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ffmpeg/libavcodec/ra144.c
Vitor Sessak 1d46ba661c Simplify do_voice(). 
Patch by Vitor Sessak (vitor1001 gmail com)

Originally committed as revision 13124 to svn://svn.ffmpeg.org/ffmpeg/trunk
2008-05-11 18:47:16 +00:00

526 lines
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/*
* Real Audio 1.0 (14.4K)
* Copyright (c) 2003 the ffmpeg project
*
* This file is part of FFmpeg.
*
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "bitstream.h"
#include "ra144.h"
#define NBLOCKS 4 /* number of segments within a block */
#define BLOCKSIZE 40 /* (quarter) block size in 16-bit words (80 bytes) */
#define HALFBLOCK 20 /* BLOCKSIZE/2 */
#define BUFFERSIZE 146 /* for do_output */
/* internal globals */
typedef struct {
unsigned int resetflag, val, oldval;
unsigned int unpacked[28]; /* buffer for unpacked input */
unsigned int *iptr; /* pointer to current input (from unpacked) */
unsigned int gval;
unsigned short *gsp;
unsigned int gbuf1[8];
unsigned short gbuf2[120];
signed short output_buffer[40];
unsigned int *decptr; /* decoder ptr */
signed short *decsp;
/* the swapped buffers */
unsigned int swapb1a[10];
unsigned int swapb2a[10];
unsigned int swapb1b[10];
unsigned int swapb2b[10];
unsigned int *swapbuf1;
unsigned int *swapbuf2;
unsigned int *swapbuf1alt;
unsigned int *swapbuf2alt;
unsigned int buffer[5];
unsigned short int buffer_2[148];
unsigned short int buffer_a[40];
unsigned short int buffer_b[40];
unsigned short int buffer_c[40];
unsigned short int buffer_d[40];
unsigned short int work[50];
unsigned short *sptr;
int buffer1[10];
int buffer2[10];
signed short wavtable1[2304];
unsigned short wavtable2[2304];
} Real144_internal;
static int ra144_decode_init(AVCodecContext * avctx)
{
Real144_internal *glob = avctx->priv_data;
glob->resetflag = 1;
glob->swapbuf1 = glob->swapb1a;
glob->swapbuf2 = glob->swapb2a;
glob->swapbuf1alt = glob->swapb1b;
glob->swapbuf2alt = glob->swapb2b;
memcpy(glob->wavtable1, wavtable1, sizeof(wavtable1));
memcpy(glob->wavtable2, wavtable2, sizeof(wavtable2));
return 0;
}
static void final(Real144_internal *glob, short *i1, short *i2, void *out, int *statbuf, int len);
static void add_wav(Real144_internal *glob, int n, int f, int m1, int m2, int m3, short *s1, short *s2, short *s3, short *dest);
static int irms(short *data, int factor);
static void rotate_block(short *source, short *target, int offset);
/* lookup square roots in table */
static int t_sqrt(unsigned int x)
{
int s = 0;
while (x > 0xfff) {
s++;
x = x >> 2;
}
return (sqrt_table[x] << s) << 2;
}
/* do 'voice' */
static void do_voice(int *a1, int *a2)
{
int buffer[10];
int *b1 = buffer;
int *b2 = a2;
int x, y;
for (x=0; x < 10; x++) {
b1[x] = a1[x] << 4;
for (y=0; y < x; y++)
b1[y] = ((a1[x] * (b2[x-y-1])) >> 12) + b2[y];
FFSWAP(int *, b1, b2);
}
for (x=0; x < 10; x++)
a2[x] >>= 4;
}
/* do quarter-block output */
static void do_output_subblock(Real144_internal *glob, unsigned int x)
{
int a, b, c, d, e, f, g;
if (x == 1)
memset(glob->buffer, 0, 20);
if ((*glob->iptr) == 0)
a = 0;
else
a = (*glob->iptr) + HALFBLOCK - 1;
glob->iptr++;
b = *(glob->iptr++);
c = *(glob->iptr++);
d = *(glob->iptr++);
if (a)
rotate_block(glob->buffer_2, glob->buffer_a, a);
memcpy(glob->buffer_b, etable1 + b * BLOCKSIZE, BLOCKSIZE * 2);
e = ((ftable1[b] >> 4) *glob->gval) >> 8;
memcpy(glob->buffer_c, etable2 + c * BLOCKSIZE, BLOCKSIZE * 2);
