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Simplify (drop useless intermediate sum and diff arrays). 

Originally committed as revision 15023 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2008-08-29 14:44:47 +00:00
parent c55ecb9c27
commit addafb0e0a
1 changed files with 3 additions and 10 deletions
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13
libavcodec/dca.c
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@ -673,7 +673,7 @@ static void qmf_32_subbands(DCAContext * s, int chans,
/* Reconstructed channel sample index */
for (subindex = 0; subindex < 8; subindex++) {
float t1, t2, sum[16], diff[16];
float t1, t2;
/* Load in one sample from each subband and clear inactive subbands */
for (i = 0; i < s->subband_activity[chans]; i++)
@ -690,17 +690,10 @@ static void qmf_32_subbands(DCAContext * s, int chans,
t1 += (raXin[2 * i] + raXin[2 * i + 1]) * cos_mod[j];
t2 += (raXin[2 * i] + raXin[2 * i - 1]) * cos_mod[j + 256];
}
sum[k] = t1 + t2;
diff[k] = t1 - t2;
subband_fir_hist[ k ] = cos_mod[k+512 ] * (t1 + t2);
subband_fir_hist[32-k-1] = cos_mod[k+512+16] * (t1 - t2);
}
j = 512;
/* Store history */
for (k = 0; k < 16; k++)
subband_fir_hist[k] = cos_mod[j++] * sum[k];
for (k = 0; k < 16; k++)
subband_fir_hist[32-k-1] = cos_mod[j++] * diff[k];
/* Multiply by filter coefficients */
for (k = 31, i = 0; i < 32; i++, k--)
for (j = 0; j < 512; j += 64){