mpegvideo.c

手机端的H264源码

    /* convert fourcc to upper case */
    s->avctx->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->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?
    
    
    CHECKED_ALLOCZ(s->picture, MAX_PICTURE_COUNT * sizeof(Picture))
        

    /* which mb is a intra block */
    CHECKED_ALLOCZ(s->mbintra_table, mb_array_size);
    memset(s->mbintra_table, 1, mb_array_size);
    
    /* init macroblock skip table */
    CHECKED_ALLOCZ(s->mbskip_table, mb_array_size+2);
    //Note the +1 is for a quicker mpeg4 slice_end detection
    CHECKED_ALLOCZ(s->prev_pict_types, PREV_PICT_TYPES_BUFFER_SIZE);
    
    s->parse_context.state= -1;    

    s->context_initialized = 1;

    s->thread_context[0]= s;
    for(i=1; i<s->avctx->thread_count; i++){
        s->thread_context[i]= av_malloc(sizeof(MpegEncContext));
        memcpy(s->thread_context[i], s, sizeof(MpegEncContext));
    }

    for(i=0; i<s->avctx->thread_count; i++){
        if(init_duplicate_context(s->thread_context[i], s) < 0)
           goto fail;
        s->thread_context[i]->start_mb_y= (s->mb_height*(i  ) + s->avctx->thread_count/2) / s->avctx->thread_count;
        s->thread_context[i]->end_mb_y  = (s->mb_height*(i+1) + s->avctx->thread_count/2) / s->avctx->thread_count;
    }

    return 0;
 fail:
    MPV_common_end(s);
    return -1;
}

/* init common structure for both encoder and decoder */


/* draw the edges of width 'w' of an image of size width, height */
//FIXME check that this is ok for mpeg4 interlaced
static void draw_edges_c(uint8_t *buf, int wrap, int width, int height, int w)
{
    uint8_t *ptr, *last_line;
    int i;

    last_line = buf + (height - 1) * wrap;
    for(i=0;i<w;i++) {
        /* top and bottom */
        memcpy(buf - (i + 1) * wrap, buf, width);
        memcpy(last_line + (i + 1) * wrap, last_line, width);
    }
    /* left and right */
    ptr = buf;
    for(i=0;i<height;i++) {
        memset(ptr - w, ptr[0], w);
        memset(ptr + width, ptr[width-1], w);
        ptr += wrap;
    }
    /* corners */
    for(i=0;i<w;i++) {
        memset(buf - (i + 1) * wrap - w, buf[0], w); /* top left */
        memset(buf - (i + 1) * wrap + width, buf[width-1], w); /* top right */
        memset(last_line + (i + 1) * wrap - w, last_line[0], w); /* top left */
        memset(last_line + (i + 1) * wrap + width, last_line[width-1], w); /* top right */
    }
}

int ff_find_unused_picture(MpegEncContext *s, int shared){
    int i;
    
    if(shared){
        for(i=0; i<MAX_PICTURE_COUNT; i++){
            if(s->picture[i].data[0]==NULL && s->picture[i].type==0) return i;
        }
    }else{
        for(i=0; i<MAX_PICTURE_COUNT; i++){
            if(s->picture[i].data[0]==NULL && s->picture[i].type!=0) return i; //FIXME
        }
        for(i=0; i<MAX_PICTURE_COUNT; i++){
            if(s->picture[i].data[0]==NULL) return i;
        }
    }
#ifndef WINCE //assert
    assert(0);
#endif
    return -1;
}

/**
 * generic function for encode/decode called after coding/decoding the header and before a frame is coded/decoded
 */
int MPV_frame_start(MpegEncContext *s, AVCodecContext *avctx)
{
    int i;
    AVFrame *pic;
    s->mb_skiped = 0;
#ifndef WINCE //assert
    assert(s->last_picture_ptr==NULL || s->out_format != FMT_H264 || s->codec_id == CODEC_ID_SVQ3);
#endif
    /* mark&release old frames */
    if (s->pict_type != B_TYPE && s->last_picture_ptr && s->last_picture_ptr->data[0]) {
        avctx->release_buffer(avctx, (AVFrame*)s->last_picture_ptr);

