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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 "get_bits.h"
29 #include "mpegvideo.h"
30 #include "rl.h"
31 
32 // shapes
33 #define RECT_SHAPE       0
34 #define BIN_SHAPE        1
35 #define BIN_ONLY_SHAPE   2
36 #define GRAY_SHAPE       3
37 
38 #define SIMPLE_VO_TYPE           1
39 #define CORE_VO_TYPE             3
40 #define MAIN_VO_TYPE             4
41 #define NBIT_VO_TYPE             5
42 #define ARTS_VO_TYPE            10
43 #define ACE_VO_TYPE             12
44 #define SIMPLE_STUDIO_VO_TYPE   14
45 #define CORE_STUDIO_VO_TYPE     15
46 #define ADV_SIMPLE_VO_TYPE      17
47 
48 #define VOT_VIDEO_ID 1
49 #define VOT_STILL_TEXTURE_ID 2
50 
51 // aspect_ratio_info
52 #define EXTENDED_PAR 15
53 
54 //vol_sprite_usage / sprite_enable
55 #define STATIC_SPRITE 1
56 #define GMC_SPRITE 2
57 
58 #define MOTION_MARKER 0x1F001
59 #define DC_MARKER     0x6B001
60 
61 #define VOS_STARTCODE        0x1B0
62 #define USER_DATA_STARTCODE  0x1B2
63 #define GOP_STARTCODE        0x1B3
64 #define VISUAL_OBJ_STARTCODE 0x1B5
65 #define VOP_STARTCODE        0x1B6
66 #define SLICE_STARTCODE      0x1B7
67 #define EXT_STARTCODE        0x1B8
68 
69 #define QUANT_MATRIX_EXT_ID  0x3
70 
71 /* smaller packets likely don't contain a real frame */
72 #define MAX_NVOP_SIZE 19
73 
74 typedef struct Mpeg4DecContext {
75     MpegEncContext m;
76 
77     /// number of bits to represent the fractional part of time
78     int time_increment_bits;
79     int shape;
80     int vol_sprite_usage;
81     int sprite_brightness_change;
82     int num_sprite_warping_points;
83     /// sprite trajectory points
84     uint16_t sprite_traj[4][2];
85     /// sprite shift [isChroma]
86     int sprite_shift[2];
87 
88     // reversible vlc
89     int rvlc;
90     /// could this stream contain resync markers
91     int resync_marker;
92     /// time distance of first I -> B, used for interlaced B-frames
93     int t_frame;
94 
95     int new_pred;
96     int enhancement_type;
97     int scalability;
98     int use_intra_dc_vlc;
99 
100     /// QP above which the ac VLC should be used for intra dc
101     int intra_dc_threshold;
102 
103     /* bug workarounds */
104     int divx_version;
105     int divx_build;
106     int xvid_build;
107     int lavc_build;
108 
109     /// flag for having shown the warning about invalid Divx B-frames
110     int showed_packed_warning;
111     /** does the stream contain the low_delay flag,
112      *  used to work around buggy encoders. */
113     int vol_control_parameters;
114     int cplx_estimation_trash_i;
115     int cplx_estimation_trash_p;
116     int cplx_estimation_trash_b;
117 
118     int rgb;
119 } Mpeg4DecContext;
120 
121 static const uint8_t mpeg4_block_count[4] = {0, 6, 8, 12};
122 
123 /* dc encoding for MPEG-4 */
124 extern const uint8_t ff_mpeg4_DCtab_lum[13][2];
125 extern const uint8_t ff_mpeg4_DCtab_chrom[13][2];
126 
127 extern const uint16_t ff_mpeg4_intra_vlc[103][2];
128 extern const int8_t ff_mpeg4_intra_level[102];
129 extern const int8_t ff_mpeg4_intra_run[102];
130 
131 extern RLTable ff_mpeg4_rl_intra;
132 
133 /* Note this is identical to the intra rvlc except that it is reordered. */
134 extern RLTable ff_rvlc_rl_inter;
135 extern RLTable ff_rvlc_rl_intra;
136 
137 extern const uint8_t ff_sprite_trajectory_lens[15];
138 extern const uint8_t ff_mb_type_b_tab[4][2];
139 
140 /* these matrixes will be permuted for the idct */
141 extern const int16_t ff_mpeg4_default_intra_matrix[64];
142 extern const int16_t ff_mpeg4_default_non_intra_matrix[64];
143 
144 extern const uint8_t ff_mpeg4_y_dc_scale_table[32];
145 extern const uint8_t ff_mpeg4_c_dc_scale_table[32];
146 extern const uint16_t ff_mpeg4_resync_prefix[8];
147 
148 extern const uint8_t ff_mpeg4_dc_threshold[8];
149 
150 extern const uint8_t ff_mpeg4_studio_dc_luma[19][2];
151 extern const uint8_t ff_mpeg4_studio_dc_chroma[19][2];
152 extern const uint8_t ff_mpeg4_studio_intra[12][24][2];
153 
154 void ff_mpeg4_encode_mb(MpegEncContext *s,
155                         int16_t block[6][64],
156                         int motion_x, int motion_y);
157 void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n,
