1/*
2 * HEVC Annex B format parser
3 *
4 * Copyright (C) 2012 - 2013 Guillaume Martres
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#include "libavutil/common.h"
24
25#include "golomb.h"
26#include "hevc.h"
27#include "hevc_parse.h"
28#include "hevc_ps.h"
29#include "hevc_sei.h"
30#include "h2645_parse.h"
31#include "parser.h"
32
33#define START_CODE 0x000001 ///< start_code_prefix_one_3bytes
34
35#define IS_IRAP_NAL(nal) (nal->type >= 16 && nal->type <= 23)
36#define IS_IDR_NAL(nal) (nal->type == HEVC_NAL_IDR_W_RADL || nal->type == HEVC_NAL_IDR_N_LP)
37
38typedef struct HEVCParserContext {
39    ParseContext pc;
40
41    H2645Packet pkt;
42    HEVCParamSets ps;
43    HEVCSEI sei;
44
45    int is_avc;
46    int nal_length_size;
47    int parsed_extradata;
48
49    int poc;
50    int pocTid0;
51} HEVCParserContext;
52
53static int hevc_parse_slice_header(AVCodecParserContext *s, H2645NAL *nal,
54                                   AVCodecContext *avctx)
55{
56    HEVCParserContext *ctx = s->priv_data;
57    HEVCParamSets *ps = &ctx->ps;
58    HEVCSEI *sei = &ctx->sei;
59    GetBitContext *gb = &nal->gb;
60    const HEVCWindow *ow;
61    int i, num = 0, den = 0;
62
63    unsigned int pps_id, first_slice_in_pic_flag, dependent_slice_segment_flag;
64    enum HEVCSliceType slice_type;
65
66    first_slice_in_pic_flag = get_bits1(gb);
67    s->picture_structure = sei->picture_timing.picture_struct;
68    s->field_order = sei->picture_timing.picture_struct;
69
70    if (IS_IRAP_NAL(nal)) {
71        s->key_frame = 1;
72        skip_bits1(gb); // no_output_of_prior_pics_flag
73    }
74
75    pps_id = get_ue_golomb(gb);
76    if (pps_id >= HEVC_MAX_PPS_COUNT || !ps->pps_list[pps_id]) {
77        av_log(avctx, AV_LOG_ERROR, "PPS id out of range: %d\n", pps_id);
78        return AVERROR_INVALIDDATA;
79    }
80    ps->pps = (HEVCPPS*)ps->pps_list[pps_id]->data;
81
82    if (ps->pps->sps_id >= HEVC_MAX_SPS_COUNT || !ps->sps_list[ps->pps->sps_id]) {
83        av_log(avctx, AV_LOG_ERROR, "SPS id out of range: %d\n", ps->pps->sps_id);
84        return AVERROR_INVALIDDATA;
85    }
86    if (ps->sps != (HEVCSPS*)ps->sps_list[ps->pps->sps_id]->data) {
87        ps->sps = (HEVCSPS*)ps->sps_list[ps->pps->sps_id]->data;
88        ps->vps = (HEVCVPS*)ps->vps_list[ps->sps->vps_id]->data;
89    }
90    ow  = &ps->sps->output_window;
91
92    s->coded_width  = ps->sps->width;
93    s->coded_height = ps->sps->height;
94    s->width        = ps->sps->width  - ow->left_offset - ow->right_offset;
95    s->height       = ps->sps->height - ow->top_offset  - ow->bottom_offset;
96    s->format       = ps->sps->pix_fmt;
97    avctx->profile  = ps->sps->ptl.general_ptl.profile_idc;
98    avctx->level    = ps->sps->ptl.general_ptl.level_idc;
99
100    if (ps->vps->vps_timing_info_present_flag) {
101        num = ps->vps->vps_num_units_in_tick;
102        den = ps->vps->vps_time_scale;
103    } else if (ps->sps->vui.vui_timing_info_present_flag) {
104        num = ps->sps->vui.vui_num_units_in_tick;
105        den = ps->sps->vui.vui_time_scale;
106    }
107
108    if (num != 0 && den != 0)
109        av_reduce(&avctx->framerate.den, &avctx->framerate.num,
110                  num, den, 1 << 30);
111
112    if (!first_slice_in_pic_flag) {
113        unsigned int slice_segment_addr;
114        int slice_address_length;
115
116        if (ps->pps->dependent_slice_segments_enabled_flag)
117            dependent_slice_segment_flag = get_bits1(gb);
118        else
119            dependent_slice_segment_flag = 0;
120
121        slice_address_length = av_ceil_log2_c(ps->sps->ctb_width *
122                                              ps->sps->ctb_height);
123        slice_segment_addr = get_bitsz(gb, slice_address_length);
124        if (slice_segment_addr >= ps->sps->ctb_width * ps->sps->ctb_height) {
125            av_log(avctx, AV_LOG_ERROR, "Invalid slice segment address: %u.\n",
126                   slice_segment_addr);
127            return AVERROR_INVALIDDATA;
128        }
129    } else
130        dependent_slice_segment_flag = 0;
131
132    if (dependent_slice_segment_flag)
133        return 0; /* break; */
134
135    for (i = 0; i < ps->pps->num_extra_slice_header_bits; i++)
136        skip_bits(gb, 1); // slice_reserved_undetermined_flag[]
137
138    slice_type = get_ue_golomb_31(gb);
