2 * Real Audio 1.0 (14.4K)
3 * Copyright (c) 2003 the ffmpeg project
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "bitstream.h"
26 #define NBLOCKS 4 /* number of segments within a block */
27 #define BLOCKSIZE 40 /* (quarter) block size in 16-bit words (80 bytes) */
28 #define HALFBLOCK 20 /* BLOCKSIZE/2 */
29 #define BUFFERSIZE 146 /* for do_output */
32 /* internal globals */
35 unsigned int gbuf1[8];
36 unsigned short gbuf2[120];
37 unsigned int *decptr; /* decoder ptr */
40 /* the swapped buffers */
41 unsigned int swapbuffers[4][10];
42 unsigned int *swapbuf1;
43 unsigned int *swapbuf2;
44 unsigned int *swapbuf1alt;
45 unsigned int *swapbuf2alt;
47 unsigned int buffer[5];
48 unsigned short int buffer_2[148];
53 static int ra144_decode_init(AVCodecContext * avctx)
55 Real144_internal *glob = avctx->priv_data;
57 glob->swapbuf1 = glob->swapbuffers[0];
58 glob->swapbuf2 = glob->swapbuffers[1];
59 glob->swapbuf1alt = glob->swapbuffers[2];
60 glob->swapbuf2alt = glob->swapbuffers[3];
65 static void final(const short *i1, const short *i2, void *out, int *statbuf, int len);
66 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);
67 static int irms(const short *data, int factor);
68 static void rotate_block(const short *source, short *target, int offset);
70 /* lookup square roots in table */
71 static int t_sqrt(unsigned int x)
79 return (sqrt_table[x] << s) << 2;
83 static void do_voice(const int *a1, int *a2)
90 for (x=0; x < 10; x++) {
94 b1[y] = ((a1[x] * b2[x-y-1]) >> 12) + b2[y];
96 FFSWAP(int *, b1, b2);
99 for (x=0; x < 10; x++)
104 /* do quarter-block output */
105 static void do_output_subblock(Real144_internal *glob, const unsigned short *gsp, unsigned int gval, signed short *output_buffer, GetBitContext *gb)
107 unsigned short int buffer_a[40];
108 unsigned short int buffer_d[40];
110 int a = get_bits(gb, 7);
111 int d = get_bits(gb, 8);
112 int b = get_bits(gb, 7);
113 int c = get_bits(gb, 7);
117 rotate_block(glob->buffer_2, buffer_a, a);
120 e = ((ftable1[b] >> 4) * gval) >> 8;
121 f=((ftable2[c] >> 4) * gval) >> 8;
124 g = irms(buffer_a, gval) >> 12;
128 add_wav(d, a, g, e, f, buffer_a, etable1 + b*BLOCKSIZE,
129 etable2 + c*BLOCKSIZE, buffer_d);
131 memmove(glob->buffer_2, glob->buffer_2 + BLOCKSIZE, (BUFFERSIZE - BLOCKSIZE) * 2);
132 memcpy(glob->buffer_2 + BUFFERSIZE - BLOCKSIZE, buffer_d, BLOCKSIZE * 2);
134 final(gsp, buffer_d, output_buffer, glob->buffer, BLOCKSIZE);
138 static void rotate_block(const short *source, short *target, int offset)
141 const short *ptr1 = source + BUFFERSIZE - offset;
143 while (i<BLOCKSIZE) {
144 target[i++] = ptr1[k++];
151 /* inverse root mean square */
152 static int irms(const short *data, int factor)
154 const short *p1, *p2;
157 p2 = (p1 = data) + BLOCKSIZE;
158 for (sum=0; p2 > p1; p1++)
159 sum += (*p1) * (*p1);
162 return 0; /* OOPS - division by zero */
164 return (0x20000000 / (t_sqrt(sum) >> 8)) * factor;
167 /* multiply/add wavetable */
168 static void add_wav(int n, int f, int m1, int m2, int m3, const short *s1,
169 const short *s2, const short *s3, short *dest)
172 const short *ptr, *ptr2;
174 ptr = wavtable1 + n * 9;
175 ptr2 = wavtable2 + n * 9;
178 a = ((*ptr) * m1) >> ((*ptr2) + 1);
184 b = ((*ptr) * m2) >> ((*ptr2) + 1);
187 c = ((*ptr) * m3) >> ((*ptr2) + 1);
190 for (i=0; i < BLOCKSIZE; i++)
191 dest[i] = ((*(s1++)) * a + (*(s2++)) * b + (*(s3++)) * c) >> 12;
193 for (i=0; i < BLOCKSIZE; i++)
194 dest[i] = ((*(s2++)) * b + (*(s3++)) * c) >> 12;
198 static void final(const short *i1, const short *i2,
199 void *out, int *statbuf, int len)
