dv.c

tcpmp播放器的flv插件

              bi->bit_size[area] += dv_rl2vlc_size(i - prev  - 1, level);
              bi->next[prev]= i;
              prev= i;
          }
       }
    }
    bi->next[prev]= i;
    for(bi->cno = 0; max > classes[bi->cno]; bi->cno++);

    bi->cno += bias;
    
    if (bi->cno >= 3) {
        bi->cno = 3;
        prev=0;
        i= bi->next[prev];
        for (area = 0; area < 4; area++) {
            bi->prev[area] = prev;
            bi->bit_size[area] = 1; // 4 areas 4 bits for EOB :)
            for (; i<mb_area_start[area+1]; i= bi->next[i]) {
                bi->mb[i] >>=1;
            
                if (bi->mb[i]) {
                    bi->bit_size[area] += dv_rl2vlc_size(i - prev - 1, bi->mb[i]);
                    bi->next[prev]= i;
                    prev= i;
                }
            }
        }
        bi->next[prev]= i;
    }
}

//FIXME replace this by dsputil
#define SC(x, y) ((s[x] - s[y]) ^ ((s[x] - s[y]) >> 7))
static always_inline int dv_guess_dct_mode(DCTELEM *blk) {
    DCTELEM *s;
    int score88 = 0;
    int score248 = 0;
    int i;
    
    /* Compute 8-8 score (small values give a better chance for 8-8 DCT) */
    s = blk;
    for(i=0; i<7; i++) {
        score88 += SC(0,  8) + SC(1, 9) + SC(2, 10) + SC(3, 11) + 
	           SC(4, 12) + SC(5,13) + SC(6, 14) + SC(7, 15);
        s += 8;
    }
    /* Compute 2-4-8 score (small values give a better chance for 2-4-8 DCT) */
    s = blk;
    for(i=0; i<6; i++) {
        score248 += SC(0, 16) + SC(1,17) + SC(2, 18) + SC(3, 19) +
	            SC(4, 20) + SC(5,21) + SC(6, 22) + SC(7, 23);
        s += 8;
    }

    return (score88 - score248 > -10);
}

static inline void dv_guess_qnos(EncBlockInfo* blks, int* qnos)
{
    int size[5];
    int i, j, k, a, prev;
    EncBlockInfo* b;

    do {
       b = blks;
       for (i=0; i<5; i++) {
          if (!qnos[i])
	      continue;
	  
	  qnos[i]--;
	  size[i] = 0;
          for (j=0; j<6; j++, b++) {
	     for (a=0; a<4; a++) {
	        if (b->area_q[a] != dv_quant_shifts[qnos[i] + dv_quant_offset[b->cno]][a]) {
		    b->bit_size[a] = 1; // 4 areas 4 bits for EOB :)
		    b->area_q[a]++;
                    prev= b->prev[a];
                    for (k= b->next[prev] ; k<mb_area_start[a+1]; k= b->next[k]) {
		       b->mb[k] >>= 1;
		       if (b->mb[k]) {
                           b->bit_size[a] += dv_rl2vlc_size(k - prev - 1, b->mb[k]);
	                   prev= k;
                       } else {
                           b->next[prev] = b->next[k];
                       }
		    }
                    b->prev[a+1]= prev;
		}
		size[i] += b->bit_size[a];
	     }
	  }
       }
    } while ((vs_total_ac_bits < size[0] + size[1] + size[2] + size[3] + size[4]) && 
             (qnos[0]|qnos[1]|qnos[2]|qnos[3]|qnos[4]));
}

/*
 * This is a very rough initial implementaion. The performance is
 * horrible and the weighting is missing. But it's missing from the 
 * decoding step also -- so at least we're on the same page with decoder ;-)
 */
static inline void dv_encode_video_segment(DVVideoContext *s, 
                                           uint8_t *dif, 
                                           const uint16_t *mb_pos_ptr)
{
    int mb_index, i, j, v;
    int mb_x, mb_y, c_offset, linesize; 
    uint8_t*  y_ptr;
    uint8_t*  data;
    uint8_t*  ptr;
    int       do_edge_wrap;
    DCTELEM   block[64] __align8;
    EncBlockInfo  enc_blks[5*6];
    PutBitContext pbs[5*6];
    PutBitContext* pb; 
    EncBlockInfo* enc_blk;
    int       vs_bit_size = 0;
    int       qnos[5];
    
