ProTracker Module Compression

[h0ffman]

Hi Guys

Sorry if this is in the wrong place. I'm looking to put together an old school A500 music disk. Track loaded using only 512k.

My question is whats the best way to compress a protracker module under these restrictions?

I know there was a lossy sample compression routine used on the Suburban Base music disks, but not really interested in loosing quality.

I was thinking of writting a little routine which would change the samples so the first byte is like a key frame and then its only the differences between each byte. Chuck that through Imploder and see what happends?

Any thoughts?

Cheers

[Photon]

If they have to be compressed while playing, The Player and maybe Noisepacker are two options. If they only have to fit on the disk, crunch them with anything you like. Others can give you tips on those 'make executable music' programs, and you can crunch them with Powerpacker or something and just run them as commands. (A bit trickier if OS is not on.)

Crunching notedata as per above gives a healthy gain, but if the songs have a lot of sampledata, you can try misc. things, like the deltaconversion you mentioned. Anything that will gain more than a few percent is likely to take a long time decrunching on the 68000. I'm sure you would get much smaller modules by forcing the musicians to optimize the samples by hand with the usual methods.

You could always go with multiple disks... ?

[Leffmann]

I would go with The Player 6.1. Its converter tool can do delta conversion on the samples as you mentioned, and it removes redundant space in the pattern data to reduce file size as well.

For additional file compression you could try CrunchMania, which is probably the best file compressor for the classic Amigas. It can do in-place decompression, the decompressor is small in size and the M68K source code is available as well.

Photon, being the the mild mannered, modest and humble person he is, forgot to mention he has recently optimized the P61 replayer as well. P61 has been the de facto standard way of replaying PT modules on the Amiga for many years, and with his updates to it I honestly don't see any reason for using any of the alternatives.

[pmc]

I agree with Leffmann - after Photon's updates The Player is the one to use for module compression / playback really.

Personally I prefer using ProRunner2.0 as my module player but that's just a personal preference - although it can compress (and play back compressed) ProTracker modules it's not as good at compressing them as The Player is.

As regards then also compressing the data on disk I'd personally go with StoneCracker for the crunch / decrunch.

I'm sure you don't need any help with the routines h0ffman but if you like you're more than welcome to have my trackloader code - it has the ultra quick StoneCracker decrunch code already integrated.

[ant512]

I used to use CrunchMania. I had an executable that would run in the background and transparently decrunch any CrunchMania data files that were accessed without any user or programmer effort. I wonder what that was called?

EDIT: rtdd - RunTime Data Decruncher.

[h0ffman]

Cheers for the tips guys, looks like The Player 6.1 is the way forward, managed to get my largest module for this music disk down to 465k playable size.

Although that leaves me with about 45k to get the loader and menu in!! JEEEZZ this is gonna be a squeeze!

@PMC - Any help on this would be greatly appreciated mate, I haven't done any 68000 for over 15 years!! and to be fair, when I did cracking I used to nick other peoples loaders.

So guys, what do you reckon I can squeeze in 45k?

[pmc]

Originally Posted by h0ffman

@PMC - Any help on this would be greatly appreciated mate, I haven't done any 68000 for over 15 years!! and to be fair, when I did cracking I used to nick other peoples loaders.

So guys, what do you reckon I can squeeze in 45k?

My trackloader along with decrunch routine is 766 bytes - that small enough for you...?

Although to get it down that small I had a fair bit of help from StingRay and others to be fair.

So, that still leaves you over 44Kb for your music selector.

A nice elegant selector should be do-able in that space I would've thought...

[StingRay]

Originally Posted by h0ffman

So guys, what do you reckon I can squeeze in 45k?

Not that much since a standard 40*256 5 bitplane screen would need 51200 bytes already. However, what about loading the samples for that very large module on the fly? That's what I would do at least.

[sun68]

All most Module-Packer running How? -->

Protracker - Module - Example - Assembling:

THE HEAD

NAME "My Lame Module" -> TYPE : CHAR : BYTE
TRACKS "12" -> TYPE : CHAR : BYTE
PATTERNS "40" -> TYPE : CHAR : BYTE
SAMPLE NR "31" -> TYPE : CHAR : BYTE
etc.

THE SAMPLES

1 - 31 in RAW

-> converted THE HEAD BYTES to BITS
-> 8 BITS = 1 BYTES
-> its Smale its Fast
______________

Shorter Head, but not Samples are packed.

[h0ffman]

Managed to do a bit more optimisation in protracker on the samples. The file size as P61 is now 394,214 bytes, now leaving 130,074 bytes (or there abouts!)

[Asle]

[rant almost off topic]
Please don't use The Player as it destroys the protracker header.
If size matters more than speed, you can always remember that His Master Noise contained more than 100 protracker (~13 Mb) on two disks, and there was _no_ The Player at that time.
[/rant]
Now, flame me while I go hiding

Sylvain

[StingRay]

Originally Posted by Asle

Please don't use The Player as it destroys the protracker header.

What does that matter in a music disk? If you want the original modules you can always ask the musician anyway.

Originally Posted by Asle

If size matters more than speed, you can always remember that His Master Noise contained more than 100 protracker (~13 Mb) on two disks, and there was _no_ The Player at that time.

Not Protracker but Noisetracker songs. And Mahoney & Kaktus actually coded their own tracker/play routine for it so it doesn't differ much from any other custom player such as P61.

[Leffmann]

The reason they could fit so much music into HMN was because all songs used a common set of samples.