/*
* MP3 bitstream Output interface for LAME
*
* Copyright (c) 1999-2000 Mark Taylor
* Copyright (c) 1999-2002 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: bitstream.c,v 1.99 2017/08/31 14:14:46 robert Exp $
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include "lame.h"
#include "machine.h"
#include "encoder.h"
#include "util.h"
#include "tables.h"
#include "quantize_pvt.h"
#include "lame_global_flags.h"
#include "gain_analysis.h"
#include "VbrTag.h"
#include "bitstream.h"
#include "tables.h"
/* unsigned int is at least this large: */
/* we work with ints, so when doing bit manipulation, we limit
* ourselves to MAX_LENGTH-2 just to be on the safe side */
#define MAX_LENGTH 32
#ifdef DEBUG
static int hogege;
#endif
static int
calcFrameLength(SessionConfig_t const *const cfg, int kbps, int pad)
{
return 8 * ((cfg->version + 1) * 72000 * kbps / cfg->samplerate_out + pad);
}
/***********************************************************************
* compute bitsperframe and mean_bits for a layer III frame
**********************************************************************/
int
getframebits(const lame_internal_flags * gfc)
{
SessionConfig_t const *const cfg = &gfc->cfg;
EncResult_t const *const eov = &gfc->ov_enc;
int bit_rate;
/* get bitrate in kbps [?] */
if (eov->bitrate_index)
bit_rate = bitrate_table[cfg->version][eov->bitrate_index];
else
bit_rate = cfg->avg_bitrate;
/*assert(bit_rate <= 550); */
assert(8 <= bit_rate && bit_rate <= 640);
/* main encoding routine toggles padding on and off */
/* one Layer3 Slot consists of 8 bits */
return calcFrameLength(cfg, bit_rate, eov->padding);
}
int
get_max_frame_buffer_size_by_constraint(SessionConfig_t const * cfg, int constraint)
{
int maxmp3buf = 0;
if (cfg->avg_bitrate > 320) {
/* in freeformat the buffer is constant */
if (constraint == MDB_STRICT_ISO) {
maxmp3buf = calcFrameLength(cfg, cfg->avg_bitrate, 0);
}
else {
/* maximum allowed bits per granule are 7680 */
maxmp3buf = 7680 * (cfg->version + 1);
}
}
else {
int max_kbps;
if (cfg->samplerate_out < 16000) {
max_kbps = bitrate_table[cfg->version][8]; /* default: allow 64 kbps (MPEG-2.5) */
}
else {
max_kbps = bitrate_table[cfg->version][14];
}
switch (constraint)
{
default:
case MDB_DEFAULT:
/* Bouvigne suggests this more lax interpretation of the ISO doc instead of using 8*960. */
/* All mp3 decoders should have enough buffer to handle this value: size of a 320kbps 32kHz frame */
maxmp3buf = 8 * 1440;
break;
case MDB_STRICT_ISO:
maxmp3buf = calcFrameLength(cfg, max_kbps, 0);
break;
case MDB_MAXIMUM:
maxmp3buf = 7680 * (cfg->version + 1);
break;
}
}
return maxmp3buf;
}
static void
putheader_bits(lame_internal_flags * gfc)
{
SessionConfig_t const *const cfg = &gfc->cfg;
EncStateVar_t *const esv = &gfc->sv_enc;
Bit_stream_struc *bs = &gfc->bs;
#ifdef DEBUG
hogege += cfg->sideinfo_len * 8;
#endif
memcpy(&bs->buf[bs->buf_byte_idx], esv->header[esv->w_ptr].buf, cfg->sideinfo_len);
bs->buf_byte_idx += cfg->sideinfo_len;
bs->totbit += cfg->sideinfo_len * 8;
esv->w_ptr = (esv->w_ptr + 1) & (MAX_HEADER_BUF - 1);
}
/*write j bits into the bit stream */
inline static void
putbits2(lame_internal_flags * gfc, int val, int j)
{
EncStateVar_t const *const esv = &gfc->sv_enc;
Bit_stream_struc *bs;
bs = &gfc->bs;
assert(j < MAX_LENGTH - 2);
while (j > 0) {
int k;
if (bs->buf_bit_idx == 0) {
bs->buf_bit_idx = 8;
bs->buf_byte_idx++;
assert(bs->buf_byte_idx < BUFFER_SIZE);
assert(esv->header[esv->w_ptr].write_timing >= bs->totbit);
if (esv->header[esv->w_ptr].write_timing == bs->totbit) {