    assert((((int)block) & 7) == 0);
   
    enc_blk = &enc_blks[0];
    pb = &pbs[0];
    for(mb_index = 0; mb_index < 5; mb_index++) {
        v = *mb_pos_ptr++;
        mb_x = v & 0xff;
        mb_y = v >> 8;
        y_ptr = s->picture.data[0] + (mb_y * s->picture.linesize[0] * 8) + (mb_x * 8);
	c_offset = (s->sys->pix_fmt == PIX_FMT_YUV411P) ?
	           ((mb_y * s->picture.linesize[1] * 8) + ((mb_x >> 2) * 8)) :
		   (((mb_y >> 1) * s->picture.linesize[1] * 8) + ((mb_x >> 1) * 8));
	do_edge_wrap = 0;
	qnos[mb_index] = 15; /* No quantization */
        ptr = dif + mb_index*80 + 4;
        for(j = 0;j < 6; j++) {
            if (j < 4) {  /* Four Y blocks */
		/* NOTE: at end of line, the macroblock is handled as 420 */
		if (s->sys->pix_fmt == PIX_FMT_YUV411P && mb_x < (704 / 8)) {
                    data = y_ptr + (j * 8);
                } else {
                    data = y_ptr + ((j & 1) * 8) + ((j >> 1) * 8 * s->picture.linesize[0]);
                }
		linesize = s->picture.linesize[0];
            } else {      /* Cr and Cb blocks */
	        /* don't ask Fabrice why they inverted Cb and Cr ! */
	        data = s->picture.data[6 - j] + c_offset;
		linesize = s->picture.linesize[6 - j];
		if (s->sys->pix_fmt == PIX_FMT_YUV411P && mb_x >= (704 / 8))
		    do_edge_wrap = 1;
	    }	
            
	    /* Everything is set up -- now just copy data -> DCT block */
	    if (do_edge_wrap) {  /* Edge wrap copy: 4x16 -> 8x8 */
		uint8_t* d;
		DCTELEM *b = block;
	        for (i=0;i<8;i++) {
		   d = data + 8 * linesize;
		   b[0] = data[0]; b[1] = data[1]; b[2] = data[2]; b[3] = data[3];
                   b[4] =    d[0]; b[5] =    d[1]; b[6] =    d[2]; b[7] =    d[3];
		   data += linesize;
		   b += 8;
		}
	    } else {             /* Simple copy: 8x8 -> 8x8 */
	        s->get_pixels(block, data, linesize);
	    }
	  
            if(s->avctx->flags & CODEC_FLAG_INTERLACED_DCT)
                enc_blk->dct_mode = dv_guess_dct_mode(block);
            else
                enc_blk->dct_mode = 0;
	    enc_blk->area_q[0] = enc_blk->area_q[1] = enc_blk->area_q[2] = enc_blk->area_q[3] = 0;
	    enc_blk->partial_bit_count = 0;
	    enc_blk->partial_bit_buffer = 0;
	    enc_blk->cur_ac = 0;
	    
	    s->fdct[enc_blk->dct_mode](block);
	    
	    dv_set_class_number(block, enc_blk, 
	                        enc_blk->dct_mode ? ff_zigzag248_direct : ff_zigzag_direct, j/4);
           
            init_put_bits(pb, ptr, block_sizes[j]/8);
	    put_bits(pb, 9, (uint16_t)(((enc_blk->mb[0] >> 3) - 1024 + 2) >> 2));
	    put_bits(pb, 1, enc_blk->dct_mode);
	    put_bits(pb, 2, enc_blk->cno);
	    
	    vs_bit_size += enc_blk->bit_size[0] + enc_blk->bit_size[1] +
	                   enc_blk->bit_size[2] + enc_blk->bit_size[3];
	    ++enc_blk;
	    ++pb;
	    ptr += block_sizes[j]/8;
        }
    }

    if (vs_total_ac_bits < vs_bit_size)
        dv_guess_qnos(&enc_blks[0], &qnos[0]);

    for (i=0; i<5; i++) {
       dif[i*80 + 3] = qnos[i];
    }

    /* First pass over individual cells only */
    for (j=0; j<5*6; j++)
       dv_encode_ac(&enc_blks[j], &pbs[j], &pbs[j+1]);

