mpegvideo.c

linux下的MPEG1

            if(src->ref_index[i] && src->ref_index[i] != dst->ref_index[i]){
                memcpy(dst->ref_index[i], src->ref_index[i], s->b8_stride*2*s->mb_height*sizeof(int8_t));
            }
        }
    }
}
#endif

/**
 * allocates a Picture
 * The pixels are allocated/set by calling get_buffer() if shared=0
 */
static int alloc_picture(MpegEncContext *s, Picture *pic, int shared){
    const int big_mb_num= s->mb_stride*(s->mb_height+1) + 1; //the +1 is needed so memset(,,stride*height) doesnt sig11
    const int mb_array_size= s->mb_stride*s->mb_height;
    const int b8_array_size= s->b8_stride*s->mb_height*2;
    const int b4_array_size= s->b4_stride*s->mb_height*4;
    int i;

    if(shared){
        assert(pic->data[0]);
        assert(pic->type == 0 || pic->type == FF_BUFFER_TYPE_SHARED);
        pic->type= FF_BUFFER_TYPE_SHARED;
    }else{
        int r;

        assert(!pic->data[0]);

        r= s->avctx->get_buffer(s->avctx, (AVFrame*)pic);

        if(r<0 || !pic->age || !pic->type || !pic->data[0]){
            av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed (%d %d %d %p)\n", r, pic->age, pic->type, pic->data[0]);
            return -1;
        }

        if(s->linesize && (s->linesize != pic->linesize[0] || s->uvlinesize != pic->linesize[1])){
            av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed (stride changed)\n");
            return -1;
        }

        if(pic->linesize[1] != pic->linesize[2]){
            av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed (uv stride mismatch)\n");
            return -1;
        }

        s->linesize  = pic->linesize[0];
        s->uvlinesize= pic->linesize[1];
    }

    if(pic->qscale_table==NULL){
        if (s->encoding) {
            CHECKED_ALLOCZ(pic->mb_var   , mb_array_size * sizeof(int16_t))
            CHECKED_ALLOCZ(pic->mc_mb_var, mb_array_size * sizeof(int16_t))
            CHECKED_ALLOCZ(pic->mb_mean  , mb_array_size * sizeof(int8_t))
        }

        CHECKED_ALLOCZ(pic->mbskip_table , mb_array_size * sizeof(uint8_t)+2) //the +2 is for the slice end check
        CHECKED_ALLOCZ(pic->qscale_table , mb_array_size * sizeof(uint8_t))
        CHECKED_ALLOCZ(pic->mb_type_base , big_mb_num    * sizeof(uint32_t))
        pic->mb_type= pic->mb_type_base + s->mb_stride+1;
        if(s->out_format == FMT_H264){
            for(i=0; i<2; i++){
                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b4_array_size+4)  * sizeof(int16_t))
                pic->motion_val[i]= pic->motion_val_base[i]+4;
                CHECKED_ALLOCZ(pic->ref_index[i], b8_array_size * sizeof(uint8_t))
            }
            pic->motion_subsample_log2= 2;
        }else if(s->out_format == FMT_H263 || s->encoding || (s->avctx->debug&FF_DEBUG_MV) || (s->avctx->debug_mv)){
            for(i=0; i<2; i++){
                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b8_array_size+4) * sizeof(int16_t))
                pic->motion_val[i]= pic->motion_val_base[i]+4;
                CHECKED_ALLOCZ(pic->ref_index[i], b8_array_size * sizeof(uint8_t))
            }
            pic->motion_subsample_log2= 3;
        }
        if(s->avctx->debug&FF_DEBUG_DCT_COEFF) {
            CHECKED_ALLOCZ(pic->dct_coeff, 64 * mb_array_size * sizeof(DCTELEM)*6)
        }
        pic->qstride= s->mb_stride;
        CHECKED_ALLOCZ(pic->pan_scan , 1 * sizeof(AVPanScan))
    }

