/*
* LAME MP3 encoding engine
*
* Copyright (c) 1999 Mark Taylor
* Copyright (c) 2000-2002 Takehiro Tominaga
* Copyright (c) 2000-2005 Robert Hegemann
* Copyright (c) 2001 Gabriel Bouvigne
* Copyright (c) 2001 John Dahlstrom
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser 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 Lesser 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: Encoder.java,v 1.21 2011/05/24 21:45:14 kenchis Exp $ */
package mp3;
public class Encoder {
BitStream bs;
public PsyModel psy;
VBRTag vbr;
QuantizePVT qupvt;
public final void setModules(BitStream bs, PsyModel psy, QuantizePVT qupvt,
VBRTag vbr) {
this.bs = bs;
this.psy = psy;
this.vbr = vbr;
this.qupvt = qupvt;
}
private NewMDCT newMDCT = new NewMDCT();
/***********************************************************************
*
* encoder and decoder delays
*
***********************************************************************/
/**
*
* layer III enc->dec delay: 1056 (1057?) (observed)
* layer II enc->dec delay: 480 (481?) (observed)
*
* polyphase 256-16 (dec or enc) = 240
* mdct 256+32 (9*32) (dec or enc) = 288
* total: 512+16
*
* My guess is that delay of polyphase filterbank is actualy 240.5
* (there are technical reasons for this, see postings in mp3encoder).
* So total Encode+Decode delay = ENCDELAY + 528 + 1
*
*/
/**
* ENCDELAY The encoder delay.
*
* Minimum allowed is MDCTDELAY (see below)
*
* The first 96 samples will be attenuated, so using a value less than 96
* will result in corrupt data for the first 96-ENCDELAY samples.
*
* suggested: 576 set to 1160 to sync with FhG.
*/
public static final int ENCDELAY = 576;
/**
* make sure there is at least one complete frame after the last frame
* containing real data
*
* Using a value of 288 would be sufficient for a a very sophisticated
* decoder that can decode granule-by-granule instead of frame by frame. But
* lets not assume this, and assume the decoder will not decode frame N
* unless it also has data for frame N+1
*/
public static final int POSTDELAY = 1152;
/**
* delay of the MDCT used in mdct.c original ISO routines had a delay of
* 528! Takehiro's routines:
*/
public static final int MDCTDELAY = 48;
public static final int FFTOFFSET = (224 + MDCTDELAY);
/**
* Most decoders, including the one we use, have a delay of 528 samples.
*/
public static final int DECDELAY = 528;
/**
* number of subbands
*/
public static final int SBLIMIT = 32;
/**
* parition bands bands
*/
public static final int CBANDS = 64;
/**
* number of critical bands/scale factor bands where masking is computed
*/
public static final int SBPSY_l = 21;
public static final int SBPSY_s = 12;
/**
* total number of scalefactor bands encoded
*/
public static final int SBMAX_l = 22;
public static final int SBMAX_s = 13;
public static final int PSFB21 = 6;
public static final int PSFB12 = 6;
/**
* FFT sizes
*/
public static final int BLKSIZE = 1024;
public static final int HBLKSIZE = (BLKSIZE / 2 + 1);
public static final int BLKSIZE_s = 256;
public static final int HBLKSIZE_s = (BLKSIZE_s / 2 + 1);
public static final int NORM_TYPE = 0;
public static final int START_TYPE = 1;
public static final int SHORT_TYPE = 2;
public static final int STOP_TYPE = 3;
/**
*
* Mode Extention:
* When we are in stereo mode, there are 4 possible methods to store these
* two channels. The stereo modes -m? are using a subset of them.