f=((ftable2[c] >> 4) *glob->gval) >> 8;
if (a)
g = irms(glob->buffer_a, glob->gval) >> 12;
else
g = 0;
add_wav(glob, d, a, g, e, f, glob->buffer_a, glob->buffer_b,
glob->buffer_c, glob->buffer_d);
memmove(glob->buffer_2, glob->buffer_2 + BLOCKSIZE, (BUFFERSIZE - BLOCKSIZE) * 2);
memcpy(glob->buffer_2 + BUFFERSIZE - BLOCKSIZE, glob->buffer_d, BLOCKSIZE * 2);
final(glob,glob->gsp, glob->buffer_d, glob->output_buffer, glob->buffer,
BLOCKSIZE);
}
/* rotate block */
static void rotate_block(short *source, short *target, int offset)
{
short *end;
short *ptr1;
short *ptr2;
short *ptr3;
ptr2 = source + BUFFERSIZE;
ptr3 = ptr1 = ptr2 - offset;
end = target + BLOCKSIZE;
while (target < end) {
*(target++) = *(ptr3++);
if (ptr3 == ptr2)
ptr3 = ptr1;
}
}
/* inverse root mean square */
static int irms(short *data, int factor)
{
short *p1, *p2;
unsigned int sum;
p2 = (p1 = data) + BLOCKSIZE;
for (sum=0; p2 > p1; p1++)
sum += (*p1) * (*p1);
if (sum == 0)
return 0; /* OOPS - division by zero */
return (0x20000000 / (t_sqrt(sum) >> 8)) * factor;
}
/* multiply/add wavetable */
static void add_wav(Real144_internal *glob, int n, int f, int m1, int m2,
int m3, short *s1, short *s2, short *s3, short *dest)
{
int a, b, c;
short *ptr, *ptr2;
ptr = glob->wavtable1 + n * 9;
ptr2 = glob->wavtable2 + n * 9;
if (f != 0)
a = ((*ptr) * m1) >> ((*ptr2) + 1);
else
a = 0;
ptr++;
ptr2++;
b = ((*ptr) * m2) >> ((*ptr2) + 1);
ptr++;
ptr2++;
c = ((*ptr) * m3) >> ((*ptr2) + 1);
ptr2 = (ptr = dest) + BLOCKSIZE;
if (f != 0)
while (ptr < ptr2)
*(ptr++) = ((*(s1++)) * a + (*(s2++)) * b + (*(s3++)) * c) >> 12;
else
while (ptr < ptr2)
*(ptr++) = ((*(s2++)) * b + (*(s3++)) * c) >> 12;
}
static void final(Real144_internal *glob, short *i1, short *i2, void *out,
int *statbuf, int len)
{
int x, sum, i;
int buffer[10];
short *ptr;
short *ptr2;
memcpy(glob->work, statbuf,20);
memcpy(glob->work + 10, i2, len * 2);
for(i=0; i<10; i++)
buffer[9-i] = i1[i];
ptr2 = (ptr = glob->work) + len;
while (ptr < ptr2) {
for(sum=0, x=0; x<=9; x++)
sum += buffer[x] * (ptr[x]);
sum = sum >> 12;
x = ptr[10] - sum;
if (x<-32768 || x>32767) {
memset(out, 0, len * 2);
memset(statbuf, 0, 20);
return;
}
ptr[10] = x;
ptr++;
}
memcpy(out, ptr+10 - len, len * 2);
memcpy(statbuf, ptr, 20);
}
/* Decode 20-byte input */
static void unpack_input(const unsigned char *input, unsigned int *output)
{
int i;
static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
GetBitContext gb;
init_get_bits(&gb, input, 20 * 8);
for (i=0; i<10; i++)
output[i+1] = get_bits(&gb, sizes[i]);
output[0] = get_bits(&gb, 5);
output += 11;
for (i=0; i<4; i++) {
output[0] = get_bits(&gb, 7);
output[3] = get_bits(&gb, 8);
output[1] = get_bits(&gb, 7);
output[2] = get_bits(&gb, 7);
output += 4;
}
}
static unsigned int rms(int *data, int f)
{
int *c;
int x;
unsigned int res;
int b;
c = data;
b = 0;
res = 0x10000;
for (x=0; x<10; x++) {
res = (((0x1000000 - (*c) * (*c)) >> 12) * res) >> 12;
if (res == 0)
return 0;
if (res <= 0x3fff) {
while (res <= 0x3fff) {
b++;
res <<= 2;
}
} else {
if (res > 0x10000)
return 0; /* We're screwed, might as well go out with a bang. :P */
}
c++;
}
if (res > 0)
res = t_sqrt(res);
res >>= (b + 10);
res = (res * f) >> 10;
return res;
}
static void dec1(Real144_internal *glob, int *data, int *inp, int n, int f)
{
short *ptr,*end;
*(glob->decptr++) = rms(data, f);
glob->decptr++;
end = (ptr = glob->decsp) + (n * 10);
while (ptr < end)
*(ptr++) = *(inp++);
}