139    if (!(slice_type == HEVC_SLICE_I || slice_type == HEVC_SLICE_P ||
140          slice_type == HEVC_SLICE_B)) {
141        av_log(avctx, AV_LOG_ERROR, "Unknown slice type: %d.\n",
142               slice_type);
143        return AVERROR_INVALIDDATA;
144    }
145    s->pict_type = slice_type == HEVC_SLICE_B ? AV_PICTURE_TYPE_B :
146                   slice_type == HEVC_SLICE_P ? AV_PICTURE_TYPE_P :
147                                                AV_PICTURE_TYPE_I;
148
149    if (ps->pps->output_flag_present_flag)
150        skip_bits1(gb); // pic_output_flag
151
152    if (ps->sps->separate_colour_plane_flag)
153        skip_bits(gb, 2);   // colour_plane_id
154
155    if (!IS_IDR_NAL(nal)) {
156        int pic_order_cnt_lsb = get_bits(gb, ps->sps->log2_max_poc_lsb);
157        s->output_picture_number = ctx->poc =
158            ff_hevc_compute_poc(ps->sps, ctx->pocTid0, pic_order_cnt_lsb, nal->type);
159    } else
160        s->output_picture_number = ctx->poc = 0;
161
162    if (nal->temporal_id == 0 &&
163        nal->type != HEVC_NAL_TRAIL_N &&
164        nal->type != HEVC_NAL_TSA_N &&
165        nal->type != HEVC_NAL_STSA_N &&
166        nal->type != HEVC_NAL_RADL_N &&
167        nal->type != HEVC_NAL_RASL_N &&
168        nal->type != HEVC_NAL_RADL_R &&
169        nal->type != HEVC_NAL_RASL_R)
170        ctx->pocTid0 = ctx->poc;
171
172    return 1; /* no need to evaluate the rest */
173}
174
175/**
176 * Parse NAL units of found picture and decode some basic information.
177 *
178 * @param s parser context.
179 * @param avctx codec context.
180 * @param buf buffer with field/frame data.
181 * @param buf_size size of the buffer.
182 */
183static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
184                           int buf_size, AVCodecContext *avctx)
185{
186    HEVCParserContext *ctx = s->priv_data;
187    HEVCParamSets *ps = &ctx->ps;
188    HEVCSEI *sei = &ctx->sei;
189    int ret, i;
190
191    /* set some sane default values */
192    s->pict_type         = AV_PICTURE_TYPE_I;
193    s->key_frame         = 0;
194    s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
195
196    ff_hevc_reset_sei(sei);
197
198    ret = ff_h2645_packet_split(&ctx->pkt, buf, buf_size, avctx, ctx->is_avc,
199                                ctx->nal_length_size, AV_CODEC_ID_HEVC, 1, 0);
200    if (ret < 0)
201        return ret;
202
203    for (i = 0; i < ctx->pkt.nb_nals; i++) {
204        H2645NAL *nal = &ctx->pkt.nals[i];
205        GetBitContext *gb = &nal->gb;
206
207        if (nal->nuh_layer_id > 0)
208            continue;
209
210        switch (nal->type) {
211        case HEVC_NAL_VPS:
212            ff_hevc_decode_nal_vps(gb, avctx, ps);
213            break;
214        case HEVC_NAL_SPS:
215            ff_hevc_decode_nal_sps(gb, avctx, ps, 1);
216            break;
217        case HEVC_NAL_PPS:
218            ff_hevc_decode_nal_pps(gb, avctx, ps);
219            break;
220        case HEVC_NAL_SEI_PREFIX:
221        case HEVC_NAL_SEI_SUFFIX:
222            ff_hevc_decode_nal_sei(gb, avctx, sei, ps, nal->type);
223            break;
224        case HEVC_NAL_TRAIL_N:
225        case HEVC_NAL_TRAIL_R:
226        case HEVC_NAL_TSA_N:
227        case HEVC_NAL_TSA_R:
228        case HEVC_NAL_STSA_N:
229        case HEVC_NAL_STSA_R:
230        case HEVC_NAL_BLA_W_LP:
231        case HEVC_NAL_BLA_W_RADL:
232        case HEVC_NAL_BLA_N_LP:
233        case HEVC_NAL_IDR_W_RADL:
234        case HEVC_NAL_IDR_N_LP:
235        case HEVC_NAL_CRA_NUT:
236        case HEVC_NAL_RADL_N:
237        case HEVC_NAL_RADL_R:
238        case HEVC_NAL_RASL_N:
239        case HEVC_NAL_RASL_R:
240            if (ctx->sei.picture_timing.picture_struct == HEVC_SEI_PIC_STRUCT_FRAME_DOUBLING) {
241                s->repeat_pict = 1;
242            } else if (ctx->sei.picture_timing.picture_struct == HEVC_SEI_PIC_STRUCT_FRAME_TRIPLING) {
243                s->repeat_pict = 2;
244            }
245            ret = hevc_parse_slice_header(s, nal, avctx);
246            if (ret)
247                return ret;
248            break;
249        }
250    }
251    /* didn't find a picture! */
252    av_log(avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
253    return -1;
254}
255
256/**
257 * Find the end of the current frame in the bitstream.
