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mpeg4video.c
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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 "mpegutils.h"
24 #include "mpegvideo.h"
25 #include "mpeg4video.h"
26 #include "mpeg4data.h"
27 
29 
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 
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 mpeg4 and rv10 decoder
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 
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  */
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);
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 |
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];
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
182  }
183 }
int8_t * ref_index[2]
Definition: mpegpicture.h:62
const char * s
Definition: avisynth_c.h:631
S(GMC)-VOP MPEG4.
Definition: avutil.h:269
#define MV_TYPE_FIELD
2 vectors, one per field
Definition: mpegvideo.h:277
int last_mv[2][2][2]
last MV, used for MV prediction in MPEG1 & B-frame MPEG4
Definition: mpegvideo.h:286
int16_t(*[3] ac_val)[16]
used for mpeg4 AC prediction, all 3 arrays must be continuous
Definition: mpegvideo.h:201
#define tab_bias
Definition: mpeg4video.c:68
int16_t(*[2][2] p_field_mv_table)[2]
MV table (2MV per MB) interlaced p-frame encoding.
Definition: mpegvideo.h:261
mpegvideo header.
int field_select[2][2]
Definition: mpegvideo.h:285
void ff_mpeg4_clean_buffers(MpegEncContext *s)
Definition: mpeg4video.c:45
uint8_t
mpeg4 tables.
uint16_t pp_time
time distance between the last 2 p,s,i frames
Definition: mpegvideo.h:397
#define MAX_LEVEL
Definition: rl.h:35
#define FF_BUG_DIRECT_BLOCKSIZE
Definition: avcodec.h:2800
int16_t direct_scale_mv[2][64]
precomputed to avoid divisions in ff_mpeg4_set_direct_mv
Definition: mpegvideo.h:288
void ff_mpeg4_init_direct_mv(MpegEncContext *s)
Definition: mpeg4video.c:71
int quarter_sample
1->qpel, 0->half pel ME/MC
Definition: mpegvideo.h:406
uint8_t ff_mpeg4_static_rl_table_store[3][2][2 *MAX_RUN+MAX_LEVEL+3]
Definition: mpeg4video.c:28
int top_field_first
Definition: mpegvideo.h:467
#define MB_TYPE_DIRECT2
Definition: avcodec.h:1148
#define MB_TYPE_INTERLACED
Definition: avcodec.h:1147
int16_t(*[2] motion_val)[2]
Definition: mpegpicture.h:53
#define MB_TYPE_L0L1
Definition: avcodec.h:1158
int block_index[6]
index to current MB in block based arrays with edges
Definition: mpegvideo.h:301
#define MV_TYPE_16X16
1 vector for the whole mb
Definition: mpegvideo.h:274
#define IS_INTERLACED(a)
Definition: mpegutils.h:79
#define MB_TYPE_16x16
Definition: avcodec.h:1143
int f_code
forward MV resolution
Definition: mpegvideo.h:245
int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my)
Definition: mpeg4video.c:117
int pict_type
AV_PICTURE_TYPE_I, AV_PICTURE_TYPE_P, AV_PICTURE_TYPE_B, ...
Definition: mpegvideo.h:219
int ff_mpeg4_get_video_packet_prefix_length(MpegEncContext *s)
Definition: mpeg4video.c:30
uint16_t pb_field_time
like above, just for interlaced
Definition: mpegvideo.h:400
int mv[2][4][2]
motion vectors for a macroblock first coordinate : 0 = forward 1 = backward second " : depend...
Definition: mpegvideo.h:284
int b8_stride
2*mb_width+1 used for some 8x8 block arrays to allow simple addressing
Definition: mpegvideo.h:138
MpegEncContext.
Definition: mpegvideo.h:88
#define MAX_RUN
Definition: rl.h:34
struct AVCodecContext * avctx
Definition: mpegvideo.h:105
uint16_t pp_field_time
Definition: mpegvideo.h:399
int mb_stride
mb_width+1 used for some arrays to allow simple addressing of left & top MBs without sig11 ...
Definition: mpegvideo.h:137
static void ff_mpeg4_set_one_direct_mv(MpegEncContext *s, int mx, int my, int i)
Definition: mpeg4video.c:81
#define tab_size
Definition: mpeg4video.c:67
#define MB_TYPE_8x8
Definition: avcodec.h:1146
Bi-dir predicted.
Definition: avutil.h:268
int workaround_bugs
Work around bugs in encoders which sometimes cannot be detected automatically.
Definition: avcodec.h:2785
#define MB_TYPE_16x8
Definition: avcodec.h:1144
#define IS_8X8(a)
Definition: mpegutils.h:85
Picture next_picture
copy of the next picture structure.
Definition: mpegvideo.h:175
uint32_t * mb_type
types and macros are defined in mpegutils.h
Definition: mpegpicture.h:56
#define MV_TYPE_8X8
4 vectors (h263, mpeg4 4MV)
Definition: mpegvideo.h:275
int b_code
backward MV resolution for B Frames (mpeg4)
Definition: mpegvideo.h:246
#define FFMAX3(a, b, c)
Definition: common.h:65
Predicted.
Definition: avutil.h:267
uint16_t pb_time
time distance between the last b and p,s,i frame
Definition: mpegvideo.h:398