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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 oldval;
unsigned int gbuf1[4];
unsigned short gbuf2[4][30];
unsigned int *decptr; /* decoder ptr */
/* the swapped buffers */
unsigned int swapbuffers[4][10];
unsigned int *swapbuf1;
unsigned int *swapbuf2;
unsigned int *swapbuf1alt;
unsigned int *swapbuf2alt;
unsigned int buffer[5];
unsigned short int buffer_2[148];
} Real144_internal;
static int ra144_decode_init(AVCodecContext * avctx)
{
Real144_internal *glob = avctx->priv_data;
glob->swapbuf1 = glob->swapbuffers[0];
glob->swapbuf2 = glob->swapbuffers[1];
glob->swapbuf1alt = glob->swapbuffers[2];
glob->swapbuf2alt = glob->swapbuffers[3];
return 0;
}
/* lookup square roots in table */
static int t_sqrt(unsigned int x)
{
int s = 0;
while (x > 0xfff) {
s++;
x = x >> 2;
}
return (ff_sqrt(x << 20) << s) << 2;
}
/* do 'voice' */
static void do_voice(const 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;
}
/* rotate block */
static void rotate_block(const short *source, short *target, int offset)
{
int i=0, k=0;
source += BUFFERSIZE - offset;
while (i<BLOCKSIZE) {
target[i++] = source[k++];
if (k == offset)
k = 0;
}
}
/* inverse root mean square */
static int irms(const short *data, int factor)
{
unsigned int i, sum = 0;
for (i=0; i < BLOCKSIZE; i++)
sum += data[i] * data[i];
if (sum == 0)
return 0; /* OOPS - division by zero */
return (0x20000000 / (t_sqrt(sum) >> 8)) * factor;
}
/* multiply/add wavetable */
static void add_wav(int n, int f, int m1, int m2, int m3, const short *s1,
const short *s2, const short *s3, short *dest)
{
int a = 0;
int b, c, i;
const short *ptr, *ptr2;
ptr = wavtable1[n];
ptr2 = wavtable2[n];
if (f)
a = (ptr[0] * m1) >> (ptr2[0] + 1);
b = (ptr[1] * m2) >> (ptr2[1] + 1);
c = (ptr[2] * m3) >> (ptr2[2] + 1);
for (i=0; i < BLOCKSIZE; i++)
dest[i] = ((*(s1++)) * a + (*(s2++)) * b + (*(s3++)) * c) >> 12;
}
static void final(const short *i1, const short *i2,
void *out, int *statbuf, int len)
{
int x, i;
unsigned short int work[50];
short *ptr = work;
memcpy(work, statbuf,20);
memcpy(work + 10, i2, len * 2);
for (i=0; i<len; i++) {
int sum = 0;
int new_val;
for(x=0; x<10; x++)
sum += i1[9-x] * ptr[x];
sum >>= 12;
new_val = ptr[10] - sum;
if (new_val < -32768 || new_val > 32767) {
memset(out, 0, len * 2);
memset(statbuf, 0, 20);
return;
}
ptr[10] = new_val;
ptr++;
}
memcpy(out, work+10, len * 2);
memcpy(statbuf, work + 40, 20);
}
static unsigned int rms(const int *data, int f)
{
int x;
unsigned int res = 0x10000;
int b = 0;
for (x=0; x<10; x++) {
res = (((0x1000000 - (*data) * (*data)) >> 12) * res) >> 12;
if (res == 0)
return 0;
if (res > 0x10000)
return 0; /* We're screwed, might as well go out with a bang. :P */
while (res <= 0x3fff) {
b++;
res <<= 2;
}
data++;
}
if (res > 0)
res = t_sqrt(res);
res >>= (b + 10);
res = (res * f) >> 10;
return res;
}
/* do quarter-block output */
static void do_output_subblock(Real144_internal *glob, const unsigned short *gsp, unsigned int gval, signed short *output_buffer, GetBitContext *gb)
{
unsigned short int buffer_a[40];
unsigned short int *block;
int e, f, g;
int a = get_bits(gb, 7);
int d = get_bits(gb, 8);
int b = get_bits(gb, 7);
int c = get_bits(gb, 7);
if (a) {
a += HALFBLOCK - 1;
rotate_block(glob->buffer_2, buffer_a, a);
}
e = ((ftable1[b] >> 4) * gval) >> 8;
f = ((ftable2[c] >> 4) * gval) >> 8;
if (a)
