mpeglayer3.cc

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/* MPEG/WAVE Sound library

   (C) 1997 by Jung woo-jae */

// Mpeglayer3.cc
// It's for MPEG Layer 3
// I've made array of superior functions for speed.
// Extend TO_FOUR_THIRDS to negative.
// Bug fix : maplay 1.2+ have wrong TO_FOUR_THIRDS ranges.
// Force to mono!!
// MPEG-2 is implemented
// Speed up in fixstereo (maybe buggy) 
//
// Fixed point support by Nicolas Pitre <[e-mail]>

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <math.h>
#include <stdlib.h>

#include "mpegsound.h"
#include "mpegsound_locals.h"

inline void
Mpegbitwindow::wrap(void)
{
    int p = bitindex >> 3;
    point &= (WINDOWSIZE - 1);

    if (p >= point) {
	for (register int i = 4; i < point; i++)
	    buffer[WINDOWSIZE + i] = buffer[i];
    }
    *((int *) (buffer + WINDOWSIZE)) = *((int *) buffer);
}

inline int
Mpegbitwindow::getbit(void)
{
//  register int r=(buffer[(bitindex>>3)&(WINDOWSIZE-1)]>>(7-(bitindex&7)))&1;
    register int r = (buffer[bitindex >> 3] >> (7 - (bitindex & 7))) & 1;
    bitindex++;
    return r;
};

inline int
Mpegbitwindow::getbits9(int bits)
{
    register unsigned short a;

#ifndef WORDS_BIGENDIAN
    {
	//    int offset=(bitindex>>3)&(WINDOWSIZE-1);
	int offset = bitindex >> 3;

	a = (((unsigned char) buffer[offset]) << 8) | ((unsigned char)
						       buffer[offset + 1]);
    }
#else
    //  a=((unsigned short *)(buffer+((bixindex>>3)&(WINDOWSIZE-1))));
    a = ((unsigned short *) (buffer + ((bixindex >> 3))));
#endif

    a <<= (bitindex & 7);
    bitindex += bits;
    return (int) ((unsigned int) (a >> (16 - bits)));
}

inline int
Mpegtoraw::wgetbit(void)
{
    return bitwindow.getbit();
}
inline int
Mpegtoraw::wgetbits9(int bits)
{
    return bitwindow.getbits9(bits);
}
inline int
Mpegtoraw::wgetbits(int bits)
{
    return bitwindow.getbits(bits);
}

#define MUL3(a) (((a)<<1)+(a))

#define REAL0 0

#define ARRAYSIZE (SBLIMIT*SSLIMIT)
#define REALSIZE (sizeof(REAL))

#ifdef NATIVE_ASSEMBLY
inline void
long_memset(void *s, unsigned int c, int count)
{
    __asm__ __volatile__("cld\n\t" "rep ; stosl\n\t":	/* no output */
			 :"a"(c), "c"(count / 4), "D"((long) s)
			 :"cx", "di", "memory");
}
#endif

#define FOURTHIRDSTABLENUMBER (1<<13)

#define TO_FOUR_THIRDS(x) \
	(((x) >= 0) ?  TO_FOUR_THIRDSTABLE[(x)] \
		    : -TO_FOUR_THIRDSTABLE[-(x)])

typedef struct
{
    REAL l, r;
}
RATIOS;

#include "mpeglayer3tables.h"


void
Mpegtoraw::layer3initialize(void)
{
    layer3framestart = 0;
    currentprevblock = 0;

    {
	int i, j, k, l;

	for (l = 0; l < 2; l++)
	    for (i = 0; i < 2; i++)
		for (j = 0; j < SBLIMIT; j++)
		    for (k = 0; k < SSLIMIT; k++)
			prevblck[l][i][j][k] = 0.0f;
    }

    bitwindow.initialize();
}

bool
Mpegtoraw::layer3getsideinfo(void)
{
    sideinfo.main_data_begin = getbits(9);

    if (!inputstereo)
	sideinfo.private_bits = getbits(5);
    else
	sideinfo.private_bits = getbits(3);

    sideinfo.ch[LS].scfsi[0] = getbit();
    sideinfo.ch[LS].scfsi[1] = getbit();
    sideinfo.ch[LS].scfsi[2] = getbit();
    sideinfo.ch[LS].scfsi[3] = getbit();
    if (inputstereo) {
	sideinfo.ch[RS].scfsi[0] = getbit();
	sideinfo.ch[RS].scfsi[1] = getbit();
	sideinfo.ch[RS].scfsi[2] = getbit();
	sideinfo.ch[RS].scfsi[3] = getbit();
    }

    for (int gr = 0, ch; gr < 2; gr++)
	for (ch = 0;; ch++) {
	    layer3grinfo *gi = &(sideinfo.ch[ch].gr[gr]);

	    gi->part2_3_length = getbits(12);
	    gi->big_values = getbits(9);
	    gi->global_gain = getbits(8);
	    gi->scalefac_compress = getbits(4);
	    gi->window_switching_flag = getbit();
	    if (gi->window_switching_flag) {
		gi->block_type = getbits(2);
		gi->mixed_block_flag = getbit();

		gi->table_select[0] = getbits(5);
		gi->table_select[1] = getbits(5);

		gi->subblock_gain[0] = getbits(3);
		gi->subblock_gain[1] = getbits(3);
		gi->subblock_gain[2] = getbits(3);