putheader_bits(gfc);
}
bs->buf[bs->buf_byte_idx] = 0;
}
k = Min(j, bs->buf_bit_idx);
j -= k;
bs->buf_bit_idx -= k;
assert(j < MAX_LENGTH); /* 32 too large on 32 bit machines */
assert(bs->buf_bit_idx < MAX_LENGTH);
bs->buf[bs->buf_byte_idx] |= ((val >> j) << bs->buf_bit_idx);
bs->totbit += k;
}
}
/*write j bits into the bit stream, ignoring frame headers */
inline static void
putbits_noheaders(lame_internal_flags * gfc, int val, int j)
{
Bit_stream_struc *bs;
bs = &gfc->bs;
assert(j < MAX_LENGTH - 2);
while (j > 0) {
int k;
if (bs->buf_bit_idx == 0) {
bs->buf_bit_idx = 8;
bs->buf_byte_idx++;
assert(bs->buf_byte_idx < BUFFER_SIZE);
bs->buf[bs->buf_byte_idx] = 0;
}
k = Min(j, bs->buf_bit_idx);
j -= k;
bs->buf_bit_idx -= k;
assert(j < MAX_LENGTH); /* 32 too large on 32 bit machines */
assert(bs->buf_bit_idx < MAX_LENGTH);
bs->buf[bs->buf_byte_idx] |= ((val >> j) << bs->buf_bit_idx);
bs->totbit += k;
}
}
/*
Some combinations of bitrate, Fs, and stereo make it impossible to stuff
out a frame using just main_data, due to the limited number of bits to
indicate main_data_length. In these situations, we put stuffing bits into
the ancillary data...
*/
inline static void
drain_into_ancillary(lame_internal_flags * gfc, int remainingBits)
{
SessionConfig_t const *const cfg = &gfc->cfg;
EncStateVar_t *const esv = &gfc->sv_enc;
int i;
assert(remainingBits >= 0);
if (remainingBits >= 8) {
putbits2(gfc, 0x4c, 8);
remainingBits -= 8;
}
if (remainingBits >= 8) {
putbits2(gfc, 0x41, 8);
remainingBits -= 8;
}
if (remainingBits >= 8) {
putbits2(gfc, 0x4d, 8);
remainingBits -= 8;
}
if (remainingBits >= 8) {
putbits2(gfc, 0x45, 8);
remainingBits -= 8;
}
if (remainingBits >= 32) {
const char *const version = get_lame_short_version();
if (remainingBits >= 32)
for (i = 0; i < (int) strlen(version) && remainingBits >= 8; ++i) {
remainingBits -= 8;
putbits2(gfc, version[i], 8);
}
}
for (; remainingBits >= 1; remainingBits -= 1) {
putbits2(gfc, esv->ancillary_flag, 1);
esv->ancillary_flag ^= !cfg->disable_reservoir;
}
assert(remainingBits == 0);
}
/*write N bits into the header */
inline static void
writeheader(lame_internal_flags * gfc, int val, int j)
{
EncStateVar_t *const esv = &gfc->sv_enc;
int ptr = esv->header[esv->h_ptr].ptr;
while (j > 0) {
int const k = Min(j, 8 - (ptr & 7));
j -= k;
assert(j < MAX_LENGTH); /* >> 32 too large for 32 bit machines */
esv->header[esv->h_ptr].buf[ptr >> 3]
|= ((val >> j)) << (8 - (ptr & 7) - k);
ptr += k;
}
esv->header[esv->h_ptr].ptr = ptr;
}
static int
CRC_update(int value, int crc)
{
int i;
value <<= 8;
for (i = 0; i < 8; i++) {
value <<= 1;
crc <<= 1;
if (((crc ^ value) & 0x10000))
crc ^= CRC16_POLYNOMIAL;
}
return crc;
}
void
CRC_writeheader(lame_internal_flags const *gfc, char *header)
{
SessionConfig_t const *const cfg = &gfc->cfg;
int crc = 0xffff; /* (jo) init crc16 for error_protection */
int i;
crc = CRC_update(((unsigned char *) header)[2], crc);
crc = CRC_update(((unsigned char *) header)[3], crc);
for (i = 6; i < cfg->sideinfo_len; i++) {
crc = CRC_update(((unsigned char *) header)[i], crc);
}
header[4] = crc >> 8;
header[5] = crc & 255;
}
inline static void
encodeSideInfo2(lame_internal_flags * gfc, int bitsPerFrame)
{
SessionConfig_t const *const cfg = &gfc->cfg;
EncResult_t const *const eov = &gfc->ov_enc;
EncStateVar_t *const esv = &gfc->sv_enc;
III_side_info_t *l3_side;
int gr, ch;
l3_side = &gfc->l3_side;
esv->header[esv->h_ptr].ptr = 0;
memset(esv->header[esv->h_ptr].buf, 0, cfg->sideinfo_len);
if (cfg->samplerate_out < 16000)
writeheader(gfc, 0xffe, 12);
