Adpcm packer in ps2sdk?

Lukasz · Post by **Lukasz** » Sat Apr 30, 2005 7:08 pm

Recently gawd began work on a audio library (audsrv) and added the source to ps2sdk. It currently supports PCM (raw, cdda,..).

I am also working on a sound library which main focus was to support adpcm for samples but also have PCM support for music.

So when I heard about gawd's project, I thought I might aswell just "port" my adpcm code over to his library.

But here is the possible problem, since the tool which converts from wave to adpcm is just a modified version of vagpack.c by bitmaster but with a completely different header, some people might be against having it in ps2sdk since vag format is owned by Sony (I think..)

Since ps2sdk is a group project under a license and I no license expert, I want to hear what people's opinion on this is.

If the final decision is not have the vag packer in ps2sdk, I will release my audio library as a seperate library and not add adpcm support to gawd's libaray. And then there will be two libraries which will be quite similar when it comes to supporting PCM and I would like to avoid this and just contribute to gawd's library.

Post by **pixel** » Sat Apr 30, 2005 9:55 pm

Well, the "vag" file format is only adpcm-within-a-header. If you change the header, it's simply not the vag format anymore.

Compressing in "adpcm" here is just "matching the format that the PS2's SPU can decompress", right ? Just as much as compiling a texture file in the format the PS2's GS can use.

So, for me, there's not much "vag" left here if you do your custom file format around the adpcm-compression-that-matches-the-SPU. Now, well, about licenses, what's the current license of the code you're basing your own code of ?

Lukasz · Post by **Lukasz** » Sat Apr 30, 2005 10:15 pm

Thanks for the reply pixel, the code does not have a license. Bitmaster just made it available at his website : http://www.syncscroller.net/psx/psx-index.html

Post by **pixel** » Sun May 01, 2005 3:58 am

Yeah, so, I guess it's quite okay. You could produce your own code "based on" his, produce your own adpcm container (file format that is), and throw it in the SDK. Doesn't cause any problem to me.

J.F. · Post by **J.F.** » Sun May 01, 2005 3:59 am

If Sony has a patent on the vag format, you won't be able to use it without a license, period. This is very much like the S3 texture compression format which S3 got patented. Other video board companies had to either leave it out and not be MS certified (as S3 bribed MS into making S3 compression part of DX6), or pay a license fee to S3. S3 also went after anyone making software which handled importing or exporting S3 compression textures, even if they were free.

I don't see Sony as being that harsh, but if they have a patent, it's within their rights. I don't think they do or you would see patent notices when they talk about vag, so I think you're okay.

Post by **pixel** » Sun May 01, 2005 4:36 am

It's not using the "vag" format specifically. VAG is to ADPCM what's TGA is to RGBA. What I am saying to lkz is to use a different format. What's inside is ADPCM, nothing more.