2 * H.26L/H.264/AVC/JVT/14496-10/... parser
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * @file libavcodec/h264_parser.c
24 * H.264 / AVC / MPEG4 part10 parser.
25 * @author Michael Niedermayer <michaelni@gmx.at>
29 #include "h264_parser.h"
36 int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
40 ParseContext *pc = &(h->s.parse_context);
41 //printf("first %02X%02X%02X%02X\n", buf[0], buf[1],buf[2],buf[3]);
42 // mb_addr= pc->mb_addr - 1;
47 for(i=0; i<buf_size; i++){
49 #if HAVE_FAST_UNALIGNED
50 /* we check i<buf_size instead of i+3/7 because its simpler
51 * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end
54 while(i<buf_size && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
57 while(i<buf_size && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
61 for(; i<buf_size; i++){
68 if(buf[i]==1) state^= 5; //2->7, 1->4, 0->5
69 else if(buf[i]) state = 7;
70 else state>>=1; //2->1, 1->0, 0->0
73 if(v==6 || v==7 || v==8 || v==9){
74 if(pc->frame_start_found){
78 }else if(v==1 || v==2 || v==5){
79 if(pc->frame_start_found){
83 pc->frame_start_found = 1;
97 pc->frame_start_found= 0;
102 * Parse NAL units of found picture and decode some basic information.
104 * @param s parser context.
105 * @param avctx codec context.
106 * @param buf buffer with field/frame data.
107 * @param buf_size size of the buffer.
109 static inline int parse_nal_units(AVCodecParserContext *s,
110 AVCodecContext *avctx,
111 const uint8_t *buf, int buf_size)
113 H264Context *h = s->priv_data;
114 const uint8_t *buf_end = buf + buf_size;
116 unsigned int slice_type;
120 /* set some sane default values */
121 s->pict_type = FF_I_TYPE;
125 h->sei_recovery_frame_cnt = -1;
126 h->sei_dpb_output_delay = 0;
127 h->sei_cpb_removal_delay = -1;
128 h->sei_buffering_period_present = 0;
131 int src_length, dst_length, consumed;
132 buf = ff_find_start_code(buf, buf_end, &state);
136 src_length = buf_end - buf;
137 switch (state & 0x1f) {
140 // Do not walk the whole buffer just to decode slice header
145 ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
146 if (ptr==NULL || dst_length < 0)
149 init_get_bits(&h->s.gb, ptr, 8*dst_length);
150 switch(h->nal_unit_type) {
152 ff_h264_decode_seq_parameter_set(h);
155 ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
158 ff_h264_decode_sei(h);
164 get_ue_golomb(&h->s.gb); // skip first_mb_in_slice
165 slice_type = get_ue_golomb_31(&h->s.gb);
166 s->pict_type = golomb_to_pict_type[slice_type % 5];
167 if (h->sei_recovery_frame_cnt >= 0) {
168 /* key frame, since recovery_frame_cnt is set */
171 pps_id= get_ue_golomb(&h->s.gb);
172 if(pps_id>=MAX_PPS_COUNT) {
173 av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n");
176 if(!h->pps_buffers[pps_id]) {
177 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing PPS referenced\n");
180 h->pps= *h->pps_buffers[pps_id];
181 if(!h->sps_buffers[h->pps.sps_id]) {
182 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS referenced\n");
185 h->sps = *h->sps_buffers[h->pps.sps_id];
186 h->frame_num = get_bits(&h->s.gb, h->sps.log2_max_frame_num);
188 if(h->sps.frame_mbs_only_flag){
189 h->s.picture_structure= PICT_FRAME;
191 if(get_bits1(&h->s.gb)) { //field_pic_flag
192 h->s.picture_structure= PICT_TOP_FIELD + get_bits1(&h->s.gb); //bottom_field_flag
194 h->s.picture_structure= PICT_FRAME;
198 if(h->sps.pic_struct_present_flag) {
199 switch (h->sei_pic_struct) {
200 case SEI_PIC_STRUCT_TOP_FIELD:
201 case SEI_PIC_STRUCT_BOTTOM_FIELD:
204 case SEI_PIC_STRUCT_FRAME:
205 case SEI_PIC_STRUCT_TOP_BOTTOM:
206 case SEI_PIC_STRUCT_BOTTOM_TOP:
209 case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
210 case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
213 case SEI_PIC_STRUCT_FRAME_DOUBLING:
216 case SEI_PIC_STRUCT_FRAME_TRIPLING:
220 s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
224 s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
227 return 0; /* no need to evaluate the rest */
231 /* didn't find a picture! */
232 av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n");
236 static int h264_parse(AVCodecParserContext *s,
237 AVCodecContext *avctx,
238 const uint8_t **poutbuf, int *poutbuf_size,
239 const uint8_t *buf, int buf_size)
241 H264Context *h = s->priv_data;
242 ParseContext *pc = &h->s.parse_context;
245 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
248 next= ff_h264_find_frame_end(h, buf, buf_size);
250 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
256 if(next<0 && next != END_NOT_FOUND){
257 assert(pc->last_index + next >= 0 );
258 ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
261 parse_nal_units(s, avctx, buf, buf_size);
263 if (h->sei_cpb_removal_delay >= 0) {
264 s->dts_sync_point = h->sei_buffering_period_present;
265 s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
266 s->pts_dts_delta = h->sei_dpb_output_delay;
268 s->dts_sync_point = INT_MIN;
269 s->dts_ref_dts_delta = INT_MIN;
270 s->pts_dts_delta = INT_MIN;
275 *poutbuf_size = buf_size;
279 static int h264_split(AVCodecContext *avctx,
280 const uint8_t *buf, int buf_size)
286 for(i=0; i<=buf_size; i++){
287 if((state&0xFFFFFF1F) == 0x107)
289 /* if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){
291 if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
293 while(i>4 && buf[i-5]==0) i--;
298 state= (state<<8) | buf[i];
303 static void close(AVCodecParserContext *s)
305 H264Context *h = s->priv_data;
306 ParseContext *pc = &h->s.parse_context;
309 ff_h264_free_context(h);
313 AVCodecParser h264_parser = {