huffyuv.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.7平台上编译为嵌入式图形界面操作系统。

/*
 * huffyuv codec for libavcodec
 *
 * Copyright (c) 2002 Michael Niedermayer <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * see http://www.pcisys.net/~melanson/codecs/huffyuv.txt for a description of
 * the algorithm used 
 */

#include "common.h"
#include "avcodec.h"
#include "dsputil.h"

#ifndef INT64_MAX
#define INT64_MAX 9223372036854775807LL
#endif

#define VLC_BITS 11
  
typedef enum Predictor{
    LEFT= 0,
    PLANE,
    MEDIAN,
} Predictor;
 
typedef struct HYuvContext{
    AVCodecContext *avctx;
    Predictor predictor;
    GetBitContext gb;
    PutBitContext pb;
    int interlaced;
    int decorrelate;
    int bitstream_bpp;
    int version;
    int yuy2;                               //use yuy2 instead of 422P
    int bgr32;                              //use bgr32 instead of bgr24
    int width, height;
    int flags;
    int picture_number;
    int last_slice_end;
    int linesize[3];
    uint8_t __align8 temp[3][2500];
    uint64_t stats[3][256];
    uint8_t len[3][256];
    uint32_t bits[3][256];
    VLC vlc[3];
    uint8_t __align8 *picture[3];
    uint8_t __align8 bitstream_buffer[1024*1024*3]; //FIXME dynamic alloc or some other solution
    DSPContext dsp; 
}HYuvContext;

static inline void bswap_buf(uint32_t *dst, uint32_t *src, int w){
    int i;
    
    for(i=0; i+8<=w; i+=8){
        dst[i+0]= bswap_32(src[i+0]);
        dst[i+1]= bswap_32(src[i+1]);
        dst[i+2]= bswap_32(src[i+2]);
        dst[i+3]= bswap_32(src[i+3]);
        dst[i+4]= bswap_32(src[i+4]);
        dst[i+5]= bswap_32(src[i+5]);
        dst[i+6]= bswap_32(src[i+6]);
        dst[i+7]= bswap_32(src[i+7]);
    }
    for(;i<w; i++){
        dst[i+0]= bswap_32(src[i+0]);
    }
}

static inline int add_left_prediction(uint8_t *dst, uint8_t *src, int w, int acc){
    int i;

    for(i=0; i<w-1; i++){
        acc+= src[i];
        dst[i]= acc;
        i++;
        acc+= src[i];
        dst[i]= acc;
    }

    for(; i<w; i++){
        acc+= src[i];
        dst[i]= acc;
    }

    return acc;
}

static inline void add_median_prediction(uint8_t *dst, uint8_t *src1, uint8_t *diff, int w, int *left, int *left_top){
    int i;
    uint8_t l, lt;

    l= *left;
    lt= *left_top;

    for(i=0; i<w; i++){
        l= mid_pred(l, src1[i], (l + src1[i] - lt)&0xFF) + diff[i];
        lt= src1[i];
        dst[i]= l;
    }    

    *left= l;
    *left_top= lt;
}
//FIXME optimize
static inline void sub_median_prediction(uint8_t *dst, uint8_t *src1, uint8_t *src2, int w, int *left, int *left_top){
    int i;
    uint8_t l, lt;

    l= *left;
    lt= *left_top;

    for(i=0; i<w; i++){
        const int pred= mid_pred(l, src1[i], (l + src1[i] - lt)&0xFF);
        lt= src1[i];
        l= src2[i];
        dst[i]= l - pred;
    }    

    *left= l;
    *left_top= lt;
}


static inline void add_left_prediction_bgr32(uint8_t *dst, uint8_t *src, int w, int *red, int *green, int *blue){
    int i;
    int r,g,b;
    r= *red;
    g= *green;
    b= *blue;

    for(i=0; i<w; i++){
        b+= src[4*i+0];
        g+= src[4*i+1];
        r+= src[4*i+2];
        
        dst[4*i+0]= b;
        dst[4*i+1]= g;
        dst[4*i+2]= r;
    }

    *red= r;
    *green= g;
    *blue= b;
}

static inline int sub_left_prediction(HYuvContext *s, uint8_t *dst, uint8_t *src, int w, int left){
    int i;
    if(w<32){
        for(i=0; i<w; i++){
            const int temp= src[i];
            dst[i]= temp - left;
            left= temp;
        }
        return left;
    }else{
        for(i=0; i<16; i++){
            const int temp= src[i];
            dst[i]= temp - left;
            left= temp;
        }
        s->dsp.diff_bytes(dst+16, src+16, src+15, w-16);
        return src[w-1];
    }
}

static void read_len_table(uint8_t *dst, GetBitContext *gb){
    int i, val, repeat;
  
    for(i=0; i<256;){
        repeat= get_bits(gb, 3);
        val   = get_bits(gb, 5);
        if(repeat==0)
            repeat= get_bits(gb, 8);
//printf("%d %d\n", val, repeat);
        while (repeat--)
            dst[i++] = val;
    }
}

static int generate_bits_table(uint32_t *dst, uint8_t *len_table){
    int len, index;
    uint32_t bits=0;

