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1 /*
2  * MPEG-4 encoder/decoder internal header.
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 #ifndef AVCODEC_MPEG4VIDEO_H
24 #define AVCODEC_MPEG4VIDEO_H
25 
26 #include <stdint.h>
27 
28 #include "mpegvideo.h"
29 
30 // shapes
31 #define RECT_SHAPE       0
32 #define BIN_SHAPE        1
33 #define BIN_ONLY_SHAPE   2
34 #define GRAY_SHAPE       3
35 
36 #define SIMPLE_VO_TYPE           1
37 #define CORE_VO_TYPE             3
38 #define MAIN_VO_TYPE             4
39 #define NBIT_VO_TYPE             5
40 #define ARTS_VO_TYPE            10
41 #define ACE_VO_TYPE             12
42 #define SIMPLE_STUDIO_VO_TYPE   14
43 #define CORE_STUDIO_VO_TYPE     15
44 #define ADV_SIMPLE_VO_TYPE      17
45 
46 #define VOT_VIDEO_ID 1
47 #define VOT_STILL_TEXTURE_ID 2
48 
49 // aspect_ratio_info
50 #define EXTENDED_PAR 15
51 
52 //vol_sprite_usage / sprite_enable
53 #define STATIC_SPRITE 1
54 #define GMC_SPRITE 2
55 
56 #define MOTION_MARKER 0x1F001
57 #define DC_MARKER     0x6B001
58 
59 #define VOS_STARTCODE        0x1B0
60 #define USER_DATA_STARTCODE  0x1B2
61 #define GOP_STARTCODE        0x1B3
62 #define VISUAL_OBJ_STARTCODE 0x1B5
63 #define VOP_STARTCODE        0x1B6
64 #define SLICE_STARTCODE      0x1B7
65 #define EXT_STARTCODE        0x1B8
66 
67 #define QUANT_MATRIX_EXT_ID  0x3
68 
69 /* smaller packets likely don't contain a real frame */
70 #define MAX_NVOP_SIZE 19
71 
72 void ff_mpeg4_clean_buffers(MpegEncContext *s);
73 int ff_mpeg4_get_video_packet_prefix_length(MpegEncContext *s);
74 void ff_mpeg4_init_direct_mv(MpegEncContext *s);
75 
76 /**
77  * @return the mb_type
78  */
79 int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my);
80 
81 #if 0 //3IV1 is quite rare and it slows things down a tiny bit
82 #define IS_3IV1 s->codec_tag == AV_RL32("3IV1")
83 #else
84 #define IS_3IV1 0
85 #endif
86 
87 /**
88  * Predict the dc.
89  * encoding quantized level -> quantized diff
90  * decoding quantized diff -> quantized level
91  * @param n block index (0-3 are luma, 4-5 are chroma)
92  * @param dir_ptr pointer to an integer where the prediction direction will be stored
93  */
ff_mpeg4_pred_dc(MpegEncContext * s,int n,int level,int * dir_ptr,int encoding)94 static inline int ff_mpeg4_pred_dc(MpegEncContext *s, int n, int level,
95                                    int *dir_ptr, int encoding)
96 {
97     int a, b, c, wrap, pred, scale, ret;
98     int16_t *dc_val;
99 
100     /* find prediction */
101     if (n < 4)
102         scale = s->y_dc_scale;
103     else
104         scale = s->c_dc_scale;
105     if (IS_3IV1)
106         scale = 8;
107 
108     wrap   = s->block_wrap[n];
109     dc_val = s->dc_val[0] + s->block_index[n];
110 
111     /* B C
112      * A X
113      */
114     a = dc_val[-1];
115     b = dc_val[-1 - wrap];
116     c = dc_val[-wrap];
117 
118     /* outside slice handling (we can't do that by memset as we need the
119      * dc for error resilience) */
120     if (s->first_slice_line && n != 3) {
121         if (n != 2)
122             b = c = 1024;
123         if (n != 1 && s->mb_x == s->resync_mb_x)
124             b = a = 1024;
125     }
126     if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1) {
127         if (n == 0 || n == 4 || n == 5)
128             b = 1024;
129     }
130 
131     if (abs(a - b) < abs(b - c)) {
132         pred     = c;
133         *dir_ptr = 1; /* top */
134     } else {
135         pred     = a;
136         *dir_ptr = 0; /* left */
137     }
138     /* we assume pred is positive */
139     pred = FASTDIV((pred + (scale >> 1)), scale);
140 
141     if (encoding) {
142         ret = level - pred;
143     } else {
144         level += pred;
145         ret    = level;
146     }
147     level *= scale;
148     if (level & (~2047)) {
149         if (!s->encoding && (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE))) {
150             if (level < 0) {
151                 av_log(s->avctx, AV_LOG_ERROR,
152                        "dc<0 at %dx%d\n", s->mb_x, s->mb_y);
153                 return AVERROR_INVALIDDATA;
154             }
155             if (level > 2048 + scale) {
156                 av_log(s->avctx, AV_LOG_ERROR,
157                        "dc overflow at %dx%d\n", s->mb_x, s->mb_y);
158                 return AVERROR_INVALIDDATA;
159             }
160         }
161         if (level < 0)
162             level = 0;
163         else if (!(s->workaround_bugs & FF_BUG_DC_CLIP))
164             level = 2047;
165     }
166     dc_val[0] = level;
167 
168     return ret;
169 }
170 
171 #endif /* AVCODEC_MPEG4VIDEO_H */
172