    //it might be nicer if the application would keep track of these but it would require a API change
    memmove(s->prev_pict_types+1, s->prev_pict_types, PREV_PICT_TYPES_BUFFER_SIZE-1);
    s->prev_pict_types[0]= s->pict_type;
    if(pic->age < PREV_PICT_TYPES_BUFFER_SIZE && s->prev_pict_types[pic->age] == B_TYPE)
        pic->age= INT_MAX; // skipped MBs in b frames are quite rare in mpeg1/2 and its a bit tricky to skip them anyway

    return 0;
fail: //for the CHECKED_ALLOCZ macro
    return -1;
}

/**
 * deallocates a picture
 */
static void free_picture(MpegEncContext *s, Picture *pic){
    int i;

    if(pic->data[0] && pic->type!=FF_BUFFER_TYPE_SHARED){
        s->avctx->release_buffer(s->avctx, (AVFrame*)pic);
    }

    av_freep(&pic->mb_var);
    av_freep(&pic->mc_mb_var);
    av_freep(&pic->mb_mean);
    av_freep(&pic->mbskip_table);
    av_freep(&pic->qscale_table);
    av_freep(&pic->mb_type_base);
    av_freep(&pic->dct_coeff);
    av_freep(&pic->pan_scan);
    pic->mb_type= NULL;
    for(i=0; i<2; i++){
        av_freep(&pic->motion_val_base[i]);
        av_freep(&pic->ref_index[i]);
    }

    if(pic->type == FF_BUFFER_TYPE_SHARED){
        for(i=0; i<4; i++){
            pic->base[i]=
            pic->data[i]= NULL;
        }
        pic->type= 0;
    }
}

static int init_duplicate_context(MpegEncContext *s, MpegEncContext *base){
    int i;

    // edge emu needs blocksize + filter length - 1 (=17x17 for halfpel / 21x21 for h264)
    CHECKED_ALLOCZ(s->allocated_edge_emu_buffer, (s->width+64)*2*21*2); //(width + edge + align)*interlaced*MBsize*tolerance
    s->edge_emu_buffer= s->allocated_edge_emu_buffer + (s->width+64)*2*21;

     //FIXME should be linesize instead of s->width*2 but that isnt known before get_buffer()
    CHECKED_ALLOCZ(s->me.scratchpad,  (s->width+64)*4*16*2*sizeof(uint8_t))
    s->rd_scratchpad=   s->me.scratchpad;
    s->b_scratchpad=    s->me.scratchpad;
    s->obmc_scratchpad= s->me.scratchpad + 16;
    if (s->encoding) {
        CHECKED_ALLOCZ(s->me.map      , ME_MAP_SIZE*sizeof(uint32_t))
        CHECKED_ALLOCZ(s->me.score_map, ME_MAP_SIZE*sizeof(uint32_t))
        if(s->avctx->noise_reduction){
            CHECKED_ALLOCZ(s->dct_error_sum, 2 * 64 * sizeof(int))
        }
    }
    CHECKED_ALLOCZ(s->blocks, 64*12*2 * sizeof(DCTELEM))
    s->block= s->blocks[0];

    for(i=0;i<12;i++){
        s->pblocks[i] = (short *)(&s->block[i]);
    }
    return 0;
fail:
    return -1; //free() through MPV_common_end()
}

static void free_duplicate_context(MpegEncContext *s){
    if(s==NULL) return;

    av_freep(&s->allocated_edge_emu_buffer); s->edge_emu_buffer= NULL;
    av_freep(&s->me.scratchpad);
    s->rd_scratchpad=
    s->b_scratchpad=
    s->obmc_scratchpad= NULL;

    av_freep(&s->dct_error_sum);
    av_freep(&s->me.map);
    av_freep(&s->me.score_map);
    av_freep(&s->blocks);
    s->block= NULL;
}