		/* Set region_count parameters since they are implicit in this case. */
		if (gi->block_type == 0) {
		    /* printf("Side info bad: block_type == 0 in split block.\n");
		       exit(0); */
		    return false;
		} else if (gi->block_type == 2 && gi->mixed_block_flag == 0)
		    gi->region0_count = 8;	/* MI 9; */
		else
		    gi->region0_count = 7;	/* MI 8; */
		gi->region1_count = 20 - (gi->region0_count);
	    } else {
		gi->table_select[0] = getbits(5);
		gi->table_select[1] = getbits(5);
		gi->table_select[2] = getbits(5);
		gi->region0_count = getbits(4);
		gi->region1_count = getbits(3);
		gi->block_type = 0;
	    }
	    gi->preflag = getbit();
	    gi->scalefac_scale = getbit();
	    gi->count1table_select = getbit();

	    gi->generalflag = gi->window_switching_flag
		&& (gi->block_type == 2);

	    if (!inputstereo || ch)
		break;
	}

    return true;
}

bool
Mpegtoraw::layer3getsideinfo_2(void)
{
    sideinfo.main_data_begin = getbits(8);

    if (!inputstereo)
	sideinfo.private_bits = getbit();
    else
	sideinfo.private_bits = getbits(2);

    for (int ch = 0;; ch++) {
	layer3grinfo *gi = &(sideinfo.ch[ch].gr[0]);

	gi->part2_3_length = getbits(12);
	gi->big_values = getbits(9);
	gi->global_gain = getbits(8);
	gi->scalefac_compress = getbits(9);
	gi->window_switching_flag = getbit();
	if (gi->window_switching_flag) {
	    gi->block_type = getbits(2);
	    gi->mixed_block_flag = getbit();

	    gi->table_select[0] = getbits(5);
	    gi->table_select[1] = getbits(5);

	    gi->subblock_gain[0] = getbits(3);
	    gi->subblock_gain[1] = getbits(3);
	    gi->subblock_gain[2] = getbits(3);

	    /* Set region_count parameters since they are implicit in this case. */
	    if (gi->block_type == 0) {
		/* printf("Side info bad: block_type == 0 in split block.\n");
		   exit(0); */
		return false;
	    } else if (gi->block_type == 2 && gi->mixed_block_flag == 0)
		gi->region0_count = 8;	/* MI 9; */
	    else
		gi->region0_count = 7;	/* MI 8; */
	    gi->region1_count = 20 - (gi->region0_count);
	} else {
	    gi->table_select[0] = getbits(5);
	    gi->table_select[1] = getbits(5);
	    gi->table_select[2] = getbits(5);
	    gi->region0_count = getbits(4);
	    gi->region1_count = getbits(3);
	    gi->block_type = 0;
	}
	gi->scalefac_scale = getbit();
	gi->count1table_select = getbit();

	gi->generalflag = gi->window_switching_flag && (gi->block_type == 2);

	if (!inputstereo || ch)
	    break;
    }

    return true;
}

void
Mpegtoraw::layer3getscalefactors(int ch, int gr)
{
    static int slen[2][16] =
	{ {0, 0, 0, 0, 3, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4},
    {0, 1, 2, 3, 0, 1, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3}
    };

    layer3grinfo *gi = &(sideinfo.ch[ch].gr[gr]);
    register layer3scalefactor *sf = (&scalefactors[ch]);
    int l0, l1;

    {
	int scale_comp = gi->scalefac_compress;

	l0 = slen[0][scale_comp];
	l1 = slen[1][scale_comp];
    }
    if (gi->generalflag) {
	if (gi->mixed_block_flag) {	/* MIXED *//* NEW-ag 11/25 */
	    sf->l[0] = wgetbits9(l0);
	    sf->l[1] = wgetbits9(l0);
	    sf->l[2] = wgetbits9(l0);
	    sf->l[3] = wgetbits9(l0);
	    sf->l[4] = wgetbits9(l0);
	    sf->l[5] = wgetbits9(l0);
	    sf->l[6] = wgetbits9(l0);
	    sf->l[7] = wgetbits9(l0);