        /* release forgotten pictures */
        /* if(mpeg124/h263) */
        if(!s->encoding){
            for(i=0; i<MAX_PICTURE_COUNT; i++){
                if(s->picture[i].data[0] && &s->picture[i] != s->next_picture_ptr && s->picture[i].reference){
                    //av_log(avctx, AV_LOG_ERROR, "releasing zombie picture\n");
                    avctx->release_buffer(avctx, (AVFrame*)&s->picture[i]);                
                }
            }
        }
    }
alloc:
    if(!s->encoding){
        /* release non refernce frames */
        for(i=0; i<MAX_PICTURE_COUNT; i++){
            if(s->picture[i].data[0] && !s->picture[i].reference /*&& s->picture[i].type!=FF_BUFFER_TYPE_SHARED*/){
                s->avctx->release_buffer(s->avctx, (AVFrame*)&s->picture[i]);
            }
        }

        if(s->current_picture_ptr && s->current_picture_ptr->data[0]==NULL)
            pic= (AVFrame*)s->current_picture_ptr; //we allready have a unused image (maybe it was set before reading the header)
        else{
            i= ff_find_unused_picture(s, 0);
            pic= (AVFrame*)&s->picture[i];
        }

        pic->reference= s->pict_type != B_TYPE ? 3 : 0;

        pic->coded_picture_number= s->coded_picture_number++;
        
        if( alloc_picture(s, (Picture*)pic, 0) < 0)
            return -1;

        s->current_picture_ptr= (Picture*)pic;
        s->current_picture_ptr->top_field_first= s->top_field_first; //FIXME use only the vars from current_pic
        s->current_picture_ptr->interlaced_frame= !s->progressive_frame && !s->progressive_sequence;
    }

    s->current_picture_ptr->pict_type= s->pict_type;
//    if(s->flags && CODEC_FLAG_QSCALE) 
  //      s->current_picture_ptr->quality= s->new_picture_ptr->quality;
    s->current_picture_ptr->key_frame= s->pict_type == I_TYPE;

    copy_picture(&s->current_picture, s->current_picture_ptr);
  
  if(s->out_format != FMT_H264 || s->codec_id == CODEC_ID_SVQ3){
    if (s->pict_type != B_TYPE) {
        s->last_picture_ptr= s->next_picture_ptr;
        s->next_picture_ptr= s->current_picture_ptr;
    }
    
    if(s->last_picture_ptr) copy_picture(&s->last_picture, s->last_picture_ptr);
    if(s->next_picture_ptr) copy_picture(&s->next_picture, s->next_picture_ptr);
    
    if(s->pict_type != I_TYPE && (s->last_picture_ptr==NULL || s->last_picture_ptr->data[0]==NULL)){
        //av_log(avctx, AV_LOG_ERROR, "warning: first frame is no keyframe\n");
#ifndef WINCE //assert
        assert(s->pict_type != B_TYPE); //these should have been dropped if we dont have a reference
#endif
		goto alloc;
    }
#ifndef WINCE //assert
    assert(s->pict_type == I_TYPE || (s->last_picture_ptr && s->last_picture_ptr->data[0]));
#endif
    if(s->picture_structure!=PICT_FRAME){
        int i;
        for(i=0; i<4; i++){
            if(s->picture_structure == PICT_BOTTOM_FIELD){
                 s->current_picture.data[i] += s->current_picture.linesize[i];
            } 
            s->current_picture.linesize[i] *= 2;
            s->last_picture.linesize[i] *=2;
            s->next_picture.linesize[i] *=2;
        }
    }
  }
   
    s->hurry_up= s->avctx->hurry_up;
    

    //if(s->dct_error_sum){
#ifndef WINCE //assert
        assert(s->avctx->noise_reduction && s->encoding);
#endif
        //update_noise_reduction(s);
    //}
        
#ifdef HAVE_XVMC
    if(s->avctx->xvmc_acceleration)
        return XVMC_field_start(s, avctx);
#endif
    return 0;
}

/* generic function for encode/decode called after a frame has been coded/decoded */
void MPV_frame_end(MpegEncContext *s)
{
    /* draw edge for correct motion prediction if outside */
#ifdef HAVE_XVMC
//just to make sure that all data is rendered.
    if(s->avctx->xvmc_acceleration){
        XVMC_field_end(s);
    }else
#endif
#if 1
    if(s->unrestricted_mv && s->pict_type != B_TYPE && !s->intra_only && !(s->flags&CODEC_FLAG_EMU_EDGE)) {
            draw_edges(s->current_picture.data[0], s->linesize  , s->h_edge_pos   , s->v_edge_pos   , EDGE_WIDTH  );
            draw_edges(s->current_picture.data[1], s->uvlinesize, s->h_edge_pos>>1, s->v_edge_pos>>1, EDGE_WIDTH/2);
            draw_edges(s->current_picture.data[2], s->uvlinesize, s->h_edge_pos>>1, s->v_edge_pos>>1, EDGE_WIDTH/2);
    }
    //emms_c();
#endif
    