static void backup_duplicate_context(MpegEncContext *bak, MpegEncContext *src){
#define COPY(a) bak->a= src->a
    COPY(allocated_edge_emu_buffer);
    COPY(edge_emu_buffer);
    COPY(me.scratchpad);
    COPY(rd_scratchpad);
    COPY(b_scratchpad);
    COPY(obmc_scratchpad);
    COPY(me.map);
    COPY(me.score_map);
    COPY(blocks);
    COPY(block);
    COPY(start_mb_y);
    COPY(end_mb_y);
    COPY(me.map_generation);
    COPY(pb);
    COPY(dct_error_sum);
    COPY(dct_count[0]);
    COPY(dct_count[1]);
#undef COPY
}

void ff_update_duplicate_context(MpegEncContext *dst, MpegEncContext *src){
    MpegEncContext bak;
    int i;
    //FIXME copy only needed parts
//START_TIMER
    backup_duplicate_context(&bak, dst);
    memcpy(dst, src, sizeof(MpegEncContext));
    backup_duplicate_context(dst, &bak);
    for(i=0;i<12;i++){
        dst->pblocks[i] = (short *)(&dst->block[i]);
    }
//STOP_TIMER("update_duplicate_context") //about 10k cycles / 0.01 sec for 1000frames on 1ghz with 2 threads
}

#ifdef CONFIG_ENCODERS
static void update_duplicate_context_after_me(MpegEncContext *dst, MpegEncContext *src){
#define COPY(a) dst->a= src->a
    COPY(pict_type);
    COPY(current_picture);
    COPY(f_code);
    COPY(b_code);
    COPY(qscale);
    COPY(lambda);
    COPY(lambda2);
    COPY(picture_in_gop_number);
    COPY(gop_picture_number);
    COPY(frame_pred_frame_dct); //FIXME don't set in encode_header
    COPY(progressive_frame); //FIXME don't set in encode_header
    COPY(partitioned_frame); //FIXME don't set in encode_header
#undef COPY
}
#endif

/**
 * sets the given MpegEncContext to common defaults (same for encoding and decoding).
 * the changed fields will not depend upon the prior state of the MpegEncContext.
 */
static void MPV_common_defaults(MpegEncContext *s){
    s->y_dc_scale_table=
    s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
    s->chroma_qscale_table= ff_default_chroma_qscale_table;
    s->progressive_frame= 1;
    s->progressive_sequence= 1;
    s->picture_structure= PICT_FRAME;

    s->coded_picture_number = 0;
    s->picture_number = 0;
    s->input_picture_number = 0;

    s->picture_in_gop_number = 0;

    s->f_code = 1;
    s->b_code = 1;
}

/**
 * sets the given MpegEncContext to defaults for decoding.
 * the changed fields will not depend upon the prior state of the MpegEncContext.
 */
void MPV_decode_defaults(MpegEncContext *s){
    MPV_common_defaults(s);
}

/**
 * sets the given MpegEncContext to defaults for encoding.
 * the changed fields will not depend upon the prior state of the MpegEncContext.
 */

#ifdef CONFIG_ENCODERS
static void MPV_encode_defaults(MpegEncContext *s){
    static int done=0;

    MPV_common_defaults(s);

    if(!done){
        int i;
        done=1;

        default_mv_penalty= av_mallocz( sizeof(uint8_t)*(MAX_FCODE+1)*(2*MAX_MV+1) );
        memset(default_fcode_tab , 0, sizeof(uint8_t)*(2*MAX_MV+1));

        for(i=-16; i<16; i++){
            default_fcode_tab[i + MAX_MV]= 1;
        }
    }
    s->me.mv_penalty= default_mv_penalty;
    s->fcode_tab= default_fcode_tab;
}
#endif //CONFIG_ENCODERS

