aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/hevc_parser.c
blob: dc63c6b95433bf3e13dbd84fa35ef914dc04f980 (plain) (blame)
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
/*
 * HEVC Annex B format parser
 *
 * Copyright (C) 2012 - 2013 Guillaume Martres
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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.
 *
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "libavutil/common.h"

#include "golomb.h"
#include "hevc.h"
#include "hevc_ps.h"
#include "hevc_sei.h"
#include "h2645_parse.h"
#include "internal.h"
#include "parser.h"

#define START_CODE 0x000001 ///< start_code_prefix_one_3bytes

#define IS_IRAP_NAL(nal) (nal->type >= 16 && nal->type <= 23)
#define IS_IDR_NAL(nal) (nal->type == HEVC_NAL_IDR_W_RADL || nal->type == HEVC_NAL_IDR_N_LP)

typedef struct HEVCParserContext {
    ParseContext pc;

    H2645Packet pkt;
    HEVCParamSets ps;
    HEVCSEIContext sei;
    SliceHeader sh;

    int parsed_extradata;

    int poc;
    int pocTid0;
} HEVCParserContext;

static int hevc_parse_slice_header(AVCodecParserContext *s, H2645NAL *nal,
                                   AVCodecContext *avctx)
{
    HEVCParserContext *ctx = s->priv_data;
    HEVCParamSets *ps = &ctx->ps;
    HEVCSEIContext *sei = &ctx->sei;
    SliceHeader *sh = &ctx->sh;
    GetBitContext *gb = &nal->gb;
    const HEVCWindow *ow;
    int i, num = 0, den = 0;

    sh->first_slice_in_pic_flag = get_bits1(gb);
    s->picture_structure = sei->picture_timing.picture_struct;
    s->field_order = sei->picture_timing.picture_struct;

    if (IS_IRAP_NAL(nal)) {
        s->key_frame = 1;
        sh->no_output_of_prior_pics_flag = get_bits1(gb);
    }

    sh->pps_id = get_ue_golomb(gb);
    if (sh->pps_id >= HEVC_MAX_PPS_COUNT || !ps->pps_list[sh->pps_id]) {
        av_log(avctx, AV_LOG_ERROR, "PPS id out of range: %d\n", sh->pps_id);
        return AVERROR_INVALIDDATA;
    }
    ps->pps = (HEVCPPS*)ps->pps_list[sh->pps_id]->data;

    if (ps->pps->sps_id >= HEVC_MAX_SPS_COUNT || !ps->sps_list[ps->pps->sps_id]) {
        av_log(avctx, AV_LOG_ERROR, "SPS id out of range: %d\n", ps->pps->sps_id);
        return AVERROR_INVALIDDATA;
    }
    if (ps->sps != (HEVCSPS*)ps->sps_list[ps->pps->sps_id]->data) {
        ps->sps = (HEVCSPS*)ps->sps_list[ps->pps->sps_id]->data;
        ps->vps = (HEVCVPS*)ps->vps_list[ps->sps->vps_id]->data;
    }
    ow  = &ps->sps->output_window;

    s->coded_width  = ps->sps->width;
    s->coded_height = ps->sps->height;
    s->width        = ps->sps->width  - ow->left_offset - ow->right_offset;
    s->height       = ps->sps->height - ow->top_offset  - ow->bottom_offset;
    s->format       = ps->sps->pix_fmt;
    avctx->profile  = ps->sps->ptl.general_ptl.profile_idc;
    avctx->level    = ps->sps->ptl.general_ptl.level_idc;

    if (ps->vps->vps_timing_info_present_flag) {
        num = ps->vps->vps_num_units_in_tick;
        den = ps->vps->vps_time_scale;
    } else if (ps->sps->vui.vui_timing_info_present_flag) {
        num = ps->sps->vui.vui_num_units_in_tick;
        den = ps->sps->vui.vui_time_scale;
    }

    if (num != 0 && den != 0)
        av_reduce(&avctx->framerate.den, &avctx->framerate.num,
                  num, den, 1 << 30);

    if (!sh->first_slice_in_pic_flag) {
        int slice_address_length;

        if (ps->pps->dependent_slice_segments_enabled_flag)
            sh->dependent_slice_segment_flag = get_bits1(gb);
        else
            sh->dependent_slice_segment_flag = 0;