205 unsigned short int work[50];
207 memcpy(work, statbuf,20);
208 memcpy(work + 10, i2, len * 2);
213 ptr2 = (ptr = work) + len;
216 for(sum=0, x=0; x<=9; x++)
217 sum += buffer[x] * (ptr[x]);
222 if (x<-32768 || x>32767) {
223 memset(out, 0, len * 2);
224 memset(statbuf, 0, 20);
231 memcpy(out, ptr+10 - len, len * 2);
232 memcpy(statbuf, ptr, 20);
235 static unsigned int rms(const int *data, int f)
245 for (x=0; x<10; x++) {
246 res = (((0x1000000 - (*c) * (*c)) >> 12) * res) >> 12;
252 while (res <= 0x3fff) {
258 return 0; /* We're screwed, might as well go out with a bang. :P */
267 res = (res * f) >> 10;
271 static void dec1(Real144_internal *glob, const int *data, const int *inp,
276 *(glob->decptr++) = rms(data, f);
278 end = (ptr = glob->decsp) + (n * 10);
284 static int eq(const short *in, int *target)
292 int *ptr1, *ptr2, *ptr3;
300 ptr2 = (ptr3 = buffer2) + 9;
304 *(ptr3++) = *(sptr++);
310 if (a + 0x1000 > 0x1fff)
311 return 0; /* We're screwed, might as well go out with a bang. :P */
323 b = 0x1000-((u * u) >> 12);
329 ptr1 = (ptr3 = bp2) + c;
332 *(ptr2++) = ((*(ptr3++) - (((*target) * (*(ptr1--))) >> 12)) * (0x1000000 / b)) >> 12;
334 *(--target) = u = bp1[(c--)];
336 if ((u + 0x1000) > 0x1fff)
339 FFSWAP(int *, bp1, bp2);
344 static void dec2(Real144_internal *glob, const int *data, const int *inp,
345 int n, int f, const int *inp2, int l)
347 unsigned const int *ptr1,*ptr2;
353 if(l + 1 < NBLOCKS / 2)
354 a = NBLOCKS - (l + 1);
361 glob->decsp = glob->sptr = glob->gbuf2;
362 glob->decptr = glob->gbuf1;
367 for (x=0; x<10*n; x++)
368 *(glob->sptr++) = (a * (*ptr1++) + b * (*ptr2++)) >> 2;
370 result = eq(glob->decsp, work);
373 dec1(glob, data, inp, n, f);
375 *(glob->decptr++) = rms(work, f);
378 glob->decsp += n * 10;
381 /* Uncompress one block (20 bytes -> 160*2 bytes) */
382 static int ra144_decode_frame(AVCodecContext * avctx,
383 void *vdata, int *data_size,
384 const uint8_t * buf, int buf_size)
386 static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
387 unsigned int a, b, c;
391 int16_t *data = vdata;
394 Real144_internal *glob = avctx->priv_data;
402 init_get_bits(&gb, buf, 20 * 8);
405 // "<< 1"? Doesn't this make one value out of two of the table useless?
406 glob->swapbuf1[i] = decodetable[i][get_bits(&gb, sizes[i]) << 1];
408 do_voice(glob->swapbuf1, glob->swapbuf2);
410 val = decodeval[get_bits(&gb, 5) << 1]; // Useless table entries?
411 a = t_sqrt(val*glob->oldval) >> 12;
413 for (c=0; c < NBLOCKS; c++) {
414 if (c == (NBLOCKS - 1)) {
415 dec1(glob, glob->swapbuf1, glob->swapbuf2, 3, val);
417 if (c * 2 == (NBLOCKS - 2)) {
418 if (glob->oldval < val) {
419 dec2(glob, glob->swapbuf1, glob->swapbuf2, 3, a, glob->swapbuf2alt, c);
421 dec2(glob, glob->swapbuf1alt, glob->swapbuf2alt, 3, a, glob->swapbuf2, c);
424 if (c * 2 < (NBLOCKS - 2)) {
425 dec2(glob, glob->swapbuf1alt, glob->swapbuf2alt, 3, glob->oldval, glob->swapbuf2, c);
427 dec2(glob, glob->swapbuf1, glob->swapbuf2, 3, val, glob->swapbuf2alt, c);
434 for (b=0, c=0; c<4; c++) {
435 unsigned int gval = glob->gbuf1[c * 2];
436 unsigned short *gsp = glob->gbuf2 + b;
437 signed short output_buffer[40];
439 do_output_subblock(glob, gsp, gval, output_buffer, &gb);
441 shptr = output_buffer;
442 while (shptr < output_buffer + BLOCKSIZE)
443 *data++ = av_clip_int16(*(shptr++) << 2);
449 FFSWAP(unsigned int *, glob->swapbuf1alt, glob->swapbuf1);
450 FFSWAP(unsigned int *, glob->swapbuf2alt, glob->swapbuf2);
452 *data_size = (data-datao)*sizeof(*data);
457 AVCodec ra_144_decoder =
462 sizeof(Real144_internal),
467 .long_name = "RealAudio 1.0 (14.4K)",