From c448303df66c5e918cc2385bd1851e55c9b00e98 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 7 Jul 2006 22:41:43 +0000 Subject: seems i forgot to commit this simplification ... Originally committed as revision 5662 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/flac.c | 51 ++++++++++++++------------------------------------- 1 file changed, 14 insertions(+), 37 deletions(-) (limited to 'libavcodec/flac.c') diff --git a/libavcodec/flac.c b/libavcodec/flac.c index 8bf00b2d04..4978d0e515 100644 --- a/libavcodec/flac.c +++ b/libavcodec/flac.c @@ -697,6 +697,17 @@ static int flac_decode_frame(AVCodecContext *avctx, } } #else +#define DECORRELATE(left, right)\ + assert(s->channels == 2);\ + for (i = 0; i < s->blocksize; i++)\ + {\ + int a= s->decoded[0][i];\ + int b= s->decoded[1][i];\ + *(samples++) = (left ) >> (16 - s->bps);\ + *(samples++) = (right) >> (16 - s->bps);\ + }\ + break; + switch(s->decorrelation) { case INDEPENDENT: @@ -707,45 +718,11 @@ static int flac_decode_frame(AVCodecContext *avctx, } break; case LEFT_SIDE: - assert(s->channels == 2); - for (i = 0; i < s->blocksize; i++) - { - *(samples++) = shift_to_16_bits(s->decoded[0][i], s->bps); - *(samples++) = shift_to_16_bits(s->decoded[0][i] - - s->decoded[1][i], s->bps); - } - break; + DECORRELATE(a,a-b) case RIGHT_SIDE: - assert(s->channels == 2); - for (i = 0; i < s->blocksize; i++) - { - *(samples++) = shift_to_16_bits(s->decoded[0][i] - + s->decoded[1][i], s->bps); - *(samples++) = shift_to_16_bits(s->decoded[1][i], s->bps); - } - break; + DECORRELATE(a+b,b) case MID_SIDE: - assert(s->channels == 2); - for (i = 0; i < s->blocksize; i++) - { - int mid, side; - mid = s->decoded[0][i]; - side = s->decoded[1][i]; - -#if 1 //needs to be checked but IMHO it should be binary identical - mid -= side>>1; - *(samples++) = shift_to_16_bits(mid + side, s->bps); - *(samples++) = shift_to_16_bits(mid, s->bps); -#else - - mid <<= 1; - if (side & 1) - mid++; - *(samples++) = (mid + side) >> 1; - *(samples++) = (mid - side) >> 1; -#endif - } - break; + DECORRELATE( (a-=b>>1) + b, a) } #endif -- cgit v1.2.3