ref: bf645afaac246967b9590ae7463f243c11d97480
dir: /sys/src/cmd/audio/mp3enc/bitstream.c/
/*
* MP3 bitstream Output interface for LAME
*
* Copyright (c) 1999 Takehiro TOMINAGA
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <assert.h>
#include <stdio.h>
#include "tables.h"
#include "bitstream.h"
#include "quantize.h"
#include "quantize_pvt.h"
#include "version.h"
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif
/* This is the scfsi_band table from 2.4.2.7 of the IS */
const int scfsi_band[5] = { 0, 6, 11, 16, 21 };
/* 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 hoge, hogege;
#endif
void putheader_bits(lame_internal_flags *gfc,int w_ptr)
{
Bit_stream_struc *bs;
bs = &gfc->bs;
#ifdef DEBUG
hoge += gfc->sideinfo_len * 8;
hogege += gfc->sideinfo_len * 8;
#endif
memcpy(&bs->buf[bs->buf_byte_idx], gfc->header[gfc->w_ptr].buf,
gfc->sideinfo_len);
bs->buf_byte_idx += gfc->sideinfo_len;
bs->totbit += gfc->sideinfo_len * 8;
gfc->w_ptr = (gfc->w_ptr + 1) & (MAX_HEADER_BUF - 1);
}
/*write j bits into the bit stream */
static void
putbits2(lame_global_flags *gfp, int val, int j)
{
lame_internal_flags *gfc=gfp->internal_flags;
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(gfc->header[gfc->w_ptr].write_timing >= bs->totbit);
if (gfc->header[gfc->w_ptr].write_timing == bs->totbit)
putheader_bits(gfc, gfc->w_ptr);
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 */
static void
putbits_noheaders(lame_global_flags *gfp, int val, int j)
{
lame_internal_flags *gfc=gfp->internal_flags;
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...
*/
static void
drain_into_ancillary(lame_global_flags *gfp,int remainingBits)
{
lame_internal_flags *gfc=gfp->internal_flags;
int i;
assert(remainingBits >= 0);
if (remainingBits >= 8) {
putbits2(gfp,0x4c,8);
remainingBits -= 8;
}
if (remainingBits >= 8) {
putbits2(gfp,0x41,8);
remainingBits -= 8;
}
if (remainingBits >= 8) {
putbits2(gfp,0x4d,8);
remainingBits -= 8;
}
if (remainingBits >= 8) {
putbits2(gfp,0x45,8);
remainingBits -= 8;
}
if (remainingBits >= 32) {
const char *version = get_lame_short_version ();
if (remainingBits >= 32)
for (i=0; i<(int)strlen(version) && remainingBits >=8 ; ++i) {
remainingBits -= 8;
putbits2(gfp,version[i],8);
}
}
for (; remainingBits >= 1; remainingBits -= 1 ) {
putbits2 ( gfp, gfc->ancillary_flag, 1 );
gfc->ancillary_flag ^= 1;
}
assert (remainingBits == 0);
}
/*write N bits into the header */
inline static void
writeheader(lame_internal_flags *gfc,int val, int j)
{
int ptr = gfc->header[gfc->h_ptr].ptr;
while (j > 0) {
int k = Min(j, 8 - (ptr & 7));
j -= k;
assert (j < MAX_LENGTH); /* >> 32 too large for 32 bit machines */
gfc->header[gfc->h_ptr].buf[ptr >> 3]
|= ((val >> j)) << (8 - (ptr & 7) - k);
ptr += k;
}
gfc->header[gfc->h_ptr].ptr = ptr;
}
/* (jo) this wrapper function for BF_addEntry() updates also the crc */
static void
CRC_writeheader(lame_internal_flags *gfc, int value, int length,int *crc)
