www.pudn.com > lame3(mp3编码程序和资料).zip > bitstream.c, change:2000-07-02,size:23753b
/*
* 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.
*/
#include
#include
#include
#include "tables.h"
#include "bitstream.h"
#include "quantize.h"
#include "quantize-pvt.h"
#include "version.h"
/* This is the scfsi_band table from 2.4.2.7 of the IS */
const int scfsi_band[5] = { 0, 6, 11, 16, 21 };
#define MAX_LENGTH 32 /* Maximum length of word written or
read from bit stream */
#ifdef DEBUG
static int hoge, hogege;
#endif
const int pmask[8]={0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff};
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 N bits into the bit stream */
static INLINE void
putbits2(lame_global_flags *gfp, unsigned int val, int j)
{
lame_internal_flags *gfc=gfp->internal_flags;
Bit_stream_struc *bs;
bs = &gfc->bs;
assert(j <= MAX_LENGTH);
if (j= (1 << j)) {
DEBUGF("val=%ui %i \n",val,(1< 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);
bs->buf[bs->buf_byte_idx]
|= ((val >> (j-k)) & pmask[k - 1]) << (bs->buf_bit_idx - k);
bs->buf_bit_idx -= k;
j -= k;
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 INLINE void
drain_into_ancillary(lame_global_flags *gfp,int remainingBits)
{
lame_internal_flags *gfc=gfp->internal_flags;
int i,bits;
assert(remainingBits >= 0);
#ifdef DEBUG
DEBUGF("remain %d\n",remainingBits);
hoge += remainingBits;
hogege += remainingBits;
#endif
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) {
char * version;
version = get_lame_version();
if (remainingBits >= 32)
for (i=0; i=8 ; ++i) {
remainingBits -= 8;
putbits2(gfp,(unsigned int)version[i],8);
}
}
bits = remainingBits & (MAX_LENGTH - 1);
for (i=0; iancillary_flag,1);
gfc->ancillary_flag = 1-gfc->ancillary_flag;
}
remainingBits /= MAX_LENGTH;
for (; remainingBits > 0; remainingBits--) {
if (gfc->ancillary_flag)
putbits2(gfp,0xAAAAAAAA, MAX_LENGTH);
else
putbits2(gfp,0x55555555, MAX_LENGTH);
}
}
/*write N bits into the header */
static INLINE void
writeheader(lame_internal_flags *gfc,unsigned int val, int j)
{
int ptr = gfc->header[gfc->h_ptr].ptr;
assert(j <= MAX_LENGTH);
while (j > 0) {
int k = Min(j, 8 - (ptr & 7));
gfc->header[gfc->h_ptr].buf[ptr >> 3]
|= ((val >> (j-k)) & pmask[k-1]) << (8 - (ptr & 7) - k);
ptr += k;
j -= 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,unsigned int value, int length,unsigned int *crc)
{
unsigned int bit = 1 << length;
while((bit >>= 1)){
*crc <<= 1;
if (!(*crc & 0x10000) ^ !(value & bit))
*crc ^= CRC16_POLYNOMIAL;
}
*crc &= 0xffff;
writeheader(gfc,value, length);
}
static INLINE void
encodeSideInfo2(lame_global_flags *gfp,int bitsPerFrame)
{
lame_internal_flags *gfc=gfp->internal_flags;
III_side_info_t *l3_side;
int gr, ch;
unsigned 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,(unsigned int)(gfp->version), 1);
writeheader(gfc,4 - 3, 2);
writeheader(gfc,(unsigned int)(!gfp->error_protection), 1);
/* (jo) from now on call the CRC_writeheader() wrapper to update crc */
CRC_writeheader(gfc,(unsigned int)(gfc->bitrate_index), 4,&crc);
CRC_writeheader(gfc,(unsigned int)(gfc->samplerate_index), 2,&crc);
CRC_writeheader(gfc,(unsigned int)(gfc->padding), 1,&crc);
CRC_writeheader(gfc,(unsigned int)(gfp->extension), 1,&crc);
CRC_writeheader(gfc,(unsigned int)(gfp->mode), 2,&crc);
CRC_writeheader(gfc,(unsigned int)(gfc->mode_ext), 2,&crc);
CRC_writeheader(gfc,(unsigned int)(gfp->copyright), 1,&crc);
