xref: /third_party/ffmpeg/libavcodec/vp56.h (revision cabdff1a) 
1/*
2 * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/**
22 * @file
23 * VP5 and VP6 compatible video decoder (common features)
24 */
25
26#ifndef AVCODEC_VP56_H
27#define AVCODEC_VP56_H
28
29#include "libavutil/mem_internal.h"
30
31#include "avcodec.h"
32#include "get_bits.h"
33#include "hpeldsp.h"
34#include "bytestream.h"
35#include "h264chroma.h"
36#include "videodsp.h"
37#include "vp3dsp.h"
38#include "vp56dsp.h"
39
40typedef struct vp56_context VP56Context;
41
42typedef enum {
43    VP56_FRAME_NONE     =-1,
44    VP56_FRAME_CURRENT  = 0,
45    VP56_FRAME_PREVIOUS = 1,
46    VP56_FRAME_GOLDEN   = 2,
47    VP56_FRAME_GOLDEN2  = 3,
48} VP56Frame;
49
50typedef enum {
51    VP56_MB_INTER_NOVEC_PF = 0,  /**< Inter MB, no vector, from previous frame */
52    VP56_MB_INTRA          = 1,  /**< Intra MB */
53    VP56_MB_INTER_DELTA_PF = 2,  /**< Inter MB, above/left vector + delta, from previous frame */
54    VP56_MB_INTER_V1_PF    = 3,  /**< Inter MB, first vector, from previous frame */
55    VP56_MB_INTER_V2_PF    = 4,  /**< Inter MB, second vector, from previous frame */
56    VP56_MB_INTER_NOVEC_GF = 5,  /**< Inter MB, no vector, from golden frame */
57    VP56_MB_INTER_DELTA_GF = 6,  /**< Inter MB, above/left vector + delta, from golden frame */
58    VP56_MB_INTER_4V       = 7,  /**< Inter MB, 4 vectors, from previous frame */
59    VP56_MB_INTER_V1_GF    = 8,  /**< Inter MB, first vector, from golden frame */
60    VP56_MB_INTER_V2_GF    = 9,  /**< Inter MB, second vector, from golden frame */
61} VP56mb;
62
63typedef struct VP56Tree {
64  int8_t val;
65  int8_t prob_idx;
66} VP56Tree;
67
68typedef struct VP56mv {
69    DECLARE_ALIGNED(4, int16_t, x);
70    int16_t y;
71} VP56mv;
72
73#define VP56_SIZE_CHANGE 1
74
75typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,
76                                          VP56mv *vect);
77typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
78                           int offset1, int offset2, ptrdiff_t stride,
79                           VP56mv mv, int mask, int select, int luma);
80typedef int  (*VP56ParseCoeff)(VP56Context *s);
81typedef void (*VP56DefaultModelsInit)(VP56Context *s);
82typedef void (*VP56ParseVectorModels)(VP56Context *s);
83typedef int  (*VP56ParseCoeffModels)(VP56Context *s);
84typedef int  (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
85                                int buf_size);
86
87typedef struct VP56RangeCoder {
88    int high;
89    int bits; /* stored negated (i.e. negative "bits" is a positive number of
90                 bits left) in order to eliminate a negate in cache refilling */
91    const uint8_t *buffer;
92    const uint8_t *end;
93    unsigned int code_word;
94    int end_reached;
95} VP56RangeCoder;
96
97typedef struct VP56RefDc {
98    uint8_t not_null_dc;
99    VP56Frame ref_frame;
100    int16_t dc_coeff;
101} VP56RefDc;
102
103typedef struct VP56Macroblock {
104    uint8_t type;
105    VP56mv mv;
106} VP56Macroblock;
107
108typedef struct VP56Model {
109    uint8_t coeff_reorder[64];       /* used in vp6 only */
110    uint8_t coeff_index_to_pos[64];  /* used in vp6 only */
111    uint8_t coeff_index_to_idct_selector[64]; /* used in vp6 only */
112    uint8_t vector_sig[2];           /* delta sign */
113    uint8_t vector_dct[2];           /* delta coding types */
114    uint8_t vector_pdi[2][2];        /* predefined delta init */
115    uint8_t vector_pdv[2][7];        /* predefined delta values */
116    uint8_t vector_fdv[2][8];        /* 8 bit delta value definition */
117    uint8_t coeff_dccv[2][11];       /* DC coeff value */
118    uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
119    uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
120    uint8_t coeff_dcct[2][36][5];    /* DC coeff coding type */
