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1 /*
2  * VP8 compatible video decoder
3  *
4  * Copyright (C) 2010 David Conrad
5  * Copyright (C) 2010 Ronald S. Bultje
6  * Copyright (C) 2010 Fiona Glaser
7  * Copyright (C) 2012 Daniel Kang
8  *
9  * This file is part of FFmpeg.
10  *
11  * FFmpeg is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU Lesser General Public
13  * License as published by the Free Software Foundation; either
14  * version 2.1 of the License, or (at your option) any later version.
15  *
16  * FFmpeg is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * Lesser General Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser General Public
22  * License along with FFmpeg; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24  */
25 
26 #ifndef AVCODEC_VP8_H
27 #define AVCODEC_VP8_H
28 
29 #include <stdatomic.h>
30 
31 #include "libavutil/buffer.h"
32 #include "libavutil/mem_internal.h"
33 #include "libavutil/thread.h"
34 
35 #include "h264pred.h"
36 #include "thread.h"
37 #include "vp56.h"
38 #include "vp8dsp.h"
39 
40 #define VP8_MAX_QUANT 127
41 
42 enum dct_token {
43     DCT_0,
44     DCT_1,
45     DCT_2,
46     DCT_3,
47     DCT_4,
48     DCT_CAT1,
49     DCT_CAT2,
50     DCT_CAT3,
51     DCT_CAT4,
52     DCT_CAT5,
53     DCT_CAT6,
54     DCT_EOB,
55 
56     NUM_DCT_TOKENS
57 };
58 
59 // used to signal 4x4 intra pred in luma MBs
60 #define MODE_I4x4 4
61 
62 enum inter_mvmode {
63     VP8_MVMODE_ZERO = MODE_I4x4 + 1,
64     VP8_MVMODE_MV,
65     VP8_MVMODE_SPLIT
66 };
67 
68 enum inter_splitmvmode {
69     VP8_SPLITMVMODE_16x8 = 0,    ///< 2 16x8 blocks (vertical)
70     VP8_SPLITMVMODE_8x16,        ///< 2 8x16 blocks (horizontal)
71     VP8_SPLITMVMODE_8x8,         ///< 2x2 blocks of 8x8px each
72     VP8_SPLITMVMODE_4x4,         ///< 4x4 blocks of 4x4px each
73     VP8_SPLITMVMODE_NONE,        ///< (only used in prediction) no split MVs
74 };
75 
76 typedef struct VP8FilterStrength {
77     uint8_t filter_level;
78     uint8_t inner_limit;
79     uint8_t inner_filter;
80 } VP8FilterStrength;
81 
82 typedef struct VP8Macroblock {
83     uint8_t skip;
84     // TODO: make it possible to check for at least (i4x4 or split_mv)
85     // in one op. are others needed?
86     uint8_t mode;
87     uint8_t ref_frame;
88     uint8_t partitioning;
89     uint8_t chroma_pred_mode;
90     uint8_t segment;
91     uint8_t intra4x4_pred_mode_mb[16];
92     DECLARE_ALIGNED(4, uint8_t, intra4x4_pred_mode_top)[4];
93     VP56mv mv;
94     VP56mv bmv[16];
95 } VP8Macroblock;
96 
97 typedef struct VP8intmv {
98     int x;
99     int y;
100 } VP8intmv;
101 
102 typedef struct VP8mvbounds {
103     VP8intmv mv_min;
104     VP8intmv mv_max;
105 } VP8mvbounds;
106 
107 typedef struct VP8ThreadData {
108     DECLARE_ALIGNED(16, int16_t, block)[6][4][16];
109     DECLARE_ALIGNED(16, int16_t, block_dc)[16];
110     /**
111      * This is the index plus one of the last non-zero coeff
112      * for each of the blocks in the current macroblock.
113      * So, 0 -> no coeffs
114      *     1 -> dc-only (special transform)
115      *     2+-> full transform
116      */
117     DECLARE_ALIGNED(16, uint8_t, non_zero_count_cache)[6][4];
118     /**
119      * For coeff decode, we need to know whether the above block had non-zero
120      * coefficients. This means for each macroblock, we need data for 4 luma
121      * blocks, 2 u blocks, 2 v blocks, and the luma dc block, for a total of 9
122      * per macroblock. We keep the last row in top_nnz.
