diff options
author | Vitor Sessak <vitor1001@gmail.com> | 2008-08-06 06:44:59 +0400 |
---|---|---|
committer | Vitor Sessak <vitor1001@gmail.com> | 2008-08-06 06:44:59 +0400 |
commit | e3751aa6ec8147ab7ca2649d4daadf8d4dce27d5 (patch) | |
tree | ad0d0a694b54e010a1cae9f824fac64c90ba7a4a /libavcodec/ra288.c | |
parent | 00a3431cbb27ace9120a07605e79c1d0d4c13d42 (diff) |
Flip (by making buf[i] -> buf[size-i-1]) two buffers: {sp,gain}_block. This
needs duplicating a few loops, but now the code is clearer.
Originally committed as revision 14634 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/ra288.c')
-rw-r--r-- | libavcodec/ra288.c | 39 |
1 files changed, 18 insertions, 21 deletions
diff --git a/libavcodec/ra288.c b/libavcodec/ra288.c index 322f74e182..8a7719c9f6 100644 --- a/libavcodec/ra288.c +++ b/libavcodec/ra288.c @@ -70,15 +70,20 @@ static void decode(RA288Context *ractx, float gain, int cb_coef) int i, j; double sumsum; float sum, buffer[5]; + float *block = ractx->sp_block + 36; // Current block - memmove(ractx->sp_block + 5, ractx->sp_block, 36*sizeof(*ractx->sp_block)); + memmove(ractx->sp_block, ractx->sp_block + 5, 36*sizeof(*ractx->sp_block)); - for (i=4; i >= 0; i--) - ractx->sp_block[i] = -scalar_product_float(ractx->sp_block + i + 1, - ractx->sp_lpc, 36); + for (i=0; i < 5; i++) { + block[i] = 0.; + for (j=0; j < 36; j++) + block[i] -= block[i-1-j]*ractx->sp_lpc[j]; + } /* block 46 of G.728 spec */ - sum = 32. - scalar_product_float(ractx->gain_lpc, ractx->gain_block, 10); + sum = 32.; + for (i=0; i < 10; i++) + sum -= ractx->gain_block[9-i] * ractx->gain_lpc[i]; /* block 47 of G.728 spec */ sum = av_clipf(sum, 0, 60); @@ -94,10 +99,10 @@ static void decode(RA288Context *ractx, float gain, int cb_coef) sum = FFMAX(sum, 1); /* shift and store */ - memmove(ractx->gain_block, ractx->gain_block - 1, - 10 * sizeof(*ractx->gain_block)); + memmove(ractx->gain_block, ractx->gain_block + 1, + 9 * sizeof(*ractx->gain_block)); - *ractx->gain_block = 10 * log10(sum) - 32; + ractx->gain_block[9] = 10 * log10(sum) - 32; for (i=1; i < 5; i++) for (j=i-1; j >= 0; j--) @@ -105,8 +110,7 @@ static void decode(RA288Context *ractx, float gain, int cb_coef) /* output */ for (i=0; i < 5; i++) - ractx->sp_block[4-i] = - av_clipf(ractx->sp_block[4-i] + buffer[i], -4095, 4095); + block[i] = av_clipf(block[i] + buffer[i], -4095, 4095); } /** @@ -157,11 +161,6 @@ static void convolve(float *tgt, const float *src, int len, int n) /** * Hybrid window filtering. See blocks 36 and 49 of the G.728 specification. * - * @note This function is slightly different from that described in the spec. - * It expects in[0] to be the newest sample and in[n-1] to be the oldest - * one stored. The spec has in the more ordinary way (in[0] the oldest - * and in[n-1] the newest). - * * @param order the order of the filter * @param n the length of the input * @param non_rec the number of non-recursive samples @@ -184,9 +183,7 @@ static void do_hybrid_window(int order, int n, int non_rec, const float *in, /* update history */ memmove(hist, hist + n, (order + non_rec)*sizeof(*hist)); - - for (i=0; i < n; i++) - hist[order + non_rec + i] = in[n-i-1]; + memcpy (hist + order + non_rec, in, n * sizeof(*hist)); colmult(work, window, hist, order + n + non_rec); @@ -210,13 +207,13 @@ static void backward_filter(RA288Context *ractx) float temp1[37]; // RTMP in the spec float temp2[11]; // GPTPMP in the spec - do_hybrid_window(36, 40, 35, ractx->sp_block, temp1, ractx->sp_hist, + do_hybrid_window(36, 40, 35, ractx->sp_block+1, temp1, ractx->sp_hist, ractx->sp_rec, syn_window); if (!eval_lpc_coeffs(temp1, ractx->sp_lpc, 36)) colmult(ractx->sp_lpc, ractx->sp_lpc, syn_bw_tab, 36); - do_hybrid_window(10, 8, 20, ractx->gain_block, temp2, ractx->gain_hist, + do_hybrid_window(10, 8, 20, ractx->gain_block+2, temp2, ractx->gain_hist, ractx->gain_rec, gain_window); if (!eval_lpc_coeffs(temp2, ractx->gain_lpc, 10)) @@ -248,7 +245,7 @@ static int ra288_decode_frame(AVCodecContext * avctx, void *data, decode(ractx, gain, cb_coef); for (j=0; j < 5; j++) - *(out++) = 8 * ractx->sp_block[4 - j]; + *(out++) = 8 * ractx->sp_block[36 + j]; if ((i & 7) == 3) backward_filter(ractx); |