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[4];
36 unsigned short gbuf2[4][30];
37 unsigned int *decptr; /* decoder ptr */
39 /* the swapped buffers */
40 unsigned int swapbuffers[4][10];
41 unsigned int *swapbuf1;
42 unsigned int *swapbuf2;
43 unsigned int *swapbuf1alt;
44 unsigned int *swapbuf2alt;
46 unsigned int buffer[5];
47 unsigned short int buffer_2[148];
50 static int ra144_decode_init(AVCodecContext * avctx)
52 Real144_internal *glob = avctx->priv_data;
54 glob->swapbuf1 = glob->swapbuffers[0];
55 glob->swapbuf2 = glob->swapbuffers[1];
56 glob->swapbuf1alt = glob->swapbuffers[2];
57 glob->swapbuf2alt = glob->swapbuffers[3];
62 /* lookup square roots in table */
63 static int t_sqrt(unsigned int x)
71 return (ff_sqrt(x << 20) << s) << 2;
75 static void do_voice(const int *a1, int *a2)
82 for (x=0; x < 10; x++) {
86 b1[y] = ((a1[x] * b2[x-y-1]) >> 12) + b2[y];
88 FFSWAP(int *, b1, b2);
91 for (x=0; x < 10; x++)
96 static void rotate_block(const short *source, short *target, int offset)
99 source += BUFFERSIZE - offset;
101 while (i<BLOCKSIZE) {
102 target[i++] = source[k++];
109 /* inverse root mean square */
110 static int irms(const short *data, int factor)
112 unsigned int i, sum = 0;
114 for (i=0; i < BLOCKSIZE; i++)
115 sum += data[i] * data[i];
118 return 0; /* OOPS - division by zero */
120 return (0x20000000 / (t_sqrt(sum) >> 8)) * factor;
123 /* multiply/add wavetable */
124 static void add_wav(int n, int f, int m1, int m2, int m3, const short *s1,
125 const short *s2, const short *s3, short *dest)
129 const short *ptr, *ptr2;
135 a = (ptr[0] * m1) >> (ptr2[0] + 1);
137 b = (ptr[1] * m2) >> (ptr2[1] + 1);
138 c = (ptr[2] * m3) >> (ptr2[2] + 1);
140 for (i=0; i < BLOCKSIZE; i++)
141 dest[i] = ((*(s1++)) * a + (*(s2++)) * b + (*(s3++)) * c) >> 12;
145 static void final(const short *i1, const short *i2,
146 void *out, int *statbuf, int len)
152 unsigned short int work[50];
154 memcpy(work, statbuf,20);
155 memcpy(work + 10, i2, len * 2);
160 ptr2 = (ptr = work) + len;
163 for(sum=0, x=0; x<=9; x++)
164 sum += buffer[x] * (ptr[x]);
169 if (x<-32768 || x>32767) {
170 memset(out, 0, len * 2);
171 memset(statbuf, 0, 20);
178 memcpy(out, ptr+10 - len, len * 2);
179 memcpy(statbuf, ptr, 20);
182 static unsigned int rms(const int *data, int f)
185 unsigned int res = 0x10000;
188 for (x=0; x<10; x++) {
189 res = (((0x1000000 - (*data) * (*data)) >> 12) * res) >> 12;
195 return 0; /* We're screwed, might as well go out with a bang. :P */
197 while (res <= 0x3fff) {
208 res = (res * f) >> 10;
212 /* do quarter-block output */
213 static void do_output_subblock(Real144_internal *glob, const unsigned short *gsp, unsigned int gval, signed short *output_buffer, GetBitContext *gb)
215 unsigned short int buffer_a[40];
216 unsigned short int *block;
218 int a = get_bits(gb, 7);
219 int d = get_bits(gb, 8);
220 int b = get_bits(gb, 7);
221 int c = get_bits(gb, 7);
225 rotate_block(glob->buffer_2, buffer_a, a);
228 e = ((ftable1[b] >> 4) * gval) >> 8;
