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Viewing changes to libavcodec/h264_parser.c

  • Committer: Bazaar Package Importer
  • Author(s): Reinhard Tartler
  • Date: 2009-03-13 09:18:28 UTC
  • mfrom: (1.1.8 upstream)
  • Revision ID: james.westby@ubuntu.com-20090313091828-n4ktby5eca487uhv
Tags: 3:0.svn20090303-1ubuntu1+unstripped1
merge from ubuntu.jaunty branch

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libavcodec/h264_parser.c
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#include "parser.h"
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#include "h264_parser.h"
 
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#include "h264data.h"
 
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#include "golomb.h"
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#include <assert.h>
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         * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end
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         */
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#    if HAVE_FAST_64BIT
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            while(i<buf_size && !((~*(uint64_t*)(buf+i) & (*(uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
 
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            while(i<buf_size && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
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                i+=8;
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#    else
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            while(i<buf_size && !((~*(uint32_t*)(buf+i) & (*(uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
 
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            while(i<buf_size && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
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                i+=4;
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#    endif
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#endif
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    return i-(state&5);
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}
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/*!
 
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 * Parse NAL units of found picture and decode some basic information.
 
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 *
 
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 * @param s parser context.
 
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 * @param avctx codec context.
 
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 * @param buf buffer with field/frame data.
 
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 * @param buf_size size of the buffer.
 
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 */
 
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static inline int parse_nal_units(AVCodecParserContext *s,
 
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                                  AVCodecContext *avctx,
 
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                                  const uint8_t *buf, int buf_size)
 
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{
 
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    H264Context *h = s->priv_data;
 
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    const uint8_t *buf_end = buf + buf_size;
 
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    unsigned int pps_id;
 
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    unsigned int slice_type;
 
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    int state;
 
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    const uint8_t *ptr;
 
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    /* set some sane default values */
 
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    s->pict_type = FF_I_TYPE;
 
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    s->key_frame = 0;
 
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    h->s.avctx= avctx;
 
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    h->sei_recovery_frame_cnt = -1;
 
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    h->sei_dpb_output_delay         =  0;
 
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    h->sei_cpb_removal_delay        = -1;
 
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    h->sei_buffering_period_present =  0;
 
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    for(;;) {
 
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        int src_length, dst_length, consumed;
 
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        buf = ff_find_start_code(buf, buf_end, &state);
 
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        if(buf >= buf_end)
 
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            break;
 
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        --buf;
 
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        src_length = buf_end - buf;
 
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        switch (state & 0x1f) {
 
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        case NAL_SLICE:
 
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        case NAL_IDR_SLICE:
 
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            // Do not walk the whole buffer just to decode slice header
 
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            if (src_length > 20)
 
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                src_length = 20;
 
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            break;
 
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        }
 
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        ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
 
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        if (ptr==NULL || dst_length < 0)
 
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            break;
 
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        init_get_bits(&h->s.gb, ptr, 8*dst_length);
 
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        switch(h->nal_unit_type) {
 
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        case NAL_SPS:
 
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            ff_h264_decode_seq_parameter_set(h);
 
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            break;
 
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        case NAL_PPS:
 
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            ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
 
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            break;
 
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        case NAL_SEI:
 
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            ff_h264_decode_sei(h);
 
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            break;
 
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        case NAL_IDR_SLICE:
 
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            s->key_frame = 1;
 
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            /* fall through */
 
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        case NAL_SLICE:
 
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            get_ue_golomb(&h->s.gb);  // skip first_mb_in_slice
 
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            slice_type = get_ue_golomb_31(&h->s.gb);
 
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            s->pict_type = golomb_to_pict_type[slice_type % 5];
 
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            if (h->sei_recovery_frame_cnt >= 0) {
 
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                /* key frame, since recovery_frame_cnt is set */
 
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                s->key_frame = 1;
 
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            }
 
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            pps_id= get_ue_golomb(&h->s.gb);
 
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            if(pps_id>=MAX_PPS_COUNT) {
 
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                av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n");
 
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                return -1;
 
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            }
 
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            if(!h->pps_buffers[pps_id]) {
 
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                av_log(h->s.avctx, AV_LOG_ERROR, "non-existing PPS referenced\n");
 
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                return -1;
 
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            }
 
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            h->pps= *h->pps_buffers[pps_id];
 
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            if(!h->sps_buffers[h->pps.sps_id]) {
 
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                av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS referenced\n");
 
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                return -1;
 
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            }
 
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            h->sps = *h->sps_buffers[h->pps.sps_id];
 
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            h->frame_num = get_bits(&h->s.gb, h->sps.log2_max_frame_num);
 
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            if(h->sps.frame_mbs_only_flag){
 
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                h->s.picture_structure= PICT_FRAME;
 
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            }else{
 
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                if(get_bits1(&h->s.gb)) { //field_pic_flag
 
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                    h->s.picture_structure= PICT_TOP_FIELD + get_bits1(&h->s.gb); //bottom_field_flag
 
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                } else {
 
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                    h->s.picture_structure= PICT_FRAME;
 
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                }
 
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            }
 
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            if(h->sps.pic_struct_present_flag) {
 
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                switch (h->sei_pic_struct) {
 
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                    case SEI_PIC_STRUCT_TOP_FIELD:
 
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                    case SEI_PIC_STRUCT_BOTTOM_FIELD:
 
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                        s->repeat_pict = 0;
 
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                        break;
 
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                    case SEI_PIC_STRUCT_FRAME:
 
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                    case SEI_PIC_STRUCT_TOP_BOTTOM:
 
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                    case SEI_PIC_STRUCT_BOTTOM_TOP:
 
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                        s->repeat_pict = 1;
 
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                        break;
 
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                    case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
 
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                    case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
 
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                        s->repeat_pict = 2;
 
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                        break;
 
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                    case SEI_PIC_STRUCT_FRAME_DOUBLING:
 
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                        s->repeat_pict = 3;
 
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                        break;
 
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                    case SEI_PIC_STRUCT_FRAME_TRIPLING:
 
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                        s->repeat_pict = 5;
 
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                        break;
 
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                    default:
 
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                        s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
 
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                        break;
 
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                }
 
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            } else {
 
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                s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
 
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            }
 
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            return 0; /* no need to evaluate the rest */
 
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        }
 
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        buf += consumed;
 
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    }
 
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    /* didn't find a picture! */
 
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    av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n");
 
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    return -1;
 
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}
 
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static int h264_parse(AVCodecParserContext *s,
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                      AVCodecContext *avctx,
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                      const uint8_t **poutbuf, int *poutbuf_size,
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            assert(pc->last_index + next >= 0 );
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            ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
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        }
 
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        parse_nal_units(s, avctx, buf, buf_size);
 
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        if (h->sei_cpb_removal_delay >= 0) {
 
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            s->dts_sync_point    = h->sei_buffering_period_present;
 
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            s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
 
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            s->pts_dts_delta     = h->sei_dpb_output_delay;
 
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        } else {
 
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            s->dts_sync_point    = INT_MIN;
 
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            s->dts_ref_dts_delta = INT_MIN;
 
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            s->pts_dts_delta     = INT_MIN;
 
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        }
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    }
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    *poutbuf = buf;