/**
 * init common structure for both encoder and decoder.
 * this assumes that some variables like width/height are already set
 */
int MPV_common_init(MpegEncContext *s)
{
    int y_size, c_size, yc_size, i, mb_array_size, mv_table_size, x, y;

    s->mb_height = (s->height + 15) / 16;

    if(s->avctx->thread_count > MAX_THREADS || (s->avctx->thread_count > s->mb_height && s->mb_height)){
        av_log(s->avctx, AV_LOG_ERROR, "too many threads\n");
        return -1;
    }

    if((s->width || s->height) && avcodec_check_dimensions(s->avctx, s->width, s->height))
        return -1;

    dsputil_init(&s->dsp, s->avctx);
    DCT_common_init(s);

    s->flags= s->avctx->flags;
    s->flags2= s->avctx->flags2;

    s->mb_width  = (s->width  + 15) / 16;
    s->mb_stride = s->mb_width + 1;
    s->b8_stride = s->mb_width*2 + 1;
    s->b4_stride = s->mb_width*4 + 1;
    mb_array_size= s->mb_height * s->mb_stride;
    mv_table_size= (s->mb_height+2) * s->mb_stride + 1;

    /* set chroma shifts */
    avcodec_get_chroma_sub_sample(s->avctx->pix_fmt,&(s->chroma_x_shift),
                                                    &(s->chroma_y_shift) );

    /* set default edge pos, will be overriden in decode_header if needed */
    s->h_edge_pos= s->mb_width*16;
    s->v_edge_pos= s->mb_height*16;

    s->mb_num = s->mb_width * s->mb_height;

    s->block_wrap[0]=
    s->block_wrap[1]=
    s->block_wrap[2]=
    s->block_wrap[3]= s->b8_stride;
    s->block_wrap[4]=
    s->block_wrap[5]= s->mb_stride;

    y_size = s->b8_stride * (2 * s->mb_height + 1);
    c_size = s->mb_stride * (s->mb_height + 1);
    yc_size = y_size + 2 * c_size;

    /* convert fourcc to upper case */
    s->codec_tag=          toupper( s->avctx->codec_tag     &0xFF)
                        + (toupper((s->avctx->codec_tag>>8 )&0xFF)<<8 )
                        + (toupper((s->avctx->codec_tag>>16)&0xFF)<<16)
                        + (toupper((s->avctx->codec_tag>>24)&0xFF)<<24);

    s->stream_codec_tag=          toupper( s->avctx->stream_codec_tag     &0xFF)
                               + (toupper((s->avctx->stream_codec_tag>>8 )&0xFF)<<8 )
                               + (toupper((s->avctx->stream_codec_tag>>16)&0xFF)<<16)
                               + (toupper((s->avctx->stream_codec_tag>>24)&0xFF)<<24);

    s->avctx->coded_frame= (AVFrame*)&s->current_picture;

    CHECKED_ALLOCZ(s->mb_index2xy, (s->mb_num+1)*sizeof(int)) //error ressilience code looks cleaner with this
    for(y=0; y<s->mb_height; y++){
        for(x=0; x<s->mb_width; x++){
            s->mb_index2xy[ x + y*s->mb_width ] = x + y*s->mb_stride;
        }
    }
    s->mb_index2xy[ s->mb_height*s->mb_width ] = (s->mb_height-1)*s->mb_stride + s->mb_width; //FIXME really needed?

    if (s->encoding) {
        /* Allocate MV tables */
        CHECKED_ALLOCZ(s->p_mv_table_base            , mv_table_size * 2 * sizeof(int16_t))
        CHECKED_ALLOCZ(s->b_forw_mv_table_base       , mv_table_size * 2 * sizeof(int16_t))
        CHECKED_ALLOCZ(s->b_back_mv_table_base       , mv_table_size * 2 * sizeof(int16_t))
        CHECKED_ALLOCZ(s->b_bidir_forw_mv_table_base , mv_table_size * 2 * sizeof(int16_t))
        CHECKED_ALLOCZ(s->b_bidir_back_mv_table_base , mv_table_size * 2 * sizeof(int16_t))
        CHECKED_ALLOCZ(s->b_direct_mv_table_base     , mv_table_size * 2 * sizeof(int16_t))
        s->p_mv_table           = s->p_mv_table_base            + s->mb_stride + 1;