229 f = ((ftable2[c] >> 4) * gval) >> 8;
232 g = irms(buffer_a, gval) >> 12;
236 memmove(glob->buffer_2, glob->buffer_2 + BLOCKSIZE, (BUFFERSIZE - BLOCKSIZE) * 2);
237 block = glob->buffer_2 + BUFFERSIZE - BLOCKSIZE;
239 add_wav(d, a, g, e, f, buffer_a, etable1[b],
242 final(gsp, block, output_buffer, glob->buffer, BLOCKSIZE);
245 static void dec1(Real144_internal *glob, const int *data, const int *inp,
246 int n, int f, int block_idx)
249 signed short *decsp = glob->gbuf2[block_idx];
251 *(glob->decptr++) = rms(data, f);
252 end = (ptr = decsp) + (n * 10);
258 static int eq(const short *in, int *target)
266 int *ptr1, *ptr2, *ptr3;
274 ptr2 = (ptr3 = buffer2) + 9;
278 *(ptr3++) = *(sptr++);
284 if (a + 0x1000 > 0x1fff)
285 return 0; /* We're screwed, might as well go out with a bang. :P */
297 b = 0x1000-((u * u) >> 12);
303 ptr1 = (ptr3 = bp2) + c;
306 *(ptr2++) = ((*(ptr3++) - (((*target) * (*(ptr1--))) >> 12)) * (0x1000000 / b)) >> 12;
308 *(--target) = u = bp1[(c--)];
310 if ((u + 0x1000) > 0x1fff)
313 FFSWAP(int *, bp1, bp2);
318 static void dec2(Real144_internal *glob, const int *data, const int *inp,
319 int n, int f, const int *inp2, int l)
321 unsigned const int *ptr1,*ptr2;
326 signed short *decsp = glob->gbuf2[l];
327 unsigned short *sptr = decsp;
329 if(l + 1 < NBLOCKS / 2)
330 a = NBLOCKS - (l + 1);
337 glob->decptr = glob->gbuf1;
342 for (x=0; x<10*n; x++)
343 *(sptr++) = (a * (*ptr1++) + b * (*ptr2++)) >> 2;
345 result = eq(decsp, work);
348 dec1(glob, data, inp, n, f, l);
350 *(glob->decptr++) = rms(work, f);
354 /* Uncompress one block (20 bytes -> 160*2 bytes) */
355 static int ra144_decode_frame(AVCodecContext * avctx,
356 void *vdata, int *data_size,
357 const uint8_t * buf, int buf_size)
359 static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
362 int16_t *data = vdata;
365 Real144_internal *glob = avctx->priv_data;
371 init_get_bits(&gb, buf, 20 * 8);
374 // "<< 1"? Doesn't this make one value out of two of the table useless?
375 glob->swapbuf1[i] = decodetable[i][get_bits(&gb, sizes[i]) << 1];
377 do_voice(glob->swapbuf1, glob->swapbuf2);
379 val = decodeval[get_bits(&gb, 5) << 1]; // Useless table entries?
380 a = t_sqrt(val*glob->oldval) >> 12;
382 dec2(glob, glob->swapbuf1alt, glob->swapbuf2alt, 3, glob->oldval, glob->swapbuf2, 0);
383 if (glob->oldval < val) {
384 dec2(glob, glob->swapbuf1, glob->swapbuf2, 3, a, glob->swapbuf2alt, 1);
386 dec2(glob, glob->swapbuf1alt, glob->swapbuf2alt, 3, a, glob->swapbuf2, 1);
388 dec2(glob, glob->swapbuf1, glob->swapbuf2, 3, val, glob->swapbuf2alt, 2);
389 dec1(glob, glob->swapbuf1, glob->swapbuf2, 3, val, 3);
392 for (c=0; c<4; c++) {
393 do_output_subblock(glob, glob->gbuf2[c], glob->gbuf1[c], data, &gb);
395 for (i=0; i<BLOCKSIZE; i++) {
396 *data = av_clip_int16(*data << 2);
403 FFSWAP(unsigned int *, glob->swapbuf1alt, glob->swapbuf1);
404 FFSWAP(unsigned int *, glob->swapbuf2alt, glob->swapbuf2);
411 AVCodec ra_144_decoder =
416 sizeof(Real144_internal),
421 .long_name = "RealAudio 1.0 (14.4K)",