summaryrefslogtreecommitdiff
path: root/libavcodec/h264_parser.c
blob: 99ced4a8efb2a1c9f230882e638038ae04e51742 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
/*
 * H.26L/H.264/AVC/JVT/14496-10/... parser
 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * H.264 / AVC / MPEG4 part10 parser.
 * @author Michael Niedermayer <michaelni@gmx.at>
 */

#include <assert.h>
#include <stdint.h>

#include "libavutil/avutil.h"
#include "libavutil/error.h"
#include "libavutil/log.h"
#include "libavutil/mem.h"
#include "libavutil/pixfmt.h"

#include "get_bits.h"
#include "golomb.h"
#include "h264.h"
#include "h264_sei.h"
#include "h264data.h"
#include "internal.h"
#include "mpegutils.h"
#include "parser.h"

typedef struct H264ParseContext {
    ParseContext pc;
    H264ParamSets ps;
    H264DSPContext h264dsp;
    H264POCContext poc;
    H264SEIContext sei;
    int is_avc;
    int nal_length_size;
    int got_first;
    int picture_structure;
} H264ParseContext;


static int h264_find_frame_end(H264ParseContext *p, const uint8_t *buf,
                               int buf_size)
{
    int i;
    uint32_t state;
    ParseContext *pc = &p->pc;
//    mb_addr= pc->mb_addr - 1;
    state = pc->state;
    if (state > 13)
        state = 7;

    for (i = 0; i < buf_size; i++) {
        if (state == 7) {
            i += p->h264dsp.startcode_find_candidate(buf + i, buf_size - i);
            if (i < buf_size)
                state = 2;
        } else if (state <= 2) {
            if (buf[i] == 1)
                state ^= 5;            // 2->7, 1->4, 0->5
            else if (buf[i])
                state = 7;
            else
                state >>= 1;           // 2->1, 1->0, 0->0
        } else if (state <= 5) {
            int nalu_type = buf[i] & 0x1F;
            if (nalu_type == NAL_SEI || nalu_type == NAL_SPS ||
                nalu_type == NAL_PPS || nalu_type == NAL_AUD) {
                if (pc->frame_start_found) {
                    i++;
                    goto found;
                }
            } else if (nalu_type == NAL_SLICE || nalu_type == NAL_DPA ||
                       nalu_type == NAL_IDR_SLICE) {
                if (pc->frame_start_found) {
                    state += 8;
                    continue;
                } else
                    pc->frame_start_found = 1;
            }
            state = 7;
        } else {
            // first_mb_in_slice is 0, probably the first nal of a new slice
            if (buf[i] & 0x80)
                goto found;
            state = 7;
        }
    }
    pc->state = state;
    return END_NOT_FOUND;

found:
    pc->state             = 7;
    pc->frame_start_found = 0;
    return i - (state & 5);
}

static int scan_mmco_reset(AVCodecParserContext *s, GetBitContext *gb,
                           AVCodecContext *avctx)
{
    H264PredWeightTable pwt;
    int slice_type_nos = s->pict_type & 3;
    H264ParseContext *p = s->priv_data;
    int list_count, ref_count[2];


    if (p->ps.pps->redundant_pic_cnt_present)
        get_ue_golomb(gb); // redundant_pic_count

    if (slice_type_nos == AV_PICTURE_TYPE_B)
        get_bits1(gb); // direct_spatial_mv_pred

    if (ff_h264_parse_ref_count(&list_count, ref_count, gb, p->ps.pps,
                                slice_type_nos, p->picture_structure) < 0)
        return AVERROR_INVALIDDATA;

    if (slice_type_nos != AV_PICTURE_TYPE_I) {
        int list;
        for (list = 0; list < list_count; list++) {
            if (get_bits1(gb)) {
                int index;
                for (index = 0; ; index++) {
                    unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(gb);

                    if (reordering_of_pic_nums_idc < 3)
                        get_ue_golomb(gb);
                    else if (reordering_of_pic_nums_idc > 3) {
                        av_log(avctx, AV_LOG_ERROR,
                               "illegal reordering_of_pic_nums_idc %d\n",
                               reordering_of_pic_nums_idc);
                        return AVERROR_INVALIDDATA;
                    } else
                        break;

