Author: faust3 Date: Sat May 30 22:36:24 2009 New Revision: 4346 Log: use a sine table when calculating the decorrelation matrix Modified: wmapro/wma3.h wmapro/wma3dec.c Modified: wmapro/wma3.h ============================================================================== --- wmapro/wma3.h Sat May 30 21:22:28 2009 (r4345) +++ wmapro/wma3.h Sat May 30 22:36:24 2009 (r4346) @@ -93,6 +93,7 @@ typedef struct WMA3DecodeContext { MDCTContext mdct_ctx[BLOCK_NB_SIZES]; ///< MDCT context per block size DECLARE_ALIGNED_16(float, tmp[BLOCK_MAX_SIZE]); ///< imdct output buffer float* windows[BLOCK_NB_SIZES]; ///< window per block size + float sin64[33]; ///< sinus table for decorrelation VLC sf_vlc; ///< scale factor dpcm vlc VLC sf_rl_vlc; ///< scale factor run length vlc VLC vec4_vlc; ///< 4 coefficients per symbol Modified: wmapro/wma3dec.c ============================================================================== --- wmapro/wma3dec.c Sat May 30 21:22:28 2009 (r4345) +++ wmapro/wma3dec.c Sat May 30 22:36:24 2009 (r4346) @@ -432,6 +432,10 @@ static av_cold int wma_decode_init(AVCod } } + /** calculate sine values for the decorrelation matrix */ + for(i=0;i<33;i++) + s->sin64[i] = sin(i*M_PI / 64.0); + wma_dump_context(s); avctx->channel_layout = channel_mask; return 0; @@ -644,11 +648,19 @@ static void wma_decode_decorrelation_mat float v1 = tmp1[y]; float v2 = tmp2[y]; int n = rotation_offset[offset + x]; - float cosv = sin(n*M_PI / 64.0); // FIXME: use one table for this - float sinv = -cos(n*M_PI / 64.0); + float sinv; + float cosv; - chgroup->decorrelation_matrix[y + x * chgroup->num_channels] = (v1 * cosv) + (v2 * sinv); - chgroup->decorrelation_matrix[y + i * chgroup->num_channels] = (v1 * -sinv) + (v2 * cosv); + if(n<32){ + sinv = s->sin64[n]; + cosv = s->sin64[32-n]; + }else{ + sinv = s->sin64[64-n]; + cosv = -s->sin64[n-32]; + } + + chgroup->decorrelation_matrix[y + x * chgroup->num_channels] = (v1 * sinv) - (v2 * cosv); + chgroup->decorrelation_matrix[y + i * chgroup->num_channels] = (v1 * cosv) + (v2 * sinv); } } offset += i;