*
* -ms: MPG_MD_LR_LR
* -mj: MPG_MD_LR_LR and MPG_MD_MS_LR
* -mf: MPG_MD_MS_LR
* -mi: all
*
*/
public static final int MPG_MD_LR_LR = 0;
public static final int MPG_MD_LR_I = 1;
public static final int MPG_MD_MS_LR = 2;
public static final int MPG_MD_MS_I = 3;
/**
* auto-adjust of ATH, useful for low volume Gabriel Bouvigne 3 feb 2001
*
* modifies some values in gfp.internal_flags.ATH (gfc.ATH)
*/
private void adjust_ATH(final LameInternalFlags gfc) {
float gr2_max, max_pow;
if (gfc.ATH.useAdjust == 0) {
gfc.ATH.adjust = 1.0f;
/* no adjustment */
return;
}
/* jd - 2001 mar 12, 27, jun 30 */
/* loudness based on equal loudness curve; */
/* use granule with maximum combined loudness */
max_pow = gfc.loudness_sq[0][0];
gr2_max = gfc.loudness_sq[1][0];
if (gfc.channels_out == 2) {
max_pow += gfc.loudness_sq[0][1];
gr2_max += gfc.loudness_sq[1][1];
} else {
max_pow += max_pow;
gr2_max += gr2_max;
}
if (gfc.mode_gr == 2) {
max_pow = Math.max(max_pow, gr2_max);
}
max_pow *= 0.5; /* max_pow approaches 1.0 for full band noise */
/* jd - 2001 mar 31, jun 30 */
/* user tuning of ATH adjustment region */
max_pow *= gfc.ATH.aaSensitivityP;
/*
* adjust ATH depending on range of maximum value
*/
/* jd - 2001 feb27, mar12,20, jun30, jul22 */
/* continuous curves based on approximation */
/* to GB's original values. */
/* For an increase in approximate loudness, */
/* set ATH adjust to adjust_limit immediately */
/* after a delay of one frame. */
/* For a loudness decrease, reduce ATH adjust */
/* towards adjust_limit gradually. */
/* max_pow is a loudness squared or a power. */
if (max_pow > 0.03125) { /* ((1 - 0.000625)/ 31.98) from curve below */
if (gfc.ATH.adjust >= 1.0) {
gfc.ATH.adjust = 1.0f;
} else {
/* preceding frame has lower ATH adjust; */
/* ascend only to the preceding adjust_limit */
/* in case there is leading low volume */
if (gfc.ATH.adjust < gfc.ATH.adjustLimit) {
gfc.ATH.adjust = gfc.ATH.adjustLimit;
}
}
gfc.ATH.adjustLimit = 1.0f;
} else { /* adjustment curve */
/* about 32 dB maximum adjust (0.000625) */
final float adj_lim_new = 31.98f * max_pow + 0.000625f;
if (gfc.ATH.adjust >= adj_lim_new) { /* descend gradually */
gfc.ATH.adjust *= adj_lim_new * 0.075 + 0.925;
if (gfc.ATH.adjust < adj_lim_new) { /* stop descent */
gfc.ATH.adjust = adj_lim_new;
}
} else { /* ascend */
if (gfc.ATH.adjustLimit >= adj_lim_new) {
gfc.ATH.adjust = adj_lim_new;
} else {
/* preceding frame has lower ATH adjust; */
/* ascend only to the preceding adjust_limit */
if (gfc.ATH.adjust < gfc.ATH.adjustLimit) {
gfc.ATH.adjust = gfc.ATH.adjustLimit;
}
}
}
gfc.ATH.adjustLimit = adj_lim_new;
}
}
/**
*
* some simple statistics
*
* bitrate index 0: free bitrate . not allowed in VBR mode
* : bitrates, kbps depending on MPEG version
* bitrate index 15: forbidden
*
* mode_ext:
* 0: LR
* 1: LR-i
* 2: MS
* 3: MS-i
*
*/
private void updateStats(final LameInternalFlags gfc) {
int gr, ch;
assert (0 <= gfc.bitrate_index && gfc.bitrate_index < 16);
assert (0 <= gfc.mode_ext && gfc.mode_ext < 4);
/* count bitrate indices */
gfc.bitrate_stereoMode_Hist[gfc.bitrate_index][4]++;
