yading@10: /*
yading@10:  * H.26L/H.264/AVC/JVT/14496-10/... parser
yading@10:  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * H.264 / AVC / MPEG4 part10 parser.
yading@10:  * @author Michael Niedermayer <michaelni@gmx.at>
yading@10:  */
yading@10: 
yading@10: #define UNCHECKED_BITSTREAM_READER 1
yading@10: 
yading@10: #include "parser.h"
yading@10: #include "h264data.h"
yading@10: #include "golomb.h"
yading@10: #include "internal.h"
yading@10: 
yading@10: 
yading@10: static int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     int i, j;
yading@10:     uint32_t state;
yading@10:     ParseContext *pc = &h->parse_context;
yading@10:     int next_avc= h->is_avc ? 0 : buf_size;
yading@10: 
yading@10: //    mb_addr= pc->mb_addr - 1;
yading@10:     state= pc->state;
yading@10:     if(state>13)
yading@10:         state= 7;
yading@10: 
yading@10:     if(h->is_avc && !h->nal_length_size)
yading@10:         av_log(h->avctx, AV_LOG_ERROR, "AVC-parser: nal length size invalid\n");
yading@10: 
yading@10:     for(i=0; i<buf_size; i++){
yading@10:         if(i >= next_avc) {
yading@10:             int nalsize = 0;
yading@10:             i = next_avc;
yading@10:             for(j = 0; j < h->nal_length_size; j++)
yading@10:                 nalsize = (nalsize << 8) | buf[i++];
yading@10:             if(nalsize <= 0 || nalsize > buf_size - i){
yading@10:                 av_log(h->avctx, AV_LOG_ERROR, "AVC-parser: nal size %d remaining %d\n", nalsize, buf_size - i);
yading@10:                 return buf_size;
yading@10:             }
yading@10:             next_avc= i + nalsize;
yading@10:             state= 5;
yading@10:         }
yading@10: 
yading@10:         if(state==7){
yading@10: #if HAVE_FAST_UNALIGNED
yading@10:         /* we check i<buf_size instead of i+3/7 because its simpler
yading@10:          * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end
yading@10:          */
yading@10: #    if HAVE_FAST_64BIT
yading@10:             while(i<next_avc && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
yading@10:                 i+=8;
yading@10: #    else
yading@10:             while(i<next_avc && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
yading@10:                 i+=4;
yading@10: #    endif
yading@10: #endif
yading@10:             for(; i<next_avc; i++){
yading@10:                 if(!buf[i]){
yading@10:                     state=2;
yading@10:                     break;
yading@10:                 }
yading@10:             }
yading@10:         }else if(state<=2){
yading@10:             if(buf[i]==1)   state^= 5; //2->7, 1->4, 0->5
yading@10:             else if(buf[i]) state = 7;
yading@10:             else            state>>=1; //2->1, 1->0, 0->0
yading@10:         }else if(state<=5){
yading@10:             int v= buf[i] & 0x1F;
yading@10:             if(v==6 || v==7 || v==8 || v==9){
yading@10:                 if(pc->frame_start_found){
yading@10:                     i++;
yading@10:                     goto found;
yading@10:                 }
yading@10:             }else if(v==1 || v==2 || v==5){
yading@10:                 state+=8;
yading@10:                 continue;
yading@10:             }
yading@10:             state= 7;
yading@10:         }else{
yading@10:             h->parse_history[h->parse_history_count++]= buf[i];
yading@10:             if(h->parse_history_count>3){
yading@10:                 unsigned int mb, last_mb= h->parse_last_mb;
yading@10:                 GetBitContext gb;
yading@10: 
yading@10:                 init_get_bits(&gb, h->parse_history, 8*h->parse_history_count);
yading@10:                 h->parse_history_count=0;
yading@10:                 mb= get_ue_golomb_long(&gb);
yading@10:                 last_mb= h->parse_last_mb;
yading@10:                 h->parse_last_mb= mb;
yading@10:                 if(pc->frame_start_found){
yading@10:                     if(mb <= last_mb)
yading@10:                         goto found;
yading@10:                 }else
yading@10:                     pc->frame_start_found = 1;
yading@10:                 state= 7;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10:     pc->state= state;
yading@10:     if(h->is_avc)
yading@10:         return next_avc;
yading@10:     return END_NOT_FOUND;
yading@10: 
yading@10: found:
yading@10:     pc->state=7;
yading@10:     pc->frame_start_found= 0;
yading@10:     if(h->is_avc)
yading@10:         return next_avc;
yading@10:     return i-(state&5) - 3*(state>7);
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Parse NAL units of found picture and decode some basic information.
