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 */
36 /* the swapped buffers */
37 unsigned int swapbuffers[4][10];
38 unsigned int *swapbuf1;
39 unsigned int *swapbuf2;
40 unsigned int *swapbuf1alt;
41 unsigned int *swapbuf2alt;
43 unsigned int buffer[5];
44 uint16_t buffer_2[148];
47 static int ra144_decode_init(AVCodecContext * avctx)
49 Real144_internal *glob = avctx->priv_data;
51 glob->swapbuf1 = glob->swapbuffers[0];
52 glob->swapbuf2 = glob->swapbuffers[1];
53 glob->swapbuf1alt = glob->swapbuffers[2];
54 glob->swapbuf2alt = glob->swapbuffers[3];
59 /* lookup square roots in table */
60 static int t_sqrt(unsigned int x)
68 return (ff_sqrt(x << 20) << s) << 2;
72 static void do_voice(const int *a1, int *a2)
79 for (x=0; x < 10; x++) {
83 b1[y] = ((a1[x] * b2[x-y-1]) >> 12) + b2[y];
85 FFSWAP(int *, b1, b2);
88 for (x=0; x < 10; x++)
93 static void rotate_block(const int16_t *source, int16_t *target, int offset)
96 source += BUFFERSIZE - offset;
99 target[i++] = source[k++];
106 /* inverse root mean square */
107 static int irms(const int16_t *data, int factor)
109 unsigned int i, sum = 0;
111 for (i=0; i < BLOCKSIZE; i++)
112 sum += data[i] * data[i];
115 return 0; /* OOPS - division by zero */
117 return (0x20000000 / (t_sqrt(sum) >> 8)) * factor;
120 /* multiply/add wavetable */
121 static void add_wav(int n, int skip_first, int *m, const int16_t *s1,
122 const int8_t *s2, const int8_t *s3, int16_t *dest)
128 for (i=!skip_first; i<3; i++)
129 v[i] = (wavtable1[n][i] * m[i]) >> (wavtable2[n][i] + 1);
131 for (i=0; i < BLOCKSIZE; i++)
132 dest[i] = ((*(s1++))*v[0] + (*(s2++))*v[1] + (*(s3++))*v[2]) >> 12;
136 static void final(const int16_t *i1, const int16_t *i2,
137 void *out, int *statbuf, int len)
143 memcpy(work, statbuf,20);
144 memcpy(work + 10, i2, len * 2);
146 for (i=0; i<len; i++) {
151 sum += i1[9-x] * ptr[x];
155 new_val = ptr[10] - sum;
157 if (new_val < -32768 || new_val > 32767) {
158 memset(out, 0, len * 2);
159 memset(statbuf, 0, 20);
167 memcpy(out, work+10, len * 2);
168 memcpy(statbuf, work + 40, 20);
171 static unsigned int rms(const int *data, int f)
174 unsigned int res = 0x10000;
177 for (x=0; x<10; x++) {
178 res = (((0x1000000 - (*data) * (*data)) >> 12) * res) >> 12;
184 return 0; /* We're screwed, might as well go out with a bang. :P */
186 while (res <= 0x3fff) {
197 res = (res * f) >> 10;
201 /* do quarter-block output */
202 static void do_output_subblock(Real144_internal *glob,
203 const uint16_t *gsp, unsigned int gval,
204 int16_t *output_buffer, GetBitContext *gb)
206 uint16_t buffer_a[40];
208 int a = get_bits(gb, 7);
209 int d = get_bits(gb, 8);
210 int b = get_bits(gb, 7);
211 int c = get_bits(gb, 7);
216 rotate_block(glob->buffer_2, buffer_a, a);
219 m[1] = ((ftable1[b] >> 4) * gval) >> 8;
220 m[2] = ((ftable2[c] >> 4) * gval) >> 8;
223 m[0] = irms(buffer_a, gval) >> 12;
227 memmove(glob->buffer_2, glob->buffer_2 + BLOCKSIZE,
228 (BUFFERSIZE - BLOCKSIZE) * 2);
230 block = glob->buffer_2 + BUFFERSIZE - BLOCKSIZE;
232 add_wav(d, a, m, buffer_a, etable1[b], etable2[c], block);
234 final(gsp, block, output_buffer, glob->buffer, BLOCKSIZE);
237 static int dec1(int16_t *decsp, const int *data, const int *inp, int f)
242 *(decsp++) = *(inp++);
247 static int eq(const int16_t *in, int *target)
257 for (i=0; i < 10; i++)
260 u = target[9] = bp2[9];
262 if (u + 0x1000 > 0x1fff)
263 return 0; /* We're screwed, might as well go out with a bang. :P */
265 for (c=8; c >= 0; c--) {
272 b = 0x1000-((u * u) >> 12);
278 bp1[u] = ((bp2[u] - ((target[c+1] * bp2[c-u]) >> 12)) * (0x1000000 / b)) >> 12;
280 target[c] = u = bp1[c];
282 if ((u + 0x1000) > 0x1fff)
285 FFSWAP(int *, bp1, bp2);
290 static int dec2(int16_t *decsp, const int *data, const int *inp,
291 int f, const int *inp2, int a)
298 decsp[x] = (a * inp[x] + b * inp2[x]) >> 2;
301 return dec1(decsp, data, inp, f);
306 /* Uncompress one block (20 bytes -> 160*2 bytes) */
307 static int ra144_decode_frame(AVCodecContext * avctx,
308 void *vdata, int *data_size,
309 const uint8_t * buf, int buf_size)
311 static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
312 unsigned int gbuf1[4];
313 uint16_t gbuf2[4][30];
316 int16_t *data = vdata;
319 Real144_internal *glob = avctx->priv_data;
323 av_log(avctx, AV_LOG_ERROR,
324 "Frame too small (%d bytes). Truncated file?\n", buf_size);
327 init_get_bits(&gb, buf, 20 * 8);
330 // "<< 1"? Doesn't this make one value out of two of the table useless?
331 glob->swapbuf1[i] = decodetable[i][get_bits(&gb, sizes[i]) << 1];
333 do_voice(glob->swapbuf1, glob->swapbuf2);
335 val = decodeval[get_bits(&gb, 5) << 1]; // Useless table entries?
336 a = t_sqrt(val*glob->oldval) >> 12;
338 gbuf1[0] = dec2(gbuf2[0], glob->swapbuf1alt, glob->swapbuf2alt, glob->oldval, glob->swapbuf2, 3);
339 if (glob->oldval < val) {
340 gbuf1[1] = dec2(gbuf2[1], glob->swapbuf1, glob->swapbuf2, a, glob->swapbuf2alt, 2);
342 gbuf1[1] = dec2(gbuf2[1], glob->swapbuf1alt, glob->swapbuf2alt, a, glob->swapbuf2, 2);
344 gbuf1[2] = dec2(gbuf2[2], glob->swapbuf1, glob->swapbuf2, val, glob->swapbuf2alt, 3);
345 gbuf1[3] = dec1(gbuf2[3], glob->swapbuf1, glob->swapbuf2, val);
348 for (c=0; c<4; c++) {
349 do_output_subblock(glob, gbuf2[c], gbuf1[c], data, &gb);
351 for (i=0; i<BLOCKSIZE; i++) {
352 *data = av_clip_int16(*data << 2);
359 FFSWAP(unsigned int *, glob->swapbuf1alt, glob->swapbuf1);
360 FFSWAP(unsigned int *, glob->swapbuf2alt, glob->swapbuf2);
367 AVCodec ra_144_decoder =
372 sizeof(Real144_internal),
377 .long_name = "RealAudio 1.0 (14.4K)",