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| author | Loren Merritt <lorenm@u.washington.edu> | 2007-09-30 03:36:13 +0000 |
|---|---|---|
| committer | Loren Merritt <lorenm@u.washington.edu> | 2007-09-30 03:36:13 +0000 |
| commit | b8de342919d6ff7bae2c7ce6fff5fc2138108674 (patch) | |
| tree | f42f05ff44f512fb42ce4e9b05f3d6dad4002ec1 | |
| parent | d1a5c4216c5774b1513f15542c4b2a1a8a9f39a2 (diff) | |
| download | ffmpeg-b8de342919d6ff7bae2c7ce6fff5fc2138108674.tar.gz | |
simplify lpc
Originally committed as revision 10628 to svn://svn.ffmpeg.org/ffmpeg/trunk
| -rw-r--r-- | libavcodec/flacenc.c | 29 |
1 files changed, 14 insertions, 15 deletions
diff --git a/libavcodec/flacenc.c b/libavcodec/flacenc.c index fb69561010..d02b3e4626 100644 --- a/libavcodec/flacenc.c +++ b/libavcodec/flacenc.c @@ -876,10 +876,10 @@ static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n, } #define LPC1(x) {\ - int s = smp[i-(x)+1];\ - p1 += c*s;\ - c = coefs[(x)-2];\ + int c = coefs[(x)-1];\ p0 += c*s;\ + s = smp[i-(x)+1];\ + p1 += c*s;\ } static av_always_inline void encode_residual_lpc_unrolled( @@ -888,9 +888,8 @@ static av_always_inline void encode_residual_lpc_unrolled( { int i; for(i=order; i<n; i+=2) { - int c = coefs[order-1]; - int p0 = c * smp[i-order]; - int p1 = 0; + int s = smp[i-order]; + int p0 = 0, p1 = 0; if(big) { switch(order) { case 32: LPC1(32) @@ -924,6 +923,7 @@ static av_always_inline void encode_residual_lpc_unrolled( LPC1( 4) LPC1( 3) LPC1( 2) + LPC1( 1) } } else { switch(order) { @@ -934,9 +934,9 @@ static av_always_inline void encode_residual_lpc_unrolled( case 4: LPC1( 4) case 3: LPC1( 3) case 2: LPC1( 2) + case 1: LPC1( 1) } } - p1 += c * smp[i]; res[i ] = smp[i ] - (p0 >> shift); res[i+1] = smp[i+1] - (p1 >> shift); } @@ -952,16 +952,15 @@ static void encode_residual_lpc(int32_t *res, const int32_t *smp, int n, #ifdef CONFIG_SMALL for(i=order; i<n; i+=2) { int j; - int32_t c = coefs[0]; - int32_t p0 = 0, p1 = c*smp[i]; - for(j=1; j<order; j++) { - int32_t s = smp[i-j]; - p0 += c*s; - c = coefs[j]; + int s = smp[i]; + int p0 = 0, p1 = 0; + for(j=0; j<order; j++) { + int c = coefs[j]; p1 += c*s; + s = smp[i-j-1]; + p0 += c*s; } - p0 += c*smp[i-order]; - res[i+0] = smp[i+0] - (p0 >> shift); + res[i ] = smp[i ] - (p0 >> shift); res[i+1] = smp[i+1] - (p1 >> shift); } #else |