lame.c

音频编码

    for (i = 0; i < SBMAX_s + 1; i++)
        gfc->scalefac_band.s[i] = sfBandIndex[j].s[i];

    for (i = 0; i < PSFB12 + 1; i++){
        int size = (gfc->scalefac_band.s[ 13 ] - gfc->scalefac_band.s[ 12 ])/PSFB12;
        int start = gfc->scalefac_band.s[ 12 ] + i*size;
        gfc->scalefac_band.psfb12[i] = start;
    }
    gfc->scalefac_band.psfb12[PSFB12] = 192;

    /* determine the mean bitrate for main data */
    if (gfp->version == 1) /* MPEG 1 */
        gfc->sideinfo_len = (gfc->channels_out == 1) ? 4 + 17 : 4 + 32;
    else                /* MPEG 2 */
        gfc->sideinfo_len = (gfc->channels_out == 1) ? 4 + 9 : 4 + 17;

    if (gfp->error_protection)
        gfc->sideinfo_len += 2;

    lame_init_bitstream(gfp);

    gfc->Class_ID = LAME_ID;

    /*if (gfp->exp_nspsytune & 1)*/ {
        int     i;

        for (i = 0; i < 19; i++)
            gfc->nsPsy.pefirbuf[i] = 700*gfc->mode_gr*gfc->channels_out;

        if (gfp->ATHtype == -1)
            gfp->ATHtype = 4;

	if (gfp->exp_nspsytune2.pointer[0])
	    gfc->nsPsy.pass1fp = gfp->exp_nspsytune2.pointer[0];
	else
	    gfc->nsPsy.pass1fp = NULL;
    }

    assert( gfp->VBR_q <= 9 );
    assert( gfp->VBR_q >= 0 );
    
    gfc->PSY->tonalityPatch = 0;
  
    switch (gfp->VBR) {

    case vbr_mt:
        gfp->VBR = vbr_mtrh;
        
    case vbr_mtrh: {

        apply_preset(gfp, 500 - (gfp->VBR_q*10), 0);
        
        if (gfp->quality < 0) gfp->quality = LAME_DEFAULT_QUALITY;
        if (gfp->quality > 7) {
            gfp->quality = 7;     /* needs psymodel */
            ERRORF( gfc, "VBR needs a psymodel, switching to quality level 7\n");
        }

        /*  tonality
         */
        if (gfp->cwlimit <= 0) gfp->cwlimit = 0.42 * gfp->out_samplerate;
        gfc->PSY->tonalityPatch = 1;

        gfc->PSY->mask_adjust = gfp->maskingadjust;
        gfc->PSY->mask_adjust_short = gfp->maskingadjust_short;
        
        /*  sfb21 extra only with MPEG-1 at higher sampling rates
         */
        if ( gfp->experimentalY )
            gfc->sfb21_extra = 0;
        else 
            gfc->sfb21_extra = (gfp->out_samplerate > 44000);
            
        break;
        
    }
    case vbr_rh: {

        apply_preset(gfp, 500 - (gfp->VBR_q*10), 0);
        
        gfc->PSY->mask_adjust = gfp->maskingadjust;
        gfc->PSY->mask_adjust_short = gfp->maskingadjust_short;

        if ( gfp->psymodel == PSY_GPSYCHO )
            gfc->PSY->tonalityPatch = 1;
        
        /*  sfb21 extra only with MPEG-1 at higher sampling rates
         */
        if ( gfp->experimentalY )
            gfc->sfb21_extra = 0;
        else 
            gfc->sfb21_extra = (gfp->out_samplerate > 44000);

        /*  VBR needs at least the output of GPSYCHO,
         *  so we have to garantee that by setting a minimum 
         *  quality level, actually level 6 does it.
         *  down to level 6
         */
        if (gfp->quality > 6)
            gfp->quality = 6;


        if (gfp->quality < 0)
            gfp->quality = LAME_DEFAULT_QUALITY;

        break;
    }

    default: /* cbr/abr */{
        vbr_mode vbrmode;