        slice_address_length = av_ceil_log2_c(ps->sps->ctb_width *
                                              ps->sps->ctb_height);
        sh->slice_segment_addr = get_bitsz(gb, slice_address_length);
        if (sh->slice_segment_addr >= ps->sps->ctb_width * ps->sps->ctb_height) {
            av_log(avctx, AV_LOG_ERROR, "Invalid slice segment address: %u.\n",
                   sh->slice_segment_addr);
            return AVERROR_INVALIDDATA;
        }
    } else
        sh->dependent_slice_segment_flag = 0;

    if (sh->dependent_slice_segment_flag)
        return 0; /* break; */

    for (i = 0; i < ps->pps->num_extra_slice_header_bits; i++)
        skip_bits(gb, 1); // slice_reserved_undetermined_flag[]

    sh->slice_type = get_ue_golomb(gb);
    if (!(sh->slice_type == HEVC_SLICE_I || sh->slice_type == HEVC_SLICE_P ||
          sh->slice_type == HEVC_SLICE_B)) {
        av_log(avctx, AV_LOG_ERROR, "Unknown slice type: %d.\n",
               sh->slice_type);
        return AVERROR_INVALIDDATA;
    }
    s->pict_type = sh->slice_type == HEVC_SLICE_B ? AV_PICTURE_TYPE_B :
                   sh->slice_type == HEVC_SLICE_P ? AV_PICTURE_TYPE_P :
                                               AV_PICTURE_TYPE_I;

    if (ps->pps->output_flag_present_flag)
        sh->pic_output_flag = get_bits1(gb);

    if (ps->sps->separate_colour_plane_flag)
        sh->colour_plane_id = get_bits(gb, 2);

    if (!IS_IDR_NAL(nal)) {
        sh->pic_order_cnt_lsb = get_bits(gb, ps->sps->log2_max_poc_lsb);
        s->output_picture_number = ctx->poc = ff_hevc_compute_poc(ps->sps, ctx->pocTid0, sh->pic_order_cnt_lsb, nal->type);
    } else
        s->output_picture_number = ctx->poc = 0;

    if (nal->temporal_id == 0 &&
        nal->type != HEVC_NAL_TRAIL_N &&
        nal->type != HEVC_NAL_TSA_N &&
        nal->type != HEVC_NAL_STSA_N &&
        nal->type != HEVC_NAL_RADL_N &&
        nal->type != HEVC_NAL_RASL_N &&
        nal->type != HEVC_NAL_RADL_R &&
        nal->type != HEVC_NAL_RASL_R)
        ctx->pocTid0 = ctx->poc;

    return 1; /* no need to evaluate the rest */
}

/**
 * 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 int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
                           int buf_size, AVCodecContext *avctx)
{
    HEVCParserContext *ctx = s->priv_data;
    HEVCParamSets *ps = &ctx->ps;
    HEVCSEIContext *sei = &ctx->sei;
    int is_global = buf == avctx->extradata;
    int ret, i;

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

    ff_hevc_reset_sei(sei);

    ret = ff_h2645_packet_split(&ctx->pkt, buf, buf_size, avctx, 0, 0,
                                AV_CODEC_ID_HEVC, 1);
    if (ret < 0)
        return ret;

    for (i = 0; i < ctx->pkt.nb_nals; i++) {
        H2645NAL *nal = &ctx->pkt.nals[i];
        GetBitContext *gb = &nal->gb;

        switch (nal->type) {
        case HEVC_NAL_VPS:
            ff_hevc_decode_nal_vps(gb, avctx, ps);
            break;
        case HEVC_NAL_SPS:
            ff_hevc_decode_nal_sps(gb, avctx, ps, 1);
            break;
        case HEVC_NAL_PPS:
            ff_hevc_decode_nal_pps(gb, avctx, ps);
            break;
        case HEVC_NAL_SEI_PREFIX:
        case HEVC_NAL_SEI_SUFFIX:
            ff_hevc_decode_nal_sei(gb, avctx, sei, ps, nal->type);
            break;
        case HEVC_NAL_TRAIL_N:
        case HEVC_NAL_TRAIL_R:
        case HEVC_NAL_TSA_N:
        case HEVC_NAL_TSA_R:
        case HEVC_NAL_STSA_N:
        case HEVC_NAL_STSA_R:
        case HEVC_NAL_BLA_W_LP:
        case HEVC_NAL_BLA_W_RADL:
        case HEVC_NAL_BLA_N_LP:
        case HEVC_NAL_IDR_W_RADL:
        case HEVC_NAL_IDR_N_LP:
        case HEVC_NAL_CRA_NUT:
        case HEVC_NAL_RADL_N:
        case HEVC_NAL_RADL_R:
        case HEVC_NAL_RASL_N:
        case HEVC_NAL_RASL_R:

