AT3 replay via Audiocodec.prx on 1.5

hitchhikr · Post by **hitchhikr** » Mon Aug 28, 2006 6:16 pm

Here is the at3 replay (while waiting for the mp3 one), hopefully it'll work correctly on any other psp than mine this time ;D:

http://perso.orange.fr/franck.charlet/t ... Replay.zip

Any report welcome.

mbf · Post by **mbf** » Mon Aug 28, 2006 6:53 pm

woops: "Error 403 - Access forbidden by rule."

Looks like you forgot to change the permissions on the file ;)

hitchhikr · Post by **hitchhikr** » Mon Aug 28, 2006 6:57 pm

No problems to download it from here. The public read flag is set as usual.

AnonymousTipster · Post by **AnonymousTipster** » Mon Aug 28, 2006 7:10 pm

Works fine on my 1.5 PSP.

I was just looking for some At3 playback code, and this looks perfect, thanks.

hitchhikr · Post by **hitchhikr** » Mon Aug 28, 2006 8:10 pm

I forgot to include the prototypes for the audiocodec in the archive:

http://perso.orange.fr/franck.charlet/t ... oCodec.zip

Blackrider · Post by **Blackrider** » Wed Aug 30, 2006 10:58 am

What are the advanatages with using this method to play at3 files compared to the other one?

hitchhikr · Post by **hitchhikr** » Wed Aug 30, 2006 1:20 pm

- It takes less user memory (no need to load the atrac3plus.prx).
- When i'll know how to fill the structure accordingly, it'll be able to replay mp3 files on the media engine aswell (at3 only so far).

hitchhikr · Post by **hitchhikr** » Wed Aug 30, 2006 1:31 pm

Also it doesn't require any own made external prx.

Cpasjuste · Post by **Cpasjuste** » Wed Aug 30, 2006 10:17 pm

Hello.
I have a question that could be stupid since i'm a crapy coder but i would like to ask you why it would be better to use this directly in my code instead of using it as a prx module.
Also is there a reason why its named replayer and not player ? (of course yes:p)

hitchhikr · Post by **hitchhikr** » Thu Aug 31, 2006 8:02 am

I have a question that could be stupid since i'm a crapy coder but i would like to ask you why it would be better to use this directly in my code instead of using it as a prx module.

It'll take slightly less user memory but more important if you want to use a non encrypted module you'll have to patch the kernel and of all the patches provided in the sdk only pspSdkInstallNoDeviceCheckPatch() (the only one i'm using here) is working on higher firmwares versions, all others just crash which is unfortunate because you'd probably need pspSdkInstallNoPlainModuleCheckPatch() to be able to run your own prx.

Also is there a reason why its named replayer and not player ? (of course yes:p)

Nope, no particular reason.

kz · Post by kz » Sun Sep 03, 2006 6:40 am

great work on this...

just a note to anyone who plans on using the stubs in AT3.c to do playback in another app... the AT3_Datas_Start (hardcoded to 0x48 at the top for the sample .at3 file included in the distribution) changes depending on the specifics of the RIFF header of the file.

The easiest way to find the byte offset count to store in AT3_Datas_Start is to look for the 'data' tag in the RIFF header, go another four bytes after the tag, and that's the start of the actual data.

/Andrew

hitchhikr · Post by **hitchhikr** » Sun Sep 03, 2006 2:59 pm

You're right but i haven't seen an at3 file with a different structure yet, so i took the short way, you could aswell parse the various headers until the data one is found (they have a id / length format like all riff files).

kz · Post by kz » Sun Sep 03, 2006 11:35 pm

hitchhikr wrote:You're right but i haven't seen an at3 file with a different structure yet, so i took the short way, you could aswell parse the various headers until the data one is found (they have a id / length format like all riff files).

I generated about 30 AT3 files with EAC PSP Edition, and almost all of them had offsets of 0x48, but I've seen a few with 0x44... turns out, that was the problem with the first file I was testing with and I spent a lot of time trying to figure out what was wrong. :)

/Andrew

hitchhikr · Post by **hitchhikr** » Mon Sep 04, 2006 12:49 am

Oki, i've updated the archive, the at3.c should now retrieve the correct datas position from the file, tell me if it works or not.