158                       int dir);
159 void ff_set_mpeg4_time(MpegEncContext *s);
160 int ff_mpeg4_encode_picture_header(MpegEncContext *s, int picture_number);
161 
162 int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb, int header);
163 void ff_mpeg4_encode_video_packet_header(MpegEncContext *s);
164 void ff_mpeg4_clean_buffers(MpegEncContext *s);
165 void ff_mpeg4_stuffing(PutBitContext *pbc);
166 void ff_mpeg4_init_partitions(MpegEncContext *s);
167 void ff_mpeg4_merge_partitions(MpegEncContext *s);
168 void ff_clean_mpeg4_qscales(MpegEncContext *s);
169 int ff_mpeg4_decode_partitions(Mpeg4DecContext *ctx);
170 int ff_mpeg4_get_video_packet_prefix_length(MpegEncContext *s);
171 int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx);
172 int ff_mpeg4_decode_studio_slice_header(Mpeg4DecContext *ctx);
173 void ff_mpeg4_init_direct_mv(MpegEncContext *s);
174 void ff_mpeg4videodec_static_init(void);
175 int ff_mpeg4_workaround_bugs(AVCodecContext *avctx);
176 int ff_mpeg4_frame_end(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
177 
178 /**
179  * @return the mb_type
180  */
181 int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my);
182 
183 extern uint8_t ff_mpeg4_static_rl_table_store[3][2][2 * MAX_RUN + MAX_LEVEL + 3];
184 
185 #if 0 //3IV1 is quite rare and it slows things down a tiny bit
186 #define IS_3IV1 s->codec_tag == AV_RL32("3IV1")
187 #else
188 #define IS_3IV1 0
189 #endif
190 
191 /**
192  * Predict the dc.
193  * encoding quantized level -> quantized diff
194  * decoding quantized diff -> quantized level
195  * @param n block index (0-3 are luma, 4-5 are chroma)
196  * @param dir_ptr pointer to an integer where the prediction direction will be stored
197  */
ff_mpeg4_pred_dc(MpegEncContext * s,int n,int level,int * dir_ptr,int encoding)198 static inline int ff_mpeg4_pred_dc(MpegEncContext *s, int n, int level,
199                                    int *dir_ptr, int encoding)
200 {
201     int a, b, c, wrap, pred, scale, ret;
202     int16_t *dc_val;
203 
204     /* find prediction */
205     if (n < 4)
206         scale = s->y_dc_scale;
207     else
208         scale = s->c_dc_scale;
209     if (IS_3IV1)
210         scale = 8;
211 
212     wrap   = s->block_wrap[n];
213     dc_val = s->dc_val[0] + s->block_index[n];
214 
215     /* B C
216      * A X
217      */
218     a = dc_val[-1];
219     b = dc_val[-1 - wrap];
220     c = dc_val[-wrap];
221 
222     /* outside slice handling (we can't do that by memset as we need the
223      * dc for error resilience) */
224     if (s->first_slice_line && n != 3) {
225         if (n != 2)
226             b = c = 1024;
227         if (n != 1 && s->mb_x == s->resync_mb_x)
228             b = a = 1024;
229     }
230     if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1) {
231         if (n == 0 || n == 4 || n == 5)
232             b = 1024;
233     }
234 
235     if (abs(a - b) < abs(b - c)) {
236         pred     = c;
237         *dir_ptr = 1; /* top */
238     } else {
239         pred     = a;
240         *dir_ptr = 0; /* left */
241     }
242     /* we assume pred is positive */
243     pred = FASTDIV((pred + (scale >> 1)), scale);
244 
245     if (encoding) {
246         ret = level - pred;
247     } else {
248         level += pred;
249         ret    = level;
250     }
251     level *= scale;
252     if (level & (~2047)) {
253         if (!s->encoding && (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE))) {
254             if (level < 0) {
255                 av_log(s->avctx, AV_LOG_ERROR,
256                        "dc<0 at %dx%d\n", s->mb_x, s->mb_y);
257                 return AVERROR_INVALIDDATA;
258             }
259             if (level > 2048 + scale) {
260                 av_log(s->avctx, AV_LOG_ERROR,
261                        "dc overflow at %dx%d\n", s->mb_x, s->mb_y);
262                 return AVERROR_INVALIDDATA;
263             }
264         }
265         if (level < 0)
266             level = 0;
267         else if (!(s->workaround_bugs & FF_BUG_DC_CLIP))
268             level = 2047;
269     }
270     dc_val[0] = level;
271 
272     return ret;
273 }
274 
275 #endif /* AVCODEC_MPEG4VIDEO_H */
276