        /*  no sfb21 extra with CBR code
         */
        gfc->sfb21_extra = 0;

        if (gfp->quality < 0)
            gfp->quality = LAME_DEFAULT_QUALITY;


        vbrmode = lame_get_VBR(gfp);
        if (vbrmode == vbr_off)
            lame_set_VBR_mean_bitrate_kbps(gfp, gfp->brate);
        /* second, set parameters depending on bitrate */
        apply_preset(gfp, gfp->VBR_mean_bitrate_kbps, 0);
        lame_set_VBR(gfp, vbrmode);

        gfc->PSY->mask_adjust = gfp->maskingadjust;
        gfc->PSY->mask_adjust_short = gfp->maskingadjust_short;

        break;
    }
    }

    /*initialize default values common for all modes*/


    if (lame_get_VBR(gfp) != vbr_off) {              /* choose a min/max bitrate for VBR */
        /* if the user didn't specify VBR_max_bitrate: */
        gfc->VBR_min_bitrate = 1; /* default: allow   8 kbps (MPEG-2) or  32 kbps (MPEG-1) */
        gfc->VBR_max_bitrate = 14; /* default: allow 160 kbps (MPEG-2) or 320 kbps (MPEG-1) */

        if (gfp->VBR_min_bitrate_kbps)
            if (
                (gfc->VBR_min_bitrate =
                 BitrateIndex(gfp->VBR_min_bitrate_kbps, gfp->version,
                              gfp->out_samplerate)) < 0) return -1;
        if (gfp->VBR_max_bitrate_kbps)
            if (
                (gfc->VBR_max_bitrate =
                 BitrateIndex(gfp->VBR_max_bitrate_kbps, gfp->version,
                              gfp->out_samplerate)) < 0) return -1;

        gfp->VBR_min_bitrate_kbps =
            bitrate_table[gfp->version][gfc->VBR_min_bitrate];
        gfp->VBR_max_bitrate_kbps =
            bitrate_table[gfp->version][gfc->VBR_max_bitrate];

        gfp->VBR_mean_bitrate_kbps =
            Min(bitrate_table[gfp->version][gfc->VBR_max_bitrate],
                gfp->VBR_mean_bitrate_kbps);
        gfp->VBR_mean_bitrate_kbps =
            Max(bitrate_table[gfp->version][gfc->VBR_min_bitrate],
                gfp->VBR_mean_bitrate_kbps);


    }


    /*  just another daily changing developer switch  */
    if ( gfp->tune ) gfc->PSY->mask_adjust = gfp->tune_value_a;

    /* initialize internal qval settings */
    lame_init_qval(gfp);


    /*  automatic ATH adjustment on
     */
    if ( gfp->athaa_type < 0 )
        gfc->ATH->use_adjust = 3;
    else
        gfc->ATH->use_adjust = gfp->athaa_type;


    /* initialize internal adaptive ATH settings  -jd */
    gfc->ATH->aa_sensitivity_p = pow( 10.0, gfp->athaa_sensitivity / -10.0 );


    gfc->PSY->cwlimit = gfp->cwlimit <= 0 ? 8871.7f : gfp->cwlimit;
    
    if (gfp->short_blocks == short_block_not_set) {
        gfp->short_blocks =  short_block_allowed;
    }

    /*Note Jan/2003: Many hardware decoders cannot handle short blocks in regular
      stereo mode unless they are coupled (same type in both channels)
      it is a rare event (1 frame per min. or so) that LAME would use
      uncoupled short blocks, so lets turn them off until we decide
      how to handle this.  No other encoders allow uncoupled short blocks,
      even though it is in the standard.  */
    /* rh 20040217: coupling makes no sense for mono and dual-mono streams
     */
    if (gfp->short_blocks == short_block_allowed && (gfp->mode == JOINT_STEREO || gfp->mode == STEREO) ) {
        gfp->short_blocks =  short_block_coupled;
    } 

    
    if (lame_get_quant_comp(gfp) < 0 ) lame_set_quant_comp(gfp, 1);
    if (lame_get_quant_comp_short(gfp) < 0 ) lame_set_quant_comp_short(gfp, 0);

    if (lame_get_msfix(gfp) < 0 ) lame_set_msfix(gfp, 0);