{
int bit = 1 << length;
assert(length < MAX_LENGTH-2);
while((bit >>= 1)){
*crc <<= 1;
if (!(*crc & 0x10000) ^ !(value & bit))
*crc ^= CRC16_POLYNOMIAL;
}
*crc &= 0xffff;
writeheader(gfc,value, length);
}
void main_CRC_init (void) {}
inline static void
encodeSideInfo2(lame_global_flags *gfp,int bitsPerFrame)
{
lame_internal_flags *gfc=gfp->internal_flags;
III_side_info_t *l3_side;
int gr, ch;
int crc;
l3_side = &gfc->l3_side;
gfc->header[gfc->h_ptr].ptr = 0;
memset(gfc->header[gfc->h_ptr].buf, 0, gfc->sideinfo_len);
crc = 0xffff; /* (jo) init crc16 for error_protection */
if (gfp->out_samplerate < 16000)
writeheader(gfc,0xffe, 12);
else
writeheader(gfc,0xfff, 12);
writeheader(gfc,(gfp->version), 1);
writeheader(gfc,4 - 3, 2);
writeheader(gfc,(!gfp->error_protection), 1);
/* (jo) from now on call the CRC_writeheader() wrapper to update crc */
CRC_writeheader(gfc,(gfc->bitrate_index), 4,&crc);
CRC_writeheader(gfc,(gfc->samplerate_index), 2,&crc);
CRC_writeheader(gfc,(gfc->padding), 1,&crc);
CRC_writeheader(gfc,(gfp->extension), 1,&crc);
CRC_writeheader(gfc,(gfp->mode), 2,&crc);
CRC_writeheader(gfc,(gfc->mode_ext), 2,&crc);
CRC_writeheader(gfc,(gfp->copyright), 1,&crc);
CRC_writeheader(gfc,(gfp->original), 1,&crc);
CRC_writeheader(gfc,(gfp->emphasis), 2,&crc);
if (gfp->error_protection) {
writeheader(gfc,0, 16); /* dummy */
}
if (gfp->version == 1) {
/* MPEG1 */
assert(l3_side->main_data_begin >= 0);
CRC_writeheader(gfc,(l3_side->main_data_begin), 9,&crc);
if (gfc->channels_out == 2)
CRC_writeheader(gfc,l3_side->private_bits, 3,&crc);
else
CRC_writeheader(gfc,l3_side->private_bits, 5,&crc);
for (ch = 0; ch < gfc->channels_out; ch++) {
int band;
for (band = 0; band < 4; band++) {
CRC_writeheader(gfc,l3_side->scfsi[ch][band], 1,&crc);
}
}
for (gr = 0; gr < 2; gr++) {
for (ch = 0; ch < gfc->channels_out; ch++) {
gr_info *gi = &l3_side->gr[gr].ch[ch].tt;
CRC_writeheader(gfc,gi->part2_3_length, 12,&crc);
CRC_writeheader(gfc,gi->big_values / 2, 9,&crc);
CRC_writeheader(gfc,gi->global_gain, 8,&crc);
CRC_writeheader(gfc,gi->scalefac_compress, 4,&crc);
CRC_writeheader(gfc,gi->window_switching_flag, 1,&crc);
if (gi->window_switching_flag) {
CRC_writeheader(gfc,gi->block_type, 2,&crc);
CRC_writeheader(gfc,gi->mixed_block_flag, 1,&crc);
if (gi->table_select[0] == 14)
gi->table_select[0] = 16;
CRC_writeheader(gfc,gi->table_select[0], 5,&crc);
if (gi->table_select[1] == 14)
gi->table_select[1] = 16;
CRC_writeheader(gfc,gi->table_select[1], 5,&crc);
CRC_writeheader(gfc,gi->subblock_gain[0], 3,&crc);
CRC_writeheader(gfc,gi->subblock_gain[1], 3,&crc);
CRC_writeheader(gfc,gi->subblock_gain[2], 3,&crc);
} else {
assert(gi->block_type == NORM_TYPE);
if (gi->table_select[0] == 14)
gi->table_select[0] = 16;
CRC_writeheader(gfc,gi->table_select[0], 5,&crc);
if (gi->table_select[1] == 14)
gi->table_select[1] = 16;
CRC_writeheader(gfc,gi->table_select[1], 5,&crc);
