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00025 #include "libavutil/intmath.h"
00026 #include "avcodec.h"
00027 #include "get_bits.h"
00028 #include "ra144.h"
00029 #include "celp_filters.h"
00030
00031 #define NBLOCKS 4
00032 #define BLOCKSIZE 40
00033 #define BUFFERSIZE 146
00034
00035
00036 typedef struct {
00037 AVCodecContext *avctx;
00038
00039 unsigned int old_energy;
00040
00041 unsigned int lpc_tables[2][10];
00042
00045 unsigned int *lpc_coef[2];
00046
00047 unsigned int lpc_refl_rms[2];
00048
00050 int16_t curr_sblock[50];
00051
00054 uint16_t adapt_cb[146+2];
00055 } RA144Context;
00056
00057 static av_cold int ra144_decode_init(AVCodecContext * avctx)
00058 {
00059 RA144Context *ractx = avctx->priv_data;
00060
00061 ractx->avctx = avctx;
00062
00063 ractx->lpc_coef[0] = ractx->lpc_tables[0];
00064 ractx->lpc_coef[1] = ractx->lpc_tables[1];
00065
00066 avctx->sample_fmt = SAMPLE_FMT_S16;
00067 return 0;
00068 }
00069
00074 static int t_sqrt(unsigned int x)
00075 {
00076 int s = 2;
00077 while (x > 0xfff) {
00078 s++;
00079 x >>= 2;
00080 }
00081
00082 return ff_sqrt(x << 20) << s;
00083 }
00084
00089 static void eval_coefs(int *coefs, const int *refl)
00090 {
00091 int buffer[10];
00092 int *b1 = buffer;
00093 int *b2 = coefs;
00094 int i, j;
00095
00096 for (i=0; i < 10; i++) {
00097 b1[i] = refl[i] << 4;
00098
00099 for (j=0; j < i; j++)
00100 b1[j] = ((refl[i] * b2[i-j-1]) >> 12) + b2[j];
00101
00102 FFSWAP(int *, b1, b2);
00103 }
00104
00105 for (i=0; i < 10; i++)
00106 coefs[i] >>= 4;
00107 }
00108
00113 static void copy_and_dup(int16_t *target, const int16_t *source, int offset)
00114 {
00115 source += BUFFERSIZE - offset;
00116
00117 memcpy(target, source, FFMIN(BLOCKSIZE, offset)*sizeof(*target));
00118 if (offset < BLOCKSIZE)
00119 memcpy(target + offset, source, (BLOCKSIZE - offset)*sizeof(*target));
00120 }
00121
00123 static int irms(const int16_t *data)
00124 {
00125 unsigned int i, sum = 0;
00126
00127 for (i=0; i < BLOCKSIZE; i++)
00128 sum += data[i] * data[i];
00129
00130 if (sum == 0)
00131 return 0;
00132
00133 return 0x20000000 / (t_sqrt(sum) >> 8);
00134 }
00135
00136 static void add_wav(int16_t *dest, int n, int skip_first, int *m,
00137 const int16_t *s1, const int8_t *s2, const int8_t *s3)
00138 {
00139 int i;
00140 int v[3];
00141
00142 v[0] = 0;
00143 for (i=!skip_first; i<3; i++)
00144 v[i] = (gain_val_tab[n][i] * m[i]) >> gain_exp_tab[n];
00145
00146 if (v[0]) {
00147 for (i=0; i < BLOCKSIZE; i++)
00148 dest[i] = (s1[i]*v[0] + s2[i]*v[1] + s3[i]*v[2]) >> 12;
00149 } else {
00150 for (i=0; i < BLOCKSIZE; i++)
00151 dest[i] = ( s2[i]*v[1] + s3[i]*v[2]) >> 12;
00152 }
00153 }
00154
00155 static unsigned int rescale_rms(unsigned int rms, unsigned int energy)
00156 {
00157 return (rms * energy) >> 10;
00158 }
00159
00160 static unsigned int rms(const int *data)
00161 {
00162 int i;
00163 unsigned int res = 0x10000;
00164 int b = 10;
00165
00166 for (i=0; i < 10; i++) {
00167 res = (((0x1000000 - data[i]*data[i]) >> 12) * res) >> 12;
00168
00169 if (res == 0)
00170 return 0;
00171
00172 while (res <= 0x3fff) {
00173 b++;
00174 res <<= 2;
00175 }
00176 }
00177
00178 return t_sqrt(res) >> b;
00179 }
00180
00181 static void do_output_subblock(RA144Context *ractx, const uint16_t *lpc_coefs,
00182 int gval, GetBitContext *gb)
00183 {
00184 uint16_t buffer_a[40];
00185 uint16_t *block;
00186 int cba_idx = get_bits(gb, 7);
00187 int gain = get_bits(gb, 8);
00188 int cb1_idx = get_bits(gb, 7);
00189 int cb2_idx = get_bits(gb, 7);
00190 int m[3];
00191
00192 if (cba_idx) {
00193 cba_idx += BLOCKSIZE/2 - 1;
00194 copy_and_dup(buffer_a, ractx->adapt_cb, cba_idx);
00195 m[0] = (irms(buffer_a) * gval) >> 12;
00196 } else {
00197 m[0] = 0;
00198 }
00199
00200 m[1] = (cb1_base[cb1_idx] * gval) >> 8;
00201 m[2] = (cb2_base[cb2_idx] * gval) >> 8;
00202
00203 memmove(ractx->adapt_cb, ractx->adapt_cb + BLOCKSIZE,
00204 (BUFFERSIZE - BLOCKSIZE) * sizeof(*ractx->adapt_cb));
00205
00206 block = ractx->adapt_cb + BUFFERSIZE - BLOCKSIZE;
00207
00208 add_wav(block, gain, cba_idx, m, cba_idx? buffer_a: NULL,