    /* Second pass over each MB space */
    for (j=0; j<5*6; j+=6) {
        pb= &pbs[j];
        for (i=0; i<6; i++) {
            if (enc_blks[i+j].partial_bit_count)
                pb=dv_encode_ac(&enc_blks[i+j], pb, &pbs[j+6]);
        }
    }

    /* Third and final pass over the whole vides segment space */
    pb= &pbs[0];
    for (j=0; j<5*6; j++) {
       if (enc_blks[j].partial_bit_count)
           pb=dv_encode_ac(&enc_blks[j], pb, &pbs[6*5]);
    }

    for (j=0; j<5*6; j++)
       flush_put_bits(&pbs[j]);
}

static int dv_decode_mt(AVCodecContext *avctx, void* sl)
{
    DVVideoContext *s = avctx->priv_data;
    int slice = (size_t)sl;
    dv_decode_video_segment(s, &s->buf[((slice/27)*6+(slice/3)+slice*5+7)*80],
	                    &s->sys->video_place[slice*5]);
    return 0;
}

static int dv_encode_mt(AVCodecContext *avctx, void* sl)
{
    DVVideoContext *s = avctx->priv_data;
    int slice = (size_t)sl;
    dv_encode_video_segment(s, &s->buf[((slice/27)*6+(slice/3)+slice*5+7)*80],
	                    &s->sys->video_place[slice*5]);
    return 0;
}

/* NOTE: exactly one frame must be given (120000 bytes for NTSC,
   144000 bytes for PAL) */
static int dvvideo_decode_frame(AVCodecContext *avctx, 
                                 void *data, int *data_size,
                                 uint8_t *buf, int buf_size)
{
    DVVideoContext *s = avctx->priv_data;
  
    s->sys = dv_frame_profile(buf);
    if (!s->sys || buf_size < s->sys->frame_size)
        return -1; /* NOTE: we only accept several full frames */

    if(s->picture.data[0])
        avctx->release_buffer(avctx, &s->picture);
    
    s->picture.reference = 0;
    s->picture.key_frame = 1;
    s->picture.pict_type = FF_I_TYPE;
    avctx->pix_fmt = s->sys->pix_fmt;
    avcodec_set_dimensions(avctx, s->sys->width, s->sys->height);
    if(avctx->get_buffer(avctx, &s->picture) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }
    s->picture.interlaced_frame = 1;
    s->picture.top_field_first = 0;

    s->buf = buf;
    avctx->execute(avctx, dv_decode_mt, (void**)&dv_anchor[0], NULL, 
	           s->sys->difseg_size * 27);
    
    emms_c();

    /* return image */
    *data_size = sizeof(AVFrame);
    *(AVFrame*)data= s->picture;
    
    return s->sys->frame_size;
}

static int dvvideo_encode_frame(AVCodecContext *c, uint8_t *buf, int buf_size, 
                                void *data)
{
    DVVideoContext *s = c->priv_data;

    s->sys = dv_codec_profile(c);
    if (!s->sys)
	return -1;
    if(buf_size < s->sys->frame_size)
        return -1;

    c->pix_fmt = s->sys->pix_fmt;
    s->picture = *((AVFrame *)data);
    s->picture.key_frame = 1;
    s->picture.pict_type = FF_I_TYPE;

    s->buf = buf;
    c->execute(c, dv_encode_mt, (void**)&dv_anchor[0], NULL, 
	       s->sys->difseg_size * 27);

    emms_c();
    return s->sys->frame_size;
}

#ifdef CONFIG_DVVIDEO_ENCODER
AVCodec dvvideo_encoder = {
    "dvvideo",
    CODEC_TYPE_VIDEO,
    CODEC_ID_DVVIDEO,
    sizeof(DVVideoContext),
    dvvideo_init,
    dvvideo_encode_frame,
    NULL,
    NULL,
    CODEC_CAP_DR1,
    NULL
};
#endif // CONFIG_DVVIDEO_ENCODER

AVCodec dvvideo_decoder = {
    "dvvideo",
    CODEC_TYPE_VIDEO,
    CODEC_ID_DVVIDEO,
    sizeof(DVVideoContext),
    dvvideo_init,
    NULL,
    NULL,
    dvvideo_decode_frame,
    CODEC_CAP_DR1,
    NULL
};