Rev 1624 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1624 | giacomo | 1 | /* Predict.c, motion compensation routines */ |
| 2 | |||
| 3 | /* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */ |
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| 4 | |||
| 5 | /* |
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| 6 | * Disclaimer of Warranty |
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| 7 | * |
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| 8 | * These software programs are available to the user without any license fee or |
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| 9 | * royalty on an "as is" basis. The MPEG Software Simulation Group disclaims |
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| 10 | * any and all warranties, whether express, implied, or statuary, including any |
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| 11 | * implied warranties or merchantability or of fitness for a particular |
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| 12 | * purpose. In no event shall the copyright-holder be liable for any |
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| 13 | * incidental, punitive, or consequential damages of any kind whatsoever |
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| 14 | * arising from the use of these programs. |
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| 15 | * |
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| 16 | * This disclaimer of warranty extends to the user of these programs and user's |
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| 17 | * customers, employees, agents, transferees, successors, and assigns. |
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| 18 | * |
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| 19 | * The MPEG Software Simulation Group does not represent or warrant that the |
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| 20 | * programs furnished hereunder are free of infringement of any third-party |
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| 21 | * patents. |
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| 22 | * |
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| 23 | * Commercial implementations of MPEG-1 and MPEG-2 video, including shareware, |
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| 24 | * are subject to royalty fees to patent holders. Many of these patents are |
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| 25 | * general enough such that they are unavoidable regardless of implementation |
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| 26 | * design. |
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| 27 | * |
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| 28 | */ |
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| 29 | |||
| 30 | #include "config.h" |
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| 31 | #include "global.h" |
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| 32 | |||
| 33 | /* private prototypes */ |
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| 34 | static void form_prediction _ANSI_ARGS_((unsigned char *src[], int sfield, |
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| 35 | unsigned char *dst[], int dfield, |
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| 36 | int lx, int lx2, int w, int h, int x, int y, int dx, int dy, |
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| 37 | int average_flag)); |
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| 38 | |||
| 39 | static void form_component_prediction _ANSI_ARGS_((unsigned char *src, unsigned char *dst, |
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| 40 | int lx, int lx2, int w, int h, int x, int y, int dx, int dy, int average_flag)); |
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| 41 | |||
| 42 | void form_predictions(bx,by,macroblock_type,motion_type,PMV,motion_vertical_field_select,dmvector,stwtype) |
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| 43 | int bx, by; |
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| 44 | int macroblock_type; |
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| 45 | int motion_type; |
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| 46 | int PMV[2][2][2], motion_vertical_field_select[2][2], dmvector[2]; |
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| 47 | int stwtype; |
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| 48 | { |
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| 49 | int currentfield; |
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| 50 | unsigned char **predframe; |
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| 51 | int DMV[2][2]; |
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| 52 | int stwtop, stwbot; |
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| 53 | |||
| 54 | stwtop = stwtype%3; /* 0:temporal, 1:(spat+temp)/2, 2:spatial */ |
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| 55 | stwbot = stwtype/3; |
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| 56 | |||
| 57 | if ((macroblock_type & MACROBLOCK_MOTION_FORWARD) |
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| 58 | || (picture_coding_type==P_TYPE)) |
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| 59 | { |
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| 60 | if (picture_structure==FRAME_PICTURE) |
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| 61 | { |
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| 62 | if ((motion_type==MC_FRAME) |
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| 63 | || !(macroblock_type & MACROBLOCK_MOTION_FORWARD)) |
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| 64 | { |
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| 65 | /* frame-based prediction (broken into top and bottom halves |
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| 66 | for spatial scalability prediction purposes) */ |
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| 67 | if (stwtop<2) |
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| 68 | form_prediction(forward_reference_frame,0,current_frame,0, |
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| 69 | Coded_Picture_Width,Coded_Picture_Width<<1,16,8,bx,by, |
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| 70 | PMV[0][0][0],PMV[0][0][1],stwtop); |