121    uint8_t coeff_runv[2][14];       /* run value (vp6 only) */
122    uint8_t mb_type[3][10][10];      /* model for decoding MB type */
123    uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
124} VP56Model;
125
126struct vp56_context {
127    AVCodecContext *avctx;
128    H264ChromaContext h264chroma;
129    HpelDSPContext hdsp;
130    VideoDSPContext vdsp;
131    VP3DSPContext vp3dsp;
132    VP56DSPContext vp56dsp;
133    uint8_t idct_scantable[64];
134    AVFrame *frames[4];
135    uint8_t *edge_emu_buffer_alloc;
136    uint8_t *edge_emu_buffer;
137    VP56RangeCoder c;
138    VP56RangeCoder cc;
139    VP56RangeCoder *ccp;
140    int sub_version;
141
142    /* frame info */
143    int golden_frame;
144    int plane_width[4];
145    int plane_height[4];
146    int mb_width;   /* number of horizontal MB */
147    int mb_height;  /* number of vertical MB */
148    int block_offset[6];
149
150    int quantizer;
151    uint16_t dequant_dc;
152    uint16_t dequant_ac;
153
154    /* DC predictors management */
155    VP56RefDc *above_blocks;
156    VP56RefDc left_block[4];
157    int above_block_idx[6];
158    int16_t prev_dc[3][3];    /* [plan][ref_frame] */
159
160    /* blocks / macroblock */
161    VP56mb mb_type;
162    VP56Macroblock *macroblocks;
163    DECLARE_ALIGNED(16, int16_t, block_coeff)[6][64];
164    int idct_selector[6];
165
166    /* motion vectors */
167    VP56mv mv[6];  /* vectors for each block in MB */
168    VP56mv vector_candidate[2];
169    int vector_candidate_pos;
170
171    /* filtering hints */
172    int filter_header;               /* used in vp6 only */
173    int deblock_filtering;
174    int filter_selection;
175    int filter_mode;
176    int max_vector_length;
177    int sample_variance_threshold;
178    DECLARE_ALIGNED(8, int, bounding_values_array)[256];
179
180    uint8_t coeff_ctx[4][64];              /* used in vp5 only */
181    uint8_t coeff_ctx_last[4];             /* used in vp5 only */
182
183    int has_alpha;
184
185    /* upside-down flipping hints */
186    int flip;  /* are we flipping ? */
187    int frbi;  /* first row block index in MB */
188    int srbi;  /* second row block index in MB */
189    ptrdiff_t stride[4];  /* stride for each plan */
190
191    const uint8_t *vp56_coord_div;
192    VP56ParseVectorAdjustment parse_vector_adjustment;
193    VP56Filter filter;
194    VP56ParseCoeff parse_coeff;
195    VP56DefaultModelsInit default_models_init;
196    VP56ParseVectorModels parse_vector_models;
197    VP56ParseCoeffModels parse_coeff_models;
198    VP56ParseHeader parse_header;
199
200    /* for "slice" parallelism between YUV and A */
201    VP56Context *alpha_context;
202
203    VP56Model *modelp;
204    VP56Model model;
205
206    /* huffman decoding */
207    int use_huffman;
208    GetBitContext gb;
209    VLC dccv_vlc[2];
210    VLC runv_vlc[2];
211    VLC ract_vlc[2][3][6];
212    unsigned int nb_null[2][2];       /* number of consecutive NULL DC/AC */
213
214    int have_undamaged_frame;
215    int discard_frame;
216};
217
218
219/**
220 * Initializes an VP56Context. Expects its caller to clean up
221 * in case of error.
222 */
223int ff_vp56_init_context(AVCodecContext *avctx, VP56Context *s,
224                          int flip, int has_alpha);
225int ff_vp56_free_context(VP56Context *s);
226void ff_vp56_init_dequant(VP56Context *s, int quantizer);
227int ff_vp56_decode_frame(AVCodecContext *avctx, AVFrame *frame,
228                         int *got_frame, AVPacket *avpkt);
229
230
231/**
232 * vp56 specific range coder implementation
233 */
234
235extern const uint8_t ff_vp56_norm_shift[256];
236int ff_vp56_init_range_decoder(VP56RangeCoder *c, const uint8_t *buf, int buf_size);
237
238/**
239 * vp5689 returns 1 if the end of the stream has been reached, 0 otherwise.
