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Half the size of subband_fir_noidea and get rid of memmove & memset of it. 

Originally committed as revision 15033 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2008-08-29 18:37:40 +00:00
parent e9df66a7af
commit b854197919
1 changed files with 9 additions and 10 deletions
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19
libavcodec/dca.c
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@ -158,7 +158,7 @@ typedef struct {
/* Subband samples history (for ADPCM) */
float subband_samples_hist[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS][4];
float subband_fir_hist[DCA_PRIM_CHANNELS_MAX][512];
float subband_fir_noidea[DCA_PRIM_CHANNELS_MAX][64];
float subband_fir_noidea[DCA_PRIM_CHANNELS_MAX][32];
int output; ///< type of output
int bias; ///< output bias
@ -693,20 +693,19 @@ static void qmf_32_subbands(DCAContext * s, int chans,
}
/* Multiply by filter coefficients */
for (k = 31, i = 0; i < 32; i++, k--)
for (k = 31, i = 0; i < 32; i++, k--){
float a= subband_fir_hist2[i];
float b= 0;
for (j = 0; j < 512; j += 64){
subband_fir_hist2[i] += prCoeff[i+j] * ( subband_fir_hist[i+j] - subband_fir_hist[j+k]);
subband_fir_hist2[i+32] += prCoeff[i+j+32]*(-subband_fir_hist[i+j] - subband_fir_hist[j+k]);
a += prCoeff[i+j ]*( subband_fir_hist[i+j] - subband_fir_hist[j+k]);
b += prCoeff[i+j+32]*(-subband_fir_hist[i+j] - subband_fir_hist[j+k]);
}
/* Create 32 PCM output samples */
for (i = 0; i < 32; i++)
samples_out[chindex++] = subband_fir_hist2[i] * scale + bias;
samples_out[chindex++] = a * scale + bias;
subband_fir_hist2[i] = b;
}
/* Update working arrays */
memmove(&subband_fir_hist[32], &subband_fir_hist[0], (512 - 32) * sizeof(float));
memmove(&subband_fir_hist2[0], &subband_fir_hist2[32], 32 * sizeof(float));
memset(&subband_fir_hist2[32], 0, 32 * sizeof(float));
}
}