ref: dfb4b522830edab8f3856289d326d6cf5e930644
dir: /sys/src/cmd/audio/mp3enc/quantize.c/
/* * MP3 quantization * * Copyright (c) 1999 Mark Taylor * * 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: quantize.c,v 1.57 2001/02/27 06:14:57 markt Exp $ */ #ifdef HAVE_CONFIG_H # include <config.h> #endif #include <math.h> #include <assert.h> #include "util.h" #include "l3side.h" #include "quantize.h" #include "reservoir.h" #include "quantize_pvt.h" #include "lame-analysis.h" #ifdef WITH_DMALLOC #include <dmalloc.h> #endif /************************************************************************ * * init_outer_loop() * mt 6/99 * * initializes cod_info, scalefac and xrpow * * returns 0 if all energies in xr are zero, else 1 * ************************************************************************/ static int init_outer_loop( gr_info *const cod_info, III_scalefac_t *const scalefac, const int is_mpeg1, const FLOAT8 xr[576], FLOAT8 xrpow[576] ) { FLOAT8 tmp, sum = 0; int i; /* initialize fresh cod_info */ cod_info->part2_3_length = 0; cod_info->big_values = 0; cod_info->count1 = 0; cod_info->global_gain = 210; cod_info->scalefac_compress = 0; /* window_switching_flag was set in psymodel.c? */ /* block_type was set in psymodel.c? */ /* mixed_block_flag would be set in ^ */ cod_info->table_select [0] = 0; cod_info->table_select [1] = 0; cod_info->table_select [2] = 0; cod_info->subblock_gain[0] = 0; cod_info->subblock_gain[1] = 0; cod_info->subblock_gain[2] = 0; cod_info->region0_count = 0; cod_info->region1_count = 0; cod_info->preflag = 0; cod_info->scalefac_scale = 0; cod_info->count1table_select = 0; cod_info->part2_length = 0; if (cod_info->block_type == SHORT_TYPE) { cod_info->sfb_lmax = 0; cod_info->sfb_smin = 0; if (cod_info->mixed_block_flag) { /* * MPEG-1: sfbs 0-7 long block, 3-12 short blocks * MPEG-2(.5): sfbs 0-5 long block, 3-12 short blocks */ cod_info->sfb_lmax = is_mpeg1 ? 8 : 6; cod_info->sfb_smin = 3; } } else { cod_info->sfb_lmax = SBPSY_l; cod_info->sfb_smin = SBPSY_s; } cod_info->count1bits = 0; cod_info->sfb_partition_table = nr_of_sfb_block[0][0]; cod_info->slen[0] = 0; cod_info->slen[1] = 0; cod_info->slen[2] = 0; cod_info->slen[3] = 0; /* fresh scalefactors are all zero */ memset(scalefac, 0, sizeof(III_scalefac_t)); /* check if there is some energy we have to quantize * and calculate xrpow matching our fresh scalefactors */ for (i = 0; i < 576; ++i) { tmp = fabs (xr[i]); sum += tmp; xrpow[i] = sqrt (tmp * sqrt(tmp)); } /* return 1 if we have something to quantize, else 0 */ return sum > (FLOAT8)1E-20; } /************************************************************************ * * bin_search_StepSize() * * author/date?? * * binary step size search * used by outer_loop to get a quantizer step size to start with * ************************************************************************/ typedef enum { BINSEARCH_NONE, BINSEARCH_UP, BINSEARCH_DOWN } binsearchDirection_t; int bin_search_StepSize( lame_internal_flags * const gfc, gr_info * const cod_info, const int desired_rate, const int start, const FLOAT8 xrpow [576], int l3enc [576] ) { int nBits; int CurrentStep; int flag_GoneOver = 0; int StepSize = start; binsearchDirection_t Direction = BINSEARCH_NONE; assert(gfc->CurrentStep); CurrentStep = gfc->CurrentStep; do { cod_info->global_gain = StepSize; nBits = count_bits(gfc,l3enc,xrpow,cod_info); if (CurrentStep == 1) break; /* nothing to adjust anymore */ if (flag_GoneOver) CurrentStep /= 2; if (nBits > desired_rate) { /* increase Quantize_StepSize */ if (Direction == BINSEARCH_DOWN && !flag_GoneOver) { flag_GoneOver = 1; CurrentStep /= 2; /* late adjust */ } Direction = BINSEARCH_UP; StepSize += CurrentStep; if (StepSize > 255) break; } else if (nBits < desired_rate) { /* decrease Quantize_StepSize */ if (Direction == BINSEARCH_UP && !flag_GoneOver) { flag_GoneOver = 1; CurrentStep /= 2; /* late adjust */ } Direction = BINSEARCH_DOWN; StepSize -= CurrentStep; if (StepSize < 0) break; } else break; /* nBits == desired_rate;; most unlikely to happen.*/ } while (1); /* For-ever, break is adjusted. */ CurrentStep = start - StepSize; gfc->CurrentStep = CurrentStep/4 != 0 ? 4 : 2; return nBits; } /*************************************************************************** * * inner_loop () * * author/date?? * * The code selects the best global gain for a particular set of scalefacs * ***************************************************************************/ int inner_loop( lame_internal_flags * const gfc, gr_info * const cod_info, const int max_bits, const FLOAT8 xrpow [576], int l3enc [576] ) { int bits; assert(max_bits >= 0); /* scalefactors may have changed, so count bits */ bits=count_bits(gfc,l3enc,xrpow,cod_info); /* increase quantizer stepsize until needed bits are below maximum */ while (bits > max_bits) { cod_info->global_gain++; bits = count_bits (gfc, l3enc, xrpow, cod_info); } return bits; } /************************************************************************* * * loop_break() * * author/date?? * * Function: Returns zero if there is a scalefac which has not been * amplified. Otherwise it returns one. * *************************************************************************/ inline static int loop_break( const gr_info * const cod_info, const III_scalefac_t * const scalefac ) { unsigned int i, sfb; for (sfb = 0; sfb < cod_info->sfb_lmax; sfb++) if (scalefac->l[sfb] == 0) return 0; for (sfb = cod_info->sfb_smin; sfb < SBPSY_s; sfb++) for (i = 0; i < 3; i++) if (scalefac->s[sfb][i] == 