else
writeheader(gfc, 0xfff, 12);
writeheader(gfc, (cfg->version), 1);
writeheader(gfc, 4 - 3, 2);
writeheader(gfc, (!cfg->error_protection), 1);
writeheader(gfc, (eov->bitrate_index), 4);
writeheader(gfc, (cfg->samplerate_index), 2);
writeheader(gfc, (eov->padding), 1);
writeheader(gfc, (cfg->extension), 1);
writeheader(gfc, (cfg->mode), 2);
writeheader(gfc, (eov->mode_ext), 2);
writeheader(gfc, (cfg->copyright), 1);
writeheader(gfc, (cfg->original), 1);
writeheader(gfc, (cfg->emphasis), 2);
if (cfg->error_protection) {
writeheader(gfc, 0, 16); /* dummy */
}
if (cfg->version == 1) {
/* MPEG1 */
assert(l3_side->main_data_begin >= 0);
writeheader(gfc, (l3_side->main_data_begin), 9);
if (cfg->channels_out == 2)
writeheader(gfc, l3_side->private_bits, 3);
else
writeheader(gfc, l3_side->private_bits, 5);
for (ch = 0; ch < cfg->channels_out; ch++) {
int band;
for (band = 0; band < 4; band++) {
writeheader(gfc, l3_side->scfsi[ch][band], 1);
}
}
for (gr = 0; gr < 2; gr++) {
for (ch = 0; ch < cfg->channels_out; ch++) {
gr_info *const gi = &l3_side->tt[gr][ch];
writeheader(gfc, gi->part2_3_length + gi->part2_length, 12);
writeheader(gfc, gi->big_values / 2, 9);
writeheader(gfc, gi->global_gain, 8);
writeheader(gfc, gi->scalefac_compress, 4);
if (gi->block_type != NORM_TYPE) {
writeheader(gfc, 1, 1); /* window_switching_flag */
writeheader(gfc, gi->block_type, 2);
writeheader(gfc, gi->mixed_block_flag, 1);
if (gi->table_select[0] == 14)
gi->table_select[0] = 16;
writeheader(gfc, gi->table_select[0], 5);
if (gi->table_select[1] == 14)
gi->table_select[1] = 16;
writeheader(gfc, gi->table_select[1], 5);
writeheader(gfc, gi->subblock_gain[0], 3);
writeheader(gfc, gi->subblock_gain[1], 3);
writeheader(gfc, gi->subblock_gain[2], 3);
}
else {
writeheader(gfc, 0, 1); /* window_switching_flag */
if (gi->table_select[0] == 14)
gi->table_select[0] = 16;
writeheader(gfc, gi->table_select[0], 5);
if (gi->table_select[1] == 14)
gi->table_select[1] = 16;
writeheader(gfc, gi->table_select[1], 5);
if (gi->table_select[2] == 14)
gi->table_select[2] = 16;
writeheader(gfc, gi->table_select[2], 5);
assert(0 <= gi->region0_count && gi->region0_count < 16);
assert(0 <= gi->region1_count && gi->region1_count < 8);
writeheader(gfc, gi->region0_count, 4);
writeheader(gfc, gi->region1_count, 3);
}
writeheader(gfc, gi->preflag, 1);
writeheader(gfc, gi->scalefac_scale, 1);
writeheader(gfc, gi->count1table_select, 1);
}
}
}
else {
/* MPEG2 */
assert(l3_side->main_data_begin >= 0);
writeheader(gfc, (l3_side->main_data_begin), 8);
writeheader(gfc, l3_side->private_bits, cfg->channels_out);
gr = 0;
for (ch = 0; ch < cfg->channels_out; ch++) {
gr_info *const gi = &l3_side->tt[gr][ch];
writeheader(gfc, gi->part2_3_length + gi->part2_length, 12);
writeheader(gfc, gi->big_values / 2, 9);
writeheader(gfc, gi->global_gain, 8);
writeheader(gfc, gi->scalefac_compress, 9);
if (gi->block_type != NORM_TYPE) {
writeheader(gfc, 1, 1); /* window_switching_flag */
writeheader(gfc, gi->block_type, 2);
writeheader(gfc, gi->mixed_block_flag, 1);
if (gi->table_select[0] == 14)
gi->table_select[0] = 16;
writeheader(gfc, gi->table_select[0], 5);
if (gi->table_select[1] == 14)
gi->table_select[1] = 16;
writeheader(gfc, gi->table_select[1], 5);
writeheader(gfc, gi->subblock_gain[0], 3);
writeheader(gfc, gi->subblock_gain[1], 3);
writeheader(gfc, gi->subblock_gain[2], 3);
}
else {
writeheader(gfc, 0, 1); /* window_switching_flag */
if (gi->table_select[0] == 14)
gi->table_select[0] = 16;
writeheader(gfc, gi->table_select[0], 5);