	    sf->s[0][3] = wgetbits9(l0);
	    sf->s[1][3] = wgetbits9(l0);
	    sf->s[2][3] = wgetbits9(l0);
	    sf->s[0][4] = wgetbits9(l0);
	    sf->s[1][4] = wgetbits9(l0);
	    sf->s[2][4] = wgetbits9(l0);
	    sf->s[0][5] = wgetbits9(l0);
	    sf->s[1][5] = wgetbits9(l0);
	    sf->s[2][5] = wgetbits9(l0);

	    sf->s[0][6] = wgetbits9(l1);
	    sf->s[1][6] = wgetbits9(l1);
	    sf->s[2][6] = wgetbits9(l1);
	    sf->s[0][7] = wgetbits9(l1);
	    sf->s[1][7] = wgetbits9(l1);
	    sf->s[2][7] = wgetbits9(l1);
	    sf->s[0][8] = wgetbits9(l1);
	    sf->s[1][8] = wgetbits9(l1);
	    sf->s[2][8] = wgetbits9(l1);
	    sf->s[0][9] = wgetbits9(l1);
	    sf->s[1][9] = wgetbits9(l1);
	    sf->s[2][9] = wgetbits9(l1);
	    sf->s[0][10] = wgetbits9(l1);
	    sf->s[1][10] = wgetbits9(l1);
	    sf->s[2][10] = wgetbits9(l1);
	    sf->s[0][11] = wgetbits9(l1);
	    sf->s[1][11] = wgetbits9(l1);
	    sf->s[2][11] = wgetbits9(l1);

	    sf->s[0][12] = sf->s[1][12] = sf->s[2][12] = 0;
	} else {		/* SHORT */
	    sf->s[0][0] = wgetbits9(l0);
	    sf->s[1][0] = wgetbits9(l0);
	    sf->s[2][0] = wgetbits9(l0);
	    sf->s[0][1] = wgetbits9(l0);
	    sf->s[1][1] = wgetbits9(l0);
	    sf->s[2][1] = wgetbits9(l0);
	    sf->s[0][2] = wgetbits9(l0);
	    sf->s[1][2] = wgetbits9(l0);
	    sf->s[2][2] = wgetbits9(l0);
	    sf->s[0][3] = wgetbits9(l0);
	    sf->s[1][3] = wgetbits9(l0);
	    sf->s[2][3] = wgetbits9(l0);
	    sf->s[0][4] = wgetbits9(l0);
	    sf->s[1][4] = wgetbits9(l0);
	    sf->s[2][4] = wgetbits9(l0);
	    sf->s[0][5] = wgetbits9(l0);
	    sf->s[1][5] = wgetbits9(l0);
	    sf->s[2][5] = wgetbits9(l0);

	    sf->s[0][6] = wgetbits9(l1);
	    sf->s[1][6] = wgetbits9(l1);
	    sf->s[2][6] = wgetbits9(l1);
	    sf->s[0][7] = wgetbits9(l1);
	    sf->s[1][7] = wgetbits9(l1);
	    sf->s[2][7] = wgetbits9(l1);
	    sf->s[0][8] = wgetbits9(l1);
	    sf->s[1][8] = wgetbits9(l1);
	    sf->s[2][8] = wgetbits9(l1);
	    sf->s[0][9] = wgetbits9(l1);
	    sf->s[1][9] = wgetbits9(l1);
	    sf->s[2][9] = wgetbits9(l1);
	    sf->s[0][10] = wgetbits9(l1);
	    sf->s[1][10] = wgetbits9(l1);
	    sf->s[2][10] = wgetbits9(l1);
	    sf->s[0][11] = wgetbits9(l1);
	    sf->s[1][11] = wgetbits9(l1);
	    sf->s[2][11] = wgetbits9(l1);