240 */
241static av_always_inline int vpX_rac_is_end(VP56RangeCoder *c)
242{
243    if (c->end <= c->buffer && c->bits >= 0)
244        c->end_reached ++;
245    return c->end_reached > 10;
246}
247
248static av_always_inline unsigned int vp56_rac_renorm(VP56RangeCoder *c)
249{
250    int shift = ff_vp56_norm_shift[c->high];
251    int bits = c->bits;
252    unsigned int code_word = c->code_word;
253
254    c->high   <<= shift;
255    code_word <<= shift;
256    bits       += shift;
257    if(bits >= 0 && c->buffer < c->end) {
258        code_word |= bytestream_get_be16(&c->buffer) << bits;
259        bits -= 16;
260    }
261    c->bits = bits;
262    return code_word;
263}
264
265#if   ARCH_ARM
266#include "arm/vp56_arith.h"
267#elif ARCH_X86
268#include "x86/vp56_arith.h"
269#endif
270
271#ifndef vp56_rac_get_prob
272#define vp56_rac_get_prob vp56_rac_get_prob
273static av_always_inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob)
274{
275    unsigned int code_word = vp56_rac_renorm(c);
276    unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
277    unsigned int low_shift = low << 16;
278    int bit = code_word >= low_shift;
279
280    c->high = bit ? c->high - low : low;
281    c->code_word = bit ? code_word - low_shift : code_word;
282
283    return bit;
284}
285#endif
286
287#ifndef vp56_rac_get_prob_branchy
288// branchy variant, to be used where there's a branch based on the bit decoded
289static av_always_inline int vp56_rac_get_prob_branchy(VP56RangeCoder *c, int prob)
290{
291    unsigned long code_word = vp56_rac_renorm(c);
292    unsigned low = 1 + (((c->high - 1) * prob) >> 8);
293    unsigned low_shift = low << 16;
294
295    if (code_word >= low_shift) {
296        c->high     -= low;
297        c->code_word = code_word - low_shift;
298        return 1;
299    }
300
301    c->high = low;
302    c->code_word = code_word;
303    return 0;
304}
305#endif
306
307static av_always_inline int vp56_rac_get(VP56RangeCoder *c)
308{
309    unsigned int code_word = vp56_rac_renorm(c);
310    /* equiprobable */
311    int low = (c->high + 1) >> 1;
312    unsigned int low_shift = low << 16;
313    int bit = code_word >= low_shift;
314    if (bit) {
315        c->high   -= low;
316        code_word -= low_shift;
317    } else {
318        c->high = low;
319    }
320
321    c->code_word = code_word;
322    return bit;
323}
324
325// rounding is different than vp56_rac_get, is vp56_rac_get wrong?
326static av_always_inline int vp8_rac_get(VP56RangeCoder *c)
327{
328    return vp56_rac_get_prob(c, 128);
329}
330
331static int vp56_rac_gets(VP56RangeCoder *c, int bits)
332{
333    int value = 0;
334
335    while (bits--) {
336        value = (value << 1) | vp56_rac_get(c);
337    }
338
339    return value;
340}
341
342static int vp8_rac_get_uint(VP56RangeCoder *c, int bits)
343{
344    int value = 0;
345
346    while (bits--) {
347        value = (value << 1) | vp8_rac_get(c);
348    }
349
350    return value;
351}
352
353// fixme: add 1 bit to all the calls to this?
354static av_unused int vp8_rac_get_sint(VP56RangeCoder *c, int bits)
355{
356    int v;
357
358    if (!vp8_rac_get(c))
359        return 0;
360
361    v = vp8_rac_get_uint(c, bits);
362
363    if (vp8_rac_get(c))
364        v = -v;
365
366    return v;
367}
368
369// P(7)
370static av_unused int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)
371{
372    int v = vp56_rac_gets(c, 7) << 1;
373    return v + !v;
374}
375
376static av_unused int vp8_rac_get_nn(VP56RangeCoder *c)
377{
378    int v = vp8_rac_get_uint(c, 7) << 1;
379    return v + !v;
380}
381
382static av_always_inline
383int vp56_rac_get_tree(VP56RangeCoder *c,
384                      const VP56Tree *tree,
385                      const uint8_t *probs)
386{
387    while (tree->val > 0) {
388        if (vp56_rac_get_prob_branchy(c, probs[tree->prob_idx]))
389            tree += tree->val;
390        else
391            tree++;
392    }
393    return -tree->val;
394}
395
396// how probabilities are associated with decisions is different I think
397// well, the new scheme fits in the old but this way has one fewer branches per decision
398static av_always_inline int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
399                                   const uint8_t *probs)
400{
401    int i = 0;
402
403    do {
404        i = tree[i][vp56_rac_get_prob(c, probs[i])];
405    } while (i > 0);
406
407    return -i;
408}
409
410// DCTextra
411static av_always_inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)
412{
413    int v = 0;
414
415    do {
416        v = (v<<1) + vp56_rac_get_prob(c, *prob++);
417    } while (*prob);
418
419    return v;
420}
421
422#endif /* AVCODEC_VP56_H */
423