0 && cod_info->subblock_gain[i] == 0) return 0; return 1; } /************************************************************************* * * quant_compare() * * author/date?? * * several different codes to decide which quantization is better * *************************************************************************/ inline static int quant_compare( const int experimentalX, const calc_noise_result * const best, const calc_noise_result * const calc ) { /* noise is given in decibels (dB) relative to masking thesholds. over_noise: ??? (the previous comment is fully wrong) tot_noise: ??? (the previous comment is fully wrong) max_noise: max quantization noise */ int better; switch (experimentalX) { default: case 0: better = calc->over_count < best->over_count || ( calc->over_count == best->over_count && calc->over_noise < best->over_noise ) || ( calc->over_count == best->over_count && calc->over_noise == best->over_noise && calc->tot_noise < best->tot_noise ); break; case 1: better = calc->max_noise < best->max_noise; break; case 2: better = calc->tot_noise < best->tot_noise; break; case 3: better = calc->tot_noise < best->tot_noise && calc->max_noise < best->max_noise+2; break; case 4: better = ( calc->max_noise <= 0 && best->max_noise > 2 ) || ( calc->max_noise <= 0 && best->max_noise < 0 && best->max_noise > calc->max_noise-2 && calc->tot_noise < best->tot_noise ) || ( calc->max_noise <= 0 && best->max_noise > 0 && best->max_noise > calc->max_noise-2 && calc->tot_noise < best->tot_noise+best->over_noise ) || ( calc->max_noise > 0 && best->max_noise > -0.5 && best->max_noise > calc->max_noise-1 && calc->tot_noise+calc->over_noise < best->tot_noise+best->over_noise ) || ( calc->max_noise > 0 && best->max_noise > -1 && best->max_noise > calc->max_noise-1.5 && calc->tot_noise+calc->over_noise+calc->over_noise < best->tot_noise+best->over_noise+best->over_noise ); break; case 5: better = calc->over_noise < best->over_noise || ( calc->over_noise == best->over_noise && calc->tot_noise < best->tot_noise ); break; case 6: better = calc->over_noise < best->over_noise || ( calc->over_noise == best->over_noise && ( calc->max_noise < best->max_noise || ( calc->max_noise == best->max_noise && calc->tot_noise <= best->tot_noise ) )); break; case 7: better = calc->over_count < best->over_count || calc->over_noise < best->over_noise; break; case 8: better = calc->klemm_noise < best->klemm_noise; break; } return better; } /************************************************************************* * * amp_scalefac_bands() * * author/date?? * * Amplify the scalefactor bands that violate the masking threshold. * See ISO 11172-3 Section C.1.5.4.3.5 * * distort[] = noise/masking * distort[] > 1 ==> noise is not masked * distort[] < 1 ==> noise is masked * max_dist = maximum value of distort[] * * Three algorithms: * noise_shaping_amp * 0 Amplify all bands with distort[]>1. * * 1 Amplify all bands with distort[] >= max_dist^(.5); * ( 50% in the db scale) * * 2 Amplify first band with distort[] >= max_dist; * * * For algorithms 0 and 1, if max_dist < 1, then amplify all bands * with distort[] >= .95*max_dist. This is to make sure we always * amplify at least one band. * * *************************************************************************/ static void amp_scalefac_bands( lame_global_flags *gfp, const gr_info *const cod_info, III_scalefac_t *const scalefac, III_psy_xmin *distort, FLOAT8 xrpow[576] ) { lame_internal_flags *gfc=gfp->internal_flags; int start, end, l,i,j,sfb; FLOAT8 ifqstep34, trigger; if (cod_info->scalefac_scale == 0) { ifqstep34 = 1.29683955465100964055; /* 2**(.75*.5)*/ } else { ifqstep34 = 1.68179283050742922612; /* 2**(.75*1) */ } /* compute maximum value of distort[] */ trigger = 0; for (sfb = 0; sfb < cod_info->sfb_lmax; sfb++) { if (trigger < distort->l[sfb]) trigger = distort->l[sfb]; } for (sfb = cod_info->sfb_smin; sfb < SBPSY_s; sfb++) { for (i = 0; i < 3; i++ ) { if (trigger < distort->s[sfb][i]) trigger = distort->s[sfb][i]; } } switch (gfc->noise_shaping_amp) { case 2: /* amplify exactly 1 band */ //trigger = distort_thresh; break; case 1: /* amplify bands within 50% of max (on db scale) */ if (trigger>1.0) trigger = pow(trigger, .5); else trigger *= .95; break; case 0: default: /* ISO algorithm. amplify all bands with distort>1 */ if (trigger>1.0) trigger=1.0; else trigger *= .95; break; } for (sfb = 0; sfb < cod_info->sfb_lmax; sfb++ ) { start = gfc->scalefac_band.l[sfb]; end = gfc->scalefac_band.l[sfb+1]; if (distort->l[sfb]>=trigger ) { scalefac->l[sfb]++; for ( l = start; l < end; l++ ) xrpow[l] *= ifqstep34; if (gfc->noise_shaping_amp==2) goto done; } } for ( j=0,sfb = cod_info->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++ ) { int j2 = j; if ( distort->s[sfb][i]>=trigger) { scalefac->s[sfb][i]++; for (l = start; l < end; l++) xrpow[j2++] *= ifqstep34; if (gfc->noise_shaping_amp==2) goto done; } j += end-start; } } done: return; } /************************************************************************* * * inc_scalefac_scale() * * Takehiro Tominaga 2000-xx-xx * * turns on scalefac scale and adjusts scalefactors * *************************************************************************/ static void inc_scalefac_scale ( const lame_internal_flags * const gfc, gr_info * const cod_info, III_scalefac_t * const scalefac, FLOAT8 xrpow[576] ) { int start, end, l,i,j; int sfb; const FLOAT8 ifqstep34 = 1.29683955465100964055; for (sfb = 0; sfb < cod_info->sfb_lmax; sfb++) { int s = scalefac->l[sfb] + (cod_info->preflag ? pretab[sfb] : 0); if (s & 1) { s++; start = gfc->scalefac_band.l[sfb]; end = gfc->scalefac_band.l[sfb+1]; for (l = start; l < end; l++) xrpow[l] *= ifqstep34; } scalefac->l[sfb] = s >> 1; cod_info->preflag = 0; } for (j = 0, sfb = cod_info->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++) { int j2 = j; if (scalefac->s[sfb][i] & 1) { scalefac->s[sfb][i]++; for (l = start; l < end; l++) xrpow[j2++] *= ifqstep34; } scalefac->s[sfb][i] >>= 1; j += end-start; } } cod_info->scalefac_scale = 1; } /************************************************************************* * * inc_subblock_gain() * * Takehiro Tominaga 2000-xx-xx * * increases the subblock gain and adjusts scalefactors * *************************************************************************/ static int inc_subblock_gain ( const lame_internal_flags * const gfc, gr_info * const cod_info, III_scalefac_t * const scalefac, FLOAT8 xrpow[576] ) { int window; for (window = 0; window < 3; window++) { int s1, s2, l; int sfb; s1 = s2 = 0; for (sfb = cod_info->sfb_smin; sfb < 6; sfb++) { if (s1 < scalefac->s[sfb][window]) s1 = scalefac->s[sfb][window]; } for (; sfb < SBPSY_s; sfb++) { if (s2 < scalefac->s[sfb][window]) s2 = scalefac->s[sfb][window]; } if (s1 < 16 && s2 < 8) continue; if (cod_info->subblock_gain[window] >= 7) return 1; /* even though there is no scalefactor for sfb12 * subblock gain affects upper frequencies too, that's why * we have to go up to SBMAX_s */ cod_info->subblock_gain[window]++; for (sfb = cod_info->sfb_smin; sfb < SBMAX_s; sfb++) { int i, width; int s = scalefac->s[sfb][window]; FLOAT8 amp; if (s < 0) continue; s = s - (4 >> cod_info->scalefac_scale); if (s >= 0) { scalefac->s[sfb][window] = s; continue; } scalefac->s[sfb][window] = 0; width = gfc->scalefac_band.s[sfb] - gfc->scalefac_band.s[sfb+1]; i = gfc->scalefac_band.s[sfb] * 3 + width * window; amp = IPOW20(210 + (s << (cod_info->scalefac_scale + 1))); for (l = 0; l < width; l++) { xrpow[l] *= amp; } } } return 0; } /******************************************************************** * * balance_noise() * * Takehiro Tominaga /date?? * Robert Hegemann 2000-09-06: made a function of it * * amplifies scalefactor bands, * - if all are already amplified returns 0 * - if some bands are amplified too much: * * try to increase scalefac_scale * * if already scalefac_scale was set * try on short blocks to increase subblock gain * ********************************************************************/ inline static int balance_noise ( lame_global_flags *const gfp, gr_info * const cod_info, III_scalefac_t * const scalefac, III_psy_xmin *distort, FLOAT8 xrpow[576] ) { lame_internal_flags *const gfc = (lame_internal_flags *)gfp->internal_flags; int status; amp_scalefac_bands ( gfp, cod_info, scalefac, distort, xrpow); /* check to make sure we have not amplified too much * loop_break returns 0 if there is an unamplified scalefac * scale_bitcount returns 0 if no scalefactors are too large */ status = loop_break (cod_info, scalefac); if (status) return 0; /* all bands amplified */ /* not all scalefactors have been amplified. so these * scalefacs are possibly valid. encode them: */ if (gfc->is_mpeg1) status = scale_bitcount (scalefac, cod_info); else status = scale_bitcount_lsf (gfc, scalefac, cod_info); if (!status) return 1; /* amplified some bands not exceeding limits */ /* some scalefactors are too large. * lets try setting scalefac_scale=1 */ if (gfc->noise_shaping > 1) { if (!cod_info->scalefac_scale) { inc_scalefac_scale (gfc, cod_info, scalefac, xrpow); status = 0; } else { if (cod_info->block_type == SHORT_TYPE ) { status = inc_subblock_gain (gfc, cod_info, scalefac, xrpow) || loop_break (cod_info, scalefac); } } } if (!status) { if (gfc->is_mpeg1 == 1) status = scale_bitcount (scalefac, cod_info); else status = scale_bitcount_lsf (gfc, scalefac, cod_info); } return !status; } /************************************************************************ * * outer_loop () * * Function: The outer iteration loop controls the masking conditions * of all scalefactorbands. It computes the best scalefac and * global gain. This module calls the inner iteration loop * * mt 5/99 completely rewritten to allow for bit reservoir control, * mid/side channels with L/R or mid/side masking thresholds, * and chooses best quantization instead of last quantization when * no distortion free quantization can be found. * * added VBR support mt 5/99 * * some code shuffle rh 9/00 ************************************************************************/ static int outer_loop ( lame_global_flags *gfp, gr_info * const cod_info, const FLOAT8 xr[576], /* magnitudes of spectral values */ const III_psy_xmin * const l3_xmin, /* allowed distortion of the scalefactor */ III_scalefac_t * const scalefac, /* scalefactors */ FLOAT8 xrpow[576], /* coloured magnitudes of spectral values */ int l3enc[576], /* vector of quantized values ix(0..575) */ const int ch, const int targ_bits ) /* maximum allowed bits */ { lame_internal_flags *gfc=gfp->internal_flags; III_scalefac_t save_scalefac; gr_info save_cod_info; FLOAT8 save_xrpow[576]; III_psy_xmin distort; calc_noise_result noise_info; calc_noise_result best_noise_info; int l3_enc_w[576]; int iteration = 0; int bits_found = 0; int huff_bits; int real_bits; int better; int over=0; int notdone = 1; int copy = 0; int age = 0; noise_info.over_count = 100; noise_info.tot_count = 100; noise_info.max_noise = 0; noise_info.tot_noise = 0; noise_info.over_noise = 