if (gi->table_select[2] == 14)
gi->table_select[2] = 16;
CRC_writeheader(gfc,gi->table_select[2], 5,&crc);
assert(gi->region0_count < 16U);
assert(gi->region1_count < 8U);
CRC_writeheader(gfc,gi->region0_count, 4,&crc);
CRC_writeheader(gfc,gi->region1_count, 3,&crc);
}
CRC_writeheader(gfc,gi->preflag, 1,&crc);
CRC_writeheader(gfc,gi->scalefac_scale, 1,&crc);
CRC_writeheader(gfc,gi->count1table_select, 1,&crc);
}
}
} else {
/* MPEG2 */
assert(l3_side->main_data_begin >= 0);
CRC_writeheader(gfc,(l3_side->main_data_begin), 8,&crc);
CRC_writeheader(gfc,l3_side->private_bits, gfc->channels_out,&crc);
gr = 0;
for (ch = 0; ch < gfc->channels_out; ch++) {
gr_info *gi = &l3_side->gr[gr].ch[ch].tt;
CRC_writeheader(gfc,gi->part2_3_length, 12,&crc);
CRC_writeheader(gfc,gi->big_values / 2, 9,&crc);
CRC_writeheader(gfc,gi->global_gain, 8,&crc);
CRC_writeheader(gfc,gi->scalefac_compress, 9,&crc);
CRC_writeheader(gfc,gi->window_switching_flag, 1,&crc);
if (gi->window_switching_flag) {
CRC_writeheader(gfc,gi->block_type, 2,&crc);
CRC_writeheader(gfc,gi->mixed_block_flag, 1,&crc);
if (gi->table_select[0] == 14)
gi->table_select[0] = 16;
CRC_writeheader(gfc,gi->table_select[0], 5,&crc);
if (gi->table_select[1] == 14)
gi->table_select[1] = 16;
CRC_writeheader(gfc,gi->table_select[1], 5,&crc);
CRC_writeheader(gfc,gi->subblock_gain[0], 3,&crc);
CRC_writeheader(gfc,gi->subblock_gain[1], 3,&crc);
CRC_writeheader(gfc,gi->subblock_gain[2], 3,&crc);
} else {
if (gi->table_select[0] == 14)
gi->table_select[0] = 16;
CRC_writeheader(gfc,gi->table_select[0], 5,&crc);
if (gi->table_select[1] == 14)
gi->table_select[1] = 16;
CRC_writeheader(gfc,gi->table_select[1], 5,&crc);
if (gi->table_select[2] == 14)
gi->table_select[2] = 16;
CRC_writeheader(gfc,gi->table_select[2], 5,&crc);
assert(gi->region0_count < 16U);
assert(gi->region1_count < 8U);
CRC_writeheader(gfc,gi->region0_count, 4,&crc);
CRC_writeheader(gfc,gi->region1_count, 3,&crc);
}
CRC_writeheader(gfc,gi->scalefac_scale, 1,&crc);
CRC_writeheader(gfc,gi->count1table_select, 1,&crc);
}
}
if (gfp->error_protection) {
/* (jo) error_protection: add crc16 information to header */
gfc->header[gfc->h_ptr].buf[4] = crc >> 8;
gfc->header[gfc->h_ptr].buf[5] = crc & 255;
}
{
int old = gfc->h_ptr;
assert(gfc->header[old].ptr == gfc->sideinfo_len * 8);
gfc->h_ptr = (old + 1) & (MAX_HEADER_BUF - 1);
gfc->header[gfc->h_ptr].write_timing =
gfc->header[old].write_timing + bitsPerFrame;
if (gfc->h_ptr == gfc->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_global_flags *gfp,int *ix, gr_info *gi)
{
#ifdef DEBUG
lame_internal_flags *gfc = gfp->internal_flags;
#endif
/* Write count1 area */
const struct huffcodetab *h = &ht[gi->count1table_select + 32];
int i,bits=0;
#ifdef DEBUG
int gegebo = gfc->bs.totbit;
#endif
ix += 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 (v < 0)
huffbits++;
assert(-1 <= v && v <= 1);
}
v = ix[1];
if (v) {