                    if (index >= ref_count[list]) {
                        av_log(avctx, AV_LOG_ERROR,
                               "reference count %d overflow\n", index);
                        return AVERROR_INVALIDDATA;
                    }
                }
            }
        }
    }

    if ((p->ps.pps->weighted_pred && slice_type_nos == AV_PICTURE_TYPE_P) ||
        (p->ps.pps->weighted_bipred_idc == 1 && slice_type_nos == AV_PICTURE_TYPE_B))
        ff_h264_pred_weight_table(gb, p->ps.sps, ref_count, slice_type_nos,
                                  &pwt);

    if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
        int i;
        for (i = 0; i < MAX_MMCO_COUNT; i++) {
            MMCOOpcode opcode = get_ue_golomb_31(gb);
            if (opcode > (unsigned) MMCO_LONG) {
                av_log(avctx, AV_LOG_ERROR,
                       "illegal memory management control operation %d\n",
                       opcode);
                return AVERROR_INVALIDDATA;
            }
            if (opcode == MMCO_END)
               return 0;
            else if (opcode == MMCO_RESET)
                return 1;

            if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG)
                get_ue_golomb(gb);
            if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED ||
                opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG)
                get_ue_golomb_31(gb);
        }
    }

    return 0;
}

/**
 * Parse NAL units of found picture and decode some basic information.
 *
 * @param s parser context.
 * @param avctx codec context.
 * @param buf buffer with field/frame data.
 * @param buf_size size of the buffer.
 */
static inline int parse_nal_units(AVCodecParserContext *s,
                                  AVCodecContext *avctx,
                                  const uint8_t *buf, int buf_size)
{
    H264ParseContext *p = s->priv_data;
    const uint8_t *buf_end = buf + buf_size;

    H2645NAL nal = { NULL };

    unsigned int pps_id;
    unsigned int slice_type;
    int state = -1, got_reset = 0;
    int field_poc[2];
    int ret;

    /* set some sane default values */
    s->pict_type         = AV_PICTURE_TYPE_I;
    s->key_frame         = 0;
    s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;

    ff_h264_sei_uninit(&p->sei);

    if (!buf_size)
        return 0;

    for (;;) {
        const SPS *sps;
        int src_length, consumed;
        buf = avpriv_find_start_code(buf, buf_end, &state);
        if (buf >= buf_end)
            break;
        --buf;
        src_length = buf_end - buf;
        switch (state & 0x1f) {
        case NAL_SLICE:
        case NAL_IDR_SLICE:
            // Do not walk the whole buffer just to decode slice header
            if ((state & 0x1f) == NAL_IDR_SLICE || ((state >> 5) & 0x3) == 0) {
                /* IDR or disposable slice
                 * No need to decode many bytes because MMCOs shall not be present. */
                if (src_length > 60)
                    src_length = 60;
            } else {
                /* To decode up to MMCOs */
                if (src_length > 1000)
                    src_length = 1000;
            }
            break;
        }

        consumed = ff_h2645_extract_rbsp(buf, src_length, &nal);
        if (consumed < 0)
            break;

        ret = init_get_bits(&nal.gb, nal.data, nal.size * 8);
        if (ret < 0)
            goto fail;
        get_bits1(&nal.gb);
        nal.ref_idc = get_bits(&nal.gb, 2);
        nal.type    = get_bits(&nal.gb, 5);

        switch (nal.type) {
        case NAL_SPS:
            ff_h264_decode_seq_parameter_set(&nal.gb, avctx, &p->ps);
            break;
        case NAL_PPS:
            ff_h264_decode_picture_parameter_set(&nal.gb, avctx, &p->ps,
                                                 nal.size_bits);
            break;
        case NAL_SEI:
            ff_h264_sei_decode(&p->sei, &nal.gb, &p->ps, avctx);
            break;
        case NAL_IDR_SLICE:
            s->key_frame = 1;