gfc.bitrate_stereoMode_Hist[15][4]++;
/* count 'em for every mode extension in case of 2 channel encoding */
if (gfc.channels_out == 2) {
gfc.bitrate_stereoMode_Hist[gfc.bitrate_index][gfc.mode_ext]++;
gfc.bitrate_stereoMode_Hist[15][gfc.mode_ext]++;
}
for (gr = 0; gr < gfc.mode_gr; ++gr) {
for (ch = 0; ch < gfc.channels_out; ++ch) {
int bt = gfc.l3_side.tt[gr][ch].block_type;
if (gfc.l3_side.tt[gr][ch].mixed_block_flag != 0)
bt = 4;
gfc.bitrate_blockType_Hist[gfc.bitrate_index][bt]++;
gfc.bitrate_blockType_Hist[gfc.bitrate_index][5]++;
gfc.bitrate_blockType_Hist[15][bt]++;
gfc.bitrate_blockType_Hist[15][5]++;
}
}
}
private void lame_encode_frame_init(final LameGlobalFlags gfp,
final float inbuf[][]) {
final LameInternalFlags gfc = gfp.internal_flags;
int ch, gr;
if (gfc.lame_encode_frame_init == 0) {
/* prime the MDCT/polyphase filterbank with a short block */
int i, j;
float primebuff0[] = new float[286 + 1152 + 576];
float primebuff1[] = new float[286 + 1152 + 576];
gfc.lame_encode_frame_init = 1;
for (i = 0, j = 0; i < 286 + 576 * (1 + gfc.mode_gr); ++i) {
if (i < 576 * gfc.mode_gr) {
primebuff0[i] = 0;
if (gfc.channels_out == 2)
primebuff1[i] = 0;
} else {
primebuff0[i] = inbuf[0][j];
if (gfc.channels_out == 2)
primebuff1[i] = inbuf[1][j];
++j;
}
}
/* polyphase filtering / mdct */
for (gr = 0; gr < gfc.mode_gr; gr++) {
for (ch = 0; ch < gfc.channels_out; ch++) {
gfc.l3_side.tt[gr][ch].block_type = SHORT_TYPE;
}
}
newMDCT.mdct_sub48(gfc, primebuff0, primebuff1);
/* check FFT will not use a negative starting offset */
assert (576 >= FFTOFFSET);
/* check if we have enough data for FFT */
assert (gfc.mf_size >= (BLKSIZE + gfp.framesize - FFTOFFSET));
/* check if we have enough data for polyphase filterbank */
assert (gfc.mf_size >= (512 + gfp.framesize - 32));
}
}
/**
*
* encodeframe() Layer 3
*
* encode a single frame
*
*
* lame_encode_frame()
*
*
* gr 0 gr 1
* inbuf: |--------------|--------------|--------------|
*
*
* Polyphase (18 windows, each shifted 32)
* gr 0:
* window1 <----512---.
* window18 <----512---.
*
* gr 1:
* window1 <----512---.
* window18 <----512---.
*
*
*
* MDCT output: |--------------|--------------|--------------|
*
* FFT's <---------1024---------.
* <---------1024-------.
*
*
*
* inbuf = buffer of PCM data size=MP3 framesize
* encoder acts on inbuf[ch][0], but output is delayed by MDCTDELAY
* so the MDCT coefficints are from inbuf[ch][-MDCTDELAY]
*
* psy-model FFT has a 1 granule delay, so we feed it data for the
* next granule.
* FFT is centered over granule: 224+576+224
* So FFT starts at: 576-224-MDCTDELAY
*
* MPEG2: FFT ends at: BLKSIZE+576-224-MDCTDELAY (1328)
* MPEG1: FFT ends at: BLKSIZE+2*576-224-MDCTDELAY (1904)
*
* MPEG2: polyphase first window: [0..511]
* 18th window: [544..1055] (1056)
* MPEG1: 36th window: [1120..1631] (1632)
* data needed: 512+framesize-32
*
* A close look newmdct.c shows that the polyphase filterbank
* only uses data from [0..510] for each window. Perhaps because the window
* used by the filterbank is zero for the last point, so Takehiro's
* code doesn't bother to compute with it.