	    sf->s[0][12] = sf->s[1][12] = sf->s[2][12] = 0;
	}
    } else {			/* LONG types 0,1,3 */
	if (gr == 0) {
	    sf->l[0] = wgetbits9(l0);
	    sf->l[1] = wgetbits9(l0);
	    sf->l[2] = wgetbits9(l0);
	    sf->l[3] = wgetbits9(l0);
	    sf->l[4] = wgetbits9(l0);
	    sf->l[5] = wgetbits9(l0);
	    sf->l[6] = wgetbits9(l0);
	    sf->l[7] = wgetbits9(l0);
	    sf->l[8] = wgetbits9(l0);
	    sf->l[9] = wgetbits9(l0);
	    sf->l[10] = wgetbits9(l0);
	    sf->l[11] = wgetbits9(l1);
	    sf->l[12] = wgetbits9(l1);
	    sf->l[13] = wgetbits9(l1);
	    sf->l[14] = wgetbits9(l1);
	    sf->l[15] = wgetbits9(l1);
	    sf->l[16] = wgetbits9(l1);
	    sf->l[17] = wgetbits9(l1);
	    sf->l[18] = wgetbits9(l1);
	    sf->l[19] = wgetbits9(l1);
	    sf->l[20] = wgetbits9(l1);
	} else {
	    if (sideinfo.ch[ch].scfsi[0] == 0) {
		sf->l[0] = wgetbits9(l0);
		sf->l[1] = wgetbits9(l0);
		sf->l[2] = wgetbits9(l0);
		sf->l[3] = wgetbits9(l0);
		sf->l[4] = wgetbits9(l0);
		sf->l[5] = wgetbits9(l0);
	    }
	    if (sideinfo.ch[ch].scfsi[1] == 0) {
		sf->l[6] = wgetbits9(l0);
		sf->l[7] = wgetbits9(l0);
		sf->l[8] = wgetbits9(l0);
		sf->l[9] = wgetbits9(l0);
		sf->l[10] = wgetbits9(l0);
	    }
	    if (sideinfo.ch[ch].scfsi[2] == 0) {
		sf->l[11] = wgetbits9(l1);
		sf->l[12] = wgetbits9(l1);
		sf->l[13] = wgetbits9(l1);
		sf->l[14] = wgetbits9(l1);
		sf->l[15] = wgetbits9(l1);
	    }
	    if (sideinfo.ch[ch].scfsi[3] == 0) {
		sf->l[16] = wgetbits9(l1);
		sf->l[17] = wgetbits9(l1);
		sf->l[18] = wgetbits9(l1);
		sf->l[19] = wgetbits9(l1);
		sf->l[20] = wgetbits9(l1);
	    }
	}
	sf->l[21] = sf->l[22] = 0;
    }
}

void
Mpegtoraw::layer3getscalefactors_2(int ch)
{
    static int sfbblockindex[6][3][4] = {
	{{6, 5, 5, 5}, {9, 9, 9, 9}, {6, 9, 9, 9}},
	{{6, 5, 7, 3}, {9, 9, 12, 6}, {6, 9, 12, 6}},
	{{11, 10, 0, 0}, {18, 18, 0, 0}, {15, 18, 0, 0}},
	{{7, 7, 7, 0}, {12, 12, 12, 0}, {6, 15, 12, 0}},
	{{6, 6, 6, 3}, {12, 9, 9, 6}, {6, 12, 9, 6}},
	{{8, 8, 5, 0}, {15, 12, 9, 0}, {6, 18, 9, 0}}
    };

    int sb[54];
    layer3grinfo *gi = &(sideinfo.ch[ch].gr[0]);
    register layer3scalefactor *sf = (&scalefactors[ch]);

    {
	int blocktypenumber, sc;
	int blocknumber;
	int slen[4];

	if (gi->block_type == 2)
	    blocktypenumber = 1 + gi->mixed_block_flag;
	else
	    blocktypenumber = 0;

	sc = gi->scalefac_compress;
	if (!((extendedmode == 1 || extendedmode == 3) && (ch == 1))) {
	    if (sc < 400) {
		slen[0] = (sc >> 4) / 5;
		slen[1] = (sc >> 4) % 5;
		slen[2] = (sc % 16) >> 2;
		slen[3] = (sc % 4);
		gi->preflag = 0;
		blocknumber = 0;
	    } else if (sc < 500) {
		sc -= 400;
		slen[0] = (sc >> 2) / 5;
		slen[1] = (sc >> 2) % 5;
		slen[2] = sc % 4;
		slen[3] = 0;
		gi->preflag = 0;
		blocknumber = 1;
	    } else		// if(sc<512)
	    {
		sc -= 500;
		slen[0] = sc / 3;
		slen[1] = sc % 3;
		slen[2] = 0;
		slen[3] = 0;
		gi->preflag = 1;
		blocknumber = 2;
	    }
	} else {
	    sc >>= 1;
	    if (sc < 180) {
		slen[0] = sc / 36;
		slen[1] = (sc % 36) / 6;
		slen[2] = (sc % 36) % 6;
		slen[3] = 0;
		gi->preflag = 0;
		blocknumber = 3;
	    } else if (sc < 244) {
		sc -= 180;
		slen[0] = (sc % 64) >> 4;
		slen[1] = (sc % 16) >> 2;
		slen[2] = sc % 4;
		slen[3] = 0;
		gi->preflag = 0;
		blocknumber = 4;
	    } else		// if(sc<255)
	    {
		sc -= 244;
		slen[0] = sc / 3;
		slen[1] = sc % 3;
		slen[2] = slen[3] = 0;
		gi->preflag = 0;
		blocknumber = 5;
	    }
	}

	{
	    int i, j, k, *si;

	    si = sfbblockindex[blocknumber][blocktypenumber];
	    for (i = 0; i < 45; i++)
		sb[i] = 0;