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| 71 | |||
| 72 | if (stwbot<2) |
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| 73 | form_prediction(forward_reference_frame,1,current_frame,1, |
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| 74 | Coded_Picture_Width,Coded_Picture_Width<<1,16,8,bx,by, |
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| 75 | PMV[0][0][0],PMV[0][0][1],stwbot); |
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| 76 | } |
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| 77 | else if (motion_type==MC_FIELD) /* field-based prediction */ |
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| 78 | { |
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| 79 | /* top field prediction */ |
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| 80 | if (stwtop<2) |
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| 81 | form_prediction(forward_reference_frame,motion_vertical_field_select[0][0], |
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| 82 | current_frame,0,Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8, |
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| 83 | bx,by>>1,PMV[0][0][0],PMV[0][0][1]>>1,stwtop); |
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| 84 | |||
| 85 | /* bottom field prediction */ |
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| 86 | if (stwbot<2) |
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| 87 | form_prediction(forward_reference_frame,motion_vertical_field_select[1][0], |
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| 88 | current_frame,1,Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8, |
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| 89 | bx,by>>1,PMV[1][0][0],PMV[1][0][1]>>1,stwbot); |
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| 90 | } |
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| 91 | else if (motion_type==MC_DMV) /* dual prime prediction */ |
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| 92 | { |
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| 93 | /* calculate derived motion vectors */ |
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| 94 | Dual_Prime_Arithmetic(DMV,dmvector,PMV[0][0][0],PMV[0][0][1]>>1); |
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| 95 | |||
| 96 | if (stwtop<2) |
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| 97 | { |
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| 98 | /* predict top field from top field */ |
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| 99 | form_prediction(forward_reference_frame,0,current_frame,0, |
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| 100 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8,bx,by>>1, |
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| 101 | PMV[0][0][0],PMV[0][0][1]>>1,0); |
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| 102 | |||
| 103 | /* predict and add to top field from bottom field */ |
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| 104 | form_prediction(forward_reference_frame,1,current_frame,0, |
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| 105 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8,bx,by>>1, |
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| 106 | DMV[0][0],DMV[0][1],1); |
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| 107 | } |
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| 108 | |||
| 109 | if (stwbot<2) |
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| 110 | { |
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| 111 | /* predict bottom field from bottom field */ |
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| 112 | form_prediction(forward_reference_frame,1,current_frame,1, |
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| 113 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8,bx,by>>1, |
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| 114 | PMV[0][0][0],PMV[0][0][1]>>1,0); |
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| 115 | |||
| 116 | /* predict and add to bottom field from top field */ |
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| 117 | form_prediction(forward_reference_frame,0,current_frame,1, |
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| 118 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8,bx,by>>1, |
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| 119 | DMV[1][0],DMV[1][1],1); |
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| 120 | } |
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| 121 | } |
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| 122 | else |
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| 123 | /* invalid motion_type */ |
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| 124 | cprintf("invalid motion_type\n"); |
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| 125 | } |
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| 126 | else /* TOP_FIELD or BOTTOM_FIELD */ |
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| 127 | { |
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| 128 | /* field picture */ |
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| 129 | currentfield = (picture_structure==BOTTOM_FIELD); |
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| 130 | |||
| 131 | /* determine which frame to use for prediction */ |
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| 132 | if ((picture_coding_type==P_TYPE) && Second_Field |
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| 133 | && (currentfield!=motion_vertical_field_select[0][0])) |
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| 134 | predframe = backward_reference_frame; /* same frame */ |
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| 135 | else |
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| 136 | predframe = forward_reference_frame; /* previous frame */ |
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| 137 | |||
| 138 | if ((motion_type==MC_FIELD) |
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| 139 | || !(macroblock_type & MACROBLOCK_MOTION_FORWARD)) |
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| 140 | { |
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| 141 | /* field-based prediction */ |
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| 142 | if (stwtop<2) |
