From 006ff1cabeece7608a9ceb7ec96f10c3d0b68bc2 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 19 Jul 2006 22:21:45 +0000 Subject: [PATCH] more simplifications Originally committed as revision 5795 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/vp3.c | 68 ++++++++++++++++++++++++-------------------------------- 1 file changed, 29 insertions(+), 39 deletions(-) diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c index 39df4f5..a1c4544 100644 --- a/libavcodec/vp3.c +++ b/libavcodec/vp3.c @@ -1369,9 +1369,6 @@ static void reverse_dc_prediction(Vp3DecodeContext *s, short predicted_dc; - /* validity flags for the left, up-left, up, and up-right fragments */ - int fl, ful, fu, fur; - /* DC values for the left, up-left, up, and up-right fragments */ int vl, vul, vu, vur; @@ -1384,26 +1381,24 @@ static void reverse_dc_prediction(Vp3DecodeContext *s, * 1: up multiplier * 2: up-right multiplier * 3: left multiplier - * 4: mask - * 5: right bit shift divisor (e.g., 7 means >>=7, a.k.a. div by 128) */ - int predictor_transform[16][6] = { - { 0, 0, 0, 0, 0, 0 }, - { 0, 0, 0, 1, 0, 0 }, // PL - { 0, 0, 1, 0, 0, 0 }, // PUR - { 0, 0, 53, 75, 127, 7 }, // PUR|PL - { 0, 1, 0, 0, 0, 0 }, // PU - { 0, 1, 0, 1, 1, 1 }, // PU|PL - { 0, 1, 0, 0, 0, 0 }, // PU|PUR - { 0, 0, 53, 75, 127, 7 }, // PU|PUR|PL - { 1, 0, 0, 0, 0, 0 }, // PUL - { 0, 0, 0, 1, 0, 0 }, // PUL|PL - { 1, 0, 1, 0, 1, 1 }, // PUL|PUR - { 0, 0, 53, 75, 127, 7 }, // PUL|PUR|PL - { 0, 1, 0, 0, 0, 0 }, // PUL|PU - {-26, 29, 0, 29, 31, 5 }, // PUL|PU|PL - { 3, 10, 3, 0, 15, 4 }, // PUL|PU|PUR - {-26, 29, 0, 29, 31, 5 } // PUL|PU|PUR|PL + int predictor_transform[16][4] = { + { 0, 0, 0, 0}, + { 0, 0, 0,128}, // PL + { 0, 0,128, 0}, // PUR + { 0, 0, 53, 75}, // PUR|PL + { 0,128, 0, 0}, // PU + { 0, 64, 0, 64}, // PU|PL + { 0,128, 0, 0}, // PU|PUR + { 0, 0, 53, 75}, // PU|PUR|PL + {128, 0, 0, 0}, // PUL + { 0, 0, 0,128}, // PUL|PL + { 64, 0, 64, 0}, // PUL|PUR + { 0, 0, 53, 75}, // PUL|PUR|PL + { 0,128, 0, 0}, // PUL|PU + {-104,116, 0,116}, // PUL|PU|PL + { 24, 80, 24, 0}, // PUL|PU|PUR + {-104,116, 0,116} // PUL|PU|PUR|PL }; /* This table shows which types of blocks can use other blocks for @@ -1445,32 +1440,32 @@ static void reverse_dc_prediction(Vp3DecodeContext *s, current_frame_type = compatible_frame[s->all_fragments[i].coding_method]; - debug_dc_pred(" frag %d: group %d, orig DC = %d, ", - i, -1, DC_COEFF(i)); + debug_dc_pred(" frag %d: orig DC = %d, ", + i, DC_COEFF(i)); transform= 0; if(x){ l= i-1; vl = DC_COEFF(l); - fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l); - transform |= fl*PL; + if(FRAME_CODED(l) && COMPATIBLE_FRAME(l)) + transform |= PL; } if(y){ u= i-fragment_width; vu = DC_COEFF(u); - fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u); - transform |= fu*PU; + if(FRAME_CODED(u) && COMPATIBLE_FRAME(u)) + transform |= PU; if(x){ ul= i-fragment_width-1; vul = DC_COEFF(ul); - ful = FRAME_CODED(ul) && COMPATIBLE_FRAME(ul); - transform |= ful*PUL; + if(FRAME_CODED(ul) && COMPATIBLE_FRAME(ul)) + transform |= PUL; } if(x + 1 < fragment_width){ ur= i-fragment_width+1; vur = DC_COEFF(ur); - fur = FRAME_CODED(ur) && COMPATIBLE_FRAME(ur); - transform |= fur*PUR; + if(FRAME_CODED(ur) && COMPATIBLE_FRAME(ur)) + transform |= PUR; } } @@ -1493,13 +1488,8 @@ static void reverse_dc_prediction(Vp3DecodeContext *s, (predictor_transform[transform][2] * vur) + (predictor_transform[transform][3] * vl); - /* if there is a shift value in the transform, add - * the sign bit before the shift */ - if (predictor_transform[transform][5] != 0) { - predicted_dc += ((predicted_dc >> 15) & - predictor_transform[transform][4]); - predicted_dc >>= predictor_transform[transform][5]; - } + predicted_dc += (predicted_dc >> 15) & 127; + predicted_dc >>= 7; /* check for outranging on the [ul u l] and * [ul u ur l] predictors */ -- 2.7.4