X-Git-Url: http://git.asbjorn.biz/?a=blobdiff_plain;f=lib%2Flame%2Ftakehiro.c;fp=lib%2Flame%2Ftakehiro.c;h=13507ba353792a41060529e66bd93eb960ba52d2;hb=698acf324aaa52147b1486646f6549ffd95804da;hp=0000000000000000000000000000000000000000;hpb=f8d07c79494e8536e682da73cee2057740a0e4db;p=swftools.git diff --git a/lib/lame/takehiro.c b/lib/lame/takehiro.c new file mode 100644 index 0000000..13507ba --- /dev/null +++ b/lib/lame/takehiro.c @@ -0,0 +1,1030 @@ +/* + * MP3 huffman table selecting and bit counting + * + * Copyright (c) 1999 Takehiro TOMINAGA + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +/* $Id: takehiro.c,v 1.1 2002/04/28 17:30:29 kramm Exp $ */ + +#include "config_static.h" + +#include +#include "util.h" +#include "l3side.h" +#include "tables.h" +#include "quantize_pvt.h" + +#ifdef WITH_DMALLOC +#include +#endif + +static const struct +{ + const int region0_count; + const int region1_count; +} subdv_table[ 23 ] = +{ +{0, 0}, /* 0 bands */ +{0, 0}, /* 1 bands */ +{0, 0}, /* 2 bands */ +{0, 0}, /* 3 bands */ +{0, 0}, /* 4 bands */ +{0, 1}, /* 5 bands */ +{1, 1}, /* 6 bands */ +{1, 1}, /* 7 bands */ +{1, 2}, /* 8 bands */ +{2, 2}, /* 9 bands */ +{2, 3}, /* 10 bands */ +{2, 3}, /* 11 bands */ +{3, 4}, /* 12 bands */ +{3, 4}, /* 13 bands */ +{3, 4}, /* 14 bands */ +{4, 5}, /* 15 bands */ +{4, 5}, /* 16 bands */ +{4, 6}, /* 17 bands */ +{5, 6}, /* 18 bands */ +{5, 6}, /* 19 bands */ +{5, 7}, /* 20 bands */ +{6, 7}, /* 21 bands */ +{6, 7}, /* 22 bands */ +}; + + + + +/*************************************************************************/ +/* ix_max */ +/*************************************************************************/ + +int +ix_max(const int *ix, const int *end) +{ + int max1 = 0, max2 = 0; + + do { + int x1 = *ix++; + int x2 = *ix++; + if (max1 < x1) + max1 = x1; + + if (max2 < x2) + max2 = x2; + } while (ix < end); + if (max1 < max2) + max1 = max2; + return max1; +} + + + + + + + + +int +count_bit_ESC( + const int * ix, + const int * const end, + int t1, + const int t2, + int * const s ) +{ + /* ESC-table is used */ + int linbits = ht[t1].xlen * 65536 + ht[t2].xlen; + int sum = 0, sum2; + + do { + int x = *ix++; + int y = *ix++; + + if (x != 0) { + if (x > 14) { + x = 15; + sum += linbits; + } + x *= 16; + } + + if (y != 0) { + if (y > 14) { + y = 15; + sum += linbits; + } + x += y; + } + + sum += largetbl[x]; + } while (ix < end); + + sum2 = sum & 0xffff; + sum >>= 16; + + if (sum > sum2) { + sum = sum2; + t1 = t2; + } + + *s += sum; + return t1; +} + + +inline static int +count_bit_noESC(const int * ix, const int * const end, int * const s) +{ + /* No ESC-words */ + int sum1 = 0; + const char *hlen1 = ht[1].hlen; + + do { + int x = ix[0] * 2 + ix[1]; + ix += 2; + sum1 += hlen1[x]; + } while (ix < end); + + *s += sum1; + return 1; +} + + + +inline static int +count_bit_noESC_from2( + const int * ix, + const int * const end, + int t1, + int * const s ) +{ + /* No ESC-words */ + unsigned int sum = 0, sum2; + const int xlen = ht[t1].xlen; + const unsigned int *hlen; + if (t1 == 2) + hlen = table23; + else + hlen = table56; + + do { + int x = ix[0] * xlen + ix[1]; + ix += 2; + sum += hlen[x]; + } while (ix < end); + + sum2 = sum & 0xffff; + sum >>= 16; + + if (sum > sum2) { + sum = sum2; + t1++; + } + + *s += sum; + return t1; +} + + +inline static int +count_bit_noESC_from3( + const int * ix, + const int * const end, + int t1, + int * const s ) +{ + /* No ESC-words */ + int sum1 = 0; + int sum2 = 0; + int sum3 = 0; + const int xlen = ht[t1].xlen; + const char *hlen1 = ht[t1].hlen; + const char *hlen2 = ht[t1+1].hlen; + const char *hlen3 = ht[t1+2].hlen; + int t; + + do { + int x = ix[0] * xlen + ix[1]; + ix += 2; + sum1 += hlen1[x]; + sum2 += hlen2[x]; + sum3 += hlen3[x]; + } while (ix < end); + + t = t1; + if (sum1 > sum2) { + sum1 = sum2; + t++; + } + if (sum1 > sum3) { + sum1 = sum3; + t = t1+2; + } + *s += sum1; + + return t; +} + + +/*************************************************************************/ +/* choose table */ +/*************************************************************************/ + +/* + Choose the Huffman table that will encode ix[begin..end] with + the fewest bits. + + Note: This code contains knowledge about the sizes and characteristics + of the Huffman tables as defined in the IS (Table B.7), and will not work + with any arbitrary tables. +*/ + +static int choose_table_nonMMX( + const int * ix, + const int * const end, + int * const s ) +{ + int max; + int choice, choice2; + static const int huf_tbl_noESC[] = { + 1, 2, 5, 7, 7,10,10,13,13,13,13,13,13,13,13 /* char not enough ? */ + }; + + max = ix_max(ix, end); + + switch (max) { + case 0: + return max; + + case 1: + return count_bit_noESC(ix, end, s); + + case 2: + case 3: + return count_bit_noESC_from2(ix, end, huf_tbl_noESC[max - 1], s); + + case 4: case 5: case 6: + case 7: case 8: case 9: + case 10: case 11: case 12: + case 13: case 14: case 15: + return count_bit_noESC_from3(ix, end, huf_tbl_noESC[max - 1], s); + + default: + /* try tables with linbits */ + if (max > IXMAX_VAL) { + *s = LARGE_BITS; + return -1; + } + max -= 15; + for (choice2 = 24; choice2 < 32; choice2++) { + if (ht[choice2].linmax >= max) { + break; + } + } + + for (choice = choice2 - 8; choice < 24; choice++) { + if (ht[choice].linmax >= max) { + break; + } + } + return count_bit_ESC(ix, end, choice, choice2, s); + } +} + + + +/*************************************************************************/ +/* count_bit */ +/*************************************************************************/ + +int count_bits( + lame_internal_flags * const gfc, + int * const ix, + const FLOAT8 * const xr, + gr_info * const gi) +{ + int bits = 0; + int i, a1, a2; + /* since quantize_xrpow uses table lookup, we need to check this first: */ + FLOAT8 w = (IXMAX_VAL) / IPOW20(gi->global_gain); + for ( i = 0; i < 576; i++ ) { + if (xr[i] > w) + return LARGE_BITS; + } + + if (gfc->quantization) + quantize_xrpow(xr, ix, IPOW20(gi->global_gain)); + else + quantize_xrpow_ISO(xr, ix, IPOW20(gi->global_gain)); + + if (gfc->noise_shaping_amp==3) { + int sfb; + // 0.634521682242439 = 0.5946*2**(.5*0.1875) + FLOAT8 roundfac = 0.634521682242439 / IPOW20(gi->global_gain+gi->scalefac_scale); + i = 0; + for (sfb = 0; sfb < gi->sfb_lmax; sfb++) { + int end; + if (!gfc->pseudohalf.l[sfb]) + continue; + + end = gfc->scalefac_band.l[sfb+1]; + for (; i < end; i++) + if (xr[i] < roundfac) + ix[i] = 0; + } + + for (sfb = gi->sfb_smin; sfb < SBPSY_s; sfb++) { + int start, end, win; + start = gfc->scalefac_band.s[sfb]; + end = gfc->scalefac_band.s[sfb+1]; + for (win = 0; win < 3; win++) { + int j; + if (!gfc->pseudohalf.s[sfb][win]) + continue; + for (j = start; j < end; j++, i++) + if (xr[i] < roundfac) + ix[i] = 0; + } + } + } + + + + + + + i=576; + /* Determine count1 region */ + for (; i > 1; i -= 2) + if (ix[i - 1] | ix[i - 2]) + break; + gi->count1 = i; + + /* Determines the number of bits to encode the quadruples. */ + a1 = a2 = 0; + for (; i > 3; i -= 4) { + int p; + /* hack to check if all values <= 1 */ + if ((unsigned int)(ix[i-1] | ix[i-2] | ix[i-3] | ix[i-4]) > 1) + break; + + p = ((ix[i-4] * 2 + ix[i-3]) * 2 + ix[i-2]) * 2 + ix[i-1]; + a1 += t32l[p]; + a2 += t33l[p]; + } + + bits = a1; + gi->count1table_select = 0; + if (a1 > a2) { + bits = a2; + gi->count1table_select = 1; + } + + gi->count1bits = bits; + gi->big_values = i; + if (i == 0) + return bits; + + if (gi->block_type == SHORT_TYPE) { + a1=3*gfc->scalefac_band.s[3]; + if (a1 > gi->big_values) a1 = gi->big_values; + a2 = gi->big_values; + + }else if (gi->block_type == NORM_TYPE) { + assert(i <= 576); /* bv_scf has 576 entries (0..575) */ + a1 = gi->region0_count = gfc->bv_scf[i-2]; + a2 = gi->region1_count = gfc->bv_scf[i-1]; + + assert(a1+a2+2 < SBPSY_l); + a2 = gfc->scalefac_band.l[a1 + a2 + 2]; + a1 = gfc->scalefac_band.l[a1 + 1]; + if (a2 < i) + gi->table_select[2] = gfc->choose_table(ix + a2, ix + i, &bits); + + } else { + gi->region0_count = 7; + /*gi->region1_count = SBPSY_l - 7 - 1;*/ + gi->region1_count = SBMAX_l -1 - 7 - 1; + a1 = gfc->scalefac_band.l[7 + 1]; + a2 = i; + if (a1 > a2) { + a1 = a2; + } + } + + + /* have to allow for the case when bigvalues < region0 < region1 */ + /* (and region0, region1 are ignored) */ + a1 = Min(a1,i); + a2 = Min(a2,i); + + assert( a1 >= 0 ); + assert( a2 >= 0 ); + + /* Count the number of bits necessary to code the bigvalues region. */ + if (0 < a1) + gi->table_select[0] = gfc->choose_table(ix, ix + a1, &bits); + if (a1 < a2) + gi->table_select[1] = gfc->choose_table(ix + a1, ix + a2, &bits); + return bits; +} + +/*********************************************************************** + re-calculate the best scalefac_compress using scfsi + the saved bits are kept