p += 4;
huffbits *= 2;
if (v < 0)
huffbits++;
assert(-1 <= v && v <= 1);
}
v = ix[2];
if (v) {
p += 2;
huffbits *= 2;
if (v < 0)
huffbits++;
assert(-1 <= v && v <= 1);
}
v = ix[3];
if (v) {
p++;
huffbits *= 2;
if (v < 0)
huffbits++;
assert(-1 <= v && v <= 1);
}
ix += 4;
putbits2(gfp,huffbits + h->table[p], h->hlen[p]);
bits += h->hlen[p];
}
#ifdef DEBUG
DEBUGF("%ld %d %d %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
*/
static int
HuffmanCode(lame_global_flags* const gfp, int table_select, int x1, int x2)
{
struct huffcodetab* h = ht + table_select;
int code = 0;
int cbits = 0;
int xbits = 0;
int sgn_x1 = 0;
int sgn_x2 = 0;
int linbits = h->xlen;
int xlen = h->xlen;
int ext;
// assert ( table_select > 0 );
if (x1 < 0) {
sgn_x1++;
x1 = -x1;
}
if (x2 < 0) {
sgn_x2++;
x2 = -x2;
}
ext = sgn_x1;
if (table_select > 15) {
/* use ESC-words */
if (x1 > 14) {
int linbits_x1 = x1 - 15;
// assert ( linbits_x1 <= h->linmax );
ext |= linbits_x1 << 1;
xbits = linbits;
x1 = 15;
}
if (x2 > 14) {
int linbits_x2 = x2 - 15;
// assert ( linbits_x2 <= h->linmax );
ext <<= linbits;
ext |= linbits_x2;
xbits += linbits;
x2 = 15;
}
xlen = 16;
}
if (x1 != 0) {
cbits--;
}
if (x2 != 0) {
ext <<= 1;
ext |= sgn_x2;
cbits--;
}
xbits -= cbits;
// assert ( (x1|x2) < 16u );
x1 = x1 * xlen + x2;
code = h->table [x1];
cbits += h->hlen [x1];
// assert ( cbits <= MAX_LENGTH );
// assert ( xbits <= MAX_LENGTH );
putbits2 ( gfp, code, cbits );
putbits2 ( gfp, ext, xbits );
return cbits + xbits;
}
static int
Huffmancodebits(lame_global_flags *gfp, int tableindex, int start, int end, int *ix)
{
int i,bits;
// assert(tableindex < 32);
if (!tableindex) return 0;
bits=0;
for (i = start; i < end; i += 2) {
bits += HuffmanCode(gfp,tableindex, ix[i], ix[i + 1]);
}
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_global_flags *gfp,int *ix, gr_info *gi)
{
lame_internal_flags *gfc=gfp->internal_flags;
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 = Huffmancodebits(gfp,gi->table_select[0], 0, region1Start, ix);
bits += Huffmancodebits(gfp,gi->table_select[1], region1Start, gi->big_values, ix);
return bits;
}
static int
LongHuffmancodebits(lame_global_flags *gfp,int *ix, gr_info *gi)
{
lame_internal_flags *gfc=gfp->internal_flags;
int i, bigvalues,bits=0;
int region1Start, region2Start;
bigvalues = gi->big_values;
assert(0 <= bigvalues && bigvalues <= 576);
i = gi->region0_count + 1;
assert(i < 23);
region1Start = gfc->scalefac_band.l[i];
i += gi->region1_count + 1;
assert(i < 23);
region2Start = gfc->scalefac_band.l[i];
if (region1Start > bigvalues)
region1Start = bigvalues;
if (region2Start > bigvalues)
region2Start = bigvalues;
bits +=Huffmancodebits(gfp,gi->table_select[0], 0, region1Start, ix);
bits +=Huffmancodebits(gfp,gi->table_select[1], region1Start, region2Start, ix);
bits +=Huffmancodebits(gfp,gi->table_select[2], region2Start, bigvalues, ix);
return bits;
}
inline static int