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| 143 | form_prediction(predframe,motion_vertical_field_select[0][0],current_frame,0, |
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| 144 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,16,bx,by, |
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| 145 | PMV[0][0][0],PMV[0][0][1],stwtop); |
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| 146 | } |
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| 147 | else if (motion_type==MC_16X8) |
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| 148 | { |
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| 149 | if (stwtop<2) |
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| 150 | { |
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| 151 | form_prediction(predframe,motion_vertical_field_select[0][0],current_frame,0, |
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| 152 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8,bx,by, |
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| 153 | PMV[0][0][0],PMV[0][0][1],stwtop); |
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| 154 | |||
| 155 | /* determine which frame to use for lower half prediction */ |
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| 156 | if ((picture_coding_type==P_TYPE) && Second_Field |
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| 157 | && (currentfield!=motion_vertical_field_select[1][0])) |
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| 158 | predframe = backward_reference_frame; /* same frame */ |
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| 159 | else |
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| 160 | predframe = forward_reference_frame; /* previous frame */ |
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| 161 | |||
| 162 | form_prediction(predframe,motion_vertical_field_select[1][0],current_frame,0, |
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| 163 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8,bx,by+8, |
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| 164 | PMV[1][0][0],PMV[1][0][1],stwtop); |
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| 165 | } |
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| 166 | } |
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| 167 | else if (motion_type==MC_DMV) /* dual prime prediction */ |
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| 168 | { |
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| 169 | if (Second_Field) |
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| 170 | predframe = backward_reference_frame; /* same frame */ |
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| 171 | else |
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| 172 | predframe = forward_reference_frame; /* previous frame */ |
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| 173 | |||
| 174 | /* calculate derived motion vectors */ |
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| 175 | Dual_Prime_Arithmetic(DMV,dmvector,PMV[0][0][0],PMV[0][0][1]); |
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| 176 | |||
| 177 | /* predict from field of same parity */ |
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| 178 | form_prediction(forward_reference_frame,currentfield,current_frame,0, |
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| 179 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,16,bx,by, |
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| 180 | PMV[0][0][0],PMV[0][0][1],0); |
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| 181 | |||
| 182 | /* predict from field of opposite parity */ |
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| 183 | form_prediction(predframe,!currentfield,current_frame,0, |
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| 184 | Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,16,bx,by, |
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| 185 | DMV[0][0],DMV[0][1],1); |
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| 186 | } |
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| 187 | else |
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| 188 | /* invalid motion_type */ |
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| 189 | cprintf("invalid motion_type\n"); |
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| 190 | } |
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| 191 | stwtop = stwbot = 1; |
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| 192 | } |
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| 193 | |||
| 194 | if (macroblock_type & MACROBLOCK_MOTION_BACKWARD) |
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| 195 | { |
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| 196 | if (picture_structure==FRAME_PICTURE) |
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| 197 | { |
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| 198 | if (motion_type==MC_FRAME) |
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| 199 | { |
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| 200 | /* frame-based prediction */ |
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| 201 | if (stwtop<2) |
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| 202 | form_prediction(backward_reference_frame,0,current_frame,0, |
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| 203 | Coded_Picture_Width,Coded_Picture_Width<<1,16,8,bx,by, |
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| 204 | PMV[0][1][0],PMV[0][1][1],stwtop); |
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| 205 | |||
| 206 | if (stwbot<2) |
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| 207 | form_prediction(backward_reference_frame,1,current_frame,1, |
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| 208 | Coded_Picture_Width,Coded_Picture_Width<<1,16,8,bx,by, |
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| 209 | PMV[0][1][0],PMV[0][1][1],stwbot); |
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| 210 | } |
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| 211 | else /* field-based prediction */ |
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| 212 | { |
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| 213 | /* top field prediction */ |
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| 214 | if (stwtop<2) |
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| 215 | form_prediction(backward_reference_frame,motion_vertical_field_select[0][1], |
