Figure 5.1 Example scenario for branch playback
#define BSTM_MAX 3 /* Total number of branch streams
(BSTM1.MPG, BSTM2.MPG, BSTM3.MPG) */
#define BRANCH_MAX 2 /* Total number of branches (number of arrows in Figure 5.1) */
#define KEY_MAX 2 /* Total number of stream key types */
#define A_BTN 0 /* A button branch number */
#define B_BTN 1 /* B button branch number */
#define BR_NUM 2 /* Number of branches per stream */
#define BSTM1_ID 0 /* BSTM1.MPG branch stream identifier */
#define BSTM2_ID 1 /* BSTM2.MPG branch stream identifier */
#define BSTM3_ID 2 /* Branch stream identifier of BSTM3.MPG */
/* Branch playback library work area */
Sint32 work_bpl[BPL_WORK_SIZE(BSTM_MAX, BRANCH_MAX, KEY_MAX)/sizeof(Sint32)];
void setScenario(void)
{
StmKey key[KEY_MAX]; /* Area for setting stream key */
Sint32 brtbl[BR_NUM]; /* Area for setting branch destination */
Sint32 fid; /* File identifier */
/* Initialize branch playback */
BPL_Init(BSTM_MAX, BRANCH_MAX, KEY_MAX, work_bpl);
/* Setting branch stream information */
STM_KEY_CN(key + 0) = STM_KEY_CIMSK(key + 0) = STM_KEY_NONE;
STM_KEY_CN(key + 1) = STM_KEY_CIMSK(key + 1) = STM_KEY_NONE;
STM_KEY_SMMSK(key + 0) = STM_KEY_SMVAL(key + 0) = STM_SM_VIDEO;
STM_KEY_SMMSK(key + 1) = STM_KEY_SMVAL(key + 1) = STM_SM_AUDIO;
fid = GFS_NameToId("BSTM1.MPG");
BPL_SetStmInfo(BSTM1_ID, fid, KEY_MAX, key);
fid = GFS_NameToId("BSTM2.MPG");
BPL_SetStmInfo(BSTM2_ID, fid, KEY_MAX, key);
fid = GFS_NameToId("BSTM3.MPG");
BPL_SetStmInfo(BSTM3_ID, fid, KEY_MAX, key);
/* Setting branch destination information */
brtbl[A_BTN] = BSTM2_ID; /* Branch to BSTM2.MPG when A button is pressed */
brtbl[B_BTN] = BSTM3_ID; /* Branch to BSTM3.MPG when B button is pressed */
BPL_SetBranchInfo(BSTM1_ID, BR_NUM, brtbl); /* Setting the branch destination of BSTM1.MPG */
}
Sint32 work_gfs[GFS_WORK_SIZE(BSTM_MAX*KEY_MAX)/sizeof(Sint32)];
Sint32 work_stm[STM_WORK_SIZE(GRP_MAX, BSTM_MAX*KEY_MAX)/sizeof(Sint32)];
Sint32 brno; /* branch number */
StmHn stmtbl[KEY_MAX]; /* Table of stream handles */
Sint32 bpl_stat; /* Branch playback status */
Sint32 decode_stat; /* Decoder operating status */
DecodeHn dc_hn = NULL; /* Decoder handle */
Bool chgsw = OFF; /* Branch execution switch */
Bool endflag = FALSE;
Sint32 ret;
/* Initialize each library */
GFS_Init(...); /* Initialize the file system */
STM_Init(...); /* Initialize the stream system */
initDecoder(); /* Initialize the decoder */
setScenario(); /* Set scenario (see 5.1) */
/* Branch playback */
BPL_SetStart(BSTM1_ID); /* Specify playback start stream */
BPL_GetCurStm(KEY_MAX, stmtbl); /* Get first branch stream */
dc_hn = createDecodeHn(stmtbl); /* Create decoder handle */
while (endflag == FALSE) {
bpl_stat = BPL_ExecServer(chgsw); /* Execute branch playback server */
chgsw = OFF;
STM_ExecServer(); /* Execute stream server */
decode_stat = execDecoder(dc_hn); /* Execute decoder server function */
switch (bpl_stat) {
case BPL_SVR_COMPLETED: /* Branch playback completion status */
endflag = TRUE;
break;
case BPL_SVR_WAITSEL: /* Waiting for branch destination selection */
/* Get pad input (0: A button, 1: B button, if negative: no input */
brno = getPadEvent();
if (brno >= 0) {
BPL_SelectBranch(brno); /* Select branch destination */
}
break;
case BPL_SVR_SELECT: /* Branch destination determination state */
case BPL_SVR_NOBRN: /* No branch destination */
if (decode_stat != COMPLETED) { /* Check for decoding completion */
break;
}
chgsw = ON; /* Branch execution switch ON */
ret = BPL_GetNextStm(KEY_MAX, stmtbl); /* Get branch destination stream */
if (ret >= 0) { /* If there is a branch destination */
destroyDecodeHn(dc_hn); /* Erase the decoder handle */
dc_hn = createDecodeHn(stmtbl); /* Create decoder handle */
}
break;
}
}
destroyDecodeHn(dc_hn); /* Erase the decoder handle */