    s->last_pict_type    = s->pict_type;
    if(s->pict_type!=B_TYPE){
        s->last_non_b_pict_type= s->pict_type;
    }
#if 0
        /* copy back current_picture variables */
    for(i=0; i<MAX_PICTURE_COUNT; i++){
        if(s->picture[i].data[0] == s->current_picture.data[0]){
            s->picture[i]= s->current_picture;
            break;
        }    
    }
    assert(i<MAX_PICTURE_COUNT);
#endif    
#if 0
    if(s->encoding){
        /* release non refernce frames */
        for(i=0; i<MAX_PICTURE_COUNT; i++){
            if(s->picture[i].data[0] && !s->picture[i].reference /*&& s->picture[i].type!=FF_BUFFER_TYPE_SHARED*/){
                s->avctx->release_buffer(s->avctx, (AVFrame*)&s->picture[i]);
            }
        }
    }
#endif
    // clear copies, to avoid confusion
#if 0
    memset(&s->last_picture, 0, sizeof(Picture));
    memset(&s->next_picture, 0, sizeof(Picture));
    memset(&s->current_picture, 0, sizeof(Picture));
#endif
}


/**
 * Copies a rectangular area of samples to a temporary buffer and replicates the boarder samples.
 * @param buf destination buffer
 * @param src source buffer
 * @param linesize number of bytes between 2 vertically adjacent samples in both the source and destination buffers
 * @param block_w width of block
 * @param block_h height of block
 * @param src_x x coordinate of the top left sample of the block in the source buffer
 * @param src_y y coordinate of the top left sample of the block in the source buffer
 * @param w width of the source buffer
 * @param h height of the source buffer
 */
void ff_emulated_edge_mc(uint8_t *buf, uint8_t *src, int linesize, int block_w, int block_h, 
                                    int src_x, int src_y, int w, int h){
    int x, y;
    int start_y, start_x, end_y, end_x;

    if(src_y>= h){
        src+= (h-1-src_y)*linesize;
        src_y=h-1;
    }else if(src_y<=-block_h){
        src+= (1-block_h-src_y)*linesize;
        src_y=1-block_h;
    }
    if(src_x>= w){
        src+= (w-1-src_x);
        src_x=w-1;
    }else if(src_x<=-block_w){
        src+= (1-block_w-src_x);
        src_x=1-block_w;
    }

    start_y= FFMAX(0, -src_y);
    start_x= FFMAX(0, -src_x);
    end_y= FFMIN(block_h, h-src_y);
    end_x= FFMIN(block_w, w-src_x);

    // copy existing part
    for(y=start_y; y<end_y; y++){
        for(x=start_x; x<end_x; x++){
            buf[x + y*linesize]= src[x + y*linesize];
        }
    }

    //top
    for(y=0; y<start_y; y++){
        for(x=start_x; x<end_x; x++){
            buf[x + y*linesize]= buf[x + start_y*linesize];
        }
    }

    //bottom
    for(y=end_y; y<block_h; y++){
        for(x=start_x; x<end_x; x++){
            buf[x + y*linesize]= buf[x + (end_y-1)*linesize];
        }
    }
                                    
    for(y=0; y<block_h; y++){
       //left
        for(x=0; x<start_x; x++){
            buf[x + y*linesize]= buf[start_x + y*linesize];
        }
       
       //right
        for(x=end_x; x<block_w; x++){
            buf[x + y*linesize]= buf[end_x - 1 + y*linesize];
        }
    }
}

/**
 * combines the (truncated) bitstream to a complete frame
 * @returns -1 if no complete frame could be created
 */
int ff_combine_frame( MpegEncContext *s, int next, uint8_t **buf, int *buf_size){
    ParseContext *pc= &s->parse_context;

#if 0
    if(pc->overread){
        printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
        printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
    }
#endif

    /* copy overreaded byes from last frame into buffer */
    for(; pc->overread>0; pc->overread--){
        pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
    }
    
    pc->last_index= pc->index;

    /* copy into buffer end return */
    if(next == END_NOT_FOUND){
        pc->buffer= av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);

        memcpy(&pc->buffer[pc->index], *buf, *buf_size);
        pc->index += *buf_size;
        return -1;
    }

    *buf_size=
    pc->overread_index= pc->index + next;
    
    /* append to buffer */
    if(pc->index){
        pc->buffer= av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);

        memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
        pc->index = 0;
        *buf= pc->buffer;
    }

    /* store overread bytes */
    for(;next < 0; next++){
        pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
        pc->overread++;
    }

#if 0
    if(pc->overread){
        printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
        printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
    }
#endif

    return 0;
}