in the bit reservoir. + **********************************************************************/ + + +inline static void +recalc_divide_init( + const lame_internal_flags * const gfc, + gr_info cod_info, + int * const ix, + int r01_bits[], + int r01_div [], + int r0_tbl [], + int r1_tbl [] ) +{ + int r0, r1, bigv, r0t, r1t, bits; + + bigv = cod_info.big_values; + + for (r0 = 0; r0 <= 7 + 15; r0++) { + r01_bits[r0] = LARGE_BITS; + } + + for (r0 = 0; r0 < 16; r0++) { + int a1 = gfc->scalefac_band.l[r0 + 1], r0bits; + if (a1 >= bigv) + break; + r0bits = cod_info.part2_length; + r0t = gfc->choose_table(ix, ix + a1, &r0bits); + + for (r1 = 0; r1 < 8; r1++) { + int a2 = gfc->scalefac_band.l[r0 + r1 + 2]; + if (a2 >= bigv) + break; + + bits = r0bits; + r1t = gfc->choose_table(ix + a1, ix + a2, &bits); + if (r01_bits[r0 + r1] > bits) { + r01_bits[r0 + r1] = bits; + r01_div[r0 + r1] = r0; + r0_tbl[r0 + r1] = r0t; + r1_tbl[r0 + r1] = r1t; + } + } + } +} + +inline static void +recalc_divide_sub( + const lame_internal_flags * const gfc, + const gr_info cod_info2, + gr_info * const gi, + const int * const ix, + const int r01_bits[], + const int r01_div [], + const int r0_tbl [], + const int r1_tbl [] ) +{ + int bits, r2, a2, bigv, r2t; + + bigv = cod_info2.big_values; + + for (r2 = 2; r2 < SBMAX_l + 1; r2++) { + a2 = gfc->scalefac_band.l[r2]; + if (a2 >= bigv) + break; + + bits = r01_bits[r2 - 2] + cod_info2.count1bits; + if (gi->part2_3_length <= bits) + break; + + r2t = gfc->choose_table(ix + a2, ix + bigv, &bits); + if (gi->part2_3_length <= bits) + continue; + + memcpy(gi, &cod_info2, sizeof(gr_info)); + gi->part2_3_length = bits; + gi->region0_count = r01_div[r2 - 2]; + gi->region1_count = r2 - 2 - r01_div[r2 - 2]; + gi->table_select[0] = r0_tbl[r2 - 2]; + gi->table_select[1] = r1_tbl[r2 - 2]; + gi->table_select[2] = r2t; + } +} + + + + +void best_huffman_divide( + const lame_internal_flags * const gfc, + gr_info * const gi, + int * const ix ) +{ + int i, a1, a2; + gr_info cod_info2; + + int r01_bits[7 + 15 + 1]; + int r01_div[7 + 15 + 1]; + int r0_tbl[7 + 15 + 1]; + int r1_tbl[7 + 15 + 1]; + + + /* SHORT BLOCK stuff fails for MPEG2 */ + if (gi->block_type == SHORT_TYPE && gfc->mode_gr==1) + return; + + + memcpy(&cod_info2, gi, sizeof(gr_info)); + if (gi->block_type == NORM_TYPE) { + recalc_divide_init(gfc, cod_info2, ix, r01_bits,r01_div,r0_tbl,r1_tbl); + recalc_divide_sub(gfc, cod_info2, gi, ix, r01_bits,r01_div,r0_tbl,r1_tbl); + } + + i = cod_info2.big_values; + if (i == 0 || (unsigned int)(ix[i-2] | ix[i-1]) > 1) + return; + + i = gi->count1 + 2; + if (i > 576) + return; + + /* Determines the number of bits to encode the quadruples. */ + memcpy(&cod_info2, gi, sizeof(gr_info)); + cod_info2.count1 = i; + a1 = a2 = 0; + + assert(i <= 576); + + for (; i > cod_info2.big_values; i -= 4) { + int p = ((ix[i-4] * 2 + ix[i-3]) * 2 + ix[i-2]) * 2 + ix[i-1]; + a1 += t32l[p]; + a2 += t33l[p]; + } + cod_info2.big_values = i; + + cod_info2.count1table_select = 0; + if (a1 > a2) { + a1 = a2; + cod_info2.count1table_select = 1; + } + + cod_info2.count1bits = a1; + cod_info2.part2_3_length = a1 + cod_info2.part2_length; + + if (cod_info2.block_type == NORM_TYPE) + recalc_divide_sub(gfc, cod_info2, gi, ix, r01_bits,r01_div,r0_tbl,r1_tbl); + else { + /* Count the number of bits necessary to code the bigvalues region. */ + a1 = gfc->scalefac_band.l[7 + 1]; + if (a1 > i) { + a1 = i; + } + if (a1 > 0) + cod_info2.table_select[0] = + gfc->choose_table(ix, ix + a1, (int *)&cod_info2.part2_3_length); + if (i > a1) + cod_info2.table_select[1] = + gfc->choose_table(ix + a1, ix + i, (int *)&cod_info2.part2_3_length); + if (gi->part2_3_length > cod_info2.part2_3_length) + memcpy(gi, &cod_info2, sizeof(gr_info)); + } +} + +static const int slen1_n[16] = { 1, 1, 1, 1, 8, 2, 2, 2, 4, 4, 4, 8, 8, 8,16,16 }; +static const int slen2_n[16] = { 1, 2, 4, 8, 1, 2, 4, 8, 2, 4, 8, 2, 4, 8, 4, 8 }; + +void +scfsi_calc(int ch, + III_side_info_t *l3_side, + III_scalefac_t scalefac[2][2]) +{ + int i, s1, s2, c1, c2; + int sfb; + gr_info *gi = &l3_side->gr[1].ch[ch].tt; + + static const int scfsi_band[5] = { 0, 6, 11, 16, 21 }; +#if 0 + static const int slen1_n[16] = { 0, 1, 1, 1, 8, 2, 2, 2, 4, 4, 4, 8, 8, 8,16,16 }; + static const int slen2_n[16] = { 0, 2, 4, 8, 1, 2, 4, 8, 2, 4, 8, 2, 4, 8, 4, 8 }; +#endif + + for (i = 0; i < 4; i++) + l3_side->scfsi[ch][i] = 0; + + for (i = 0; i < (sizeof(scfsi_band) / sizeof(int)) - 1; i++) { + for (sfb = scfsi_band[i]; sfb < scfsi_band[i + 1]; sfb++) { + if (scalefac[0][ch].l[sfb] != scalefac[1][ch].l[sfb]) + break; + } + if (sfb == scfsi_band[i + 1]) { + for (sfb = scfsi_band[i]; sfb < scfsi_band[i + 1]; sfb++) { + scalefac[1][ch].l[sfb] = -1; + } + l3_side->scfsi[ch][i] = 1; + } + } + + s1 = c1 = 0; + for (sfb = 0; sfb < 11; sfb++) { + if (scalefac[1][ch].l[sfb] < 0) + continue; + c1++; + if (s1 < scalefac[1][ch].l[sfb]) + s1 = scalefac[1][ch].l[sfb]; + } + + s2 = c2 = 0; + for (; sfb < SBPSY_l; sfb++) { + if (scalefac[1][ch].l[sfb] < 0) + continue; + c2++; + if (s2 < scalefac[1][ch].l[sfb]) + s2 = scalefac[1][ch].l[sfb]; + } + + for (i = 0; i < 16; i++) { + if (s1 < slen1_n[i] && s2 < slen2_n[i]) { + int c = slen1_tab[i] * c1 + slen2_tab[i] * c2; + if (gi->part2_length > c) { + gi->part2_length = c; + gi->scalefac_compress = i; + } + } + } +} + +/* +Find the optimal way to store the scalefactors. +Only call this routine after final scalefactors have been +chosen and the channel/granule will not be re-encoded. + */ +void best_scalefac_store( + const lame_internal_flags *gfc, + const int gr, + const int ch, + int l3_enc[2][2][576], + III_side_info_t * const l3_side, + III_scalefac_t scalefac[2][2] ) +{ + + /* use scalefac_scale if we can */ + gr_info *gi = &l3_side->gr[gr].ch[ch].tt; + int sfb,i,j,j2,l,start,end; + + /* remove scalefacs from bands with ix=0. This idea comes + * from the AAC ISO docs. added mt 3/00 */ + /* check if l3_enc=0 */ + for ( sfb = 0; sfb < gi->sfb_lmax; sfb++ ) { + if (scalefac[gr][ch].l[sfb]>0) { + start = gfc->scalefac_band.l[ sfb ]; + end = gfc->scalefac_band.l[ sfb+1 ]; + for ( l = start; l < end; l++ ) if (l3_enc[gr][ch][l]!