yading@10:  *
yading@10:  * @param s parser context.
yading@10:  * @param avctx codec context.
yading@10:  * @param buf buffer with field/frame data.
yading@10:  * @param buf_size size of the buffer.
yading@10:  */
yading@10: static inline int parse_nal_units(AVCodecParserContext *s,
yading@10:                                   AVCodecContext *avctx,
yading@10:                                   const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     H264Context *h = s->priv_data;
yading@10:     const uint8_t *buf_end = buf + buf_size;
yading@10:     unsigned int pps_id;
yading@10:     unsigned int slice_type;
yading@10:     int state = -1;
yading@10:     const uint8_t *ptr;
yading@10:     int q264 = buf_size >=4 && !memcmp("Q264", buf, 4);
yading@10: 
yading@10:     /* set some sane default values */
yading@10:     s->pict_type = AV_PICTURE_TYPE_I;
yading@10:     s->key_frame = 0;
yading@10: 
yading@10:     h->avctx= avctx;
yading@10:     h->sei_recovery_frame_cnt = -1;
yading@10:     h->sei_dpb_output_delay         =  0;
yading@10:     h->sei_cpb_removal_delay        = -1;
yading@10:     h->sei_buffering_period_present =  0;
yading@10: 
yading@10:     if (!buf_size)
yading@10:         return 0;
yading@10: 
yading@10:     for(;;) {
yading@10:         int src_length, dst_length, consumed, nalsize = 0;
yading@10:         if (h->is_avc) {
yading@10:             int i;
yading@10:             if (h->nal_length_size >= buf_end - buf) break;
yading@10:             nalsize = 0;
yading@10:             for (i = 0; i < h->nal_length_size; i++)
yading@10:                 nalsize = (nalsize << 8) | *buf++;
yading@10:             if (nalsize <= 0 || nalsize > buf_end - buf) {
yading@10:                 av_log(h->avctx, AV_LOG_ERROR, "AVC: nal size %d\n", nalsize);
yading@10:                 break;
yading@10:             }
yading@10:             src_length = nalsize;
yading@10:         } else {
yading@10:         buf = avpriv_find_start_code(buf, buf_end, &state);
yading@10:         if(buf >= buf_end)
yading@10:             break;
yading@10:         --buf;
yading@10:         src_length = buf_end - buf;
yading@10:         }
yading@10:         switch (state & 0x1f) {
yading@10:         case NAL_SLICE:
yading@10:         case NAL_IDR_SLICE:
yading@10:             // Do not walk the whole buffer just to decode slice header
yading@10:             if (src_length > 20)
yading@10:                 src_length = 20;
yading@10:             break;
yading@10:         }
yading@10:         ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
yading@10:         if (ptr==NULL || dst_length < 0)
yading@10:             break;
yading@10: 
yading@10:         init_get_bits(&h->gb, ptr, 8*dst_length);
yading@10:         switch(h->nal_unit_type) {
yading@10:         case NAL_SPS:
yading@10:             ff_h264_decode_seq_parameter_set(h);
yading@10:             break;
yading@10:         case NAL_PPS:
yading@10:             ff_h264_decode_picture_parameter_set(h, h->gb.size_in_bits);
yading@10:             break;
yading@10:         case NAL_SEI:
yading@10:             ff_h264_decode_sei(h);
yading@10:             break;
yading@10:         case NAL_IDR_SLICE:
yading@10:             s->key_frame = 1;
yading@10:             /* fall through */
yading@10:         case NAL_SLICE:
yading@10:             get_ue_golomb_long(&h->gb);  // skip first_mb_in_slice
yading@10:             slice_type = get_ue_golomb_31(&h->gb);
yading@10:             s->pict_type = golomb_to_pict_type[slice_type % 5];
yading@10:             if (h->sei_recovery_frame_cnt >= 0) {
yading@10:                 /* key frame, since recovery_frame_cnt is set */
yading@10:                 s->key_frame = 1;
yading@10:             }
yading@10:             pps_id= get_ue_golomb(&h->gb);
yading@10:             if(pps_id>=MAX_PPS_COUNT) {
yading@10:                 av_log(h->avctx, AV_LOG_ERROR, "pps_id out of range\n");
yading@10:                 return -1;
yading@10:             }
yading@10:             if(!h->pps_buffers[pps_id]) {
