| /* |
| * 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; |
| 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 += 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 |
| } |
| } |
| |
| 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; |
| 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, |
| }; |