*
* FFT starts at 576-224-MDCTDELAY (304) = 576-FFTOFFSET
*
*
*/
private static final float fircoef[] = { -0.0207887f * 5, -0.0378413f * 5,
-0.0432472f * 5, -0.031183f * 5, 7.79609e-18f * 5, 0.0467745f * 5,
0.10091f * 5, 0.151365f * 5, 0.187098f * 5 };
public final int lame_encode_mp3_frame(final LameGlobalFlags gfp,
final float[] inbuf_l, final float[] inbuf_r, byte[] mp3buf,
int mp3bufPos, int mp3buf_size) {
int mp3count;
III_psy_ratio masking_LR[][] = new III_psy_ratio[2][2]; /*
* LR masking &
* energy
*/
masking_LR[0][0] = new III_psy_ratio();
masking_LR[0][1] = new III_psy_ratio();
masking_LR[1][0] = new III_psy_ratio();
masking_LR[1][1] = new III_psy_ratio();
III_psy_ratio masking_MS[][] = new III_psy_ratio[2][2];
/* MS masking & energy */
masking_MS[0][0] = new III_psy_ratio();
masking_MS[0][1] = new III_psy_ratio();
masking_MS[1][0] = new III_psy_ratio();
masking_MS[1][1] = new III_psy_ratio();
III_psy_ratio masking[][];
/* pointer to selected maskings */
final float[] inbuf[] = new float[2][];
final LameInternalFlags gfc = gfp.internal_flags;
float tot_ener[][] = new float[2][4];
float ms_ener_ratio[] = { .5f, .5f };
float[][] pe = { { 0.f, 0.f }, { 0.f, 0.f } }, pe_MS = { { 0.f, 0.f },
{ 0.f, 0.f } };
float[][] pe_use;
int ch, gr;
inbuf[0] = inbuf_l;
inbuf[1] = inbuf_r;
if (gfc.lame_encode_frame_init == 0) {
/* first run? */
lame_encode_frame_init(gfp, inbuf);
}
/********************** padding *****************************/
/**
*
* 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.padding = 0;
if ((gfc.slot_lag -= gfc.frac_SpF) < 0) {
gfc.slot_lag += gfp.out_samplerate;
gfc.padding = 1;
}
/****************************************
* Stage 1: psychoacoustic model *
****************************************/
if (gfc.psymodel != 0) {
/*
* psychoacoustic model psy model has a 1 granule (576) delay that
* we must compensate for (mt 6/99).
*/
int ret;
final float bufp[][] = new float[2][];
/* address of beginning of left & right granule */
int bufpPos = 0;
/* address of beginning of left & right granule */
int blocktype[] = new int[2];
for (gr = 0; gr < gfc.mode_gr; gr++) {
for (ch = 0; ch < gfc.channels_out; ch++) {
bufp[ch] = inbuf[ch];
bufpPos = 576 + gr * 576 - FFTOFFSET;
}
if (gfp.VBR == VbrMode.vbr_mtrh || gfp.VBR == VbrMode.vbr_mt) {
ret = psy.L3psycho_anal_vbr(gfp, bufp, bufpPos, gr,
masking_LR, masking_MS, pe[gr], pe_MS[gr],
tot_ener[gr], blocktype);
} else {
ret = psy.L3psycho_anal_ns(gfp, bufp, bufpPos, gr,
masking_LR, masking_MS, pe[gr], pe_MS[gr],
tot_ener[gr], blocktype);
}
if (ret != 0)
return -4;
if (gfp.mode == MPEGMode.JOINT_STEREO) {
ms_ener_ratio[gr] = tot_ener[gr][2] + tot_ener[gr][3];
if (ms_ener_ratio[gr] > 0)
ms_ener_ratio[gr] = tot_ener[gr][3] / ms_ener_ratio[gr];
}
/* block type flags */
for (ch = 0; ch < gfc.channels_out; ch++) {
final GrInfo cod_info = gfc.l3_side.tt[gr][ch];
cod_info.block_type = blocktype[ch];
cod_info.mixed_block_flag = 0;
}
}
} else {
/* no psy model */
for (gr = 0; gr < gfc.mode_gr; gr++)
for (ch = 0; ch < gfc.channels_out; ch++) {
gfc.l3_side.tt[gr][ch].block_type = NORM_TYPE;
gfc.l3_side.tt[gr][ch].mixed_block_flag = 0;
pe_MS[gr][ch] = pe[gr][ch] = 700;
}
}
/* auto-adjust of ATH, useful for low volume */
adjust_ATH(gfc);
/****************************************
* Stage 2: MDCT *
****************************************/
/* polyphase filtering / mdct */
newMDCT.mdct_sub48(gfc, inbuf[0], inbuf[1]);
/****************************************
* Stage 3: MS/LR decision *