=0) break; + if (l==end) scalefac[gr][ch].l[sfb]=0; + } + } + for ( j=0, sfb = gi->sfb_smin; sfb < SBPSY_s; sfb++ ) { + start = gfc->scalefac_band.s[ sfb ]; + end = gfc->scalefac_band.s[ sfb+1 ]; + for ( i = 0; i < 3; i++ ) { + if (scalefac[gr][ch].s[sfb][i]>0) { + j2 = j; + for ( l = start; l < end; l++ ) + if (l3_enc[gr][ch][j2++ /*3*l+i*/]!=0) break; + if (l==end) scalefac[gr][ch].s[sfb][i]=0; + } + j += end-start; + } + } + + + gi->part2_3_length -= gi->part2_length; + if (!gi->scalefac_scale && !gi->preflag) { + int b, s = 0; + for (sfb = 0; sfb < gi->sfb_lmax; sfb++) { + s |= scalefac[gr][ch].l[sfb]; + } + + for (sfb = gi->sfb_smin; sfb < SBPSY_s; sfb++) { + for (b = 0; b < 3; b++) { + s |= scalefac[gr][ch].s[sfb][b]; + } + } + + if (!(s & 1) && s != 0) { + for (sfb = 0; sfb < gi->sfb_lmax; sfb++) { + scalefac[gr][ch].l[sfb] /= 2; + } + for (sfb = gi->sfb_smin; sfb < SBPSY_s; sfb++) { + for (b = 0; b < 3; b++) { + scalefac[gr][ch].s[sfb][b] /= 2; + } + } + + gi->scalefac_scale = 1; + gi->part2_length = 99999999; + if (gfc->mode_gr == 2) { + scale_bitcount(&scalefac[gr][ch], gi); + } else { + scale_bitcount_lsf(gfc,&scalefac[gr][ch], gi); + } + } + } + + + for ( i = 0; i < 4; i++ ) + l3_side->scfsi[ch][i] = 0; + + if (gfc->mode_gr==2 && gr == 1 + && l3_side->gr[0].ch[ch].tt.block_type != SHORT_TYPE + && l3_side->gr[1].ch[ch].tt.block_type != SHORT_TYPE) { + scfsi_calc(ch, l3_side, scalefac); + } + gi->part2_3_length += gi->part2_length; +} + + +/* number of bits used to encode scalefacs */ + +/* 18*slen1_tab[i] + 18*slen2_tab[i] */ +static const int scale_short[16] = { + 0, 18, 36, 54, 54, 36, 54, 72, 54, 72, 90, 72, 90, 108, 108, 126 }; + +/* 17*slen1_tab[i] + 18*slen2_tab[i] */ +static const int scale_mixed[16] = { + 0, 18, 36, 54, 51, 35, 53, 71, 52, 70, 88, 69, 87, 105, 104, 122 }; + +/* 11*slen1_tab[i] + 10*slen2_tab[i] */ +static const int scale_long[16] = { + 0, 10, 20, 30, 33, 21, 31, 41, 32, 42, 52, 43, 53, 63, 64, 74 }; + + +/*************************************************************************/ +/* scale_bitcount */ +/*************************************************************************/ + +/* Also calculates the number of bits necessary to code the scalefactors. */ + +int scale_bitcount( + III_scalefac_t * const scalefac, gr_info * const cod_info) +{ + int i, k, sfb, max_slen1 = 0, max_slen2 = 0, ep = 2; + + /* maximum values */ + const int *tab; + + + if ( cod_info->block_type == SHORT_TYPE ) { + tab = scale_short; + if (cod_info->mixed_block_flag) { + tab = scale_mixed; + for ( sfb = 0 ; sfb < cod_info->sfb_lmax; sfb++ ) + if (max_slen1 < scalefac->l[sfb]) + max_slen1 = scalefac->l[sfb]; + } + + for ( i = 0; i < 3; i++ ) { + for ( sfb = cod_info->sfb_smin; sfb < 6; sfb++ ) + if (max_slen1 < scalefac->s[sfb][i]) + max_slen1 = scalefac->s[sfb][i]; + for (sfb = 6; sfb < SBPSY_s; sfb++ ) + if (max_slen2 < scalefac->s[sfb][i]) + max_slen2 = scalefac->s[sfb][i]; + } + } + else + { /* block_type == 1,2,or 3 */ + tab = scale_long; + for ( sfb = 0; sfb < 11; sfb++ ) + if ( scalefac->l[sfb] > max_slen1 ) + max_slen1 = scalefac->l[sfb]; + + if (!cod_info->preflag) { + for ( sfb = 11; sfb < SBPSY_l; sfb++ ) + if (scalefac->l[sfb] < pretab[sfb]) + break; + + if (sfb == SBPSY_l) { + cod_info->preflag = 1; + for ( sfb = 11; sfb < SBPSY_l; sfb++ ) + scalefac->l[sfb] -= pretab[sfb]; + } + } + + for ( sfb = 11; sfb < SBPSY_l; sfb++ ) + if ( scalefac->l[sfb] > max_slen2 ) + max_slen2 = scalefac->l[sfb]; + } + + + /* from Takehiro TOMINAGA 10/99 + * loop over *all* posible values of scalefac_compress to find the + * one which uses the smallest number of bits. ISO would stop + * at first valid index */ + cod_info->part2_length = LARGE_BITS; + for ( k = 0; k < 16; k++ ) + { + if ( (max_slen1 < slen1_n[k]) && (max_slen2 < slen2_n[k]) && + (cod_info->part2_length > tab[k])) { + cod_info->part2_length=tab[k]; + cod_info->scalefac_compress=k; + ep=0; /* we found a suitable scalefac_compress */ + } + } + return ep; +} + + + +/* + table of largest scalefactor values for MPEG2 +*/ +static const int max_range_sfac_tab[6][4] = +{ + { 15, 15, 7, 7}, + { 15, 15, 7, 0}, + { 7, 3, 0, 0}, + { 15, 31, 31, 0}, + { 7, 7, 7, 0}, + { 3, 3, 0, 0} +}; + + + + +/*************************************************************************/ +/* scale_bitcount_lsf */ +/*************************************************************************/ + +/* Also counts the number of bits to encode the scalefacs but for MPEG 2 */ +/* Lower sampling frequencies (24, 22.05 and 16 kHz.) */ + +/* This is reverse-engineered from section 2.4.3.2 of the MPEG2 IS, */ +/* "Audio Decoding Layer III" */ + +int scale_bitcount_lsf(const lame_internal_flags *gfc, + const III_scalefac_t * const scalefac, gr_info * const cod_info) +{ + int table_number, row_in_table, partition, nr_sfb, window, over; + int i, sfb, max_sfac[ 4 ]; + const int *partition_table; + + /* + Set partition table. Note that should try to use table one, + but do not yet... + */ + if ( cod_info->preflag ) + table_number = 2; + else + table_number = 0; + + for ( i = 0; i < 4; i++ ) + max_sfac[i] = 0; + + if ( cod_info->block_type == SHORT_TYPE ) + { + row_in_table = 1; + partition_table = &nr_of_sfb_block[table_number][row_in_table][0]; + for ( sfb = 0, partition = 0; partition < 4; partition++ ) + { + nr_sfb = partition_table[ partition ] / 3; + for ( i = 0; i < nr_sfb; i++, sfb++ ) + for ( window = 0; window < 3; window++ ) + if ( scalefac->s[sfb][window] > max_sfac[partition] ) + max_sfac[partition] = scalefac->s[sfb][window]; + } + } + else + { + row_in_table = 0; + partition_table = &nr_of_sfb_block[table_number][row_in_table][0]; + for ( sfb = 0, partition = 0; partition < 4; partition++ ) + { + nr_sfb = partition_table[ partition ]; + for ( i = 0; i < nr_sfb; i++, sfb++ ) + if ( scalefac->l[sfb] > max_sfac[partition] ) + max_sfac[partition] = scalefac->l[sfb]; + } + } + + for ( over = 0, partition = 0; partition < 4; partition++ ) + { + if ( max_sfac[partition] > max_range_sfac_tab[table_number][partition] ) + over++; + } + if ( !over ) + { + /* + Since no bands have been over-amplified, we can set scalefac_compress + and slen[] for the formatter + */ + static const int log2tab[] = { 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4 }; + + int slen1, slen2, slen3, slen4; + + cod_info->sfb_partition_table = nr_of_sfb_block[table_number][row_in_table]; + for ( partition = 0; partition < 4; partition++ ) + cod_info->slen[partition] = log2tab[max_sfac[partition]]; + + /* set scalefac_compress */ + slen1 = cod_info->slen[ 0 ]; + slen2 = cod_info->slen[ 1 ]; + slen3 = cod_info->slen[ 2 ]; + slen4 = cod_info->slen[ 3 ]; + + switch ( table_number ) + { + case 0: + cod_info->scalefac_compress = (((slen1 * 5) + slen2) << 4) + + (slen3 << 2) + + slen4; + break; + + case 1: + cod_info->scalefac_compress = 400 + + (((slen1 * 5) + slen2) << 2) + + slen3; + break; + + case 2: + cod_info->scalefac_compress = 500 + (slen1 * 3) + slen2; + break; + + default: + ERRORF(gfc,"intensity stereo not implemented yet\n" ); + break; + } + } +#ifdef DEBUG + if ( over ) + ERRORF(gfc, "---WARNING !! Amplification of some bands over limits\n" ); +#endif + if (!over) { + assert( cod_info->sfb_partition_table ); + cod_info->part2_length=0; + for ( partition = 0; partition < 4; partition++ ) + cod_info->part2_length += cod_info->slen[partition] * cod_info->sfb_partition_table[partition]; + } + return over; +} + + + +void huffman_init(lame_internal_flags * const gfc) +{ + int i; + + gfc->choose_table = choose_table_nonMMX; + +#ifdef MMX_choose_table + if (gfc->CPU_features.MMX) { + extern int choose_table_MMX(const int *ix, const int *end, int *s); + gfc->choose_table = choose_table_MMX; + } +#endif + + for (i = 2; i <= 576; i += 2) { + int scfb_anz = 0, index; + while (gfc->scalefac_band.l[++scfb_anz] < i) + ; + + index = subdv_table[scfb_anz].region0_count; + while (gfc->scalefac_band.l[index + 1] > i) + index--; + + if (index < 0) { + /* this is an indication that everything is going to + be encoded as region0: bigvalues < region0 < region1 + so lets set region0, region1 to some value larger + than bigvalues */ + index = subdv_table[scfb_anz].region0_count; + } + + gfc->bv_scf[i-2] = index; + + index = subdv_table[scfb_anz].region1_count; + while (gfc->scalefac_band.l[index + gfc->bv_scf[i-2] + 2] > i) + index--; + + if (index < 0) { + index = subdv_table[scfb_anz].region1_count; + } + + gfc->bv_scf[i-1] = index; + } +}