00209 cb1_vects[cb1_idx], cb2_vects[cb2_idx]);
00210
00211 memcpy(ractx->curr_sblock, ractx->curr_sblock + 40,
00212 10*sizeof(*ractx->curr_sblock));
00213
00214 if (ff_celp_lp_synthesis_filter(ractx->curr_sblock + 10, lpc_coefs,
00215 block, BLOCKSIZE, 10, 1, 0xfff))
00216 memset(ractx->curr_sblock, 0, 50*sizeof(*ractx->curr_sblock));
00217 }
00218
00219 static void int_to_int16(int16_t *out, const int *inp)
00220 {
00221 int i;
00222
00223 for (i=0; i < 10; i++)
00224 *out++ = *inp++;
00225 }
00226
00234 static int eval_refl(int *refl, const int16_t *coefs, AVCodecContext *avctx)
00235 {
00236 int b, i, j;
00237 int buffer1[10];
00238 int buffer2[10];
00239 int *bp1 = buffer1;
00240 int *bp2 = buffer2;
00241
00242 for (i=0; i < 10; i++)
00243 buffer2[i] = coefs[i];
00244
00245 refl[9] = bp2[9];
00246
00247 if ((unsigned) bp2[9] + 0x1000 > 0x1fff) {
00248 av_log(avctx, AV_LOG_ERROR, "Overflow. Broken sample?\n");
00249 return 1;
00250 }
00251
00252 for (i=8; i >= 0; i--) {
00253 b = 0x1000-((bp2[i+1] * bp2[i+1]) >> 12);
00254
00255 if (!b)
00256 b = -2;
00257
00258 for (j=0; j <= i; j++)
00259 bp1[j] = ((bp2[j] - ((refl[i+1] * bp2[i-j]) >> 12)) * (0x1000000 / b)) >> 12;
00260
00261 if ((unsigned) bp1[i] + 0x1000 > 0x1fff)
00262 return 1;
00263
00264 refl[i] = bp1[i];
00265
00266 FFSWAP(int *, bp1, bp2);
00267 }
00268 return 0;
00269 }
00270
00271 static int interp(RA144Context *ractx, int16_t *out, int a,
00272 int copyold, int energy)
00273 {
00274 int work[10];
00275 int b = NBLOCKS - a;
00276 int i;
00277
00278
00279
00280 for (i=0; i<10; i++)
00281 out[i] = (a * ractx->lpc_coef[0][i] + b * ractx->lpc_coef[1][i])>> 2;
00282
00283 if (eval_refl(work, out, ractx->avctx)) {
00284
00285
00286 int_to_int16(out, ractx->lpc_coef[copyold]);
00287 return rescale_rms(ractx->lpc_refl_rms[copyold], energy);
00288 } else {
00289 return rescale_rms(rms(work), energy);
00290 }
00291 }
00292
00294 static int ra144_decode_frame(AVCodecContext * avctx, void *vdata,
00295 int *data_size, AVPacket *avpkt)
00296 {
00297 const uint8_t *buf = avpkt->data;
00298 int buf_size = avpkt->size;
00299 static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
00300 unsigned int refl_rms[4];
00301 uint16_t block_coefs[4][10];
00302 unsigned int lpc_refl[10];
00303 int i, j;
00304 int16_t *data = vdata;
00305 unsigned int energy;
00306
00307 RA144Context *ractx = avctx->priv_data;
00308 GetBitContext gb;
00309
00310 if (*data_size < 2*160)
00311 return -1;
00312
00313 if(buf_size < 20) {
00314 av_log(avctx, AV_LOG_ERROR,
00315 "Frame too small (%d bytes). Truncated file?\n", buf_size);
00316 *data_size = 0;
00317 return buf_size;
00318 }
00319 init_get_bits(&gb, buf, 20 * 8);
00320
00321 for (i=0; i<10; i++)
00322 lpc_refl[i] = lpc_refl_cb[i][get_bits(&gb, sizes[i])];
00323
00324 eval_coefs(ractx->lpc_coef[0], lpc_refl);
00325 ractx->lpc_refl_rms[0] = rms(lpc_refl);
00326
00327 energy = energy_tab[get_bits(&gb, 5)];
00328
00329 refl_rms[0] = interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
00330 refl_rms[1] = interp(ractx, block_coefs[1], 2, energy <= ractx->old_energy,
00331 t_sqrt(energy*ractx->old_energy) >> 12);
00332 refl_rms[2] = interp(ractx, block_coefs[2], 3, 0, energy);
00333 refl_rms[3] = rescale_rms(ractx->lpc_refl_rms[0], energy);
00334
00335 int_to_int16(block_coefs[3], ractx->lpc_coef[0]);
00336
00337 for (i=0; i < 4; i++) {
00338 do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);
00339
00340 for (j=0; j < BLOCKSIZE; j++)
00341 *data++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2);
00342 }
00343
00344 ractx->old_energy = energy;
00345 ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];
00346
00347 FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);
00348
00349 *data_size = 2*160;
00350 return 20;
00351 }
00352
00353 AVCodec ra_144_decoder =
00354 {
00355 "real_144",
00356 AVMEDIA_TYPE_AUDIO,
00357 CODEC_ID_RA_144,
00358 sizeof(RA144Context),
00359 ra144_decode_init,
00360 NULL,
00361 NULL,
00362 ra144_decode_frame,
00363 .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"),
00364 };