if (gi->table_select[1] == 14)
gi->table_select[1] = 16;
writeheader(gfc, gi->table_select[1], 5);
if (gi->table_select[2] == 14)
gi->table_select[2] = 16;
writeheader(gfc, gi->table_select[2], 5);
assert(0 <= gi->region0_count && gi->region0_count < 16);
assert(0 <= gi->region1_count && gi->region1_count < 8);
writeheader(gfc, gi->region0_count, 4);
writeheader(gfc, gi->region1_count, 3);
}
writeheader(gfc, gi->scalefac_scale, 1);
writeheader(gfc, gi->count1table_select, 1);
}
}
if (cfg->error_protection) {
/* (jo) error_protection: add crc16 information to header */
CRC_writeheader(gfc, esv->header[esv->h_ptr].buf);
}
{
int const old = esv->h_ptr;
assert(esv->header[old].ptr == cfg->sideinfo_len * 8);
esv->h_ptr = (old + 1) & (MAX_HEADER_BUF - 1);
esv->header[esv->h_ptr].write_timing = esv->header[old].write_timing + bitsPerFrame;
if (esv->h_ptr == esv->w_ptr) {
/* yikes! we are out of header buffer space */
ERRORF(gfc, "Error: MAX_HEADER_BUF too small in bitstream.c \n");
}
}
}
inline static int
huffman_coder_count1(lame_internal_flags * gfc, gr_info const *gi)
{
/* Write count1 area */
struct huffcodetab const *const h = &ht[gi->count1table_select + 32];
int i, bits = 0;
#ifdef DEBUG
int gegebo = gfc->bs.totbit;
#endif
int const *ix = &gi->l3_enc[gi->big_values];
FLOAT const *xr = &gi->xr[gi->big_values];
assert(gi->count1table_select < 2);
for (i = (gi->count1 - gi->big_values) / 4; i > 0; --i) {
int huffbits = 0;
int p = 0, v;
v = ix[0];
if (v) {
p += 8;
if (xr[0] < 0.0f)
huffbits++;
assert(v <= 1);
}
v = ix[1];
if (v) {
p += 4;
huffbits *= 2;
if (xr[1] < 0.0f)
huffbits++;
assert(v <= 1);
}
v = ix[2];
if (v) {
p += 2;
huffbits *= 2;
if (xr[2] < 0.0f)
huffbits++;
assert(v <= 1);
}
v = ix[3];
if (v) {
p++;
huffbits *= 2;
if (xr[3] < 0.0f)
huffbits++;
assert(v <= 1);
}
ix += 4;
xr += 4;
putbits2(gfc, huffbits + h->table[p], h->hlen[p]);
bits += h->hlen[p];
}
#ifdef DEBUG
DEBUGF(gfc, "count1: real: %ld counted:%d (bigv %d count1len %d)\n",
gfc->bs.totbit - gegebo, gi->count1bits, gi->big_values, gi->count1);
#endif
return bits;
}
/*
Implements the pseudocode of page 98 of the IS
*/
inline static int
Huffmancode(lame_internal_flags * const gfc, const unsigned int tableindex,
int start, int end, gr_info const *gi)
{
struct huffcodetab const *const h = &ht[tableindex];
unsigned int const linbits = h->xlen;
int i, bits = 0;
assert(tableindex < 32u);
if (!tableindex)
return bits;
for (i = start; i < end; i += 2) {
int16_t cbits = 0;
uint16_t xbits = 0;
unsigned int xlen = h->xlen;
unsigned int ext = 0;
unsigned int x1 = gi->l3_enc[i];
unsigned int x2 = gi->l3_enc[i + 1];
assert(gi->l3_enc[i] >= 0);
assert(gi->l3_enc[i+1] >= 0);
if (x1 != 0u) {
if (gi->xr[i] < 0.0f)
ext++;
cbits--;
}
if (tableindex > 15u) {
/* use ESC-words */
if (x1 >= 15u) {
uint16_t const linbits_x1 = x1 - 15u;
assert(linbits_x1 <= h->linmax);
ext |= linbits_x1 << 1u;
xbits = linbits;
x1 = 15u;
}
if (x2 >= 15u) {
uint16_t const linbits_x2 = x2 - 15u;
assert(linbits_x2 <= h->linmax);
ext <<= linbits;
ext |= linbits_x2;
xbits += linbits;
x2 = 15u;
}
xlen = 16;
}
if (x2 != 0u) {
ext <<= 1;
if (gi->xr[i + 1] < 0.0f)
ext++;
cbits--;
}
assert((x1 | x2) < 16u);
x1 = x1 * xlen + x2;
xbits -= cbits;
cbits += h->hlen[x1];
assert(cbits <= MAX_LENGTH);
assert(xbits <= MAX_LENGTH);
putbits2(gfc, h->table[x1], cbits);
putbits2(gfc, (int)ext, xbits);
bits += cbits + xbits;
}
return bits;
}
/*
Note the discussion of huffmancodebits() on pages 28
and 29 of the IS, as well as the definitions of the side
information on pages 26 and 27.
