MVD Services
This is for using the MVD hardware video decoder(unknown whether MVD can do more than decoding). The New_3DS Internet Browser uses mvd:STD for video decoding.
See here for the supported hardware decoder video codecs. Going by strings in the browser, the hw decoder seems to also support MJPEG.
A maximum of 4 sessions can be opened at a time, for all of these services combined.
MVD Service "mvd:STD"
| Command Header | Available since system version | Description |
|---|---|---|
| 0x00010082 | Initialize | |
| 0x00020000 | Shutdown | |
| 0x00030300 | CalculateVideoOutBufSize | |
| 0x00050100 | (u8 unk0, u8 unk1, u8 unk2, u8 unk3) SKATER uses value 0 for all of these params. | |
| 0x00070000 | ||
| 0x00080142 | DecodeFrame | |
| 0x00090042 | (u8 unkval, val0, kprocess handle) This writes some state beginning at cmdreply[2]. unkval is normally 0, when preparing to shutdown MVD unkval is 1. | |
| 0x000A0000 | ||
| 0x00180000 | ||
| 0x00190000 | ||
| 0x001A0000 | Used when doing MJPEG decoding? | |
| 0x001B0040 | (u8 unknown) SKATER uses value 1 for this. | |
| 0x001C0000 | ||
| 0x001D0042 | GetConfig | |
| 0x001E0044 | SetConfig |
This one uses the I/O mapped @ 0x10207000.
This service is used by the New_3DS Internet Browser.
Initialization procedures:
- MJPEG: Use command MVDSTD:Initialize with bufsize=1, then command 0x00180000.
- H.264: If needed, use MVDSTD:CalculateVideoOutBufSize. Then use MVDSTD:Initialize. Then use commands 0x00050100, 0x00180000, and 0x001B0040. Then use MVDSTD:DecodeFrame 3 times with unknown input data. Use command 0x000A0000, then use MVDSTD:DecodeFrame with unknown data.
Shutdown procedures:
- MJPEG: just use command 0x00190000, then MVDSTD:Shutdown.
- H.264: Use command 0x00090042 in a loop, waiting for it to return a retval that isn't 0x00017002. Then use commands 0x001C0000, 0x00190000, and 0x00070000. Then use MVDSTD:Shutdown.
MVD Service "l2b:u"
This one uses the I/O mapped @ 0x10130000.
MVD Service "l2b2:u"
This uses the same command-handler as "l2b:u".
MVD Service "y2r2:u"
This one uses the I/O mapped @ 0x10102000.