encoder. I remember it making a huge difference though.
| matja wrote:
| From memory a 486DX4-100 or an overclocked 486DX2-66 (to 80MHz)
| could just about handle 128kbit MP3s
| A-Train wrote:
| Ah nostalgia... This was my first PC processor. I remember my
| CPU came with some sort of a bug that prevented me running
| windows 3.11 on it.
| bane wrote:
| Yeah, I seem to remember there was that brief time period
| where my PC could barely play MP3s and I used to treat them
| like zip archives -- rendering them back out to WAV files to
| play them back.
|
| I _think_ you 're right and that was around the 486 DX2, DX4,
| Pentium transitional time period.
| SillyUsername wrote:
| Interesting. My Amiga with a 68030 @42Mhz could just about
| pull off mono 128Kbps decoding (as long as you didn't
| multitask too much). That would suggest the 486 was almost
| clock comparable to a 68030 at least for lossy decompression,
| perhaps the 486 was around ~110% had their been a 68030
| series 80Mhz equivalent.
| nubinetwork wrote:
| I know a 486 can just barely play them (while doing absolutely
| nothing else)
| pengaru wrote:
| I used to listen to mp3s on my FPU-less Sharp Zaurus clamshell
| using madplay [0] with cycles to spare.
|
| Linked from [0] is a page claiming to use MAD for mp3 playback
| on a Newton [1].
|
| Not sure how those compare to a 386SX, but it's probably a good
| place to start.
|
| [0] https://www.underbit.com/products/mad/
|
| [1] https://40hz.org/Pages/newton/packages/madnewton/
| nynyny7 wrote:
| As other commenters have pointed out, this is a C64 _controlling_
| an MP3 player.
|
| People old enough to remember the late 1990s / early 2000s might
| recall that back then it was popular, too, to hook up an external
| MP3 decoder, e.g., to the parallel port; so that the PC's CPU
| would not be at 100% just for playing MP3 music.
| ruk_booze wrote:
| mp3 on a stock C64 was showcased by Mahoney in 2010:
|
| https://csdb.dk/release/?id=87985
|
| https://youtu.be/0mF9kXZAjsI
|
| tbf, it is "mp3" but still really impressive.
| ugjka wrote:
| sound lit bit like codec 2 on noisy rf
| reaperducer wrote:
| _Resource Limit Is Reached
|
| The website is temporarily unable to service your request as it
| exceeded resource limit. Please try again later._
|
| Apparently it's a C64 web server, too.
| hummus_bae wrote:
| Limit exceeded by what?
|
| Is that really supposed to be some sort of standard response,
| or is it something idiosyncratic to this server?
| detrites wrote:
| Spoiler: it's hardware.
|
| And the opening line sounds like a challenge:
|
| > Given that the much more powerful 16-bit Amiga 500 is unable to
| play MP3's,
| ajross wrote:
| The C64 didn't have any kind of PCM output, so it basically has
| to be. Early SID chips had a voltage glitch you could use for
| 1-bit ("speaker-style") output, and a few games used it for
| some effects. But you couldn't get music out of it in any real
| sense.
| mdp2021 wrote:
| > _in any real sense_
|
| I would be sure that if Tim Follin decided to just use that,
| he would have "made full sense" (cpr. "Agent X" and
| "Chronos", ZX Spectrum).
| classichasclass wrote:
| Four-bit (the amplitude of the "click" caused by the SID's
| voltage leak is proportional to the volume, which is four-
| bit). There are many demos that used it for digitized music,
| and Rob Hubbard's Skate or Die! intro tune used it as a
| practical fourth voice. See also the original Covox Voice
| Master.
| pflanze wrote:
| There are also other techniques (found after the computer's
| heyday), up to 8 bits 44.1 KHz:
|
| https://www.livet.se/mahoney/c64-files/Musik_RunStop_Techni
| c...
| technothrasher wrote:
| > Spoiler: it's hardware.
|
| Yeah, this isn't MP3 on a C64. It's a C64 controlling an
| external MP3 player.
| Tuna-Fish wrote:
| I think mp3 playback requires a reasonably fast multiply
| instruction, and the original 68000's 70 cycles per mul @ 7MHz,
| or 100000 muls per second doesn't qualify.
| detrites wrote:
| Some info here, claims a 68020 at 50Mhz (@10 MIPS) can just
| pull it off:
|
| https://eab.abime.net/showthread.php?t=78994
|
| Might mean an A500 (@1.4 MIPS) could do it if you were happy
| waiting 10-15 minutes for the audio of a 3 min mp3 to begin.
| Someone wrote:
| I don't think a stock A500 could do that, having 1MB RAM,
| max.
|
| Where would you store 3 minutes of uncompressed audio? At
| CD quality, that's about 30MB.
| Razengan wrote:
| Wow, how far we have come.
|
| MOD is superior to MP3 anyway :)
| detrites wrote:
| Given the likely output quality you'd probably choose
| something like 32Kbps encoding for the mp3, which should
| fit 3 mins in 720KB. (Not sure how it'd affect CPU
| requirements?)
|
| It's not that bad-sounding:
|
| http://www.knowzy.com/Computers/Audio/Digital_Audio_Files
| /au...
| pixelfarmer wrote:
| I think a stock Atari Falcon is capable of playing mp3
| thanks to the DSP (56001), but it still isn't a walk in the
| park even with that (in combination with a 68030 as the
| main CPU).
| [deleted]
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(page generated 2023-02-18 23:01 UTC)