*/
static int
ShortHuffmancodebits(lame_internal_flags * gfc, gr_info const *gi)
{
int bits;
int region1Start;
region1Start = 3 * gfc->scalefac_band.s[3];
if (region1Start > gi->big_values)
region1Start = gi->big_values;
/* short blocks do not have a region2 */
bits = Huffmancode(gfc, gi->table_select[0], 0, region1Start, gi);
bits += Huffmancode(gfc, gi->table_select[1], region1Start, gi->big_values, gi);
return bits;
}
static int
LongHuffmancodebits(lame_internal_flags * gfc, gr_info const *gi)
{
unsigned int i;
int bigvalues, bits;
int region1Start, region2Start;
bigvalues = gi->big_values;
assert(0 <= bigvalues && bigvalues <= 576);
assert(gi->region0_count >= -1);
assert(gi->region1_count >= -1);
i = gi->region0_count + 1;
assert((size_t) i < dimension_of(gfc->scalefac_band.l));
region1Start = gfc->scalefac_band.l[i];
i += gi->region1_count + 1;
assert((size_t) i < dimension_of(gfc->scalefac_band.l));
region2Start = gfc->scalefac_band.l[i];
if (region1Start > bigvalues)
region1Start = bigvalues;
if (region2Start > bigvalues)
region2Start = bigvalues;
bits = Huffmancode(gfc, gi->table_select[0], 0, region1Start, gi);
bits += Huffmancode(gfc, gi->table_select[1], region1Start, region2Start, gi);
bits += Huffmancode(gfc, gi->table_select[2], region2Start, bigvalues, gi);
return bits;
}
inline static int
writeMainData(lame_internal_flags * const gfc)
{
SessionConfig_t const *const cfg = &gfc->cfg;
III_side_info_t const *const l3_side = &gfc->l3_side;
int gr, ch, sfb, data_bits, tot_bits = 0;
if (cfg->version == 1) {
/* MPEG 1 */
for (gr = 0; gr < 2; gr++) {
for (ch = 0; ch < cfg->channels_out; ch++) {
gr_info const *const gi = &l3_side->tt[gr][ch];
int const slen1 = slen1_tab[gi->scalefac_compress];
int const slen2 = slen2_tab[gi->scalefac_compress];
data_bits = 0;
#ifdef DEBUG
hogege = gfc->bs.totbit;
#endif
for (sfb = 0; sfb < gi->sfbdivide; sfb++) {
if (gi->scalefac[sfb] == -1)
continue; /* scfsi is used */
putbits2(gfc, gi->scalefac[sfb], slen1);
data_bits += slen1;
}
for (; sfb < gi->sfbmax; sfb++) {
if (gi->scalefac[sfb] == -1)
continue; /* scfsi is used */
putbits2(gfc, gi->scalefac[sfb], slen2);
data_bits += slen2;
}
assert(data_bits == gi->part2_length);
if (gi->block_type == SHORT_TYPE) {
data_bits += ShortHuffmancodebits(gfc, gi);
}
else {
data_bits += LongHuffmancodebits(gfc, gi);
}
data_bits += huffman_coder_count1(gfc, gi);
#ifdef DEBUG
DEBUGF(gfc, "<%ld> ", gfc->bs.totbit - hogege);
#endif
/* does bitcount in quantize.c agree with actual bit count? */
assert(data_bits == gi->part2_3_length + gi->part2_length);
tot_bits += data_bits;
} /* for ch */
} /* for gr */
}
else {
/* MPEG 2 */
gr = 0;
for (ch = 0; ch < cfg->channels_out; ch++) {
gr_info const *const gi = &l3_side->tt[gr][ch];
int i, sfb_partition, scale_bits = 0;
assert(gi->sfb_partition_table);
data_bits = 0;
#ifdef DEBUG
hogege = gfc->bs.totbit;
#endif
sfb = 0;
sfb_partition = 0;
if (gi->block_type == SHORT_TYPE) {
for (; sfb_partition < 4; sfb_partition++) {
int const sfbs = gi->sfb_partition_table[sfb_partition] / 3;
int const slen = gi->slen[sfb_partition];