            p->poc.prev_frame_num        = 0;
            p->poc.prev_frame_num_offset = 0;
            p->poc.prev_poc_msb          =
            p->poc.prev_poc_lsb          = 0;
        /* fall through */
        case NAL_SLICE:
            get_ue_golomb(&nal.gb);  // skip first_mb_in_slice
            slice_type   = get_ue_golomb_31(&nal.gb);
            s->pict_type = ff_h264_golomb_to_pict_type[slice_type % 5];
            if (p->sei.recovery_point.recovery_frame_cnt >= 0) {
                /* key frame, since recovery_frame_cnt is set */
                s->key_frame = 1;
            }
            pps_id = get_ue_golomb(&nal.gb);
            if (pps_id >= MAX_PPS_COUNT) {
                av_log(avctx, AV_LOG_ERROR,
                       "pps_id %u out of range\n", pps_id);
                goto fail;
            }
            if (!p->ps.pps_list[pps_id]) {
                av_log(avctx, AV_LOG_ERROR,
                       "non-existing PPS %u referenced\n", pps_id);
                goto fail;
            }
            p->ps.pps = (const PPS*)p->ps.pps_list[pps_id]->data;
            if (!p->ps.sps_list[p->ps.pps->sps_id]) {
                av_log(avctx, AV_LOG_ERROR,
                       "non-existing SPS %u referenced\n", p->ps.pps->sps_id);
                goto fail;
            }
            p->ps.sps = (SPS*)p->ps.sps_list[p->ps.pps->sps_id]->data;

            sps = p->ps.sps;

            p->poc.frame_num = get_bits(&nal.gb, sps->log2_max_frame_num);

            s->coded_width  = 16 * sps->mb_width;
            s->coded_height = 16 * sps->mb_height;
            s->width        = s->coded_width  - (sps->crop_right + sps->crop_left);
            s->height       = s->coded_height - (sps->crop_top   + sps->crop_bottom);
            if (s->width <= 0 || s->height <= 0) {
                s->width  = s->coded_width;
                s->height = s->coded_height;
            }

            switch (sps->bit_depth_luma) {
            case 9:
                if (sps->chroma_format_idc == 3)      s->format = AV_PIX_FMT_YUV444P9;
                else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P9;
                else                                  s->format = AV_PIX_FMT_YUV420P9;
                break;
            case 10:
                if (sps->chroma_format_idc == 3)      s->format = AV_PIX_FMT_YUV444P10;
                else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P10;
                else                                  s->format = AV_PIX_FMT_YUV420P10;
                break;
            case 8:
                if (sps->chroma_format_idc == 3)      s->format = AV_PIX_FMT_YUV444P;
                else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P;
                else                                  s->format = AV_PIX_FMT_YUV420P;
                break;
            default:
                s->format = AV_PIX_FMT_NONE;
            }

            avctx->profile = ff_h264_get_profile(sps);
            avctx->level   = sps->level_idc;

            if (sps->frame_mbs_only_flag) {
                p->picture_structure = PICT_FRAME;
            } else {
                if (get_bits1(&nal.gb)) { // field_pic_flag
                    p->picture_structure = PICT_TOP_FIELD + get_bits1(&nal.gb); // bottom_field_flag
                } else {
                    p->picture_structure = PICT_FRAME;
                }
            }

            if (nal.type == NAL_IDR_SLICE)
                get_ue_golomb(&nal.gb); /* idr_pic_id */
            if (sps->poc_type == 0) {
                p->poc.poc_lsb = get_bits(&nal.gb, sps->log2_max_poc_lsb);

                if (p->ps.pps->pic_order_present == 1 &&
                    p->picture_structure == PICT_FRAME)
                    p->poc.delta_poc_bottom = get_se_golomb(&nal.gb);
            }

            if (sps->poc_type == 1 &&
                !sps->delta_pic_order_always_zero_flag) {
                p->poc.delta_poc[0] = get_se_golomb(&nal.gb);

                if (p->ps.pps->pic_order_present == 1 &&
                    p->picture_structure == PICT_FRAME)
                    p->poc.delta_poc[1] = get_se_golomb(&nal.gb);
            }

