5. Basic program

5.1 Scenario processing

Figure 5.1 shows an example of a branch playback scenario.

Figure 5.1 Example of branch playback scenario

A button is pressed during playback of BSTM1.MPG → After playing BSTM1.MPG, BSTM2.MPG is played.

The B button is pressed during BSTM1.MPG playback → After BSTM1.MPG is played, BSTM3.MPG is played.

The following is an example program that sets this scenario.

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#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 Fig. 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 / * BSTM3.MPG branch stream identifier * /



/ * 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 the branch destination * /

    Sint32 fid; / * File identifier * /



    / * Initialization of branch playback * /

    BPL_Init (BSTM_MAX, BRANCH_MAX, KEY_MAX, work_bpl);



    / * Branch stream information setting * /

    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 the B button is pressed * /

    BPL_SetBranchInfo (BSTM1_ID, BR_NUM, brtbl); / * BSTM1.MPG branch destination setting * /

}

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5.2 Branch playback processing

An example of a branch playback program is shown below. ( See 5.1 for the scenario)

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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]; / * Stream handle table * /

Sint32 bpl_stat; / * Branch playback state * /

Sint32 decode_stat; / * Decoder operating status * /

DecodeHn dc_hn = NULL; / * Decoder handle * /

Bool chgsw = OFF; / * Branch execution switch * /

Bool endflag = FALSE;

Sint32 ret;



/ * Initialization of each library * /

GFS_Init (...); / * File system initialization * /

STM_Init (...); / * Stream system initialization * /

initDecoder (); / * Decoder initialization * /

setScenario (); / * Scenario settings (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); / * Run branch playback server * /

    chgsw = OFF;

    STM_ExecServer (); / * Run stream server * /

    decode_stat = execDecoder (dc_hn); / * Execution of decoder server function * /



    switch (bpl_stat) {

    case BPL_SVR_COMPLETED: / * Branch playback end state * /

        endflag = TRUE;

        break;

    case BPL_SVR_WAITSEL: / * Waiting for branch destination selection * /

        / * Get pad input (0: A button, 1: B button, negative: no input * /

        brno = getPadEvent ();

        if (brno> = 0) {

            BPL_SelectBranch (brno); / * Select branch destination * /

        }

        break;

    case BPL_SVR_SELECT: / * Branch destination decision state * /

    case BPL_SVR_NOBRN: / * No branch destination * /

        if (decode_stat! = COMPLETED) {/ * Check decoding completion * /

            break;

        }

        chgsw = ON; / * Branch execution switch ON * /

        ret = BPL_GetNextStm (KEY_MAX, stmtbl); / * Get the branch destination stream * /

        if (ret> = 0) {/ * If there is a branch destination * /

            destroyDecodeHn (dc_hn); / * Erase the handle of the decoder * /

            dc_hn = createDecodeHn (stmtbl); / * Create decoder handle * /

        }

        break;

    }

}

destroyDecodeHn (dc_hn); / * Erase the handle of the decoder * /

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Streams are opened / closed automatically by the branch playback library using the stream system. For the decoder, refer to the manual of each library.