for (i = 0; i < sfbs; i++, sfb++) {
putbits2(gfc, Max(gi->scalefac[sfb * 3 + 0], 0), slen);
putbits2(gfc, Max(gi->scalefac[sfb * 3 + 1], 0), slen);
putbits2(gfc, Max(gi->scalefac[sfb * 3 + 2], 0), slen);
scale_bits += 3 * slen;
}
}
data_bits += ShortHuffmancodebits(gfc, gi);
}
else {
for (; sfb_partition < 4; sfb_partition++) {
int const sfbs = gi->sfb_partition_table[sfb_partition];
int const slen = gi->slen[sfb_partition];
for (i = 0; i < sfbs; i++, sfb++) {
putbits2(gfc, Max(gi->scalefac[sfb], 0), slen);
scale_bits += slen;
}
}
data_bits += LongHuffmancodebits(gfc, gi);
}
data_bits += huffman_coder_count1(gfc, gi);
#ifdef DEBUG
DEBUGF(gfc, "<%ld> ", gfc->bs.totbit - hogege);
#endif
/* does bitcount in quantize.c agree with actual bit count? */
assert(data_bits == gi->part2_3_length);
assert(scale_bits == gi->part2_length);
tot_bits += scale_bits + data_bits;
} /* for ch */
} /* for gf */
return tot_bits;
} /* main_data */
/* compute the number of bits required to flush all mp3 frames
currently in the buffer. This should be the same as the
reservoir size. Only call this routine between frames - i.e.
only after all headers and data have been added to the buffer
by format_bitstream().
Also compute total_bits_output =
size of mp3 buffer (including frame headers which may not
have yet been send to the mp3 buffer) +
number of bits needed to flush all mp3 frames.
total_bytes_output is the size of the mp3 output buffer if
lame_encode_flush_nogap() was called right now.
*/
int
compute_flushbits(const lame_internal_flags * gfc, int *total_bytes_output)
{
SessionConfig_t const *const cfg = &gfc->cfg;
EncStateVar_t const *const esv = &gfc->sv_enc;
int flushbits, remaining_headers;
int bitsPerFrame;
int last_ptr, first_ptr;
first_ptr = esv->w_ptr; /* first header to add to bitstream */
last_ptr = esv->h_ptr - 1; /* last header to add to bitstream */
if (last_ptr == -1)
last_ptr = MAX_HEADER_BUF - 1;
/* add this many bits to bitstream so we can flush all headers */
flushbits = esv->header[last_ptr].write_timing - gfc->bs.totbit;
*total_bytes_output = flushbits;
if (flushbits >= 0) {
/* if flushbits >= 0, some headers have not yet been written */
/* reduce flushbits by the size of the headers */
remaining_headers = 1 + last_ptr - first_ptr;
if (last_ptr < first_ptr)
remaining_headers = 1 + last_ptr - first_ptr + MAX_HEADER_BUF;
flushbits -= remaining_headers * 8 * cfg->sideinfo_len;
}
/* finally, add some bits so that the last frame is complete
* these bits are not necessary to decode the last frame, but
* some decoders will ignore last frame if these bits are missing
*/
bitsPerFrame = getframebits(gfc);
flushbits += bitsPerFrame;
*total_bytes_output += bitsPerFrame;
/* round up: */
if (*total_bytes_output % 8)
*total_bytes_output = 1 + (*total_bytes_output / 8);
else
*total_bytes_output = (*total_bytes_output / 8);
*total_bytes_output += gfc->bs.buf_byte_idx + 1;
if (flushbits < 0) {
#if 0
/* if flushbits < 0, this would mean that the buffer looks like:
* (data...) last_header (data...) (extra data that should not be here...)