****************************************/
/* Here will be selected MS or LR coding of the 2 stereo channels */
gfc.mode_ext = MPG_MD_LR_LR;
if (gfp.force_ms) {
gfc.mode_ext = MPG_MD_MS_LR;
} else if (gfp.mode == MPEGMode.JOINT_STEREO) {
/*
* ms_ratio = is scaled, for historical reasons, to look like a
* ratio of side_channel / total. 0 = signal is 100% mono .5 = L & R
* uncorrelated
*/
/**
*
* [0] and [1] are the results for the two granules in MPEG-1,
* in MPEG-2 it's only a faked averaging of the same value
* _prev is the value of the last granule of the previous frame
* _next is the value of the first granule of the next frame
*
*/
float sum_pe_MS = 0;
float sum_pe_LR = 0;
for (gr = 0; gr < gfc.mode_gr; gr++) {
for (ch = 0; ch < gfc.channels_out; ch++) {
sum_pe_MS += pe_MS[gr][ch];
sum_pe_LR += pe[gr][ch];
}
}
/* based on PE: M/S coding would not use much more bits than L/R */
if (sum_pe_MS <= 1.00 * sum_pe_LR) {
final GrInfo gi0[] = gfc.l3_side.tt[0];
final GrInfo gi1[] = gfc.l3_side.tt[gfc.mode_gr - 1];
if (gi0[0].block_type == gi0[1].block_type
&& gi1[0].block_type == gi1[1].block_type) {
gfc.mode_ext = MPG_MD_MS_LR;
}
}
}
/* bit and noise allocation */
if (gfc.mode_ext == MPG_MD_MS_LR) {
masking = masking_MS; /* use MS masking */
pe_use = pe_MS;
} else {
masking = masking_LR; /* use LR masking */
pe_use = pe;
}
/* copy data for MP3 frame analyzer */
if (gfp.analysis && gfc.pinfo != null) {
for (gr = 0; gr < gfc.mode_gr; gr++) {
for (ch = 0; ch < gfc.channels_out; ch++) {
gfc.pinfo.ms_ratio[gr] = gfc.ms_ratio[gr];
gfc.pinfo.ms_ener_ratio[gr] = ms_ener_ratio[gr];
gfc.pinfo.blocktype[gr][ch] = gfc.l3_side.tt[gr][ch].block_type;
gfc.pinfo.pe[gr][ch] = pe_use[gr][ch];
System.arraycopy(gfc.l3_side.tt[gr][ch].xr, 0,
gfc.pinfo.xr[gr][ch], 0, 576);
/*
* in psymodel, LR and MS data was stored in pinfo. switch
* to MS data:
*/
if (gfc.mode_ext == MPG_MD_MS_LR) {
gfc.pinfo.ers[gr][ch] = gfc.pinfo.ers[gr][ch + 2];
System.arraycopy(gfc.pinfo.energy[gr][ch + 2], 0,
gfc.pinfo.energy[gr][ch], 0,
gfc.pinfo.energy[gr][ch].length);
}
}
}
}
/****************************************
* Stage 4: quantization loop *
****************************************/
if (gfp.VBR == VbrMode.vbr_off || gfp.VBR == VbrMode.vbr_abr) {
int i;
float f;
for (i = 0; i < 18; i++)
gfc.nsPsy.pefirbuf[i] = gfc.nsPsy.pefirbuf[i + 1];
f = 0.0f;
for (gr = 0; gr < gfc.mode_gr; gr++)
for (ch = 0; ch < gfc.channels_out; ch++)
f += pe_use[gr][ch];
gfc.nsPsy.pefirbuf[18] = f;
f = gfc.nsPsy.pefirbuf[9];
for (i = 0; i < 9; i++)
f += (gfc.nsPsy.pefirbuf[i] + gfc.nsPsy.pefirbuf[18 - i])
* fircoef[i];
f = (670 * 5 * gfc.mode_gr * gfc.channels_out) / f;
for (gr = 0; gr < gfc.mode_gr; gr++) {
for (ch = 0; ch < gfc.channels_out; ch++) {
pe_use[gr][ch] *= f;
}
}
}
gfc.iteration_loop.iteration_loop(gfp, pe_use, ms_ener_ratio, masking);
/****************************************
* Stage 5: bitstream formatting *
****************************************/
/* write the frame to the bitstream */
bs.format_bitstream(gfp);
/* copy mp3 bit buffer into array */
mp3count = bs.copy_buffer(gfc, mp3buf, mp3bufPos, mp3buf_size, 1);
if (gfp.bWriteVbrTag)
vbr.addVbrFrame(gfp);
if (gfp.analysis && gfc.pinfo != null) {
for (ch = 0; ch < gfc.channels_out; ch++) {
int j;
for (j = 0; j < FFTOFFSET; j++)
gfc.pinfo.pcmdata[ch][j] = gfc.pinfo.pcmdata[ch][j
+ gfp.framesize];
for (j = FFTOFFSET; j < 1600; j++) {
gfc.pinfo.pcmdata[ch][j] = inbuf[ch][j - FFTOFFSET];
}
}
qupvt.set_frame_pinfo(gfp, masking);
}
updateStats(gfc);
return mp3count;
}
}