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- /*
- * H.26L/H.264/AVC/JVT/14496-10/... parser
- * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
- *
- * 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
- */
- /**
- * @file
- * H.264 / AVC / MPEG4 part10 parser.
- * @author Michael Niedermayer <michaelni@gmx.at>
- */
- #include "parser.h"
- #include "h264data.h"
- #include "golomb.h"
- #include <assert.h>
- static int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
- {
- int i, j;
- uint32_t state;
- ParseContext *pc = &(h->s.parse_context);
- int next_avc= h->is_avc ? 0 : buf_size;
- //printf("first %02X%02X%02X%02X\n", buf[0], buf[1],buf[2],buf[3]);
- // mb_addr= pc->mb_addr - 1;
- state= pc->state;
- if(state>13)
- state= 7;
- if(h->is_avc && !h->nal_length_size)
- av_log(h->s.avctx, AV_LOG_ERROR, "AVC-parser: nal length size invalid\n");
- for(i=0; i<buf_size; i++){
- if(i >= next_avc) {
- int nalsize = 0;
- i = next_avc;
- for(j = 0; j < h->nal_length_size; j++)
- nalsize = (nalsize << 8) | buf[i++];
- if(nalsize <= 0 || nalsize > buf_size - i){
- av_log(h->s.avctx, AV_LOG_ERROR, "AVC-parser: nal size %d remaining %d\n", nalsize, buf_size - i);
- return buf_size;
- }
- next_avc= i + nalsize;
- state= 5;
- }
- if(state==7){
- #if HAVE_FAST_UNALIGNED
- /* we check i<buf_size instead of i+3/7 because its simpler
- * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end
- */
- # if HAVE_FAST_64BIT
- while(i<next_avc && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
- i+=8;
- # else
- while(i<next_avc && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
- i+=4;
- # endif
- #endif
- for(; i<next_avc; i++){
- if(!buf[i]){
- state=2;
- break;
- }
- }
- }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 v= buf[i] & 0x1F;
- if(v==6 || v==7 || v==8 || v==9){
- if(pc->frame_start_found){
- i++;
- goto found;
- }
- }else if(v==1 || v==2 || v==5){
- if(pc->frame_start_found){
- state+=8;
- continue;
- }else
- pc->frame_start_found = 1;
- }
- state= 7;
- }else{
- if(buf[i] & 0x80)
- goto found;
- state= 7;
- }
- }
- pc->state= state;
- if(h->is_avc)
- return next_avc;
- return END_NOT_FOUND;
- found:
- pc->state=7;
- pc->frame_start_found= 0;
- if(h->is_avc)
- return next_avc;
- return i-(state&5);
- }
- /**
- * 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)
- {
- H264Context *h = s->priv_data;
- const uint8_t *buf_end = buf + buf_size;
- unsigned int pps_id;
- unsigned int slice_type;
- int state = -1;
- const uint8_t *ptr;
- /* set some sane default values */
- s->pict_type = AV_PICTURE_TYPE_I;
- s->key_frame = 0;
- h->s.avctx= avctx;
- h->sei_recovery_frame_cnt = -1;
- h->sei_dpb_output_delay = 0;
- h->sei_cpb_removal_delay = -1;
- h->sei_buffering_period_present = 0;
- if (!buf_size)
- return 0;
- for(;;) {
- int src_length, dst_length, consumed;
- buf = ff_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 (src_length > 20)
- src_length = 20;
- break;
- }
- ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
- if (ptr==NULL || dst_length < 0)
- break;
- init_get_bits(&h->s.gb, ptr, 8*dst_length);
- switch(h->nal_unit_type) {
- case NAL_SPS:
- ff_h264_decode_seq_parameter_set(h);
- break;
- case NAL_PPS:
- ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
- break;
- case NAL_SEI:
- ff_h264_decode_sei(h);
- break;
- case NAL_IDR_SLICE:
- s->key_frame = 1;
- /* fall through */
- case NAL_SLICE:
- get_ue_golomb(&h->s.gb); // skip first_mb_in_slice
- slice_type = get_ue_golomb_31(&h->s.gb);
- s->pict_type = golomb_to_pict_type[slice_type % 5];
- if (h->sei_recovery_frame_cnt >= 0) {
- /* key frame, since recovery_frame_cnt is set */
- s->key_frame = 1;
- }
- pps_id= get_ue_golomb(&h->s.gb);
- if(pps_id>=MAX_PPS_COUNT) {
- av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n");
- return -1;
- }
- if(!h->pps_buffers[pps_id]) {
- av_log(h->s.avctx, AV_LOG_ERROR, "non-existing PPS referenced\n");
- return -1;
- }
- h->pps= *h->pps_buffers[pps_id];
- if(!h->sps_buffers[h->pps.sps_id]) {
- av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS referenced\n");
- return -1;
- }
- h->sps = *h->sps_buffers[h->pps.sps_id];
- h->frame_num = get_bits(&h->s.gb, h->sps.log2_max_frame_num);
- avctx->profile = ff_h264_get_profile(&h->sps);
- avctx->level = h->sps.level_idc;
- if(h->sps.frame_mbs_only_flag){
- h->s.picture_structure= PICT_FRAME;
- }else{
- if(get_bits1(&h->s.gb)) { //field_pic_flag
- h->s.picture_structure= PICT_TOP_FIELD + get_bits1(&h->s.gb); //bottom_field_flag
- } else {
- h->s.picture_structure= PICT_FRAME;
- }
- }
- if(h->sps.pic_struct_present_flag) {
- switch (h->sei_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 = h->s.picture_structure == PICT_FRAME ? 1 : 0;
- break;
- }
- } else {
- s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
- }
- return 0; /* no need to evaluate the rest */
- }
- buf += consumed;
- }
- /* didn't find a picture! */
- av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
- return -1;
- }
- static int h264_parse(AVCodecParserContext *s,
- AVCodecContext *avctx,
- const uint8_t **poutbuf, int *poutbuf_size,
- const uint8_t *buf, int buf_size)
- {
- H264Context *h = s->priv_data;
- ParseContext *pc = &h->s.parse_context;
- int next;
- if (!h->got_first) {
- h->got_first = 1;
- if (avctx->extradata_size) {
- h->s.avctx = avctx;
- // must be done like in decoder, otherwise opening the parser,
- // letting it create extradata and then closing and opening again
- // will cause has_b_frames to be always set.
- // Note that estimate_timings_from_pts does exactly this.
- if (!avctx->has_b_frames)
- h->s.low_delay = 1;
- ff_h264_decode_extradata(h, avctx->extradata, avctx->extradata_size);
- }
- }
- if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
- next= buf_size;
- }else{
- next= ff_h264_find_frame_end(h, 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 );
- ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
- }
- }
- if(!h->is_avc){
- parse_nal_units(s, avctx, buf, buf_size);
- if (h->sei_cpb_removal_delay >= 0) {
- s->dts_sync_point = h->sei_buffering_period_present;
- s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
- s->pts_dts_delta = h->sei_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) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
- 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 close(AVCodecParserContext *s)
- {
- H264Context *h = s->priv_data;
- ParseContext *pc = &h->s.parse_context;
- av_free(pc->buffer);
- ff_h264_free_context(h);
- }
- static int init(AVCodecParserContext *s)
- {
- H264Context *h = s->priv_data;
- h->thread_context[0] = h;
- return 0;
- }
- AVCodecParser ff_h264_parser = {
- { CODEC_ID_H264 },
- sizeof(H264Context),
- init,
- h264_parse,
- close,
- h264_split,
- };
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