yading@10:                 av_log(h->avctx, AV_LOG_ERROR, "non-existing PPS referenced\n");
yading@10:                 return -1;
yading@10:             }
yading@10:             h->pps= *h->pps_buffers[pps_id];
yading@10:             if(!h->sps_buffers[h->pps.sps_id]) {
yading@10:                 av_log(h->avctx, AV_LOG_ERROR, "non-existing SPS referenced\n");
yading@10:                 return -1;
yading@10:             }
yading@10:             h->sps = *h->sps_buffers[h->pps.sps_id];
yading@10:             h->frame_num = get_bits(&h->gb, h->sps.log2_max_frame_num);
yading@10: 
yading@10:             avctx->profile = ff_h264_get_profile(&h->sps);
yading@10:             avctx->level   = h->sps.level_idc;
yading@10: 
yading@10:             if(h->sps.frame_mbs_only_flag){
yading@10:                 h->picture_structure= PICT_FRAME;
yading@10:             }else{
yading@10:                 if(get_bits1(&h->gb)) { //field_pic_flag
yading@10:                     h->picture_structure= PICT_TOP_FIELD + get_bits1(&h->gb); //bottom_field_flag
yading@10:                 } else {
yading@10:                     h->picture_structure= PICT_FRAME;
yading@10:                 }
yading@10:             }
yading@10: 
yading@10:             if(h->sps.pic_struct_present_flag) {
yading@10:                 switch (h->sei_pic_struct) {
yading@10:                     case SEI_PIC_STRUCT_TOP_FIELD:
yading@10:                     case SEI_PIC_STRUCT_BOTTOM_FIELD:
yading@10:                         s->repeat_pict = 0;
yading@10:                         break;
yading@10:                     case SEI_PIC_STRUCT_FRAME:
yading@10:                     case SEI_PIC_STRUCT_TOP_BOTTOM:
yading@10:                     case SEI_PIC_STRUCT_BOTTOM_TOP:
yading@10:                         s->repeat_pict = 1;
yading@10:                         break;
yading@10:                     case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
yading@10:                     case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
yading@10:                         s->repeat_pict = 2;
yading@10:                         break;
yading@10:                     case SEI_PIC_STRUCT_FRAME_DOUBLING:
yading@10:                         s->repeat_pict = 3;
yading@10:                         break;
yading@10:                     case SEI_PIC_STRUCT_FRAME_TRIPLING:
yading@10:                         s->repeat_pict = 5;
yading@10:                         break;
yading@10:                     default:
yading@10:                         s->repeat_pict = h->picture_structure == PICT_FRAME ? 1 : 0;
yading@10:                         break;
yading@10:                 }
yading@10:             } else {
yading@10:                 s->repeat_pict = h->picture_structure == PICT_FRAME ? 1 : 0;
yading@10:             }
yading@10: 
yading@10:             return 0; /* no need to evaluate the rest */
yading@10:         }
yading@10:         buf += h->is_avc ? nalsize : consumed;
yading@10:     }
yading@10:     if (q264)
yading@10:         return 0;
yading@10:     /* didn't find a picture! */
yading@10:     av_log(h->avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
yading@10:     return -1;
yading@10: }
yading@10: 
yading@10: static int h264_parse(AVCodecParserContext *s,
yading@10:                       AVCodecContext *avctx,
yading@10:                       const uint8_t **poutbuf, int *poutbuf_size,
yading@10:                       const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     H264Context *h = s->priv_data;
yading@10:     ParseContext *pc = &h->parse_context;
yading@10:     int next;
yading@10: 
yading@10:     if (!h->got_first) {
yading@10:         h->got_first = 1;
yading@10:         if (avctx->extradata_size) {
yading@10:             h->avctx = avctx;
yading@10:             // must be done like in decoder, otherwise opening the parser,
yading@10:             // letting it create extradata and then closing and opening again
yading@10:             // will cause has_b_frames to be always set.
