1 /*
2 * MPEG-4 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 "mpegutils.h"
24 #include "mpegvideo.h"
25 #include "mpeg4video.h"
26 #include "mpeg4data.h"
27
28 uint8_t ff_mpeg4_static_rl_table_store[3][2][2 * MAX_RUN + MAX_LEVEL + 3];
29
ff_mpeg4_get_video_packet_prefix_length(MpegEncContext * s)30 int ff_mpeg4_get_video_packet_prefix_length(MpegEncContext *s)
31 {
32 switch (s->pict_type) {
33 case AV_PICTURE_TYPE_I:
34 return 16;
35 case AV_PICTURE_TYPE_P:
36 case AV_PICTURE_TYPE_S:
37 return s->f_code + 15;
38 case AV_PICTURE_TYPE_B:
39 return FFMAX3(s->f_code, s->b_code, 2) + 15;
40 default:
41 return -1;
42 }
43 }
44
ff_mpeg4_clean_buffers(MpegEncContext * s)45 void ff_mpeg4_clean_buffers(MpegEncContext *s)
46 {
47 int c_wrap, c_xy, l_wrap, l_xy;
48
49 l_wrap = s->b8_stride;
50 l_xy = (2 * s->mb_y - 1) * l_wrap + s->mb_x * 2 - 1;
51 c_wrap = s->mb_stride;
52 c_xy = (s->mb_y - 1) * c_wrap + s->mb_x - 1;
53
54 /* clean AC */
55 memset(s->ac_val[0] + l_xy, 0, (l_wrap * 2 + 1) * 16 * sizeof(int16_t));
56 memset(s->ac_val[1] + c_xy, 0, (c_wrap + 1) * 16 * sizeof(int16_t));
57 memset(s->ac_val[2] + c_xy, 0, (c_wrap + 1) * 16 * sizeof(int16_t));
58
59 /* clean MV */
60 // we can't clear the MVs as they might be needed by a B-frame
61 s->last_mv[0][0][0] =
62 s->last_mv[0][0][1] =
63 s->last_mv[1][0][0] =
64 s->last_mv[1][0][1] = 0;
65 }
66
67 #define tab_size ((signed)FF_ARRAY_ELEMS(s->direct_scale_mv[0]))
68 #define tab_bias (tab_size / 2)
69
70 // used by MPEG-4 and rv10 decoder
ff_mpeg4_init_direct_mv(MpegEncContext * s)71 void ff_mpeg4_init_direct_mv(MpegEncContext *s)
72 {
73 int i;
74 for (i = 0; i < tab_size; i++) {
75 s->direct_scale_mv[0][i] = (i - tab_bias) * s->pb_time / s->pp_time;
76 s->direct_scale_mv[1][i] = (i - tab_bias) * (s->pb_time - s->pp_time) /
77 s->pp_time;
78 }
79 }
80
ff_mpeg4_set_one_direct_mv(MpegEncContext * s,int mx,int my,int i)81 static inline void ff_mpeg4_set_one_direct_mv(MpegEncContext *s, int mx,
82 int my, int i)
83 {
84 int xy = s->block_index[i];
85 uint16_t time_pp = s->pp_time;
86 uint16_t time_pb = s->pb_time;
87 int p_mx, p_my;
88
89 p_mx = s->next_picture.motion_val[0][xy][0];
90 if ((unsigned)(p_mx + tab_bias) < tab_size) {
91 s->mv[0][i][0] = s->direct_scale_mv[0][p_mx + tab_bias] + mx;
92 s->mv[1][i][0] = mx ? s->mv[0][i][0] - p_mx
93 : s->direct_scale_mv[1][p_mx + tab_bias];
94 } else {
95 s->mv[0][i][0] = p_mx * time_pb / time_pp + mx;
96 s->mv[1][i][0] = mx ? s->mv[0][i][0] - p_mx
97 : p_mx * (time_pb - time_pp) / time_pp;
98 }
99 p_my = s->next_picture.motion_val[0][xy][1];
100 if ((unsigned)(p_my + tab_bias) < tab_size) {
101 s->mv[0][i][1] = s->direct_scale_mv[0][p_my + tab_bias] + my;
102 s->mv[1][i][1] = my ? s->mv[0][i][1] - p_my
103 : s->direct_scale_mv[1][p_my + tab_bias];
104 } else {
105 s->mv[0][i][1] = p_my * time_pb / time_pp + my;
106 s->mv[1][i][1] = my ? s->mv[0][i][1] - p_my
107 : p_my * (time_pb - time_pp) / time_pp;
108 }
109 }
110
111 #undef tab_size
112 #undef tab_bias
113
114 /**
115 * @return the mb_type
116 */
ff_mpeg4_set_direct_mv(MpegEncContext * s,int mx,int my)117 int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my)
118 {
119 const int mb_index = s->mb_x + s->mb_y * s->mb_stride;
120 const int colocated_mb_type = s->next_picture.mb_type[mb_index];
121 uint16_t time_pp;
122 uint16_t time_pb;
123 int i;
124
125 // FIXME avoid divides
126 // try special case with shifts for 1 and 3 B-frames?