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| 216 | current_frame,0,Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8, |
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| 217 | bx,by>>1,PMV[0][1][0],PMV[0][1][1]>>1,stwtop); |
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| 218 | |||
| 219 | /* bottom field prediction */ |
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| 220 | if (stwbot<2) |
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| 221 | form_prediction(backward_reference_frame,motion_vertical_field_select[1][1], |
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| 222 | current_frame,1,Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8, |
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| 223 | bx,by>>1,PMV[1][1][0],PMV[1][1][1]>>1,stwbot); |
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| 224 | } |
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| 225 | } |
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| 226 | else /* TOP_FIELD or BOTTOM_FIELD */ |
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| 227 | { |
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| 228 | /* field picture */ |
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| 229 | if (motion_type==MC_FIELD) |
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| 230 | { |
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| 231 | /* field-based prediction */ |
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| 232 | form_prediction(backward_reference_frame,motion_vertical_field_select[0][1], |
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| 233 | current_frame,0,Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,16, |
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| 234 | bx,by,PMV[0][1][0],PMV[0][1][1],stwtop); |
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| 235 | } |
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| 236 | else if (motion_type==MC_16X8) |
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| 237 | { |
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| 238 | form_prediction(backward_reference_frame,motion_vertical_field_select[0][1], |
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| 239 | current_frame,0,Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8, |
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| 240 | bx,by,PMV[0][1][0],PMV[0][1][1],stwtop); |
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| 241 | |||
| 242 | form_prediction(backward_reference_frame,motion_vertical_field_select[1][1], |
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| 243 | current_frame,0,Coded_Picture_Width<<1,Coded_Picture_Width<<1,16,8, |
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| 244 | bx,by+8,PMV[1][1][0],PMV[1][1][1],stwtop); |
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| 245 | } |
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| 246 | else |
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| 247 | /* invalid motion_type */ |
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| 248 | cprintf("invalid motion_type\n"); |
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| 249 | } |
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| 250 | } |
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| 251 | } |
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| 252 | |||
| 253 | static void form_prediction(src,sfield,dst,dfield,lx,lx2,w,h,x,y,dx,dy,average_flag) |
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| 254 | unsigned char *src[]; /* prediction source buffer */ |
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| 255 | int sfield; /* prediction source field number (0 or 1) */ |
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| 256 | unsigned char *dst[]; /* prediction destination buffer */ |
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| 257 | int dfield; /* prediction destination field number (0 or 1)*/ |
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| 258 | int lx,lx2; /* line strides */ |
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| 259 | int w,h; /* prediction block/sub-block width, height */ |
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| 260 | int x,y; /* pixel co-ordinates of top-left sample in current MB */ |
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| 261 | int dx,dy; /* horizontal, vertical prediction address */ |
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| 262 | int average_flag; /* add prediction error to prediction ? */ |
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| 263 | { |
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| 264 | /* Y */ |
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| 265 | form_component_prediction(src[0]+(sfield?lx2>>1:0),dst[0]+(dfield?lx2>>1:0), |
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| 266 | lx,lx2,w,h,x,y,dx,dy,average_flag); |
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| 267 | |||
| 268 | if (chroma_format!=CHROMA444) |
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| 269 | { |
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| 270 | lx>>=1; lx2>>=1; w>>=1; x>>=1; dx/=2; |
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| 271 | } |
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| 272 | |||
| 273 | if (chroma_format==CHROMA420) |
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| 274 | { |
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| 275 | h>>=1; y>>=1; dy/=2; |
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| 276 | } |
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| 277 | |||
| 278 | /* Cb */ |
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| 279 | form_component_prediction(src[1]+(sfield?lx2>>1:0),dst[1]+(dfield?lx2>>1:0), |
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| 280 | lx,lx2,w,h,x,y,dx,dy,average_flag); |
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| 281 | |||
| 282 | /* Cr */ |
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| 283 | form_component_prediction(src[2]+(sfield?lx2>>1:0),dst[2]+(dfield?lx2>>1:0), |
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| 284 | lx,lx2,w,h,x,y,dx,dy,average_flag); |
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| 285 | } |
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| 286 | |||