    /* select psychoacoustic model */
    if ((lame_get_psy_model(gfp) < 0) ||
        (lame_get_psy_model(gfp) == PSY_NSPSYTUNE)) {
        lame_set_psy_model(gfp, PSY_NSPSYTUNE);
        lame_set_exp_nspsytune(gfp, lame_get_exp_nspsytune(gfp) | 1);
    } else {
        lame_set_psy_model(gfp, PSY_GPSYCHO);
        lame_set_exp_nspsytune(gfp, (lame_get_exp_nspsytune(gfp) >> 1) << 1);
    }


    if (lame_get_short_threshold_lrm(gfp) < 0 ) lame_set_short_threshold_lrm(gfp, NSATTACKTHRE);
    if (lame_get_short_threshold_s(gfp) < 0 ) lame_set_short_threshold_s(gfp, NSATTACKTHRE_S);

    if ( gfp->scale < 0 ) gfp->scale = 1;
    
    if (gfp->ATHtype < 0) gfp->ATHtype = 4;

    if ( gfp->ATHcurve < 0 ) gfp->ATHcurve = 4;
    
    if ( gfp->athaa_loudapprox < 0 ) gfp->athaa_loudapprox = 2;
    
    if (gfp->interChRatio < 0 ) gfp->interChRatio = 0;

    if (gfp->useTemporal < 0 ) gfp->useTemporal = 1;  /* on by default */



    /* padding method as described in 
     * "MPEG-Layer3 / Bitstream Syntax and Decoding"
     * by Martin Sieler, Ralph Sperschneider
     *
     * note: there is no padding for the very first frame
     *
     * Robert Hegemann 2000-06-22
     */
    gfc->slot_lag = gfc->frac_SpF = 0;
    if (gfp->VBR == vbr_off)
	gfc->slot_lag = gfc->frac_SpF
	    = ((gfp->version+1)*72000L*gfp->brate) % gfp->out_samplerate;

    /* mid side sparsing */
    gfc->sparsing = gfp->sparsing;
    gfc->sparseA = gfp->sparse_low;
    gfc->sparseB = gfp->sparse_low-gfp->sparse_high;
    if ( gfc->sparseA < 0 ) gfc->sparseA = 0;
    if ( gfc->sparseB < 0 ) gfc->sparseB = 0;
    if ( gfc->sparseB > gfc->sparseA ) gfc->sparseB = gfc->sparseA;

    iteration_init(gfp);
    psymodel_init(gfp);

    return 0;
}

/*
 *  print_config
 *
 *  Prints some selected information about the coding parameters via 
 *  the macro command MSGF(), which is currently mapped to lame_errorf 
 *  (reports via a error function?), which is a printf-like function 
 *  for <stderr>.
 */

void
lame_print_config(const lame_global_flags * gfp)
{
    lame_internal_flags *gfc = gfp->internal_flags;
    double  out_samplerate = gfp->out_samplerate;
    double  in_samplerate = gfp->out_samplerate * gfc->resample_ratio;

	MSGF(gfc, "LAME %s %s (%s)\n", get_lame_version(), get_lame_os_bitness(), get_lame_url());

	if (LAME_ALPHA_VERSION)
        MSGF(gfc, "warning: alpha versions should be used for testing only\n");

    if (gfc->CPU_features.MMX
        || gfc->CPU_features.AMD_3DNow
        || gfc->CPU_features.SSE || gfc->CPU_features.SSE2) {
        MSGF(gfc, "CPU features: ");

        if (gfc->CPU_features.MMX)
#ifdef MMX_choose_table
            MSGF(gfc, "MMX (ASM used)");
#else
            MSGF(gfc, "MMX");
#endif
        if (gfc->CPU_features.AMD_3DNow)
#ifdef HAVE_NASM
            MSGF(gfc, ", 3DNow! (ASM used)");
#else
            MSGF(gfc, ", 3DNow!");
#endif
        if (gfc->CPU_features.SSE)
#ifdef HAVE_XMMINTRIN_H
            MSGF(gfc, ", SSE (ASM used)");
#else
            MSGF(gfc, ", SSE");
#endif
        if (gfc->CPU_features.SSE2)
            MSGF(gfc, ", SSE2");
        MSGF(gfc, "\n");
    }

    if (gfp->num_channels == 2 && gfc->channels_out == 1 /* mono */ ) {
        MSGF
            (gfc,
             "Autoconverting from stereo to mono. Setting encoding to mono mode.\n");
    }

    if (gfc->resample_ratio != 1.) {
        MSGF(gfc, "Resampling:  input %g kHz  output %g kHz\n",
             1.e-3 * in_samplerate, 1.e-3 * out_samplerate);
    }