*/
DEBUGF(gfc, "last header write_timing = %i \n", esv->header[last_ptr].write_timing);
DEBUGF(gfc, "first header write_timing = %i \n", esv->header[first_ptr].write_timing);
DEBUGF(gfc, "bs.totbit: %i \n", gfc->bs.totbit);
DEBUGF(gfc, "first_ptr, last_ptr %i %i \n", first_ptr, last_ptr);
DEBUGF(gfc, "remaining_headers = %i \n", remaining_headers);
DEBUGF(gfc, "bitsperframe: %i \n", bitsPerFrame);
DEBUGF(gfc, "sidelen: %i \n", cfg->sideinfo_len);
#endif
ERRORF(gfc, "strange error flushing buffer ... \n");
}
return flushbits;
}
void
flush_bitstream(lame_internal_flags * gfc)
{
EncStateVar_t *const esv = &gfc->sv_enc;
III_side_info_t *l3_side;
int nbytes;
int flushbits;
int last_ptr = esv->h_ptr - 1; /* last header to add to bitstream */
if (last_ptr == -1)
last_ptr = MAX_HEADER_BUF - 1;
l3_side = &gfc->l3_side;
if ((flushbits = compute_flushbits(gfc, &nbytes)) < 0)
return;
drain_into_ancillary(gfc, flushbits);
/* check that the 100% of the last frame has been written to bitstream */
assert(esv->header[last_ptr].write_timing + getframebits(gfc)
== gfc->bs.totbit);
/* we have padded out all frames with ancillary data, which is the
same as filling the bitreservoir with ancillary data, so : */
esv->ResvSize = 0;
l3_side->main_data_begin = 0;
}
void
add_dummy_byte(lame_internal_flags * gfc, unsigned char val, unsigned int n)
{
EncStateVar_t *const esv = &gfc->sv_enc;
int i;
while (n-- > 0u) {
putbits_noheaders(gfc, val, 8);
for (i = 0; i < MAX_HEADER_BUF; ++i)
esv->header[i].write_timing += 8;
}
}
/*
format_bitstream()
This is called after a frame of audio has been quantized and coded.
It will write the encoded audio to the bitstream. Note that
from a layer3 encoder's perspective the bit stream is primarily
a series of main_data() blocks, with header and side information
inserted at the proper locations to maintain framing. (See Figure A.7
in the IS).
*/
int
format_bitstream(lame_internal_flags * gfc)
{
SessionConfig_t const *const cfg = &gfc->cfg;
EncStateVar_t *const esv = &gfc->sv_enc;
int bits, nbytes;
III_side_info_t *l3_side;
int bitsPerFrame;
l3_side = &gfc->l3_side;
bitsPerFrame = getframebits(gfc);
drain_into_ancillary(gfc, l3_side->resvDrain_pre);
encodeSideInfo2(gfc, bitsPerFrame);
bits = 8 * cfg->sideinfo_len;
bits += writeMainData(gfc);
drain_into_ancillary(gfc, l3_side->resvDrain_post);
bits += l3_side->resvDrain_post;
l3_side->main_data_begin += (bitsPerFrame - bits) / 8;
/* compare number of bits needed to clear all buffered mp3 frames
* with what we think the resvsize is: */
if (compute_flushbits(gfc, &nbytes) != esv->ResvSize) {
ERRORF(gfc, "Internal buffer inconsistency. flushbits <> ResvSize");
}
/* compare main_data_begin for the next frame with what we
* think the resvsize is: */
if ((l3_side->main_data_begin * 8) != esv->ResvSize) {
ERRORF(gfc, "bit reservoir error: \n"
"l3_side->main_data_begin: %i \n"
"Resvoir size: %i \n"
"resv drain (post) %i \n"
"resv drain (pre) %i \n"
"header and sideinfo: %i \n"
"data bits: %i \n"
"total bits: %i (remainder: %i) \n"
"bitsperframe: %i \n",
8 * l3_side->main_data_begin,
esv->ResvSize,
l3_side->resvDrain_post,
l3_side->resvDrain_pre,
8 * cfg->sideinfo_len,
bits - l3_side->resvDrain_post - 8 * cfg->sideinfo_len,
bits, bits % 8, bitsPerFrame);
ERRORF(gfc, "This is a fatal error. It has several possible causes:");
ERRORF(gfc, "90%% LAME compiled with buggy version of gcc using advanced optimizations");
ERRORF(gfc, " 9%% Your system is overclocked");
ERRORF(gfc, " 1%% bug in LAME encoding library");
esv->ResvSize = l3_side->main_data_begin * 8;
};