| 287 | /* ISO/IEC 13818-2 section 7.6.4: Forming predictions */ |
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| 288 | /* NOTE: the arithmetic below produces numerically equivalent results |
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| 289 | * to 7.6.4, yet is more elegant. It differs in the following ways: |
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| 290 | * |
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| 291 | * 1. the vectors (dx, dy) are based on cartesian frame |
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| 292 | * coordiantes along a half-pel grid (always positive numbers) |
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| 293 | * In contrast, vector[r][s][t] are differential (with positive and |
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| 294 | * negative values). As a result, deriving the integer vectors |
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| 295 | * (int_vec[t]) from dx, dy is accomplished by a simple right shift. |
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| 296 | * |
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| 297 | * 2. Half pel flags (xh, yh) are equivalent to the LSB (Least |
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| 298 | * Significant Bit) of the half-pel coordinates (dx,dy). |
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| 299 | * |
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| 300 | * |
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| 301 | * NOTE: the work of combining predictions (ISO/IEC 13818-2 section 7.6.7) |
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| 302 | * is distributed among several other stages. This is accomplished by |
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| 303 | * folding line offsets into the source and destination (src,dst) |
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| 304 | * addresses (note the call arguments to form_prediction() in Predict()), |
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| 305 | * line stride variables lx and lx2, the block dimension variables (w,h), |
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| 306 | * average_flag, and by the very order in which Predict() is called. |
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| 307 | * This implementation design (implicitly different than the spec) |
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| 308 | * was chosen for its elegance. |
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| 309 | */ |
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| 310 | |||
| 311 | static void form_component_prediction(src,dst,lx,lx2,w,h,x,y,dx,dy,average_flag) |
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| 312 | unsigned char *src; |
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| 313 | unsigned char *dst; |
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| 314 | int lx; /* raster line increment */ |
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| 315 | int lx2; |
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| 316 | int w,h; |
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| 317 | int x,y; |
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| 318 | int dx,dy; |
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| 319 | int average_flag; /* flag that signals bi-directional or Dual-Prime |
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| 320 | averaging (7.6.7.1 and 7.6.7.4). if average_flag==1, |
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| 321 | a previously formed prediction has been stored in |
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| 322 | pel_pred[] */ |
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| 323 | { |
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| 324 | int xint; /* horizontal integer sample vector: analogous to int_vec[0] */ |
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| 325 | int yint; /* vertical integer sample vectors: analogous to int_vec[1] */ |
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| 326 | int xh; /* horizontal half sample flag: analogous to half_flag[0] */ |
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| 327 | int yh; /* vertical half sample flag: analogous to half_flag[1] */ |
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| 328 | int i, j, v; |
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| 329 | unsigned char *s; /* source pointer: analogous to pel_ref[][] */ |
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| 330 | unsigned char *d; /* destination pointer: analogous to pel_pred[][] */ |
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| 331 | |||
| 332 | /* half pel scaling for integer vectors */ |
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| 333 | xint = dx>>1; |
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| 334 | yint = dy>>1; |
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| 335 | |||
| 336 | /* derive half pel flags */ |
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| 337 | xh = dx & 1; |
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| 338 | yh = dy & 1; |
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| 339 | |||
| 340 | /* compute the linear address of pel_ref[][] and pel_pred[][] |
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| 341 | based on cartesian/raster cordinates provided */ |
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| 342 | s = src + lx*(y+yint) + x + xint; |
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| 343 | d = dst + lx*y + x; |
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| 344 | |||
| 345 | if (!xh && !yh) /* no horizontal nor vertical half-pel */ |
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| 346 | { |
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| 347 | if (average_flag) |
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| 348 | { |
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| 349 | for (j=0; j<h; j++) |
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| 350 | { |
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| 351 | for (i=0; i<w; i++) |
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| 352 | { |
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| 353 | v = d[i]+s[i]; |
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| 354 | d[i] = (v+(v>=0?1:0))>>1; |
