2 * RealAudio 2.0 (28.8K)
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 #define ALT_BITSTREAM_READER_LE
24 #include "bitstream.h"
34 float st1a[111], st1b[37], st1[37];
35 float st2a[38], st2b[11], st2[11];
40 /* Decode and produce output */
41 static void decode(Real288_internal *glob, int amp_coef, int cb_coef)
50 for (x=36; x--; glob->sb[x+5] = glob->sb[x]);
55 for (sum=0, y=36; y--; sum -= (*(++p1))*(*(p2++)));
60 f = amptable[amp_coef];
61 table = codetable[cb_coef];
63 /* convert log and do rms */
64 for (sum=32, x=10; x--; sum -= glob->pr2[x] * glob->lhist[x]);
71 sumsum = exp(sum * 0.1151292546497) * f; /* pow(10.0,sum/20)*f */
73 for (sum=0, x=5; x--;) {
74 buffer[x] = table[x] * sumsum;
75 sum += buffer[x] * buffer[x];
82 for (x=10; --x; glob->lhist[x] = glob->lhist[x-1]);
84 *glob->lhist = glob->history[glob->phase] = 10 * log10(sum) - 32;
87 for (y=x; y--; buffer[x] -= glob->pr1[x-y-1] * buffer[y]);
90 for (x=0; x < 5; x++) {
91 f = glob->sb[4-x] + buffer[x];
98 glob->output[glob->phasep+x] = glob->sb[4-x] = f;
102 /* column multiply */
103 static void colmult(float *tgt, float *m1, const float *m2, int n)
106 *(tgt++) = (*(m1++)) * (*(m2++));
109 static int pred(float *in, float *tgt, int n)
129 for (y=x; --y; f1 += (*(p1--))*(*(p2++)));
133 *(p1--) = f2 = -f1/f0;
134 for (y=x >> 1; y--;) {
135 temp = *p2 + *p1 * f2;
139 if ((f0 += f1*f2) < 0)
144 /* product sum (lsf) */
145 static void prodsum(float *tgt, float *src, int len, int n)
153 for (sum=0, x=len; x--; sum += (*p1++) * (*p2++));
158 static void co(int n, int i, int j, float *in, float *out, float *st1,
159 float *st2, const float *table)
168 /* rotate and multiply */
169 c = (b = (a = n + i) + j) - i;
171 for (x=0; x < b; x++) {
174 work[x] = *(table++) * (*(st1++) = *(fp++));
177 prodsum(buffer1, work + n, i, n);
178 prodsum(buffer2, work + a, j, n);
181 *st2 = *st2 * (0.5625) + buffer1[x];
182 out[x] = *(st2++) + buffer2[x];
184 *out *= 1.00390625; /* to prevent clipping */
187 static void update(Real288_internal *glob)
190 float buffer1[40], temp1[37];
191 float buffer2[8], temp2[11];
193 for (x=0, y=glob->phasep+5; x < 40; buffer1[x++] = glob->output[(y++)%40]);
195 co(36, 40, 35, buffer1, temp1, glob->st1a, glob->st1b, table1);
197 if (pred(temp1, glob->st1, 36))
198 colmult(glob->pr1, glob->st1, table1a, 36);
200 for (x=0, y=glob->phase + 1; x < 8; buffer2[x++] = glob->history[(y++) % 8]);
202 co(10, 8, 20, buffer2, temp2, glob->st2a, glob->st2b, table2);
204 if (pred(temp2, glob->st2, 10))
205 colmult(glob->pr2, glob->st2, table2a, 10);
208 /* Decode a block (celp) */
209 static int ra288_decode_frame(AVCodecContext * avctx, void *data,
210 int *data_size, const uint8_t * buf,
215 Real288_internal *glob = avctx->priv_data;
218 if (buf_size < avctx->block_align) {
219 av_log(avctx, AV_LOG_ERROR,
220 "Error! Input buffer is too small [%d<%d]\n",
221 buf_size, avctx->block_align);
225 init_get_bits(&gb, buf, avctx->block_align * 8);
227 for (x=0; x < 32; x++) {
228 int amp_coef = get_bits(&gb, 3);
229 int cb_coef = get_bits(&gb, 6 + (x&1));
230 glob->phasep = (glob->phase = x & 7) * 5;
231 decode(glob, amp_coef, cb_coef);
233 for (y=0; y<5; *(out++) = 8 * glob->output[glob->phasep+(y++)]);
235 if (glob->phase == 3)
239 *data_size = (char *)out - (char *)data;
240 return avctx->block_align;
243 AVCodec ra_288_decoder =
248 sizeof(Real288_internal),
253 .long_name = NULL_IF_CONFIG_SMALL("RealAudio 2.0 (28.8K)"),