258 * @return the position of the first byte of the next frame, or END_NOT_FOUND
259 */
260static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
261                               int buf_size)
262{
263    HEVCParserContext *ctx = s->priv_data;
264    ParseContext       *pc = &ctx->pc;
265    int i;
266
267    for (i = 0; i < buf_size; i++) {
268        int nut;
269
270        pc->state64 = (pc->state64 << 8) | buf[i];
271
272        if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)
273            continue;
274
275        nut = (pc->state64 >> 2 * 8 + 1) & 0x3F;
276        // Beginning of access unit
277        if ((nut >= HEVC_NAL_VPS && nut <= HEVC_NAL_EOB_NUT) || nut == HEVC_NAL_SEI_PREFIX ||
278            (nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {
279            if (pc->frame_start_found) {
280                pc->frame_start_found = 0;
281                return i - 5;
282            }
283        } else if (nut <= HEVC_NAL_RASL_R ||
284                   (nut >= HEVC_NAL_BLA_W_LP && nut <= HEVC_NAL_CRA_NUT)) {
285            int first_slice_segment_in_pic_flag = buf[i] >> 7;
286            if (first_slice_segment_in_pic_flag) {
287                if (!pc->frame_start_found) {
288                    pc->frame_start_found = 1;
289                } else { // First slice of next frame found
290                    pc->frame_start_found = 0;
291                    return i - 5;
292                }
293            }
294        }
295    }
296
297    return END_NOT_FOUND;
298}
299
300static int hevc_parse(AVCodecParserContext *s, AVCodecContext *avctx,
301                      const uint8_t **poutbuf, int *poutbuf_size,
302                      const uint8_t *buf, int buf_size)
303{
304    int next;
305    HEVCParserContext *ctx = s->priv_data;
306    ParseContext *pc = &ctx->pc;
307    int is_dummy_buf = !buf_size;
308    const uint8_t *dummy_buf = buf;
309
310    if (avctx->extradata && !ctx->parsed_extradata) {
311        ff_hevc_decode_extradata(avctx->extradata, avctx->extradata_size, &ctx->ps, &ctx->sei,
312                                 &ctx->is_avc, &ctx->nal_length_size, avctx->err_recognition,
313                                 1, avctx);
314        ctx->parsed_extradata = 1;
315    }
316
317    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
318        next = buf_size;
319    } else {
320        next = hevc_find_frame_end(s, buf, buf_size);
321        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
322            *poutbuf      = NULL;
323            *poutbuf_size = 0;
324            return buf_size;
325        }
326    }
327
328    is_dummy_buf &= (dummy_buf == buf);
329
330    if (!is_dummy_buf)
331        parse_nal_units(s, buf, buf_size, avctx);
332
333    *poutbuf      = buf;
334    *poutbuf_size = buf_size;
335    return next;
336}
337
338static void hevc_parser_close(AVCodecParserContext *s)
339{
340    HEVCParserContext *ctx = s->priv_data;
341
342    ff_hevc_ps_uninit(&ctx->ps);
343    ff_h2645_packet_uninit(&ctx->pkt);
344    ff_hevc_reset_sei(&ctx->sei);
345
346    av_freep(&ctx->pc.buffer);
347}
348
349const AVCodecParser ff_hevc_parser = {
350    .codec_ids      = { AV_CODEC_ID_HEVC },
351    .priv_data_size = sizeof(HEVCParserContext),
352    .parser_parse   = hevc_parse,
353    .parser_close   = hevc_parser_close,
354};
355