127
128 if (IS_8X8(colocated_mb_type)) {
129 s->mv_type = MV_TYPE_8X8;
130 for (i = 0; i < 4; i++)
131 ff_mpeg4_set_one_direct_mv(s, mx, my, i);
132 return MB_TYPE_DIRECT2 | MB_TYPE_8x8 | MB_TYPE_L0L1;
133 } else if (IS_INTERLACED(colocated_mb_type)) {
134 s->mv_type = MV_TYPE_FIELD;
135 for (i = 0; i < 2; i++) {
136 int field_select = s->next_picture.ref_index[0][4 * mb_index + 2 * i];
137 s->field_select[0][i] = field_select;
138 s->field_select[1][i] = i;
139 if (s->top_field_first) {
140 time_pp = s->pp_field_time - field_select + i;
141 time_pb = s->pb_field_time - field_select + i;
142 } else {
143 time_pp = s->pp_field_time + field_select - i;
144 time_pb = s->pb_field_time + field_select - i;
145 }
146 s->mv[0][i][0] = s->p_field_mv_table[i][0][mb_index][0] *
147 time_pb / time_pp + mx;
148 s->mv[0][i][1] = s->p_field_mv_table[i][0][mb_index][1] *
149 time_pb / time_pp + my;
150 s->mv[1][i][0] = mx ? s->mv[0][i][0] -
151 s->p_field_mv_table[i][0][mb_index][0]
152 : s->p_field_mv_table[i][0][mb_index][0] *
153 (time_pb - time_pp) / time_pp;
154 s->mv[1][i][1] = my ? s->mv[0][i][1] -
155 s->p_field_mv_table[i][0][mb_index][1]
156 : s->p_field_mv_table[i][0][mb_index][1] *
157 (time_pb - time_pp) / time_pp;
158 }
159 return MB_TYPE_DIRECT2 | MB_TYPE_16x8 |
160 MB_TYPE_L0L1 | MB_TYPE_INTERLACED;
161 } else {
162 ff_mpeg4_set_one_direct_mv(s, mx, my, 0);
163 s->mv[0][1][0] =
164 s->mv[0][2][0] =
165 s->mv[0][3][0] = s->mv[0][0][0];
166 s->mv[0][1][1] =
167 s->mv[0][2][1] =
168 s->mv[0][3][1] = s->mv[0][0][1];
169 s->mv[1][1][0] =
170 s->mv[1][2][0] =
171 s->mv[1][3][0] = s->mv[1][0][0];
172 s->mv[1][1][1] =
173 s->mv[1][2][1] =
174 s->mv[1][3][1] = s->mv[1][0][1];
175 if ((s->avctx->workaround_bugs & FF_BUG_DIRECT_BLOCKSIZE) ||
176 !s->quarter_sample)
177 s->mv_type = MV_TYPE_16X16;
178 else
179 s->mv_type = MV_TYPE_8X8;
180 // Note see prev line
181 return MB_TYPE_DIRECT2 | MB_TYPE_16x16 | MB_TYPE_L0L1;
182 }
183 }
184