<![CDATA[ChipMusic.org - "C64MP3"]]> https://chipmusic.org/forums/topic/637/c64mp3/ Tue, 09 Feb 2010 13:33:35 +0000 PunBB <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9888/#p9888 akira^8GB says:

It's interesting that the MP3 can be decoded in real time. The sound quality is the usual awful 4-bit smile
I don't think there's even MP3 decoders for 68000 Amigas!

]]> Tue, 09 Feb 2010 13:33:35 +0000 https://chipmusic.org/forums/post/9888/#p9888 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9882/#p9882 Sander von Focus says:

Apparently there was a good reason to use that song.
http://en.wikipedia.org/wiki/Tom%27s_Di … the_MP3.22

]]> Tue, 09 Feb 2010 12:21:29 +0000 https://chipmusic.org/forums/post/9882/#p9882 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9881/#p9881 Jellica says:

its certainly interesting, but i'd like to hear somthing a bit more interesting than suzanne vega

]]> Tue, 09 Feb 2010 12:18:04 +0000 https://chipmusic.org/forums/post/9881/#p9881 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9880/#p9880 rumpelfilter says:

the more I know about it, the more it seems amazing!

]]> Tue, 09 Feb 2010 12:14:00 +0000 https://chipmusic.org/forums/post/9880/#p9880 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9875/#p9875 Sander von Focus says:

Anders: It makes your c64 sing! wink
I found this on csdb:

th of February 2010: It is true, the Commodore 64 CAN SING! The Commodore 64 mp3-decoder is called c64mp3, and I, Mahoney, made it for the Datastorm event in Gothenburg. The download link contains the full demo and the source code for the encoder and decoder.

The song chosen is "Tom's Diner" by Suzanne Vega.

The Commodore 64 c64mp3 replay routine uses all the tricks in the book,
in order to acheive the best sound quality possible:

* The sound buffer is calculated in the stack, and it wraps
* Jitter free sample playback, by using NMI IRQ vector pointing to $dd04
* 8-bit sample output by using SID test bit for resetting oscillators
* saving clock cycles by JMP $dd0c when exiting an NMI
* Pitch tables? Good for module playback, but worthless for human voices
* Dithering noise, to make quantization smoother
* Phase-aligned wavetables with extracted formants
* Full 8-bit interpolation between formants with 16 different volume ratios
* 16 volume levels for resulting audio output
* self-modifying code, of course
* critical code run in Zero Page
* ...while only ~15 assembly instructions per sample available
* ...and still cpu-time left for a demo!

The c64mp3 encoder uses some seriously advanced signal processing as well:

* sub-sample pitch detection
* auto-tuning into constant-pitch audio
* formant extraction, sub-sample phase-alignment and normalization
* formant cross correlation and selection
* consonant detection and extraction
* run-length encoding of data with _minimal_ unpacking overhead
* requires 4GB of RAM and 500MB of hard drive space

It is true, the Commodore 64 CAN SING! ...but it took some 28 years for it to learn! wink

]]> Tue, 09 Feb 2010 10:47:20 +0000 https://chipmusic.org/forums/post/9875/#p9875 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9874/#p9874 goto80 says:

so ... what is it that the c64mp3 does?

]]> Tue, 09 Feb 2010 10:28:59 +0000 https://chipmusic.org/forums/post/9874/#p9874 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9723/#p9723 boomlinde says:

I thought the title was a bit misleading since it isn't really mp3. Aside from that, it's really impressive. Frequency domain compression for the c64!

For more sound tricks, check out the entries by Goto80 (techno aha; general multispeed trickery) and by Frantic (birdburner; bird emulation by linear analysis of bird beeps)

]]> Mon, 08 Feb 2010 18:38:34 +0000 https://chipmusic.org/forums/post/9723/#p9723 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9673/#p9673 Sander von Focus says:

"use WinVice 2.2 settings/sid settings/ sid-engine any 6581 resid-fp (importrant choose resid with "fp" at the end)"
I did this with WinVice 2.1. Or check the video above smile

]]> Mon, 08 Feb 2010 13:17:05 +0000 https://chipmusic.org/forums/post/9673/#p9673 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9669/#p9669 ant1 says:

Sounds pretty accurate in VICE, what are you using?

]]> Mon, 08 Feb 2010 13:05:10 +0000 https://chipmusic.org/forums/post/9669/#p9669 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9663/#p9663 Jellica says:

this sounds hilarious through my emulator!

]]> Mon, 08 Feb 2010 12:35:23 +0000 https://chipmusic.org/forums/post/9663/#p9663 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9637/#p9637 rumpelfilter says:
ant1 wrote:

Or so amazingly hi-fi, if you look at it like that. smile

hehe, you have a point there smile

]]> Mon, 08 Feb 2010 08:35:30 +0000 https://chipmusic.org/forums/post/9637/#p9637 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9508/#p9508 Thretris says:

crazy, that is rad indeed

]]> Sun, 07 Feb 2010 15:59:15 +0000 https://chipmusic.org/forums/post/9508/#p9508 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9507/#p9507 ant1 says:

Or so amazingly hi-fi, if you look at it like that. smile

]]> Sun, 07 Feb 2010 15:32:35 +0000 https://chipmusic.org/forums/post/9507/#p9507 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9506/#p9506 rumpelfilter says:

yeah! this is just so amazingly lo-fi!

]]> Sun, 07 Feb 2010 15:29:42 +0000 https://chipmusic.org/forums/post/9506/#p9506 <![CDATA[Re: "C64MP3"]]> https://chipmusic.org/forums/post/9503/#p9503 Sander von Focus says:


Just cool smile

]]> Sun, 07 Feb 2010 13:48:12 +0000 https://chipmusic.org/forums/post/9503/#p9503