    if (gfc->filter_type == 0) {
        if (gfc->highpass2 > 0.)
            MSGF
                (gfc,
                 "Using polyphase highpass filter, transition band: %5.0f Hz - %5.0f Hz\n",
                 0.5 * gfc->highpass1 * out_samplerate,
                 0.5 * gfc->highpass2 * out_samplerate);
        if (0. < gfc->lowpass1 && gfc->lowpass1 < 1.) {
            MSGF
                (gfc,
                 "Using polyphase lowpass filter, transition band: %5.0f Hz - %5.0f Hz\n",
                 0.5 * gfc->lowpass1 * out_samplerate,
                 0.5 * gfc->lowpass2 * out_samplerate);
        }
        else {
            MSGF(gfc, "polyphase lowpass filter disabled\n");
        }
    }
    else {
        MSGF(gfc, "polyphase filters disabled\n");
    }

    if (gfp->free_format) {
        MSGF(gfc,
             "Warning: many decoders cannot handle free format bitstreams\n");
        if (gfp->brate > 320) {
            MSGF
                (gfc,
                 "Warning: many decoders cannot handle free format bitrates >320 kbps (see documentation)\n");
        }
    }
}


/**     rh:
 *      some pretty printing is very welcome at this point!
 *      so, if someone is willing to do so, please do it!
 *      add more, if you see more...
 */
void 
lame_print_internals( const lame_global_flags * gfp )
{
    lame_internal_flags *gfc = gfp->internal_flags;
    const char * pc = "";

    /*  compiler/processor optimizations, operational, etc.
     */
    MSGF( gfc, "\nmisc:\n\n" );
    
    MSGF( gfc, "\tscaling: %g\n", gfp->scale );
    MSGF( gfc, "\tch0 (left) scaling: %g\n", gfp->scale_left );
    MSGF( gfc, "\tch1 (right) scaling: %g\n", gfp->scale_right );
    MSGF( gfc, "\tfilter type: %d\n", gfc->filter_type );
    pc = gfc->quantization ? "xr^3/4" : "ISO";
    MSGF( gfc, "\tquantization: %s\n", pc );
    switch( gfc->use_best_huffman ) {
    default: pc = "normal"; break;
    case  1: pc = "best (outside loop)"; break;
    case  2: pc = "best (inside loop, slow)"; break;
    } 
    MSGF( gfc, "\thuffman search: %s\n", pc ); 
    MSGF( gfc, "\texperimental Y=%d\n", gfp->experimentalY);
    MSGF( gfc, "\t...\n" );

    /*  everything controlling the stream format 
     */
    MSGF( gfc, "\nstream format:\n\n" );
    switch ( gfp->version ) {
    case 0:  pc = "2.5"; break;
    case 1:  pc = "1";   break;
    case 2:  pc = "2";   break;
    default: pc = "?";   break;
    }
    MSGF( gfc, "\tMPEG-%s Layer 3\n", pc );
    switch ( gfp->mode ) {
    case JOINT_STEREO: pc = "joint stereo";   break;
    case STEREO      : pc = "stereo";         break;
    case DUAL_CHANNEL: pc = "dual channel";   break;
    case MONO        : pc = "mono";           break;
    case NOT_SET     : pc = "not set (error)"; break;
    default          : pc = "unknown (error)"; break;
    }
    MSGF( gfc, "\t%d channel - %s\n", gfc->channels_out, pc );
    
    switch (gfp->VBR) {
    case vbr_off   : pc = "off";    break;
    default        : pc = "all";    break;
    }
    MSGF( gfc, "\tpadding: %s\n", pc );
    
    if ( vbr_default == gfp->VBR )  pc = "(default)";
    else if ( gfp->free_format )    pc = "(free format)";
    else pc = "";
    switch ( gfp->VBR ) {
    case vbr_off : MSGF( gfc, "\tconstant bitrate - CBR %s\n",      pc ); break;
    case vbr_abr : MSGF( gfc, "\tvariable bitrate - ABR %s\n",      pc ); break;
    case vbr_rh  : MSGF( gfc, "\tvariable bitrate - VBR rh %s\n",   pc ); break;
    case vbr_mt  : MSGF( gfc, "\tvariable bitrate - VBR mt %s\n",   pc ); break;
    case vbr_mtrh: MSGF( gfc, "\tvariable bitrate - VBR mtrh %s\n", pc ); break; 
    default      : MSGF( gfc, "\t ?? oops, some new one ?? \n" );         break;
    }
    if (gfp->bWriteVbrTag) 
    MSGF( gfc, "\tusing LAME Tag\n" );
    MSGF( gfc, "\t...\n" );
    
    /*  everything controlling psychoacoustic settings, like ATH, etc.