0; best_noise_info.over_count = 100; bits_found = bin_search_StepSize (gfc, cod_info, targ_bits, gfc->OldValue[ch], xrpow, l3_enc_w); gfc->OldValue[ch] = cod_info->global_gain; /* BEGIN MAIN LOOP */ do { iteration ++; /* inner_loop starts with the initial quantization step computed above * and slowly increases until the bits < huff_bits. * Thus it is important not to start with too large of an inital * quantization step. Too small is ok, but inner_loop will take longer */ huff_bits = targ_bits - cod_info->part2_length; if (huff_bits < 0) { assert(iteration != 1); /* scale factors too large, not enough bits. * use previous quantizaton */ break; } /* if this is the first iteration, * see if we can reuse the quantization computed in * bin_search_StepSize above */ if (iteration == 1) { if (bits_found > huff_bits) { cod_info->global_gain++; real_bits = inner_loop (gfc, cod_info, huff_bits, xrpow, l3_enc_w); } else { real_bits = bits_found; } } else { real_bits = inner_loop (gfc, cod_info, huff_bits, xrpow, l3_enc_w); } cod_info->part2_3_length = real_bits; /* compute the distortion in this quantization */ if (gfc->noise_shaping) /* coefficients and thresholds both l/r (or both mid/side) */ over = calc_noise (gfc, xr, l3_enc_w, cod_info, l3_xmin, scalefac, &distort, &noise_info); else { /* fast mode, no noise shaping, we are ready */ best_noise_info = noise_info; over = 0; copy = 0; memcpy(l3enc, l3_enc_w, sizeof(int)*576); break; } /* check if this quantization is better * than our saved quantization */ if (iteration == 1) /* the first iteration is always better */ better = 1; else better = quant_compare (gfp->experimentalX, &best_noise_info, &noise_info); /* save data so we can restore this quantization later */ if (better) { copy = 0; best_noise_info = noise_info; memcpy(l3enc, l3_enc_w, sizeof(int)*576); age = 0; } else age ++; /******************************************************************/ /* stopping criterion */ /******************************************************************/ /* if no bands with distortion and -X0, we are done */ if (0==gfc->noise_shaping_stop && 0==gfp->experimentalX && (over == 0 || best_noise_info.over_count == 0) ) break; /* Otherwise, allow up to 3 unsuccesful tries in serial, then stop * if our best quantization so far had no distorted bands. This * gives us more possibilities for different quant_compare modes. * Much more than 3 makes not a big difference, it is only slower. */ if (age > 3 && best_noise_info.over_count == 0) break; /* Check if the last scalefactor band is distorted. * in VBR mode we can't get rid of the distortion, so quit now * and VBR mode will try again with more bits. * (makes a 10% speed increase, the files I tested were * binary identical, 2000/05/20 Robert.Hegemann@gmx.de) * distort[] > 1 means noise > allowed noise */ if (gfc->sfb21_extra) { if (cod_info->block_type == SHORT_TYPE) { if (distort.s[SBMAX_s-1][0] > 1 || distort.s[SBMAX_s-1][1] > 1 || distort.s[SBMAX_s-1][2] > 1) break; } else { if (distort.l[SBMAX_l-1] > 1) break; } } /* save data so we can restore this quantization later */ if (better) { copy = 1; save_scalefac = *scalefac; save_cod_info = *cod_info; if (gfp->VBR == vbr_rh || gfp->VBR == vbr_mtrh) { /* store for later reuse */ memcpy(save_xrpow, xrpow, sizeof(FLOAT8)*576); } } notdone = balance_noise (gfp, cod_info, scalefac, &distort, xrpow); if (notdone == 0) break; } while (1); /* main iteration loop, breaks adjusted */ /* finish up */ if (copy) { *cod_info = save_cod_info; *scalefac = save_scalefac; if (gfp->VBR == vbr_rh || gfp->VBR == vbr_mtrh) /* restore for reuse on next try */ memcpy(xrpow, save_xrpow, sizeof(FLOAT8)*576); } cod_info->part2_3_length += cod_info->part2_length; assert (cod_info->global_gain < 256); return best_noise_info.over_count; } /************************************************************************ * * iteration_finish() * * Robert Hegemann 2000-09-06 * * update reservoir status after FINAL quantization/bitrate * * rh 2000-09-06: it will not work with CBR due to the bitstream formatter * you will get "Error: MAX_HEADER_BUF too small in bitstream.c" * ************************************************************************/ static void iteration_finish ( lame_internal_flags *gfc, FLOAT8 xr [2][2][576], int l3_enc [2][2][576], III_psy_ratio ratio [2][2], III_scalefac_t scalefac[2][2], const int mean_bits ) { III_side_info_t *l3_side = &gfc->l3_side; int gr, ch, i; for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < gfc->channels_out; ch++) { gr_info *cod_info = &l3_side->gr[gr].ch[ch].tt; /* try some better scalefac storage */ best_scalefac_store (gfc, gr, ch, l3_enc, l3_side, scalefac); /* best huffman_divide may save some bits too */ if (gfc->use_best_huffman == 1) best_huffman_divide (gfc, gr, ch, cod_info, l3_enc[gr][ch]); /* update reservoir status after FINAL quantization/bitrate */ ResvAdjust (gfc, cod_info, l3_side, mean_bits); /* set the sign of l3_enc from the sign of xr */ for (i = 0; i < 576; i++) { if (xr[gr][ch][i] < 0) l3_enc[gr][ch][i] *= -1; } } /* for ch */ } /* for gr */ ResvFrameEnd (gfc, l3_side, mean_bits); } /********************************************************************* * * VBR_encode_granule() * * 2000-09-04 Robert Hegemann * *********************************************************************/ static void VBR_encode_granule ( lame_global_flags *gfp, gr_info * const cod_info, FLOAT8 xr[576], /* magnitudes of spectral values */ const III_psy_xmin * const l3_xmin, /* allowed distortion