123      */
124     DECLARE_ALIGNED(8, uint8_t, left_nnz)[9];
125     int thread_nr;
126 #if HAVE_THREADS
127     pthread_mutex_t lock;
128     pthread_cond_t cond;
129 #endif
130     atomic_int thread_mb_pos; // (mb_y << 16) | (mb_x & 0xFFFF)
131     atomic_int wait_mb_pos; // What the current thread is waiting on.
132 
133 #define EDGE_EMU_LINESIZE 32
134     DECLARE_ALIGNED(16, uint8_t, edge_emu_buffer)[21 * EDGE_EMU_LINESIZE];
135     VP8FilterStrength *filter_strength;
136     VP8mvbounds mv_bounds;
137 } VP8ThreadData;
138 
139 typedef struct VP8Frame {
140     ThreadFrame tf;
141     AVBufferRef *seg_map;
142 
143     AVBufferRef *hwaccel_priv_buf;
144     void *hwaccel_picture_private;
145 } VP8Frame;
146 
147 #define MAX_THREADS 8
148 typedef struct VP8Context {
149     VP8ThreadData *thread_data;
150     AVCodecContext *avctx;
151     enum AVPixelFormat pix_fmt;
152     int actually_webp;
153 
154     VP8Frame *framep[4];
155     VP8Frame *next_framep[4];
156     VP8Frame *curframe;
157     VP8Frame *prev_frame;
158 
159     uint16_t mb_width;   /* number of horizontal MB */
160     uint16_t mb_height;  /* number of vertical MB */
161     ptrdiff_t linesize;
162     ptrdiff_t uvlinesize;
163 
164     uint8_t keyframe;
165     uint8_t deblock_filter;
166     uint8_t mbskip_enabled;
167     uint8_t profile;
168     VP8mvbounds mv_bounds;
169 
170     int8_t sign_bias[4]; ///< one state [0, 1] per ref frame type
171     int ref_count[3];
172 
173     /**
174      * Base parameters for segmentation, i.e. per-macroblock parameters.
175      * These must be kept unchanged even if segmentation is not used for
176      * a frame, since the values persist between interframes.
177      */
178     struct {
179         uint8_t enabled;
180         uint8_t absolute_vals;
181         uint8_t update_map;
182         uint8_t update_feature_data;
183         int8_t base_quant[4];
184         int8_t filter_level[4];     ///< base loop filter level
185     } segmentation;
186 
187     struct {
188         uint8_t simple;
189         uint8_t level;
190         uint8_t sharpness;
191     } filter;
192 
193     VP8Macroblock *macroblocks;
194 
195     uint8_t *intra4x4_pred_mode_top;
196     uint8_t intra4x4_pred_mode_left[4];
197 
198     /**
199      * Macroblocks can have one of 4 different quants in a frame when
200      * segmentation is enabled.
201      * If segmentation is disabled, only the first segment's values are used.
202      */
203     struct {
204         // [0] - DC qmul  [1] - AC qmul
205         int16_t luma_qmul[2];
206         int16_t luma_dc_qmul[2];    ///< luma dc-only block quant
207         int16_t chroma_qmul[2];
208     } qmat[4];
209 
210     // Raw quantisation values, which may be needed by hwaccel decode.
211     struct {
212         int yac_qi;
213         int ydc_delta;
214         int y2dc_delta;
215         int y2ac_delta;
216         int uvdc_delta;
217         int uvac_delta;
218     } quant;
219 
220     struct {
221         uint8_t enabled;    ///< whether each mb can have a different strength based on mode/ref
222         uint8_t update;
223 
224         /**
225          * filter strength adjustment for the following macroblock modes:
226          * [0-3] - i16x16 (always zero)
227          * [4]   - i4x4
228          * [5]   - zero mv
229          * [6]   - inter modes except for zero or split mv
230          * [7]   - split mv
231          *  i16x16 modes never have any adjustment
232          */
233         int8_t mode[VP8_MVMODE_SPLIT + 1];
234 
235         /**
236          * filter strength adjustment for macroblocks that reference:
237          * [0] - intra / VP56_FRAME_CURRENT
238          * [1] - VP56_FRAME_PREVIOUS
239          * [2] - VP56_FRAME_GOLDEN
240          * [3] - altref / VP56_FRAME_GOLDEN2
241          */
242         int8_t ref[4];
243     } lf_delta;
244 
245     uint8_t (*top_border)[16 + 8 + 8];
246     uint8_t (*top_nnz)[9];
247 
248     VP56RangeCoder c;   ///< header context, includes mb modes and motion vectors
249 
250     /* This contains the entropy coder state at the end of the header
251      * block, in the form specified by the standard.  For use by
252      * hwaccels, so that a hardware decoder has the information to
253      * start decoding at the macroblock layer.