            /* Decode POC of this picture.
             * The prev_ values needed for decoding POC of the next picture are not set here. */
            field_poc[0] = field_poc[1] = INT_MAX;
            ff_h264_init_poc(field_poc, &s->output_picture_number, sps,
                             &p->poc, p->picture_structure, nal.ref_idc);

            /* Continue parsing to check if MMCO_RESET is present.
             * FIXME: MMCO_RESET could appear in non-first slice.
             *        Maybe, we should parse all undisposable non-IDR slice of this
             *        picture until encountering MMCO_RESET in a slice of it. */
            if (nal.ref_idc && nal.type != NAL_IDR_SLICE) {
                got_reset = scan_mmco_reset(s, &nal.gb, avctx);
                if (got_reset < 0)
                    goto fail;
            }

            /* Set up the prev_ values for decoding POC of the next picture. */
            p->poc.prev_frame_num        = got_reset ? 0 : p->poc.frame_num;
            p->poc.prev_frame_num_offset = got_reset ? 0 : p->poc.frame_num_offset;
            if (nal.ref_idc != 0) {
                if (!got_reset) {
                    p->poc.prev_poc_msb = p->poc.poc_msb;
                    p->poc.prev_poc_lsb = p->poc.poc_lsb;
                } else {
                    p->poc.prev_poc_msb = 0;
                    p->poc.prev_poc_lsb =
                        p->picture_structure == PICT_BOTTOM_FIELD ? 0 : field_poc[0];
                }
            }

            if (sps->pic_struct_present_flag) {
                switch (p->sei.picture_timing.pic_struct) {
                case SEI_PIC_STRUCT_TOP_FIELD:
                case SEI_PIC_STRUCT_BOTTOM_FIELD:
                    s->repeat_pict = 0;
                    break;
                case SEI_PIC_STRUCT_FRAME:
                case SEI_PIC_STRUCT_TOP_BOTTOM:
                case SEI_PIC_STRUCT_BOTTOM_TOP:
                    s->repeat_pict = 1;
                    break;
                case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
                case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
                    s->repeat_pict = 2;
                    break;
                case SEI_PIC_STRUCT_FRAME_DOUBLING:
                    s->repeat_pict = 3;
                    break;
                case SEI_PIC_STRUCT_FRAME_TRIPLING:
                    s->repeat_pict = 5;
                    break;
                default:
                    s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
                    break;
                }
            } else {
                s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
            }

            if (p->picture_structure == PICT_FRAME) {
                s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
                if (sps->pic_struct_present_flag) {
                    switch (p->sei.picture_timing.pic_struct) {
                    case SEI_PIC_STRUCT_TOP_BOTTOM:
                    case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
                        s->field_order = AV_FIELD_TT;
                        break;
                    case SEI_PIC_STRUCT_BOTTOM_TOP:
                    case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
                        s->field_order = AV_FIELD_BB;
                        break;
                    default:
                        s->field_order = AV_FIELD_PROGRESSIVE;
                        break;
                    }
                } else {
                    if (field_poc[0] < field_poc[1])
                        s->field_order = AV_FIELD_TT;
                    else if (field_poc[0] > field_poc[1])
                        s->field_order = AV_FIELD_BB;
                    else
                        s->field_order = AV_FIELD_PROGRESSIVE;
                }
            } else {
                if (p->picture_structure == PICT_TOP_FIELD)
                    s->picture_structure = AV_PICTURE_STRUCTURE_TOP_FIELD;
                else
                    s->picture_structure = AV_PICTURE_STRUCTURE_BOTTOM_FIELD;
                s->field_order = AV_FIELD_UNKNOWN;
            }

            av_freep(&nal.rbsp_buffer);
            return 0; /* no need to evaluate the rest */
        }
        buf += consumed;
    }
    /* didn't find a picture! */
    av_log(avctx, AV_LOG_ERROR, "missing picture in access unit\n");
fail:
    av_freep(&nal.rbsp_buffer);
    return -1;
}

