#136088 - sanguine - Sun Jul 29, 2007 12:22 am
The play yan has a pile of free downloadable games for it on the ninty site,( http://www.nintendo.co.jp/n08/playan/garage/ )
I've looked a little into them and they are in *.ASF format (advanced
systems format created by microsoft) They play in windows media player
with a download of the sharp G.726 codec, but there is no interaction
just video and music, I assume the play yan has a built in ASF player
with added features enabling play of these games
The files include similar 'headers'
including the name of the file and format details, and the codec name.
an example of which is here
( F I R E _ 0 0 0 . A S F @R?1??? ??H?? AR?1??? ??H? I S O M P E G - 4 MP4S G . 7 2 6 3 2 k b / s , 8 k H z , M o n o
are there any projects for the ds which could be easily adapted to support ASF? even similar playback achieved from windows media player would be a start,
Ideally my thoughts led me to hope that these could be played on another flash cartridge(slot 1 or 2) other than the play yan, and since the games are available free
I should assume there would be no problem with that.
Thanks for reading
Robert
#136176 - Dood77 - Sun Jul 29, 2007 10:03 pm
Hm, interesting. I'm guessing these would be some kind of point and click adventure...?
I read a little on ASF, and wikipedia says its a media container format; it doesn't use one specific audio/video codec, rather it can use technically any codec.
The G.726 codec, wikipedia says, is an ADPCM speech codec. (Which makes sense, seeing how the DS/GBA natively do some forms of ADPCM) So I'm guessing, from the header, that the MPEG-4 codec is used in these 'games' for video. Seeing as how the Play-Yan runs on the GBA, why is it so difficult for us to do lesser codecs on the DS? Does the Play-Yan have some kind of a decoder chip in it?
Also, an interesting claim from the DS's Wikipedia article, after mentioning that the Play-Yan runs in GBA mode:
| Wikipedia wrote: |
| It also means that the device cannot utilize the enhanced power of the DS compared to its predecessors, so video playback is not as robust as it could otherwise be. |
Of course the video would benefit from a larger screen, etc., but seeing as though there has got to be an extra processor or decoder in that thing, I don't think the DS's processors would really do that much.
And feasibility on getting this on DS, let alone emulated on the PC, is probably pretty unlikely. It would most likely require a lot of reverse engineering of the Play-Yan's firmware, and all of it to play a dozen or so minigames.
_________________
If I use a term wrong or something then feel free to correct, I?m not much of a programmer.
Original DS Phat obtained on day of release + flashme v7
Supercard: miniSD, Kingston 1GB, Kingston 2GB
Ralink chipset PCI NIC
#136207 - M3d10n - Mon Jul 30, 2007 2:45 am
I'm pretty sure the Play-Yan has a MPEG4 decoder chip on it. It can even bypass the GBA audio hardware entirely, featuring its own headphone jack that outputs 44KHz sound.
#136210 - calcprogrammer1 - Mon Jul 30, 2007 3:08 am
I downloaded one of them, and opened it, but all it did was show a splash screen...is it supposed to do anything else?
As for the Play-Yan, I'm sure it has some sort of decoder chip. It's supposed to get way better performance at audio/video than the GBAMP, and the GBAMP is done in all software, and it doesn't compress videos or audio and they are still incredibly choppy and low quality, there's no way the ARM7-15MHz that the GBA has can pull off MPEG-4 and MP3 at anywhere reasonable quality, and the Play-Yan has a built in headphone port so I assume it has an audio decoder too.
_________________
DS Firmware 1, Datel Games n' Music card / Chism's FW hacked GBA MP v2 CF
There's no place like 127.0.0.1.
#137241 - sanguine - Thu Aug 09, 2007 10:16 am
Yes the play yan has its own decoder chip,
and all you should see is a splash screen and some audio when attempting
to run the file in media player,
So im assuming that as the asf file is a container format, somewhere in this code is going to be the code that tells the play yan what to do to play this game,
I own a play yan and have a hardware dump of my own cartridge,
I've run this through Interactive disassembler, and there are strings in the hardware dump the dump these strings list all of the play yan games available.
Unfortunately for reverse engineering skills thats about my lot.
however I understand from what I know that If I kept poking around in this I would possibly find the code that handles the ASF files.
keep going or stop while im sane?
Rob