static int eq(Real144_internal *glob, short *in, int *target)
{
int retval;
int a;
int b;
int c;
unsigned int u;
short *sptr;
int *ptr1, *ptr2, *ptr3;
int *bp1, *bp2;
retval = 0;
bp1 = glob->buffer1;
bp2 = glob->buffer2;
ptr2 = (ptr3 = glob->buffer2) + 9;
sptr = in;
while (ptr2 >= ptr3)
*(ptr3++) = *(sptr++);
target += 9;
a = bp2[9];
*target = a;
if (a + 0x1000 > 0x1fff)
return 0; /* We're screwed, might as well go out with a bang. :P */
c = 8;
u = a;
while (c >= 0) {
if (u == 0x1000)
u++;
if (u == 0xfffff000)
u--;
b = 0x1000-((u * u) >> 12);
if (b == 0)
b++;
ptr2 = bp1;
ptr1 = (ptr3 = bp2) + c;
for (u=0; u<=c; u++)
*(ptr2++) = ((*(ptr3++) - (((*target) * (*(ptr1--))) >> 12)) * (0x1000000 / b)) >> 12;
*(--target) = u = bp1[(c--)];
if ((u + 0x1000) > 0x1fff)
retval = 1;
FFSWAP(unsigned int *, bp1, bp2);
}
return retval;
}
static void dec2(Real144_internal *glob, int *data, int *inp, int n, int f,
int *inp2, int l)
{
unsigned int *ptr1,*ptr2;
int work[10];
int a,b;
int x;
int result;
if(l + 1 < NBLOCKS / 2)
a = NBLOCKS - (l + 1);
else
a = l + 1;
b = NBLOCKS - a;
if (l == 0) {
glob->decsp = glob->sptr = glob->gbuf2;
glob->decptr = glob->gbuf1;
}
ptr1 = inp;
ptr2 = inp2;
for (x=0; x<10*n; x++)
*(glob->sptr++) = (a * (*ptr1++) + b * (*ptr2++)) >> 2;
result = eq(glob, glob->decsp, work);
if (result == 1) {
dec1(glob, data, inp, n, f);
} else {
*(glob->decptr++) = rms(work, f);
glob->decptr++;
}
glob->decsp += n * 10;
}
/* Uncompress one block (20 bytes -> 160*2 bytes) */
static int ra144_decode_frame(AVCodecContext * avctx,
void *vdata, int *data_size,
const uint8_t * buf, int buf_size)
{
unsigned int a, b, c;
signed short *shptr;
unsigned int *lptr;
const short **dptr;
int16_t *datao;
int16_t *data = vdata;
Real144_internal *glob = avctx->priv_data;
if(buf_size == 0)
return 0;
datao = data;
unpack_input(buf, glob->unpacked);
glob->iptr = glob->unpacked;
glob->val = decodetable[0][(*(glob->iptr++)) << 1];
dptr = decodetable + 1;
lptr = glob->swapbuf1;
while (lptr<glob->swapbuf1 + 10)
*(lptr++) = (*(dptr++))[(*(glob->iptr++)) << 1];
do_voice(glob->swapbuf1, glob->swapbuf2);
a = t_sqrt(glob->val*glob->oldval) >> 12;
for (c=0; c < NBLOCKS; c++) {
if (c == (NBLOCKS - 1)) {
dec1(glob, glob->swapbuf1, glob->swapbuf2, 3, glob->val);
} else {
if (c * 2 == (NBLOCKS - 2)) {
if (glob->oldval < glob->val) {
dec2(glob, glob->swapbuf1, glob->swapbuf2, 3, a, glob->swapbuf2alt, c);
} else {
dec2(glob, glob->swapbuf1alt, glob->swapbuf2alt, 3, a, glob->swapbuf2, c);
}
} else {
if (c * 2 < (NBLOCKS - 2)) {
dec2(glob, glob->swapbuf1alt, glob->swapbuf2alt, 3, glob->oldval, glob->swapbuf2, c);
} else {
dec2(glob, glob->swapbuf1, glob->swapbuf2, 3, glob->val, glob->swapbuf2alt, c);
}
}
}
}
/* do output */
for (b=0, c=0; c<4; c++) {
glob->gval = glob->gbuf1[c * 2];
glob->gsp = glob->gbuf2 + b;
do_output_subblock(glob, glob->resetflag);
glob->resetflag = 0;
shptr = glob->output_buffer;
while (shptr < glob->output_buffer + BLOCKSIZE)
*data++ = av_clip_int16(*(shptr++) << 2);
b += 30;
}
glob->oldval = glob->val;
FFSWAP(unsigned int *, glob->swapbuf1alt, glob->swapbuf1);
FFSWAP(unsigned int *, glob->swapbuf2alt, glob->swapbuf2);
*data_size = (data-datao)*sizeof(*data);
return 20;
}
AVCodec ra_144_decoder =
{
"real_144",
CODEC_TYPE_AUDIO,
CODEC_ID_RA_144,
sizeof(Real144_internal),
ra144_decode_init,
NULL,
NULL,
ra144_decode_frame,
.long_name = "RealAudio 1.0 (14.4K)",
};
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