of the scalefactor */ III_scalefac_t * const scalefac, /* scalefactors */ FLOAT8 xrpow[576], /* coloured magnitudes of spectral values */ int l3_enc[576], /* vector of quantized values ix(0..575) */ const int ch, int min_bits, int max_bits ) { //lame_internal_flags *gfc=gfp->internal_flags; gr_info bst_cod_info; III_scalefac_t bst_scalefac; FLOAT8 bst_xrpow [576]; int bst_l3_enc[576]; int Max_bits = max_bits; int real_bits = max_bits+1; int this_bits = min_bits+(max_bits-min_bits)/2; int dbits, over; assert(Max_bits <= MAX_BITS); bst_cod_info = *cod_info; memset(&bst_scalefac, 0, sizeof(III_scalefac_t)); memcpy(&bst_xrpow, xrpow, sizeof(FLOAT8)*576); /* search within round about 40 bits of optimal */ do { assert(this_bits >= min_bits); assert(this_bits <= max_bits); over = outer_loop ( gfp, cod_info, xr, l3_xmin, scalefac, xrpow, l3_enc, ch, this_bits ); /* is quantization as good as we are looking for ? * in this case: is no scalefactor band distorted? */ if (over <= 0) { /* now we know it can be done with "real_bits" * and maybe we can skip some iterations */ real_bits = cod_info->part2_3_length; /* store best quantization so far */ bst_cod_info = *cod_info; bst_scalefac = *scalefac; memcpy(bst_xrpow, xrpow, sizeof(FLOAT8)*576); memcpy(bst_l3_enc, l3_enc, sizeof(int)*576); /* try with fewer bits */ max_bits = real_bits-32; dbits = max_bits-min_bits; this_bits = min_bits+dbits/2; } else { /* try with more bits */ min_bits = this_bits+32; dbits = max_bits-min_bits; this_bits = min_bits+dbits/2; if (dbits>8) { /* start again with best quantization so far */ *cod_info = bst_cod_info; *scalefac = bst_scalefac; memcpy(xrpow, bst_xrpow, sizeof(FLOAT8)*576); } } } while (dbits>8); if (real_bits <= Max_bits) { /* restore best quantization found */ *cod_info = bst_cod_info; *scalefac = bst_scalefac; memcpy(l3_enc, bst_l3_enc, sizeof(int)*576); } assert(cod_info->part2_3_length <= Max_bits); } /************************************************************************ * * get_framebits() * * Robert Hegemann 2000-09-05 * * calculates * * how many bits are available for analog silent granules * * how many bits to use for the lowest allowed bitrate * * how many bits each bitrate would provide * ************************************************************************/ static void get_framebits ( lame_global_flags *gfp, int * const analog_mean_bits, int * const min_mean_bits, int frameBits[15] ) { lame_internal_flags *gfc=gfp->internal_flags; int bitsPerFrame, mean_bits, i; III_side_info_t *l3_side = &gfc->l3_side; /* always use at least this many bits per granule per channel * unless we detect analog silence, see below */ gfc->bitrate_index = gfc->VBR_min_bitrate; getframebits (gfp, &bitsPerFrame, &mean_bits); *min_mean_bits = mean_bits / gfc->channels_out; /* bits for analog silence */ gfc->bitrate_index = 1; getframebits (gfp, &bitsPerFrame, &mean_bits); *analog_mean_bits = mean_bits / gfc->channels_out; for (i = 1; i <= gfc->VBR_max_bitrate; i++) { gfc->bitrate_index = i; getframebits (gfp, &bitsPerFrame, &mean_bits); frameBits[i] = ResvFrameBegin (gfp, l3_side, mean_bits, bitsPerFrame); } } /************************************************************************ * * calc_min_bits() * * Robert Hegemann 2000-09-04 * * determine minimal bit skeleton * ************************************************************************/ inline static int calc_min_bits ( lame_global_flags *gfp, const gr_info * const cod_info, const int pe, const FLOAT8 ms_ener_ratio, const int bands, const int mch_bits, const int analog_mean_bits, const int min_mean_bits, const int analog_silence, const int ch ) { lame_internal_flags *gfc=gfp->internal_flags; int min_bits, min_pe_bits; if (gfc->nsPsy.use) return 1; /* base amount of minimum bits */ min_bits = Max (125, min_mean_bits); if (gfc->mode_ext == MPG_MD_MS_LR && ch == 1) min_bits = Max (min_bits, mch_bits/5); /* bit skeleton based on PE */ if (cod_info->block_type == SHORT_TYPE) /* if LAME switches to short blocks then pe is * >= 1000 on medium surge * >= 3000 on big surge */ min_pe_bits = (pe-350) * bands/39; else min_pe_bits = (pe-350) * bands/22; if (gfc->mode_ext == MPG_MD_MS_LR && ch == 1) { /* side channel will use a lower bit skeleton based on PE */ FLOAT8 fac = .33 * (.5 - ms_ener_ratio) / .5; min_pe_bits = (int)(min_pe_bits * ((1-fac)/(1+fac))); } min_pe_bits = Min (min_pe_bits, (1820 * gfp->out_samplerate / 44100)); /* determine final minimum bits */ if (analog_silence && !gfp->VBR_hard_min) min_bits = analog_mean_bits; else min_bits = Max (min_bits, min_pe_bits); return min_bits; } /************************************************************************ * * calc_max_bits() * * Robert Hegemann 2000-09-05 * * determine maximal bit skeleton * ************************************************************************/ inline static int calc_max_bits ( const lame_internal_flags * const gfc, const int frameBits[15], const int min_bits ) { int max_bits; max_bits = frameBits[gfc->VBR_max_bitrate]; max_bits /= gfc->channels_out * gfc->mode_gr; max_bits = Min (1200 + max_bits, MAX_BITS - 195 * (gfc->channels_out - 1)); max_bits = Max (max_bits, min_bits); return max_bits; } /********************************************************************* * * VBR_prepare() * * 2000-09-04 Robert Hegemann * * * converts LR to MS coding when necessary * * calculates allowed/adjusted quantization noise amounts * * detects analog silent frames * * some remarks: * - lower masking depending on Quality setting * - quality