1/*
2 * MPEG4 decoder / encoder common code.
3 * Copyright (c) 2000,2001 Fabrice Bellard
4 * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include "mpegvideo.h"
24#include "mpeg4video.h"
25#include "mpeg4data.h"
26
27uint8_t ff_mpeg4_static_rl_table_store[3][2][2*MAX_RUN + MAX_LEVEL + 3];
28
29int ff_mpeg4_get_video_packet_prefix_length(MpegEncContext *s){
30    switch(s->pict_type){
31        case FF_I_TYPE:
32            return 16;
33        case FF_P_TYPE:
34        case FF_S_TYPE:
35            return s->f_code+15;
36        case FF_B_TYPE:
37            return FFMAX3(s->f_code, s->b_code, 2) + 15;
38        default:
39            return -1;
40    }
41}
42
43void ff_mpeg4_clean_buffers(MpegEncContext *s)
44{
45    int c_wrap, c_xy, l_wrap, l_xy;
46
47    l_wrap= s->b8_stride;
48    l_xy= (2*s->mb_y-1)*l_wrap + s->mb_x*2 - 1;
49    c_wrap= s->mb_stride;
50    c_xy= (s->mb_y-1)*c_wrap + s->mb_x - 1;
51
52#if 0
53    /* clean DC */
54    memsetw(s->dc_val[0] + l_xy, 1024, l_wrap*2+1);
55    memsetw(s->dc_val[1] + c_xy, 1024, c_wrap+1);
56    memsetw(s->dc_val[2] + c_xy, 1024, c_wrap+1);
57#endif
58
59    /* clean AC */
60    memset(s->ac_val[0] + l_xy, 0, (l_wrap*2+1)*16*sizeof(int16_t));
61    memset(s->ac_val[1] + c_xy, 0, (c_wrap  +1)*16*sizeof(int16_t));
62    memset(s->ac_val[2] + c_xy, 0, (c_wrap  +1)*16*sizeof(int16_t));
63
64    /* clean MV */
65    // we can't clear the MVs as they might be needed by a b frame
66//    memset(s->motion_val + l_xy, 0, (l_wrap*2+1)*2*sizeof(int16_t));
67//    memset(s->motion_val, 0, 2*sizeof(int16_t)*(2 + s->mb_width*2)*(2 + s->mb_height*2));
68    s->last_mv[0][0][0]=
69    s->last_mv[0][0][1]=
70    s->last_mv[1][0][0]=
71    s->last_mv[1][0][1]= 0;
72}
73
74#define tab_size ((signed)FF_ARRAY_ELEMS(s->direct_scale_mv[0]))
75#define tab_bias (tab_size/2)
76
77//used by mpeg4 and rv10 decoder
78void ff_mpeg4_init_direct_mv(MpegEncContext *s){
79    int i;
80    for(i=0; i<tab_size; i++){
81        s->direct_scale_mv[0][i] = (i-tab_bias)*s->pb_time/s->pp_time;
82        s->direct_scale_mv[1][i] = (i-tab_bias)*(s->pb_time-s->pp_time)/s->pp_time;
83    }
84}
85
86static inline void ff_mpeg4_set_one_direct_mv(MpegEncContext *s, int mx, int my, int i){
87    int xy= s->block_index[i];
88    uint16_t time_pp= s->pp_time;
89    uint16_t time_pb= s->pb_time;
90    int p_mx, p_my;
91
92    p_mx= s->next_picture.motion_val[0][xy][0];
93    if((unsigned)(p_mx + tab_bias) < tab_size){
94        s->mv[0][i][0] = s->direct_scale_mv[0][p_mx + tab_bias] + mx;
95        s->mv[1][i][0] = mx ? s->mv[0][i][0] - p_mx
96                            : s->direct_scale_mv[1][p_mx + tab_bias];
97    }else{
98        s->mv[0][i][0] = p_mx*time_pb/time_pp + mx;
99        s->mv[1][i][0] = mx ? s->mv[0][i][0] - p_mx
100                            : p_mx*(time_pb - time_pp)/time_pp;
101    }
102    p_my= s->next_picture.motion_val[0][xy][1];
103    if((unsigned)(p_my + tab_bias) < tab_size){
104        s->mv[0][i][1] = s->direct_scale_mv[0][p_my + tab_bias] + my;
105        s->mv[1][i][1] = my ? s->mv[0][i][1] - p_my
106                            : s->direct_scale_mv[1][p_my + tab_bias];
107    }else{
108        s->mv[0][i][1] = p_my*time_pb/time_pp + my;
109        s->mv[1][i][1] = my ? s->mv[0][i][1] - p_my
110                            : p_my*(time_pb - time_pp)/time_pp;
111    }
112}
113
114#undef tab_size
115#undef tab_bias
116
117/**
118 *
119 * @return the mb_type
120 */
121int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my){
122    const int mb_index= s->mb_x + s->mb_y*s->mb_stride;
123    const int colocated_mb_type= s->next_picture.mb_type[mb_index];
124    uint16_t time_pp;
125    uint16_t time_pb;
126    int i;
127
128    //FIXME avoid divides
129    // try special case with shifts for 1 and 3 B-frames?
