vgmstream/src/meta/psx_cdxa.c

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

/* Sony PSX CD-XA */
/* No looped file ! */

static off_t init_xa_channel(int *channel,STREAMFILE *streamFile);

static uint8_t AUDIO_CODING_GET_STEREO(uint8_t value) {
	return (uint8_t)(value & 3);
}

static uint8_t AUDIO_CODING_GET_FREQ(uint8_t value) {
	return (uint8_t)((value >> 2) & 3);
}

VGMSTREAM * init_vgmstream_cdxa(STREAMFILE *streamFile) {
    VGMSTREAM * vgmstream = NULL;
    char filename[PATH_LIMIT];

	int channel_count;
	int headerless=0;
	int xa_channel=0;
	uint8_t bCoding;
	off_t start_offset;

    int i;

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

    /* check RIFF Header */
    if (!((read_32bitBE(0x00,streamFile) == 0x52494646) && 
	      (read_32bitBE(0x08,streamFile) == 0x43445841) && 
		  (read_32bitBE(0x0C,streamFile) == 0x666D7420)))
        headerless=1;

    /* don't misdetect Reflections' XA ("XA30" / "04SW") */
    if (read_32bitBE(0x00,streamFile) == 0x58413330 || read_32bitBE(0x00,streamFile) == 0x30345357) goto fail;
    /* don't misdetect Maxis XA ("XAI\0" / "XAJ\0") */
    if (read_32bitBE(0x00,streamFile) == 0x58414900 || read_32bitBE(0x00,streamFile) == 0x58414A00) goto fail;

	/* First init to have the correct info of the channel */
	if (!headerless) {
		start_offset=init_xa_channel(&xa_channel,streamFile);

		/* No sound ? */
		if(start_offset==0)
			goto fail;

		bCoding = read_8bit(start_offset-5,streamFile);

		switch (AUDIO_CODING_GET_STEREO(bCoding)) {
			case 0: channel_count = 1; break;
			case 1: channel_count = 2; break;
			default: channel_count = 0; break;
		}

		/* build the VGMSTREAM */
		vgmstream = allocate_vgmstream(channel_count,0);
		if (!vgmstream) goto fail;

		/* fill in the vital statistics */
		vgmstream->channels = channel_count;
		vgmstream->xa_channel = xa_channel;

		switch (AUDIO_CODING_GET_FREQ(bCoding)) {
			case 0: vgmstream->sample_rate = 37800; break;
			case 1: vgmstream->sample_rate = 18900; break;
			default: vgmstream->sample_rate = 0; break;
		}

		/* Check for Compression Scheme */
		vgmstream->num_samples = (int32_t)((((get_streamfile_size(streamFile) - 0x3C)/2352)*0x1F80)/(2*channel_count));
	} else 
	{
		channel_count=2;
		vgmstream = allocate_vgmstream(2,0);
		if (!vgmstream) goto fail;

		vgmstream->xa_headerless=1;
		vgmstream->sample_rate=44100;
		vgmstream->channels=2;
		vgmstream->num_samples = (int32_t)(((get_streamfile_size(streamFile)/ 0x80)*0xE0)/2);
		start_offset=0;
	}

	vgmstream->coding_type = coding_XA;
    vgmstream->layout_type = layout_xa_blocked;
    vgmstream->meta_type = meta_PSX_XA;

	/* open the file for reading by each channel */
    {
        STREAMFILE *chstreamfile;
        chstreamfile = streamFile->open(streamFile,filename,2352);

        if (!chstreamfile) goto fail;

        for (i=0;i<channel_count;i++) {
            vgmstream->ch[i].streamfile = chstreamfile;
        }
    }
	
	xa_block_update(start_offset,vgmstream);

	return vgmstream;

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

off_t init_xa_channel(int* channel,STREAMFILE* streamFile) {
	
	off_t block_offset=0x44;
	size_t filelength=get_streamfile_size(streamFile);

	int8_t currentChannel;

	// 0 can't be a correct value
	if(block_offset>=(off_t)filelength)
		return 0;

	currentChannel=read_8bit(block_offset-7,streamFile);
	//subAudio=read_8bit(block_offset-6,streamFile);
	*channel=currentChannel;
	//if (!((currentChannel==channel) && (subAudio==0x64))) {
	//	block_offset+=2352;
	//	goto begin;
	//}
	return block_offset;
}