control together with adjusted ATH MDCT scaling * on lower quality setting allocate more noise from * ATH masking, and on higher quality setting allocate * less noise from ATH masking. * - experiments show that going more than 2dB over GPSYCHO's * limits ends up in very annoying artefacts * *********************************************************************/ /* RH: this one needs to be overhauled sometime */ static int VBR_prepare ( lame_global_flags *gfp, FLOAT8 pe [2][2], FLOAT8 ms_ener_ratio [2], FLOAT8 xr [2][2][576], III_psy_ratio ratio [2][2], III_psy_xmin l3_xmin [2][2], int frameBits [16], int *analog_mean_bits, int *min_mean_bits, int min_bits [2][2], int max_bits [2][2], int bands [2][2] ) { lame_internal_flags *gfc=gfp->internal_flags; static const FLOAT8 dbQ[10]={-2.,-1.0,-.66,-.33,0.,0.33,.66,1.0,1.33,1.66}; static const FLOAT8 dbQns[10]={- 4,- 3,-2,-1,0,0.7,1.4,2.1,2.8,3.5}; /*static const FLOAT8 atQns[10]={-16,-12,-8,-4,0, 1, 2, 3, 4, 5};*/ static const FLOAT8 dbQmtrh[10]= { -4., -3., -2., -1., 0., 0.5, 1., 1.5, 2., 2.5 }; FLOAT8 masking_lower_db, adjust = 0.0; int gr, ch; int used_bits = 0, bits; int analog_silence = 1; assert( gfp->VBR_q <= 9 ); assert( gfp->VBR_q >= 0 ); get_framebits (gfp, analog_mean_bits, min_mean_bits, frameBits); for (gr = 0; gr < gfc->mode_gr; gr++) { if (gfc->mode_ext == MPG_MD_MS_LR) ms_convert (xr[gr], xr[gr]); for (ch = 0; ch < gfc->channels_out; ch++) { gr_info *cod_info = &gfc->l3_side.gr[gr].ch[ch].tt; if (cod_info->block_type == SHORT_TYPE) adjust = 5/(1+exp(3.5-pe[gr][ch]/300.))-0.14; else adjust = 2/(1+exp(3.5-pe[gr][ch]/300.))-0.05; if (vbr_mtrh == gfp->VBR) { masking_lower_db = dbQmtrh[gfp->VBR_q] - adjust; } else if (gfc->nsPsy.use && gfp->ATHtype == 0) { masking_lower_db = dbQns[gfp->VBR_q] - adjust; } else { masking_lower_db = dbQ[gfp->VBR_q] - adjust; } gfc->masking_lower = pow (10.0, masking_lower_db * 0.1); bands[gr][ch] = calc_xmin (gfp, xr[gr][ch], ratio[gr]+ch, cod_info, l3_xmin[gr]+ch); if (bands[gr][ch]) analog_silence = 0; min_bits[gr][ch] = calc_min_bits (gfp, cod_info, (int)pe[gr][ch], ms_ener_ratio[gr], bands[gr][ch], 0, *analog_mean_bits, *min_mean_bits, analog_silence, ch); max_bits[gr][ch] = calc_max_bits (gfc, frameBits, min_bits[gr][ch]); used_bits += min_bits[gr][ch]; } /* for ch */ } /* for gr */ *min_mean_bits = Max(125, *min_mean_bits); bits = 0.8*frameBits[gfc->VBR_max_bitrate]; if (used_bits >= bits) for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < gfc->channels_out; ch++) { min_bits[gr][ch] *= bits; min_bits[gr][ch] /= used_bits; if (min_bits[gr][ch] < *min_mean_bits) min_bits[gr][ch] = *min_mean_bits; max_bits[gr][ch] *= bits; max_bits[gr][ch] /= used_bits; if (max_bits[gr][ch] < *min_mean_bits) max_bits[gr][ch] = *min_mean_bits; } } return analog_silence; } /************************************************************************ * * VBR_iteration_loop() * * tries to find out how many bits are needed for each granule and channel * to get an acceptable quantization. An appropriate bitrate will then be * choosed for quantization. rh 8/99 * * Robert Hegemann 2000-09-06 rewrite * ************************************************************************/ void VBR_iteration_loop ( lame_global_flags *gfp, FLOAT8 pe [2][2], FLOAT8 ms_ener_ratio[2], FLOAT8 xr [2][2][576], III_psy_ratio ratio [2][2], int l3_enc [2][2][576], III_scalefac_t scalefac [2][2] ) { lame_internal_flags *gfc=gfp->internal_flags; III_psy_xmin l3_xmin[2][2]; FLOAT8 xrpow[576]; int bands[2][2]; int frameBits[15]; int bitsPerFrame; int save_bits[2][2]; int used_bits, used_bits2; int bits; int min_bits[2][2], max_bits[2][2]; int analog_mean_bits, min_mean_bits; int mean_bits; int ch, num_chan, gr, analog_silence; int reduce_s_ch, sfb21_extra; gr_info *cod_info; III_side_info_t *l3_side = &gfc->l3_side; if (gfc->mode_ext == MPG_MD_MS_LR && gfp->quality >= 5) { /* my experiences are, that side channel reduction * does more harm than good when VBR encoding * (Robert.Hegemann@gmx.de 2000-02-18) * 2000-09-06: code is enabled at quality level 5 */ reduce_s_ch = 1; num_chan = 1; } else { reduce_s_ch = 0; num_chan = gfc->channels_out; } analog_silence = VBR_prepare (gfp, pe, ms_ener_ratio, xr, ratio, l3_xmin, frameBits, &analog_mean_bits, &min_mean_bits, min_bits, max_bits, bands); /*---------------------------------*/ do { /* quantize granules with lowest possible number of bits */ used_bits = 0; used_bits2 = 0; for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < num_chan; ch++) { int ret; cod_info = &l3_side->gr[gr].ch[ch].tt; /* init_outer_loop sets up cod_info, scalefac and xrpow */ ret = init_outer_loop(cod_info, &scalefac[gr][ch], gfc->is_mpeg1, xr[gr][ch], xrpow); if (ret == 0) { /* xr contains no energy * l3_enc, our encoding data, will be quantized to zero */ memset(l3_enc[gr][ch], 0, sizeof(int)*576); save_bits[gr][ch] = 0; continue; /* with next channel */ } #if 0 if (gfc->mode_ext == MPG_MD_MS_LR && ch == 1) min_bits[gr][ch] = Max (min_bits[gr][ch], save_bits[gr][0]/5); #endif if (gfp->VBR == vbr_mtrh) { ret = VBR_noise_shaping2 (gfp, xr[gr][ch], xrpow, &ratio[gr][ch], l3_enc[gr][ch], 0, min_bits[gr][ch], max_bits[gr][ch], &scalefac[gr][ch], &l3_xmin[gr][ch], gr, ch ); if (ret < 0) cod_info->part2_3_length = 100000; } else VBR_encode_granule (gfp, cod_info, xr[gr][ch], &l3_xmin[gr][ch], &scalefac[gr][ch], xrpow, l3_enc[gr][ch], ch, min_bits[gr][ch], max_bits[gr][ch] ); used_bits += cod_info->part2_3_length; save_bits[gr][ch] = Min(MAX_BITS, cod_info->part2_3_length); used_bits2 += Min(MAX_BITS, cod_info->part2_3_length); } /* for ch */ } /* for gr */ /* special on quality=5, we didn't quantize side channel above */ if (reduce_s_ch) { /* number of bits needed was found for MID channel above. Use formula * (fixed bitrate code) to set the side channel bits */ for (gr = 0; gr < gfc->mode_gr; gr++) { FLOAT8 fac = .33*(.5-ms_ener_ratio[gr])/.5; save_bits[gr][1] = (int)(((1-fac)/(1+fac)) * save_bits[gr][0]); save_bits[gr][1] = Max (analog_mean_bits, save_bits[gr][1]); used_bits += save_bits[gr][1]; } } /* find lowest bitrate able to hold used bits */ if (analog_silence && !gfp->VBR_hard_min) /* we detected analog silence and the user did not specify * any hard framesize limit, so start with smallest possible frame */ gfc->bitrate_index = 1; else gfc->bitrate_index = gfc->VBR_min_bitrate; for( ; gfc->bitrate_index < gfc->VBR_max_bitrate; gfc->bitrate_index++) { if (used_bits <= frameBits[gfc->bitrate_index]) break; } getframebits (gfp, &bitsPerFrame, &mean_bits); bits = ResvFrameBegin (gfp, l3_side, mean_bits, bitsPerFrame); if (used_bits > bits){ //printf("# %d used %d have %d\n",gfp->frameNum,used_bits,bits); if(gfp->VBR == vbr_mtrh) { for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < gfc->channels_out; ch++) { max_bits[gr][ch] = save_bits[gr][ch]; max_bits[gr][ch] *= frameBits[gfc->bitrate_index]; max_bits[gr][ch] /= used_bits2; max_bits[gr][ch] = Max(min_bits[gr][ch],max_bits[gr][ch]); } } } else { for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < gfc->channels_out; ch++) { int sfb; cod_info = &l3_side->gr[gr].ch[ch].tt; if (cod_info->block_type == SHORT_TYPE) { for (sfb = 0; sfb < SBMAX_s; sfb++) { l3_xmin[gr][ch].s[sfb][0] *= 1.+.029*sfb*sfb/SBMAX_s/SBMAX_s; l3_xmin[gr][ch].s[sfb][1] *= 1.+.029*sfb*sfb/SBMAX_s/SBMAX_s; l3_xmin[gr][ch].s[sfb][2] *= 1.+.029*sfb*sfb/SBMAX_s/SBMAX_s; } } else { for (sfb = 0; sfb < SBMAX_l; sfb++) l3_xmin[gr][ch].l[sfb] *= 1.+.029*sfb*sfb/SBMAX_l/SBMAX_l; } // min_bits[gr][ch] = Max(min_mean_bits, 0.9*min_bits[gr][ch]); max_bits[gr][ch] = Max(min_mean_bits, 0.9*max_bits[gr][ch]); } } } } } while (used_bits > bits); /*--------------------------------------*/ /* ignore sfb21 by the following (maybe) noise shaping */ sfb21_extra = gfc->sfb21_extra; gfc->sfb21_extra = 0; /* quantize granules which violate bit constraints again * and side channel when in quality=5 reduce_side is used */ for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < gfc->channels_out; ch++) { int ret; cod_info = &l3_side->gr[gr].ch[ch].tt; if (used_bits <= bits && ! (reduce_s_ch && ch == 1)) /* we have enough bits * and have already encoded the side channel */ continue; /* with next ch */ if (used_bits > bits) { /* repartion available bits in same proportion */ save_bits[gr][ch] *= frameBits[gfc->bitrate_index]; save_bits[gr][ch] /= used_bits; } /* init_outer_loop sets up cod_info, scalefac and xrpow */ ret = init_outer_loop(cod_info, &scalefac[gr][ch], gfc->is_mpeg1, xr[gr][ch], xrpow); if (ret == 0) { /* xr contains no energy * l3_enc, our encoding data, will be quantized to zero */ memset(l3_enc[gr][ch], 0, sizeof(int)*576); } else { /* xr contains energy we will have to encode * masking abilities were previously calculated * find some good quantization in outer_loop */ outer_loop (gfp, cod_info, xr[gr][ch], &l3_xmin[gr][ch], &scalefac[gr][ch], xrpow, l3_enc[gr][ch], ch, save_bits[gr][ch]); } } /* ch */ } /* gr */ gfc->sfb21_extra = sfb21_extra; iteration_finish (gfc, xr, l3_enc, ratio, scalefac, mean_bits); } /******************************************************************** * * calc_target_bits() * * calculates target bits for ABR encoding * * mt 2000/05/31 * ********************************************************************/ static void calc_target_bits ( lame_global_flags * gfp, FLOAT8 pe [2][2], FLOAT8 ms_ener_ratio [2], int targ_bits [2][2], int *analog_silence_bits, int *max_frame_bits ) { lame_internal_flags *gfc=gfp->internal_flags; III_side_info_t *l3_side = &gfc->l3_side; FLOAT8 res_factor; int gr, ch, totbits, mean_bits, bitsPerFrame; gfc->bitrate_index = gfc->VBR_max_bitrate; getframebits (gfp, &bitsPerFrame, &mean_bits); *max_frame_bits = ResvFrameBegin (gfp, l3_side, mean_bits, bitsPerFrame); gfc->bitrate_index = 1; getframebits (gfp, &bitsPerFrame, &mean_bits); *analog_silence_bits = mean_bits / gfc->channels_out; mean_bits = gfp->VBR_mean_bitrate_kbps * gfp->framesize * 1000; mean_bits /= gfp->out_samplerate; mean_bits -= gfc->sideinfo_len*8; mean_bits /= gfc->mode_gr; res_factor = .90 + .10 * (11.0 - gfp->compression_ratio) / (11.0 - 5.5); if (res_factor < .90) res_factor = .90; if (res_factor > 1.00) res_factor = 1.00; for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < gfc->channels_out; ch++) { targ_bits[gr][ch] = res_factor * (mean_bits / gfc->channels_out); if (pe[gr][ch] > 700) { int add_bits = (pe[gr][ch] - 700) / 1.4; gr_info *cod_info = &l3_side->gr[gr].ch[ch].tt; targ_bits[gr][ch] = res_factor * (mean_bits / gfc->channels_out); /* short blocks use a little extra, no matter what the pe */ if (cod_info->block_type == SHORT_TYPE) { if (add_bits < mean_bits/4) add_bits = mean_bits/4; } /* at most increase bits by 1.5*average */ if (add_bits > mean_bits*3/4) add_bits = mean_bits*3/4; else if (add_bits < 0) add_bits = 0; targ_bits[gr][ch] += add_bits; } }/* for ch */ } /* for gr */ if (gfc->mode_ext == MPG_MD_MS_LR) for (gr = 0; gr < gfc->mode_gr; gr++) { reduce_side (targ_bits[gr], ms_ener_ratio[gr], mean_bits, MAX_BITS); } /* sum