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00022 #include "avcodec.h"
00023 #define ALT_BITSTREAM_READER_LE
00024 #include "get_bits.h"
00025 #include "ra288.h"
00026 #include "lpc.h"
00027 #include "celp_math.h"
00028 #include "celp_filters.h"
00029
00030 typedef struct {
00031 float sp_lpc[36];
00032 float gain_lpc[10];
00033
00037 float sp_hist[111];
00038
00040 float sp_rec[37];
00041
00045 float gain_hist[38];
00046
00048 float gain_rec[11];
00049 } RA288Context;
00050
00051 static av_cold int ra288_decode_init(AVCodecContext *avctx)
00052 {
00053 avctx->sample_fmt = SAMPLE_FMT_FLT;
00054 return 0;
00055 }
00056
00057 static void apply_window(float *tgt, const float *m1, const float *m2, int n)
00058 {
00059 while (n--)
00060 *tgt++ = *m1++ * *m2++;
00061 }
00062
00063 static void convolve(float *tgt, const float *src, int len, int n)
00064 {
00065 for (; n >= 0; n--)
00066 tgt[n] = ff_dot_productf(src, src - n, len);
00067
00068 }
00069
00070 static void decode(RA288Context *ractx, float gain, int cb_coef)
00071 {
00072 int i;
00073 double sumsum;
00074 float sum, buffer[5];
00075 float *block = ractx->sp_hist + 70 + 36;
00076 float *gain_block = ractx->gain_hist + 28;
00077
00078 memmove(ractx->sp_hist + 70, ractx->sp_hist + 75, 36*sizeof(*block));
00079
00080
00081 sum = 32.;
00082 for (i=0; i < 10; i++)
00083 sum -= gain_block[9-i] * ractx->gain_lpc[i];
00084
00085
00086 sum = av_clipf(sum, 0, 60);
00087
00088
00089
00090 sumsum = exp(sum * 0.1151292546497) * gain * (1.0/(1<<23));
00091
00092 for (i=0; i < 5; i++)
00093 buffer[i] = codetable[cb_coef][i] * sumsum;
00094
00095 sum = ff_dot_productf(buffer, buffer, 5) * ((1<<24)/5.);
00096
00097 sum = FFMAX(sum, 1);
00098
00099
00100 memmove(gain_block, gain_block + 1, 9 * sizeof(*gain_block));
00101
00102 gain_block[9] = 10 * log10(sum) - 32;
00103
00104 ff_celp_lp_synthesis_filterf(block, ractx->sp_lpc, buffer, 5, 36);
00105 }
00106
00119 static void do_hybrid_window(int order, int n, int non_rec, float *out,
00120 float *hist, float *out2, const float *window)
00121 {
00122 int i;
00123 float buffer1[order + 1];
00124 float buffer2[order + 1];
00125 float work[order + n + non_rec];
00126
00127 apply_window(work, window, hist, order + n + non_rec);
00128
00129 convolve(buffer1, work + order , n , order);
00130 convolve(buffer2, work + order + n, non_rec, order);
00131
00132 for (i=0; i <= order; i++) {
00133 out2[i] = out2[i] * 0.5625 + buffer1[i];
00134 out [i] = out2[i] + buffer2[i];
00135 }
00136
00137
00138 *out *= 257./256.;
00139 }
00140
00144 static void backward_filter(float *hist, float *rec, const float *window,
00145 float *lpc, const float *tab,
00146 int order, int n, int non_rec, int move_size)
00147 {
00148 float temp[order+1];
00149
00150 do_hybrid_window(order, n, non_rec, temp, hist, rec, window);
00151
00152 if (!compute_lpc_coefs(temp, order, lpc, 0, 1, 1))
00153 apply_window(lpc, lpc, tab, order);
00154
00155 memmove(hist, hist + n, move_size*sizeof(*hist));
00156 }
00157
00158 static int ra288_decode_frame(AVCodecContext * avctx, void *data,
00159 int *data_size, AVPacket *avpkt)
00160 {
00161 const uint8_t *buf = avpkt->data;
00162 int buf_size = avpkt->size;
00163 float *out = data;
00164 int i, j;
00165 RA288Context *ractx = avctx->priv_data;
00166 GetBitContext gb;
00167
00168 if (buf_size < avctx->block_align) {
00169 av_log(avctx, AV_LOG_ERROR,
00170 "Error! Input buffer is too small [%d<%d]\n",
00171 buf_size, avctx->block_align);
00172 return 0;
00173 }
00174
00175 if (*data_size < 32*5*4)
00176 return -1;
00177
00178 init_get_bits(&gb, buf, avctx->block_align * 8);
00179
00180 for (i=0; i < 32; i++) {
00181 float gain = amptable[get_bits(&gb, 3)];
00182 int cb_coef = get_bits(&gb, 6 + (i&1));
00183
00184 decode(ractx, gain, cb_coef);
00185
00186 for (j=0; j < 5; j++)
00187 *(out++) = ractx->sp_hist[70 + 36 + j];
00188
00189 if ((i & 7) == 3) {
00190 backward_filter(ractx->sp_hist, ractx->sp_rec, syn_window,
00191 ractx->sp_lpc, syn_bw_tab, 36, 40, 35, 70);
00192
00193 backward_filter(ractx->gain_hist, ractx->gain_rec, gain_window,
00194 ractx->gain_lpc, gain_bw_tab, 10, 8, 20, 28);
00195 }
00196 }
00197
00198 *data_size = (char *)out - (char *)data;
00199 return avctx->block_align;
00200 }
00201
00202 AVCodec ra_288_decoder =
00203 {
00204 "real_288",
00205 AVMEDIA_TYPE_AUDIO,
00206 CODEC_ID_RA_288,
00207 sizeof(RA288Context),
00208 ra288_decode_init,
00209 NULL,
00210 NULL,
00211 ra288_decode_frame,
00212 .long_name = NULL_IF_CONFIG_SMALL("RealAudio 2.0 (28.8K)"),
00213 };