vgmstream/src/meta/dc_str.c

#include "meta.h"
#include "../coding/coding.h"
#include "../util.h"

VGMSTREAM * init_vgmstream_dc_str(STREAMFILE *streamFile) {
    VGMSTREAM * vgmstream = NULL;
    char filename[260];
    off_t start_offset;
    int loop_flag = 0;
    int channel_count;
    int samples;
    int i;

    /* check extension, case insensitive */
    streamFile->get_name(streamFile,filename,sizeof(filename));
    if (strcasecmp("str",filename_extension(filename))) goto fail;

    /* check header */
    if (read_32bitBE(0xD5,streamFile) != 0x53656761) /* "Sega" */
        goto fail;

    loop_flag = (read_32bitLE(0x00,streamFile)!=0x00000000);
    samples=read_32bitLE(0x08,streamFile);
    channel_count = 2;

    vgmstream = allocate_vgmstream(channel_count,loop_flag);
    if (!vgmstream) goto fail;


    /* fill in the vital statistics */
    switch (read_32bitLE(0x00,streamFile)) {
        case 1:
            channel_count = 2;
            break;
        case 2:
            channel_count = 2;
            break;
        case 3:
            channel_count = 6;
            break;
        default:
    goto fail;
    }

    switch (samples) {
        case 4:
            vgmstream->coding_type = coding_AICA;
            vgmstream->num_samples = read_32bitLE(0x14,streamFile);
        if (loop_flag) {
            vgmstream->loop_start_sample = 0;
            vgmstream->loop_end_sample = read_32bitLE(0x14,streamFile);
        }
            break;
        case 16:
            vgmstream->coding_type = coding_PCM16LE;
            vgmstream->num_samples = read_32bitLE(0x14,streamFile)/2/channel_count;
        if (loop_flag) {
            vgmstream->loop_start_sample = 0;
            vgmstream->loop_end_sample = read_32bitLE(0x14,streamFile)/2/channel_count;
        }
            break;
        default:
    goto fail;
}
    vgmstream->layout_type = layout_interleave;
    vgmstream->interleave_block_size = read_32bitLE(0x0C,streamFile);
    vgmstream->channels = channel_count;
    start_offset = 0x800;
    vgmstream->sample_rate = read_32bitLE(0x04,streamFile);
    vgmstream->meta_type = meta_DC_STR;
    
    /* open the file for reading */
    {
        int i;
        STREAMFILE * file;
        file = streamFile->open(streamFile,filename,STREAMFILE_DEFAULT_BUFFER_SIZE);
        if (!file) goto fail;
        for (i=0;i<channel_count;i++) {
            vgmstream->ch[i].streamfile = file;

			vgmstream->ch[i].channel_start_offset=
                vgmstream->ch[i].offset=start_offset+
                vgmstream->interleave_block_size*i;

        }
    }

    return vgmstream;

    /* clean up anything we may have opened */
fail:
    if (vgmstream) close_vgmstream(vgmstream);
    return NULL;
}