g = irms(buffer_a, gval) >> 12;
else
g = 0;
memmove(glob->buffer_2, glob->buffer_2 + BLOCKSIZE, (BUFFERSIZE - BLOCKSIZE) * 2);
block = glob->buffer_2 + BUFFERSIZE - BLOCKSIZE;
add_wav(d, a, g, e, f, buffer_a, etable1[b],
etable2[c], block);
final(gsp, block, output_buffer, glob->buffer, BLOCKSIZE);
}
static void dec1(Real144_internal *glob, const int *data, const int *inp,
int n, int f, int block_idx)
{
short *ptr,*end;
signed short *decsp = glob->gbuf2[block_idx];
*(glob->decptr++) = rms(data, f);
end = (ptr = decsp) + (n * 10);
while (ptr < end)
*(ptr++) = *(inp++);
}
static int eq(const short *in, int *target)
{
int retval = 0;
int b, c, i;
unsigned int u;
int buffer1[10];
int buffer2[10];
int *bp1 = buffer1;
int *bp2 = buffer2;
for (i=0; i < 10; i++)
buffer2[i] = in[i];
u = target[9] = bp2[9];
if (u + 0x1000 > 0x1fff)
return 0; /* We're screwed, might as well go out with a bang. :P */
for (c=8; c >= 0; c--) {
if (u == 0x1000)
u++;
if (u == 0xfffff000)
u--;
b = 0x1000-((u * u) >> 12);
if (b == 0)
b++;
for (u=0; u<=c; u++)
bp1[u] = ((bp2[u] - ((target[c+1] * bp2[c-u]) >> 12)) * (0x1000000 / b)) >> 12;
target[c] = u = bp1[c];
if ((u + 0x1000) > 0x1fff)
retval = 1;
FFSWAP(int *, bp1, bp2);
}
return retval;
}
static void dec2(Real144_internal *glob, const int *data, const int *inp,
int n, int f, const int *inp2, int l)
{
unsigned const int *ptr1,*ptr2;
int work[10];
int a,b;
int x;
int result;
signed short *decsp = glob->gbuf2[l];
unsigned short *sptr = decsp;
if(l + 1 < NBLOCKS / 2)
a = NBLOCKS - (l + 1);
else
a = l + 1;
b = NBLOCKS - a;
if (l == 0) {
glob->decptr = glob->gbuf1;
}
ptr1 = inp;
ptr2 = inp2;
for (x=0; x<10*n; x++)
*(sptr++) = (a * (*ptr1++) + b * (*ptr2++)) >> 2;
result = eq(decsp, work);
if (result == 1) {
dec1(glob, data, inp, n, f, l);
} else {
*(glob->decptr++) = rms(work, f);
}
}
/* 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)
{
static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
unsigned int a, c;
int i;
int16_t *data = vdata;
unsigned int val;
Real144_internal *glob = avctx->priv_data;
GetBitContext gb;
if(buf_size < 20) {
av_log(avctx, AV_LOG_ERROR,
"Frame too small (%d bytes). Truncated file?\n", buf_size);
return buf_size;
}
init_get_bits(&gb, buf, 20 * 8);
for (i=0; i<10; i++)
// "<< 1"? Doesn't this make one value out of two of the table useless?
glob->swapbuf1[i] = decodetable[i][get_bits(&gb, sizes[i]) << 1];
do_voice(glob->swapbuf1, glob->swapbuf2);
val = decodeval[get_bits(&gb, 5) << 1]; // Useless table entries?
a = t_sqrt(val*glob->oldval) >> 12;
dec2(glob, glob->swapbuf1alt, glob->swapbuf2alt, 3, glob->oldval, glob->swapbuf2, 0);
if (glob->oldval < val) {
dec2(glob, glob->swapbuf1, glob->swapbuf2, 3, a, glob->swapbuf2alt, 1);
} else {
dec2(glob, glob->swapbuf1alt, glob->swapbuf2alt, 3, a, glob->swapbuf2, 1);
}
dec2(glob, glob->swapbuf1, glob->swapbuf2, 3, val, glob->swapbuf2alt, 2);
dec1(glob, glob->swapbuf1, glob->swapbuf2, 3, val, 3);
/* do output */
for (c=0; c<4; c++) {
do_output_subblock(glob, glob->gbuf2[c], glob->gbuf1[c], data, &gb);
for (i=0; i<BLOCKSIZE; i++) {
*data = av_clip_int16(*data << 2);
data++;
}
}
glob->oldval = val;
FFSWAP(unsigned int *, glob->swapbuf1alt, glob->swapbuf1);
FFSWAP(unsigned int *, glob->swapbuf2alt, glob->swapbuf2);
*data_size = 2*160;
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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