/* * 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> */ #define UNCHECKED_BITSTREAM_READER 1 #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){ state+=8; continue; } state= 7; }else{ h->parse_history[h->parse_history_count++]= buf[i]; if(h->parse_history_count>3){ unsigned int mb, last_mb= h->parse_last_mb; GetBitContext gb; init_get_bits(&gb, h->parse_history, 8*h->parse_history_count); h->parse_history_count=0; mb= get_ue_golomb_long(&gb); last_mb= h->parse_last_mb; h->parse_last_mb= mb; if(pc->frame_start_found){ if(mb <= last_mb) goto found; }else pc->frame_start_found = 1; 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) - 3*(state>7); } /** * 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; int q264 = buf_size >=4 && !memcmp("Q264", buf, 4); /* 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, nalsize = 0; if (h->is_avc) { int i; if (h->nal_length_size >= buf_end - buf) break; nalsize = 0; for (i = 0; i < h->nal_length_size; i++) nalsize = (nalsize << 8) | *buf++; if (nalsize <= 0 || nalsize > buf_end - buf) { av_log(h->s.avctx, AV_LOG_ERROR, "AVC: nal size %d\n", nalsize); break; } src_length = nalsize; } else { buf = avpriv_mpv_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_long(&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 += h->is_avc ? nalsize : consumed; } if (q264) return 0; /* 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 } } 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; h->s.slice_context_count = 1; return 0; } AVCodecParser ff_h264_parser = { .codec_ids = { CODEC_ID_H264 }, .priv_data_size = sizeof(H264Context), .parser_init = init, .parser_parse = h264_parse, .parser_close = close, .split = h264_split, };