yading@10:             // Note that estimate_timings_from_pts does exactly this.
yading@10:             if (!avctx->has_b_frames)
yading@10:                 h->low_delay = 1;
yading@10:             ff_h264_decode_extradata(h, avctx->extradata, avctx->extradata_size);
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
yading@10:         next= buf_size;
yading@10:     }else{
yading@10:         next= ff_h264_find_frame_end(h, buf, buf_size);
yading@10: 
yading@10:         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
yading@10:             *poutbuf = NULL;
yading@10:             *poutbuf_size = 0;
yading@10:             return buf_size;
yading@10:         }
yading@10: 
yading@10:         if(next<0 && next != END_NOT_FOUND){
yading@10:             av_assert1(pc->last_index + next >= 0 );
yading@10:             ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     parse_nal_units(s, avctx, buf, buf_size);
yading@10: 
yading@10:     if (h->sei_cpb_removal_delay >= 0) {
yading@10:         s->dts_sync_point    = h->sei_buffering_period_present;
yading@10:         s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
yading@10:         s->pts_dts_delta     = h->sei_dpb_output_delay;
yading@10:     } else {
yading@10:         s->dts_sync_point    = INT_MIN;
yading@10:         s->dts_ref_dts_delta = INT_MIN;
yading@10:         s->pts_dts_delta     = INT_MIN;
yading@10:     }
yading@10: 
yading@10:     if (s->flags & PARSER_FLAG_ONCE) {
yading@10:         s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
yading@10:     }
yading@10: 
yading@10:     *poutbuf = buf;
yading@10:     *poutbuf_size = buf_size;
yading@10:     return next;
yading@10: }
yading@10: 
yading@10: static int h264_split(AVCodecContext *avctx,
yading@10:                       const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     int i;
yading@10:     uint32_t state = -1;
yading@10:     int has_sps= 0;
yading@10: 
yading@10:     for(i=0; i<=buf_size; i++){
yading@10:         if((state&0xFFFFFF1F) == 0x107)
yading@10:             has_sps=1;
yading@10: /*        if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){
yading@10:         }*/
yading@10:         if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
yading@10:             if(has_sps){
yading@10:                 while(i>4 && buf[i-5]==0) i--;
yading@10:                 return i-4;
yading@10:             }
yading@10:         }
yading@10:         if (i<buf_size)
yading@10:             state= (state<<8) | buf[i];
yading@10:     }
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static void close(AVCodecParserContext *s)
yading@10: {
yading@10:     H264Context *h = s->priv_data;
yading@10:     ParseContext *pc = &h->parse_context;
yading@10: 
yading@10:     av_free(pc->buffer);
yading@10:     ff_h264_free_context(h);
yading@10: }
yading@10: 
yading@10: static int init(AVCodecParserContext *s)
yading@10: {
yading@10:     H264Context *h = s->priv_data;
yading@10:     h->thread_context[0] = h;
yading@10:     h->slice_context_count = 1;
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodecParser ff_h264_parser = {
yading@10:     .codec_ids      = { AV_CODEC_ID_H264 },
yading@10:     .priv_data_size = sizeof(H264Context),
yading@10:     .parser_init    = init,
yading@10:     .parser_parse   = h264_parse,
yading@10:     .parser_close   = close,
yading@10:     .split          = h264_split,
yading@10: };