writeMainData ( lame_global_flags * const gfp,
int l3_enc [2] [2] [576],
III_scalefac_t scalefac [2] [2] )
{
int gr, ch, sfb,data_bits,scale_bits,tot_bits=0;
lame_internal_flags *gfc=gfp->internal_flags;
III_side_info_t *l3_side;
l3_side = &gfc->l3_side;
if (gfp->version == 1) {
/* MPEG 1 */
for (gr = 0; gr < 2; gr++) {
for (ch = 0; ch < gfc->channels_out; ch++) {
gr_info *gi = &l3_side->gr[gr].ch[ch].tt;
int slen1 = slen1_tab[gi->scalefac_compress];
int slen2 = slen2_tab[gi->scalefac_compress];
data_bits=0;
scale_bits=0;
#ifdef DEBUG
hogege = gfc->bs.totbit;
#endif
if (gi->block_type == SHORT_TYPE) {
for (sfb = 0; sfb < SBPSY_s; sfb++) {
int slen = sfb < 6 ? slen1 : slen2;
assert(scalefac[gr][ch].s[sfb][0]>=0);
assert(scalefac[gr][ch].s[sfb][1]>=0);
assert(scalefac[gr][ch].s[sfb][2]>=0);
putbits2(gfp,scalefac[gr][ch].s[sfb][0], slen);
putbits2(gfp,scalefac[gr][ch].s[sfb][1], slen);
putbits2(gfp,scalefac[gr][ch].s[sfb][2], slen);
scale_bits += 3*slen;
}
data_bits += ShortHuffmancodebits(gfp,l3_enc[gr][ch], gi);
} else {
int i;
for (i = 0; i < sizeof(scfsi_band) / sizeof(int) - 1;
i++) {
if (gr != 0 && l3_side->scfsi[ch][i])
continue;
for (sfb = scfsi_band[i]; sfb < scfsi_band[i + 1];
sfb++) {
assert(scalefac[gr][ch].l[sfb]>=0);
putbits2(gfp,scalefac[gr][ch].l[sfb],
sfb < 11 ? slen1 : slen2);
scale_bits += sfb < 11 ? slen1 : slen2;
}
}
data_bits +=LongHuffmancodebits(gfp,l3_enc[gr][ch], gi);
}
data_bits +=huffman_coder_count1(gfp,l3_enc[gr][ch], gi);
#ifdef DEBUG
DEBUGF("<%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);
assert(scale_bits==gi->part2_length);
tot_bits += scale_bits + data_bits;
} /* for ch */
} /* for gr */
} else {
/* MPEG 2 */
gr = 0;
for (ch = 0; ch < gfc->channels_out; ch++) {
gr_info *gi = &l3_side->gr[gr].ch[ch].tt;
int i, sfb_partition;
assert(gi->sfb_partition_table);
data_bits = 0;
scale_bits=0;
sfb = 0;
sfb_partition = 0;
if (gi->block_type == SHORT_TYPE) {
for (; sfb_partition < 4; sfb_partition++) {
int sfbs = gi->sfb_partition_table[sfb_partition] / 3;
int slen = gi->slen[sfb_partition];
for (i = 0; i < sfbs; i++, sfb++) {
putbits2(gfp,Max(scalefac[gr][ch].s[sfb][0], 0U), slen);
putbits2(gfp,Max(scalefac[gr][ch].s[sfb][1], 0U), slen);
putbits2(gfp,Max(scalefac[gr][ch].s[sfb][2], 0U), slen);
scale_bits += 3*slen;
}
}
data_bits += ShortHuffmancodebits(gfp,l3_enc[gr][ch], gi);
} else {
for (; sfb_partition < 4; sfb_partition++) {
int sfbs = gi->sfb_partition_table[sfb_partition];
int slen = gi->slen[sfb_partition];
for (i = 0; i < sfbs; i++, sfb++) {
putbits2(gfp,Max(scalefac[gr][ch].l[sfb], 0U), slen);
scale_bits += slen;
}
}
data_bits +=LongHuffmancodebits(gfp,l3_enc[gr][ch], gi);
}
data_bits +=huffman_coder_count1(gfp,l3_enc[gr][ch], gi);
/* does bitcount in quantize.c agree with actual bit count?*/
assert(data_bits==gi->part2_3_length-gi->part2_length);
assert(scale_bits==gi->part2_length);
tot_bits += scale_bits + data_bits;