254      */
255     struct {
256         const uint8_t *input;
257         uint32_t range;
258         uint32_t value;
259         int bit_count;
260     } coder_state_at_header_end;
261 
262     int header_partition_size;
263 
264     /**
265      * These are all of the updatable probabilities for binary decisions.
266      * They are only implicitly reset on keyframes, making it quite likely
267      * for an interframe to desync if a prior frame's header was corrupt
268      * or missing outright!
269      */
270     struct {
271         uint8_t segmentid[3];
272         uint8_t mbskip;
273         uint8_t intra;
274         uint8_t last;
275         uint8_t golden;
276         uint8_t pred16x16[4];
277         uint8_t pred8x8c[3];
278         uint8_t token[4][16][3][NUM_DCT_TOKENS - 1];
279         uint8_t mvc[2][19];
280         uint8_t scan[16];
281     } prob[2];
282 
283     VP8Macroblock *macroblocks_base;
284     int invisible;
285     int update_last;    ///< update VP56_FRAME_PREVIOUS with the current one
286     int update_golden;  ///< VP56_FRAME_NONE if not updated, or which frame to copy if so
287     int update_altref;
288 
289     /**
290      * If this flag is not set, all the probability updates
291      * are discarded after this frame is decoded.
292      */
293     int update_probabilities;
294 
295     /**
296      * All coefficients are contained in separate arith coding contexts.
297      * There can be 1, 2, 4, or 8 of these after the header context.
298      */
299     int num_coeff_partitions;
300     VP56RangeCoder coeff_partition[8];
301     int coeff_partition_size[8];
302     VideoDSPContext vdsp;
303     VP8DSPContext vp8dsp;
304     H264PredContext hpc;
305     vp8_mc_func put_pixels_tab[3][3][3];
306     VP8Frame frames[5];
307 
308     uint8_t colorspace; ///< 0 is the only value allowed (meaning bt601)
309     uint8_t fullrange;  ///< whether we can skip clamping in dsp functions
310 
311     int num_jobs;
312     /**
313      * This describes the macroblock memory layout.
314      * 0 -> Only width+height*2+1 macroblocks allocated (frame/single thread).
315      * 1 -> Macroblocks for entire frame allocated (sliced thread).
316      */
317     int mb_layout;
318 
319     int (*decode_mb_row_no_filter)(AVCodecContext *avctx, void *tdata, int jobnr, int threadnr);
320     void (*filter_mb_row)(AVCodecContext *avctx, void *tdata, int jobnr, int threadnr);
321 
322     int vp7;
323 
324     /**
325      * Fade bit present in bitstream (VP7)
326      */
327     int fade_present;
328 
329     /**
330      * Interframe DC prediction (VP7)
331      * [0] VP56_FRAME_PREVIOUS
332      * [1] VP56_FRAME_GOLDEN
333      */
334     uint16_t inter_dc_pred[2][2];
335 
336     /**
337      * Macroblock features (VP7)
338      */
339     uint8_t feature_enabled[4];
340     uint8_t feature_present_prob[4];
341     uint8_t feature_index_prob[4][3];
342     uint8_t feature_value[4][4];
343 } VP8Context;
344 
345 int ff_vp8_decode_init(AVCodecContext *avctx);
346 
347 int ff_vp8_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
348                         AVPacket *avpkt);
349 
350 int ff_vp8_decode_free(AVCodecContext *avctx);
351 
352 #endif /* AVCODEC_VP8_H */
353