    for(len=32; len>0; len--){
        int bit= 1<<(32-len);
        for(index=0; index<256; index++){
            if(len_table[index]==len){
                if(bits & (bit-1)){
                    fprintf(stderr, "Error generating huffman table\n");
                    return -1;
                }
                dst[index]= bits>>(32-len);
                bits+= bit;
            }
        }
    }
    return 0;
}

static void generate_len_table(uint8_t *dst, uint64_t *stats, int size){
    uint64_t counts[2*size];
    int up[2*size];
    int offset, i, next;
    
    for(offset=1; ; offset<<=1){
        for(i=0; i<size; i++){
            counts[i]= stats[i] + offset - 1;
        }
        
        for(next=size; next<size*2; next++){
            uint64_t min1, min2;
            int min1_i, min2_i;
            
            min1=min2= INT64_MAX;
            min1_i= min2_i=-1;
            
            for(i=0; i<next; i++){
                if(min2 > counts[i]){
                    if(min1 > counts[i]){
                        min2= min1;
                        min2_i= min1_i;
                        min1= counts[i];
                        min1_i= i;
                    }else{
                        min2= counts[i];
                        min2_i= i;
                    }
                }
            }
            
            if(min2==INT64_MAX) break;
            
            counts[next]= min1 + min2;
            counts[min1_i]=
            counts[min2_i]= INT64_MAX;
            up[min1_i]=
            up[min2_i]= next;
            up[next]= -1;
        }
        
        for(i=0; i<size; i++){
            int len;
            int index=i;
            
            for(len=0; up[index] != -1; len++)
                index= up[index];
                
            if(len > 32) break;
            
            dst[i]= len;
        }
        if(i==size) break;
    }
}

static int read_huffman_tables(HYuvContext *s, uint8_t *src, int length){
    GetBitContext gb;
    int i;
    
    init_get_bits(&gb, src, length);
    
    for(i=0; i<3; i++){
        read_len_table(s->len[i], &gb);
        
        if(generate_bits_table(s->bits[i], s->len[i])<0){
            return -1;
        }
#if 0
for(j=0; j<256; j++){
printf("%6X, %2d,  %3d\n", s->bits[i][j], s->len[i][j], j);
}
#endif
        init_vlc(&s->vlc[i], VLC_BITS, 256, s->len[i], 1, 1, s->bits[i], 4, 4);
    }
    
    return 0;
}

static int read_old_huffman_tables(HYuvContext *s){
#if 0    
    GetBitContext gb;
    int i;

    init_get_bits(&gb, classic_shift_luma, sizeof(classic_shift_luma));
    read_len_table(s->len[0], &gb);
    init_get_bits(&gb, classic_shift_chroma, sizeof(classic_shift_chroma));
    read_len_table(s->len[1], &gb);
    
    for(i=0; i<256; i++) s->bits[0][i] = classic_add_luma  [i];
    for(i=0; i<256; i++) s->bits[1][i] = classic_add_chroma[i];

    if(s->bitstream_bpp >= 24){
        memcpy(s->bits[1], s->bits[0], 256*sizeof(uint32_t));
        memcpy(s->len[1] , s->len [0], 256*sizeof(uint8_t));
    }
    memcpy(s->bits[2], s->bits[1], 256*sizeof(uint32_t));
    memcpy(s->len[2] , s->len [1], 256*sizeof(uint8_t));
    
    for(i=0; i<3; i++)
        init_vlc(&s->vlc[i], VLC_BITS, 256, s->len[i], 1, 1, s->bits[i], 4, 4);
    
    return 0;
#else
    fprintf(stderr, "v1 huffyuv is not supported \n");
    return -1;
#endif
}

static int decode_init(AVCodecContext *avctx)
{
    HYuvContext *s = avctx->priv_data;
    int width, height, y_size, c_size, stride;

    s->avctx= avctx;
    s->flags= avctx->flags;
        
    dsputil_init(&s->dsp, avctx->dsp_mask);
    
    width= s->width= avctx->width;
    height= s->height= avctx->height;
s->bgr32=1;
    assert(width && height);
//if(avctx->extradata)
//  printf("extradata:%X, extradata_size:%d\n", *(uint32_t*)avctx->extradata, avctx->extradata_size);
    if(avctx->extradata_size){
        if((avctx->bits_per_sample&7) && avctx->bits_per_sample != 12)
            s->version=1; // do such files exist at all?
        else
            s->version=2;
    }else
        s->version=0;
    
    if(s->version==2){
        int method;

        method= ((uint8_t*)avctx->extradata)[0];
        s->decorrelate= method&64 ? 1 : 0;
        s->predictor= method&63;
        s->bitstream_bpp= ((uint8_t*)avctx->extradata)[1];
        if(s->bitstream_bpp==0) 
            s->bitstream_bpp= avctx->bits_per_sample&~7;
            
        if(read_huffman_tables(s, ((uint8_t*)avctx->extradata)+4, avctx->extradata_size) < 0)
            return -1;
    }else{
        switch(avctx->bits_per_sample&7){
        case 1:
            s->predictor= LEFT;
            s->decorrelate= 0;
            break;
        case 2:
            s->predictor= LEFT;
            s->decorrelate= 1;
            break;
        case 3:
            s->predictor= PLANE;
            s->decorrelate= avctx->bits_per_sample >= 24;
            break;
        case 4:
            s->predictor= MEDIAN;
            s->decorrelate= 0;
            break;