target bits */ totbits=0; for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < gfc->channels_out; ch++) { if (targ_bits[gr][ch] > MAX_BITS) targ_bits[gr][ch] = MAX_BITS; totbits += targ_bits[gr][ch]; } } /* repartion target bits if needed */ if (totbits > *max_frame_bits) { for(gr = 0; gr < gfc->mode_gr; gr++) { for(ch = 0; ch < gfc->channels_out; ch++) { targ_bits[gr][ch] *= *max_frame_bits; targ_bits[gr][ch] /= totbits; } } } } /******************************************************************** * * ABR_iteration_loop() * * encode a frame with a disired average bitrate * * mt 2000/05/31 * ********************************************************************/ void ABR_iteration_loop( lame_global_flags *gfp, FLOAT8 pe [2][2], FLOAT8 ms_ener_ratio[2], FLOAT8 xr [2][2][576], III_psy_ratio ratio [2][2], int l3_enc [2][2][576], III_scalefac_t scalefac [2][2] ) { lame_internal_flags *gfc=gfp->internal_flags; III_psy_xmin l3_xmin; FLOAT8 xrpow[576]; int targ_bits[2][2]; int bitsPerFrame, mean_bits, totbits, max_frame_bits; int ch, gr, ath_over, ret; int analog_silence_bits; gr_info *cod_info = NULL; III_side_info_t *l3_side = &gfc->l3_side; calc_target_bits (gfp, pe, ms_ener_ratio, targ_bits, &analog_silence_bits, &max_frame_bits); /* encode granules */ totbits=0; for (gr = 0; gr < gfc->mode_gr; gr++) { if (gfc->mode_ext == MPG_MD_MS_LR) ms_convert (xr[gr], xr[gr]); for (ch = 0; ch < gfc->channels_out; ch++) { cod_info = &l3_side->gr[gr].ch[ch].tt; /* cod_info, scalefac and xrpow get initialized in init_outer_loop */ ret = init_outer_loop(cod_info, &scalefac[gr][ch], gfc->is_mpeg1, xr[gr][ch], xrpow); if (ret == 0) { /* xr contains no energy * l3_enc, our encoding data, will be quantized to zero */ memset(l3_enc[gr][ch], 0, sizeof(int)*576); } else { /* xr contains energy we will have to encode * calculate the masking abilities * find some good quantization in outer_loop */ ath_over = calc_xmin (gfp, xr[gr][ch], &ratio[gr][ch], cod_info, &l3_xmin); if (0 == ath_over) /* analog silence */ targ_bits[gr][ch] = analog_silence_bits; outer_loop (gfp, cod_info, xr[gr][ch], &l3_xmin, &scalefac[gr][ch], xrpow, l3_enc[gr][ch], ch, targ_bits[gr][ch]); } totbits += cod_info->part2_3_length; } /* ch */ } /* gr */ /* find a bitrate which can handle totbits */ for (gfc->bitrate_index = gfc->VBR_min_bitrate ; gfc->bitrate_index <= gfc->VBR_max_bitrate; gfc->bitrate_index++ ) { getframebits (gfp, &bitsPerFrame, &mean_bits); max_frame_bits = ResvFrameBegin (gfp, l3_side, mean_bits, bitsPerFrame); if (totbits <= max_frame_bits) break; } assert (gfc->bitrate_index <= gfc->VBR_max_bitrate); iteration_finish (gfc, xr, l3_enc, ratio, scalefac, mean_bits); } /************************************************************************ * * iteration_loop() * * author/date?? * * encodes one frame of MP3 data with constant bitrate * ************************************************************************/ void iteration_loop( lame_global_flags *gfp, FLOAT8 pe [2][2], FLOAT8 ms_ener_ratio[2], FLOAT8 xr [2][2][576], III_psy_ratio ratio [2][2], int l3_enc [2][2][576], III_scalefac_t scalefac [2][2] ) { lame_internal_flags *gfc=gfp->internal_flags; III_psy_xmin l3_xmin[2]; FLOAT8 xrpow[576]; int targ_bits[2]; int bitsPerFrame; int mean_bits, max_bits, bit_rate; int gr, ch, i; III_side_info_t *l3_side = &gfc->l3_side; gr_info *cod_info; bit_rate = bitrate_table [gfp->version] [gfc->bitrate_index]; getframebits (gfp, &bitsPerFrame, &mean_bits); ResvFrameBegin (gfp, l3_side, mean_bits, bitsPerFrame ); /* quantize! */ for (gr = 0; gr < gfc->mode_gr; gr++) { /* calculate needed bits */ max_bits = on_pe (gfp, pe, l3_side, targ_bits, mean_bits, gr); if (gfc->mode_ext == MPG_MD_MS_LR) { ms_convert (xr[gr], xr[gr]); reduce_side (targ_bits, ms_ener_ratio[gr], mean_bits, max_bits); } for (ch=0 ; ch < gfc->channels_out ; ch ++) { cod_info = &l3_side->gr[gr].ch[ch].tt; /* init_outer_loop sets up cod_info, scalefac and xrpow */ i = init_outer_loop(cod_info, &scalefac[gr][ch], gfc->is_mpeg1, xr[gr][ch], xrpow); if (i == 0) { /* xr contains no energy, l3_enc will be quantized to zero */ memset(l3_enc[gr][ch], 0, sizeof(int)*576); } else { /* xr contains energy we will have to encode * calculate the masking abilities * find some good quantization in outer_loop */ calc_xmin (gfp, xr[gr][ch], &ratio[gr][ch], cod_info, &l3_xmin[ch]); outer_loop (gfp, cod_info, xr[gr][ch], &l3_xmin[ch], &scalefac[gr][ch], xrpow, l3_enc[gr][ch], ch, targ_bits[ch]); } assert (cod_info->part2_3_length <= MAX_BITS); /* try some better scalefac storage */ best_scalefac_store (gfc, gr, ch, l3_enc, l3_side, scalefac); /* best huffman_divide may save some bits too */ if (gfc->use_best_huffman == 1) best_huffman_divide (gfc, gr, ch, cod_info, l3_enc[gr][ch]); /* update reservoir status after FINAL quantization/bitrate */ #undef NORES_TEST #ifndef NORES_TEST ResvAdjust (gfc, cod_info, l3_side, mean_bits); #endif /* set the sign of l3_enc from the sign of xr */ for (i = 0; i < 576; i++) { if (xr[gr][ch][i] < 0) l3_enc[gr][ch][i] *= -1; } } /* for ch */ } /* for gr */ #ifdef NORES_TEST /* replace ResvAdjust above with this code if you do not want the second granule to use bits saved by the first granule. Requires using the --nores. This is useful for testing only */ for (gr = 0; gr < gfc->mode_gr; gr++) { for (ch = 0; ch < gfc->channels_out; ch++) { cod_info = &l3_side->gr[gr].ch[ch].tt; ResvAdjust (gfc, cod_info, l3_side, mean_bits); } } #endif ResvFrameEnd (gfc, l3_side, mean_bits); }