assert(gfc->bs.totbit % 8 == 0);
if (gfc->bs.totbit > 1000000000) {
/* to avoid totbit overflow, (at 8h encoding at 128kbs) lets reset bit counter */
int i;
for (i = 0; i < MAX_HEADER_BUF; ++i)
esv->header[i].write_timing -= gfc->bs.totbit;
gfc->bs.totbit = 0;
}
return 0;
}
static int
do_gain_analysis(lame_internal_flags * gfc, unsigned char* buffer, int minimum)
{
SessionConfig_t const *const cfg = &gfc->cfg;
RpgStateVar_t const *const rsv = &gfc->sv_rpg;
RpgResult_t *const rov = &gfc->ov_rpg;
#ifdef DECODE_ON_THE_FLY
if (cfg->decode_on_the_fly) { /* decode the frame */
sample_t pcm_buf[2][1152];
int mp3_in = minimum;
int samples_out = -1;
/* re-synthesis to pcm. Repeat until we get a samples_out=0 */
while (samples_out != 0) {
samples_out = hip_decode1_unclipped(gfc->hip, buffer, mp3_in, pcm_buf[0], pcm_buf[1]);
/* samples_out = 0: need more data to decode
* samples_out = -1: error. Lets assume 0 pcm output
* samples_out = number of samples output */
/* set the lenght of the mp3 input buffer to zero, so that in the
* next iteration of the loop we will be querying mpglib about
* buffered data */
mp3_in = 0;
if (samples_out == -1) {
/* error decoding. Not fatal, but might screw up
* the ReplayGain tag. What should we do? Ignore for now */
samples_out = 0;
}
if (samples_out > 0) {
/* process the PCM data */
/* this should not be possible, and indicates we have
* overflown the pcm_buf buffer */
assert(samples_out <= 1152);
if (cfg->findPeakSample) {
int i;
/* FIXME: is this correct? maybe Max(fabs(pcm),PeakSample) */
for (i = 0; i < samples_out; i++) {
if (pcm_buf[0][i] > rov->PeakSample)
rov->PeakSample = pcm_buf[0][i];
else if (-pcm_buf[0][i] > rov->PeakSample)
rov->PeakSample = -pcm_buf[0][i];
}
if (cfg->channels_out > 1)
for (i = 0; i < samples_out; i++) {
if (pcm_buf[1][i] > rov->PeakSample)
rov->PeakSample = pcm_buf[1][i];
else if (-pcm_buf[1][i] > rov->PeakSample)
rov->PeakSample = -pcm_buf[1][i];
}
}
if (cfg->findReplayGain)
if (AnalyzeSamples
(rsv->rgdata, pcm_buf[0], pcm_buf[1], samples_out,
cfg->channels_out) == GAIN_ANALYSIS_ERROR)
return -6;
} /* if (samples_out>0) */
} /* while (samples_out!=0) */
} /* if (gfc->decode_on_the_fly) */
#endif
return minimum;
}
static int
do_copy_buffer(lame_internal_flags * gfc, unsigned char *buffer, int size)
{
Bit_stream_struc *const bs = &gfc->bs;
int const minimum = bs->buf_byte_idx + 1;
if (minimum <= 0)
return 0;
if (minimum > size)
return -1; /* buffer is too small */
memcpy(buffer, bs->buf, minimum);
bs->buf_byte_idx = -1;
bs->buf_bit_idx = 0;
return minimum;
}
/* copy data out of the internal MP3 bit buffer into a user supplied
unsigned char buffer.
mp3data=0 indicates data in buffer is an id3tags and VBR tags
mp3data=1 data is real mp3 frame data.
*/
int
copy_buffer(lame_internal_flags * gfc, unsigned char *buffer, int size, int mp3data)
{
int const minimum = do_copy_buffer(gfc, buffer, size);
if (minimum > 0 && mp3data) {
UpdateMusicCRC(&gfc->nMusicCRC, buffer, minimum);
/** sum number of bytes belonging to the mp3 stream
* this info will be written into the Xing/LAME header for seeking
*/
gfc->VBR_seek_table.nBytesWritten += minimum;
return do_gain_analysis(gfc, buffer, minimum);
} /* if (mp3data) */
return minimum;
}
void
init_bit_stream_w(lame_internal_flags * gfc)
{
EncStateVar_t *const esv = &gfc->sv_enc;
esv->h_ptr = esv->w_ptr = 0;
esv->header[esv->h_ptr].write_timing = 0;
gfc->bs.buf = lame_calloc(unsigned char, BUFFER_SIZE);
gfc->bs.buf_size = BUFFER_SIZE;
gfc->bs.buf_byte_idx = -1;
gfc->bs.buf_bit_idx = 0;
gfc->bs.totbit = 0;
}
/* end of bitstream.c */