static int h264_parse(AVCodecParserContext *s,
                      AVCodecContext *avctx,
                      const uint8_t **poutbuf, int *poutbuf_size,
                      const uint8_t *buf, int buf_size)
{
    H264ParseContext *p = s->priv_data;
    ParseContext *pc = &p->pc;
    int next;

    if (!p->got_first) {
        p->got_first = 1;
        if (avctx->extradata_size) {
            ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
                                     &p->ps, &p->is_avc, &p->nal_length_size,
                                     avctx->err_recognition, avctx);
        }
    }

    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
        next = buf_size;
    } else {
        next = h264_find_frame_end(p, buf, buf_size);

        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
            *poutbuf      = NULL;
            *poutbuf_size = 0;
            return buf_size;
        }

        if (next < 0 && next != END_NOT_FOUND) {
            assert(pc->last_index + next >= 0);
            h264_find_frame_end(p, &pc->buffer[pc->last_index + next], -next); // update state
        }
    }

    parse_nal_units(s, avctx, buf, buf_size);

    if (p->sei.picture_timing.cpb_removal_delay >= 0) {
        s->dts_sync_point    = p->sei.buffering_period.present;
        s->dts_ref_dts_delta = p->sei.picture_timing.cpb_removal_delay;
        s->pts_dts_delta     = p->sei.picture_timing.dpb_output_delay;
    } else {
        s->dts_sync_point    = INT_MIN;
        s->dts_ref_dts_delta = INT_MIN;
        s->pts_dts_delta     = INT_MIN;
    }

    if (s->flags & PARSER_FLAG_ONCE) {
        s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
    }

    *poutbuf      = buf;
    *poutbuf_size = buf_size;
    return next;
}

static int h264_split(AVCodecContext *avctx,
                      const uint8_t *buf, int buf_size)
{
    int i;
    uint32_t state = -1;
    int has_sps    = 0;

    for (i = 0; i <= buf_size; i++) {
        if ((state & 0xFFFFFF1F) == 0x107)
            has_sps = 1;
        /*  if((state&0xFFFFFF1F) == 0x101 ||
         *     (state&0xFFFFFF1F) == 0x102 ||
         *     (state&0xFFFFFF1F) == 0x105) {
         *  }
         */
        if ((state & 0xFFFFFF00) == 0x100 && (state & 0xFFFFFF1F) != 0x106 &&
            (state & 0xFFFFFF1F) != 0x107 && (state & 0xFFFFFF1F) != 0x108 &&
            (state & 0xFFFFFF1F) != 0x109 && (state & 0xFFFFFF1F) != 0x10d &&
            (state & 0xFFFFFF1F) != 0x10f) {
            if (has_sps) {
                while (i > 4 && buf[i - 5] == 0)
                    i--;
                return i - 4;
            }
        }
        if (i < buf_size)
            state = (state << 8) | buf[i];
    }
    return 0;
}

static void h264_close(AVCodecParserContext *s)
{
    H264ParseContext *p = s->priv_data;
    ParseContext *pc = &p->pc;
    int i;

    av_free(pc->buffer);

    ff_h264_sei_uninit(&p->sei);

    for (i = 0; i < FF_ARRAY_ELEMS(p->ps.sps_list); i++)
        av_buffer_unref(&p->ps.sps_list[i]);

    for (i = 0; i < FF_ARRAY_ELEMS(p->ps.pps_list); i++)
        av_buffer_unref(&p->ps.pps_list[i]);
}

static av_cold int init(AVCodecParserContext *s)
{
    H264ParseContext *p = s->priv_data;

    ff_h264dsp_init(&p->h264dsp, 8, 1);
    return 0;
}

AVCodecParser ff_h264_parser = {
    .codec_ids      = { AV_CODEC_ID_H264 },
    .priv_data_size = sizeof(H264ParseContext),
    .parser_init    = init,
    .parser_parse   = h264_parse,
    .parser_close   = h264_close,
    .split          = h264_split,
};