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| 355 | } |
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| 356 | |||
| 357 | s+= lx2; |
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| 358 | d+= lx2; |
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| 359 | } |
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| 360 | } |
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| 361 | else |
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| 362 | { |
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| 363 | for (j=0; j<h; j++) |
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| 364 | { |
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| 365 | for (i=0; i<w; i++) |
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| 366 | { |
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| 367 | d[i] = s[i]; |
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| 368 | } |
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| 369 | |||
| 370 | s+= lx2; |
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| 371 | d+= lx2; |
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| 372 | } |
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| 373 | } |
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| 374 | } |
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| 375 | else if (!xh && yh) /* no horizontal but vertical half-pel */ |
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| 376 | { |
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| 377 | if (average_flag) |
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| 378 | { |
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| 379 | for (j=0; j<h; j++) |
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| 380 | { |
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| 381 | for (i=0; i<w; i++) |
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| 382 | { |
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| 383 | v = d[i] + ((unsigned int)(s[i]+s[i+lx]+1)>>1); |
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| 384 | d[i]=(v+(v>=0?1:0))>>1; |
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| 385 | } |
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| 386 | |||
| 387 | s+= lx2; |
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| 388 | d+= lx2; |
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| 389 | } |
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| 390 | } |
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| 391 | else |
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| 392 | { |
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| 393 | for (j=0; j<h; j++) |
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| 394 | { |
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| 395 | for (i=0; i<w; i++) |
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| 396 | { |
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| 397 | d[i] = (unsigned int)(s[i]+s[i+lx]+1)>>1; |
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| 398 | } |
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| 399 | |||
| 400 | s+= lx2; |
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| 401 | d+= lx2; |
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| 402 | } |
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| 403 | } |
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| 404 | } |
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| 405 | else if (xh && !yh) /* horizontal but no vertical half-pel */ |
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| 406 | { |
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| 407 | if (average_flag) |
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| 408 | { |
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| 409 | for (j=0; j<h; j++) |
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| 410 | { |
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| 411 | for (i=0; i<w; i++) |
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| 412 | { |
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| 413 | v = d[i] + ((unsigned int)(s[i]+s[i+1]+1)>>1); |
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| 414 | d[i] = (v+(v>=0?1:0))>>1; |
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| 415 | } |
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| 416 | |||
| 417 | s+= lx2; |
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| 418 | d+= lx2; |
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| 419 | } |
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| 420 | } |
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| 421 | else |
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| 422 | { |
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| 423 | for (j=0; j<h; j++) |
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| 424 | { |
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| 425 | for (i=0; i<w; i++) |
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| 426 | { |
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| 427 | d[i] = (unsigned int)(s[i]+s[i+1]+1)>>1; |
||
| 428 | } |
||
| 429 | |||
| 430 | s+= lx2; |
||
| 431 | d+= lx2; |
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| 432 | } |
||
| 433 | } |
||
| 434 | } |
||
| 435 | else /* if (xh && yh) horizontal and vertical half-pel */ |
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| 436 | { |
||
| 437 | if (average_flag) |
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| 438 | { |
||
| 439 | for (j=0; j<h; j++) |
||
| 440 | { |
||
| 441 | for (i=0; i<w; i++) |
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| 442 | { |
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| 443 | v = d[i] + ((unsigned int)(s[i]+s[i+1]+s[i+lx]+s[i+lx+1]+2)>>2); |
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| 444 | d[i] = (v+(v>=0?1:0))>>1; |
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| 445 | } |
||
| 446 | |||
| 447 | s+= lx2; |
||
| 448 | d+= lx2; |
||
| 449 | } |
||
| 450 | } |
||
| 451 | else |
||
| 452 | { |
||
| 453 | for (j=0; j<h; j++) |
||
| 454 | { |
||
| 455 | for (i=0; i<w; i++) |
||
| 456 | { |
||
| 457 | d[i] = (unsigned int)(s[i]+s[i+1]+s[i+lx]+s[i+lx+1]+2)>>2; |
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| 458 | } |
||
| 459 | |||
| 460 | s+= lx2; |
||
| 461 | d+= lx2; |
||
| 462 | } |
||
| 463 | } |
||
| 464 | } |
||
| 465 | } |