            if (is_global) {
                av_log(avctx, AV_LOG_ERROR, "Invalid NAL unit: %d\n", nal->type);
                return AVERROR_INVALIDDATA;
            }

            ret = hevc_parse_slice_header(s, nal, avctx);
            if (ret)
                return ret;
            break;
        }
    }
    /* didn't find a picture! */
    if (!is_global)
        av_log(avctx, AV_LOG_ERROR, "missing picture in access unit\n");
    return -1;
}

/**
 * Find the end of the current frame in the bitstream.
 * @return the position of the first byte of the next frame, or END_NOT_FOUND
 */
static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
                               int buf_size)
{
    HEVCParserContext *ctx = s->priv_data;
    ParseContext       *pc = &ctx->pc;
    int i;

    for (i = 0; i < buf_size; i++) {
        int nut;

        pc->state64 = (pc->state64 << 8) | buf[i];

        if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)
            continue;

        nut = (pc->state64 >> 2 * 8 + 1) & 0x3F;
        // Beginning of access unit
        if ((nut >= HEVC_NAL_VPS && nut <= HEVC_NAL_EOB_NUT) || nut == HEVC_NAL_SEI_PREFIX ||
            (nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {
            if (pc->frame_start_found) {
                pc->frame_start_found = 0;
                return i - 5;
            }
        } else if (nut <= HEVC_NAL_RASL_R ||
                   (nut >= HEVC_NAL_BLA_W_LP && nut <= HEVC_NAL_CRA_NUT)) {
            int first_slice_segment_in_pic_flag = buf[i] >> 7;
            if (first_slice_segment_in_pic_flag) {
                if (!pc->frame_start_found) {
                    pc->frame_start_found = 1;
                } else { // First slice of next frame found
                    pc->frame_start_found = 0;
                    return i - 5;
                }
            }
        }
    }

    return END_NOT_FOUND;
}

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

    if (avctx->extradata && !ctx->parsed_extradata) {
        parse_nal_units(s, avctx->extradata, avctx->extradata_size, avctx);
        ctx->parsed_extradata = 1;
    }

    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
        next = buf_size;
    } else {
        next = hevc_find_frame_end(s, buf, buf_size);
        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
            *poutbuf      = NULL;
            *poutbuf_size = 0;
            return buf_size;
        }
    }

    parse_nal_units(s, buf, buf_size, avctx);

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

// Split after the parameter sets at the beginning of the stream if they exist.
static int hevc_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
{
    const uint8_t *ptr = buf, *end = buf + buf_size;
    uint32_t state = -1;
    int has_vps = 0;
    int has_sps = 0;
    int has_pps = 0;
    int nut;

    while (ptr < end) {
        ptr = avpriv_find_start_code(ptr, end, &state);
        if ((state >> 8) != START_CODE)
            break;
        nut = (state >> 1) & 0x3F;
        if (nut == HEVC_NAL_VPS)
            has_vps = 1;
        else if (nut == HEVC_NAL_SPS)
            has_sps = 1;
        else if (nut == HEVC_NAL_PPS)
            has_pps = 1;
        else if ((nut != HEVC_NAL_SEI_PREFIX || has_pps) &&
                  nut != HEVC_NAL_AUD) {
            if (has_vps && has_sps) {
                while (ptr - 4 > buf && ptr[-5] == 0)
                    ptr--;
                return ptr - 4 - buf;
            }
        }
    }
    return 0;
}

static void hevc_parser_close(AVCodecParserContext *s)
{
    HEVCParserContext *ctx = s->priv_data;
    int i;

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

    ctx->ps.sps = NULL;

    ff_h2645_packet_uninit(&ctx->pkt);
    ff_hevc_reset_sei(&ctx->sei);

    av_freep(&ctx->pc.buffer);
}

AVCodecParser ff_hevc_parser = {
    .codec_ids      = { AV_CODEC_ID_HEVC },
    .priv_data_size = sizeof(HEVCParserContext),
    .parser_parse   = hevc_parse,
    .parser_close   = hevc_parser_close,
    .split          = hevc_split,
};