} /* for ch */
} /* for gf */
return tot_bits;
} /* main_data */
void
flush_bitstream(lame_global_flags *gfp)
{
lame_internal_flags *gfc=gfp->internal_flags;
int flushbits,remaining_headers;
int bitsPerFrame, mean_bits;
int last_ptr,first_ptr;
first_ptr=gfc->w_ptr; /* first header to add to bitstream */
last_ptr = gfc->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 = gfc->header[last_ptr].write_timing - gfc->bs.totbit;
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*gfc->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
*/
getframebits(gfp,&bitsPerFrame,&mean_bits);
flushbits += bitsPerFrame;
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("last header write_timing = %i \n",gfc->header[last_ptr].write_timing);
DEBUGF("first header write_timing = %i \n",gfc->header[first_ptr].write_timing);
DEBUGF("bs.totbit: %i \n",gfc->bs.totbit);
DEBUGF("first_ptr, last_ptr %i %i \n",first_ptr,last_ptr);
DEBUGF("remaining_headers = %i \n",remaining_headers);
DEBUGF("bitsperframe: %i \n",bitsPerFrame);
DEBUGF("sidelen: %i \n",gfc->sideinfo_len);
#endif
ERRORF(gfc,"strange error flushing buffer ... \n");
} else {
drain_into_ancillary(gfp,flushbits);
}
assert (gfc->header[last_ptr].write_timing + bitsPerFrame == gfc->bs.totbit);
}
void add_dummy_byte ( lame_global_flags* const gfp, unsigned char val )
{
lame_internal_flags *gfc = gfp->internal_flags;
int i;
putbits_noheaders(gfp,val,8);
for (i=0 ; i< MAX_HEADER_BUF ; ++i)
gfc->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_global_flags *gfp, int bitsPerFrame,
int l3_enc[2][2][576],
III_scalefac_t scalefac[2][2] )
{
lame_internal_flags *gfc=gfp->internal_flags;
int bits;
III_side_info_t *l3_side;
l3_side = &gfc->l3_side;
drain_into_ancillary(gfp,l3_side->resvDrain_pre);
encodeSideInfo2(gfp,bitsPerFrame);
bits = 8*gfc->sideinfo_len;
bits+=writeMainData(gfp,l3_enc,scalefac);
drain_into_ancillary(gfp,l3_side->resvDrain_post);
bits += l3_side->resvDrain_post;
l3_side->main_data_begin += (bitsPerFrame-bits)/8;
if ((l3_side->main_data_begin * 8) != gfc->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,
gfc->ResvSize,
l3_side->resvDrain_post,
l3_side->resvDrain_pre,
8*gfc->sideinfo_len,
bits-l3_side->resvDrain_post-8*gfc->sideinfo_len,
bits, bits % 8,
bitsPerFrame
);
gfc->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)
gfc->header[i].write_timing -= gfc->bs.totbit;
gfc->bs.totbit=0;
}
return 0;
}
int copy_buffer(unsigned char *buffer,int size,Bit_stream_struc *bs)
{
int minimum = bs->buf_byte_idx + 1;
if (minimum <= 0) return 0;
if (size!=0 && 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;
}
void init_bit_stream_w(lame_internal_flags *gfc)
{
gfc->bs.buf = (unsigned char *) malloc(BUFFER_SIZE);
gfc->bs.buf_size = BUFFER_SIZE;
gfc->h_ptr = gfc->w_ptr = 0;
gfc->header[gfc->h_ptr].write_timing = 0;
gfc->bs.buf_byte_idx = -1;
gfc->bs.buf_bit_idx = 0;
gfc->bs.totbit = 0;
}
/* end of bitstream.c */