130
131    if(IS_8X8(colocated_mb_type)){
132        s->mv_type = MV_TYPE_8X8;
133        for(i=0; i<4; i++){
134            ff_mpeg4_set_one_direct_mv(s, mx, my, i);
135        }
136        return MB_TYPE_DIRECT2 | MB_TYPE_8x8 | MB_TYPE_L0L1;
137    } else if(IS_INTERLACED(colocated_mb_type)){
138        s->mv_type = MV_TYPE_FIELD;
139        for(i=0; i<2; i++){
140            int field_select= s->next_picture.ref_index[0][4*mb_index + 2*i];
141            s->field_select[0][i]= field_select;
142            s->field_select[1][i]= i;
143            if(s->top_field_first){
144                time_pp= s->pp_field_time - field_select + i;
145                time_pb= s->pb_field_time - field_select + i;
146            }else{
147                time_pp= s->pp_field_time + field_select - i;
148                time_pb= s->pb_field_time + field_select - i;
149            }
150            s->mv[0][i][0] = s->p_field_mv_table[i][0][mb_index][0]*time_pb/time_pp + mx;
151            s->mv[0][i][1] = s->p_field_mv_table[i][0][mb_index][1]*time_pb/time_pp + my;
152            s->mv[1][i][0] = mx ? s->mv[0][i][0] - s->p_field_mv_table[i][0][mb_index][0]
153                                : s->p_field_mv_table[i][0][mb_index][0]*(time_pb - time_pp)/time_pp;
154            s->mv[1][i][1] = my ? s->mv[0][i][1] - s->p_field_mv_table[i][0][mb_index][1]
155                                : s->p_field_mv_table[i][0][mb_index][1]*(time_pb - time_pp)/time_pp;
156        }
157        return MB_TYPE_DIRECT2 | MB_TYPE_16x8 | MB_TYPE_L0L1 | MB_TYPE_INTERLACED;
158    }else{
159        ff_mpeg4_set_one_direct_mv(s, mx, my, 0);
160        s->mv[0][1][0] = s->mv[0][2][0] = s->mv[0][3][0] = s->mv[0][0][0];
161        s->mv[0][1][1] = s->mv[0][2][1] = s->mv[0][3][1] = s->mv[0][0][1];
162        s->mv[1][1][0] = s->mv[1][2][0] = s->mv[1][3][0] = s->mv[1][0][0];
163        s->mv[1][1][1] = s->mv[1][2][1] = s->mv[1][3][1] = s->mv[1][0][1];
164        if((s->avctx->workaround_bugs & FF_BUG_DIRECT_BLOCKSIZE) || !s->quarter_sample)
165            s->mv_type= MV_TYPE_16X16;
166        else
167            s->mv_type= MV_TYPE_8X8;
168        return MB_TYPE_DIRECT2 | MB_TYPE_16x16 | MB_TYPE_L0L1; //Note see prev line
169    }
170}
171
172