SEGA SATURN DEVELOPER'S MANUAL

(6) ADPCM compatible

Link the ADPCM decompression library SEGA_ADP.LIB.
Call the ADPCM usage declaration PCM_DeclareUseAdpcm after the
initialization function.

◆ Playback of specified ADPCM format

You can play in exactly the same procedure (same program) as AIFF format. However, please note that the CPU load is higher than in AIFF format.

◆ CD-ROM XA Audio format playback

The library determines the playback frequency and the number of channels (stereo / mono) from the coding information in the subheader area. Make sure it is written correctly.
The
stream key is set by the library user.
Make the ring buffer an integral multiple of the sector size 2324 bytes.
Set playback information with
PCM_SetInfo.
CD_ROM XA Audio playback can only be used in stream playback mode.
Please refer to the sample program smppcm5.c.

(7) How to use the function

Be sure to call PCM_Init at the beginning of the program.
Be sure to call PCM_VblIn within a
V blank IN interrupt.
PCM_Start can only be executed once for a handle.
If you want to play the same file over and over again, create a handle each time.
Call
PCM_SetLoadNum, PCM_SetPcmCmdBlockNo, and PCM_SetPcmStreamNo before starting playback.
Be sure to use PCM_NotifyWriteSize for the handle created by PCM_CreateMemHandle to notify the data supply amount to the ring buffer.
When using the pause function, it is necessary to specify the work for pause processing in advance with PCM_SetPauseWork. This work need not be prepared for each handle.
Since this work is a work area that is temporarily used in the pause-on process, you can reserve the area immediately before the pause-on process and release the area immediately after.
Data transfer method from CD block to ring buffer By default, data is transferred by CPU DMA.
PCM_SetTrModeCd can be used to specify program transfer, CPU DMA, or SCU DMA.
Call PCM_SetTrModeCd before calling the task function for the first time after creating the handle.
When playing CD-ROM XA Audio, be sure to set the playback information with PCM_SetInfo.