CRC_writeheader(gfc,(unsigned int)(gfp->original), 1,&crc);
CRC_writeheader(gfc,(unsigned int)(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,(unsigned int)(l3_side->main_data_begin), 9,&crc);
if (gfc->stereo == 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->stereo; 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->stereo; 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);
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,(unsigned int)(l3_side->main_data_begin), 8,&crc);
CRC_writeheader(gfc,l3_side->private_bits, gfc->stereo,&crc);
gr = 0;
for (ch = 0; ch < gfc->stereo; 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);
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("Error: MAX_HEADER_BUF too small in bitstream.c \n");
}
}
}
static INLINE 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) {
HUFFBITS 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 INLINE int
HuffmanCode(lame_global_flags *gfp, unsigned int table_select, int x, int y)
{
/* lame_internal_flags *gfc=gfp->internal_flags;*/
unsigned int code, ext, xlen;
int cbits, xbits;
unsigned int signx, signy, linbits;
const struct huffcodetab *h;
cbits = 0;
xbits = 0;
code = 0;
signx = signy = 0;
if (x < 0) {
signx++;
x = -x;
}
if (y < 0) {
signy++;
y = -y;
}
assert(table_select>0);
h = &(ht[table_select]);
linbits = h->xlen;
ext = signx;
xlen = h->xlen;
if (table_select > 15) {
/* use ESC-words */
if (x > 14) {
int linbitsx = x - 15;
assert(linbitsx <= h->linmax);
ext |= linbitsx << 1;
xbits = linbits;
x = 15;
}
if (y > 14) {
int linbitsy = y - 15;
assert(linbitsy <= h->linmax);
ext <<= linbits;
ext |= linbitsy;
xbits += linbits;
y = 15;
}
xlen = 16;
}
if (x != 0) {
cbits--;
}
if (y != 0) {
ext <<= 1;
ext |= signy;
cbits--;
}
xbits -= cbits;
assert(x <= 15);
assert(y <= 15);
x = x * xlen + y;
code = h->table[x];
cbits += h->hlen[x];
assert(cbits <= 32);
assert(xbits <= 32);
putbits2(gfp,code, cbits);
putbits2(gfp, ext, xbits);
return cbits+xbits;
}
static int
Huffmancodebits(lame_global_flags *gfp,unsigned 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=0;
int region1Start, region2Start;
region1Start=3*gfc->scalefac_band.s[3];
if (region1Start > gi->big_values) region1Start = gi->big_values;
/* short blocks do not have a region2 */
region2Start=gi->big_values;
bits +=Huffmancodebits(gfp,gi->table_select[0], 0, region1Start, ix);
bits +=Huffmancodebits(gfp,gi->table_select[1], region1Start, region2Start, 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;
}
static INLINE int
writeMainData(lame_global_flags *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->stereo; 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->stereo; 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("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_vbrframe(lame_global_flags *gfp,int bitsPerFrame)
{
lame_internal_flags *gfc = gfp->internal_flags;
int bits;
gfc->header[gfc->h_ptr].ptr = 0;
memset(gfc->header[gfc->h_ptr].buf, 0, gfc->sideinfo_len);
bits = bitsPerFrame-8*gfc->sideinfo_len;
/* add one byte, cause header to be written */
putbits2(gfp,0,8);
/* setup for next header */
gfc->h_ptr = (gfc->h_ptr + 1) & (MAX_HEADER_BUF - 1);
gfc->header[gfc->h_ptr].write_timing = bitsPerFrame;
drain_into_ancillary(gfp,bits-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("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 > 1000000000UL ) {
/* 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;
}