jedi-academy/code/mp3code/mp3struct.h

// Filename:	mp3struct.h
//
// this file is my struct to gather all loose MP3 global vars into one struct so we can do multiple-stream decompression
//

#ifndef MP3STRUCT_H
#define MP3STRUCT_H

#pragma warning (disable : 4201 )	// nonstandard extension used : nameless struct/union

#include "small_header.h"	// for SAMPLE and IN_OUT

typedef void (*SBT_FUNCTION) (float *sample, short *pcm, int n);
typedef void (*XFORM_FUNCTION) (void *pcm, int igr);
typedef IN_OUT(*DECODE_FUNCTION) (unsigned char *bs, unsigned char *pcm);

typedef struct
{
	union
	{
		struct
		{
			SBT_FUNCTION sbt;	

			float	cs_factor[3][64];	// 768 bytes

			int		nbat[4];
			int		bat[4][16];
			int		max_sb;		
			int		stereo_sb;
			int		bit_skip;

			float*	cs_factorL1;
			int		nbatL1;

		};//L1_2;

		struct 
		{
			SBT_FUNCTION sbt_L3;
			XFORM_FUNCTION Xform;
			DECODE_FUNCTION decode_function;

			SAMPLE	sample[2][2][576];		// if this isn't kept per stream then the decode breaks up

		// the 4k version of these 2 seems to work for everything, but I'm reverting to original 8k for safety jic.
		//
		#define NBUF (8*1024)
		#define BUF_TRIGGER (NBUF-1500)
//		#define NBUF (4096)	// 2048 works for all except 133+ kbps VBR files, 4096 copes with these
//		#define BUF_TRIGGER ((NBUF/4)*3)

			unsigned char buf[NBUF];
			int		buf_ptr0;
			int		buf_ptr1;
			int		main_pos_bit;


			int		band_limit_nsb;
			int			nBand[2][22];		/* [long/short][cb] */
			int			sfBandIndex[2][22];		/* [long/short][cb] */
			int			half_outbytes;
			int			crcbytes;
			int			nchan;
			int			ms_mode;
			int			is_mode;
			unsigned int zero_level_pcm;
			int			mpeg25_flag;
			int			band_limit;
			int			band_limit21;
			int			band_limit12;
			int			gain_adjust;
			int			ncbl_mixed;
		};//L3;
	};
	// from csbt.c...
	//
	// if this isn't kept per stream then the decode breaks up
	signed int	vb_ptr;			// 
	signed int	vb2_ptr;		// 
	float		vbuf[512];		//
	float		vbuf2[512];		// this can be lost if we stick to mono samples

	// L3 only...
	//
	int			sr_index;	// L3 only (99%)
	int			id;

	// any type...
	//
	int			outvalues;
	int			outbytes;
	int			framebytes;
	int			pad;
	int			nsb_limit;	

	// stuff added now that the game uses streaming MP3s...
	//
	byte		*pbSourceData;			// a useful dup ptr only, this whole struct will be owned by an sfx_t struct that has the actual data ptr field
	int			iSourceBytesRemaining;
	int			iSourceReadIndex;
	int			iSourceFrameBytes;
#ifdef _DEBUG
	int			iSourceFrameCounter;	// not really important
#endif
	int			iBytesDecodedTotal;
	int			iBytesDecodedThisPacket;// not sure how useful this will be, it's only per-frame, so will always be full frame size (eg 2304 or below for mono) except possibly for the last frame?

	int			iRewind_FinalReductionCode;
	int			iRewind_FinalConvertCode;
	int			iRewind_SourceBytesRemaining;
	int			iRewind_SourceReadIndex;
	byte		bDecodeBuffer[2304*2];	// *2 to allow for stereo now
	int			iCopyOffset;			// used for painting to DMA-feeder, since 2304 won't match the size it wants

	// some new stuff added for dynamic music, to allow "how many seconds left to play" queries...
	//
	// ( m_lengthInSeconds = ((iUnpackedDataLength / iRate) / iChannels) / iWidth; )
	//
	// Note that these fields are only valid/initialised if MP3Stream_InitPlayingTimeFields() was called.
	//	If not, this->iTimeQuery_UnpackedLength will be zero.
	//
	int			iTimeQuery_UnpackedLength;	
	int			iTimeQuery_SampleRate;
	int			iTimeQuery_Channels;
	int			iTimeQuery_Width;

} MP3STREAM, *LP_MP3STREAM;

#define MP3STUFF_KNOWN

extern LP_MP3STREAM pMP3Stream;
extern int bFastEstimateOnly;

#pragma warning (default : 4201 )	// nonstandard extension used : nameless struct/union
#pragma warning (disable : 4711 )	// function 'xxxx' selected for automatic inline expansion

#endif	// #ifndef MP3STRUCT_H

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