mjpeg.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

    put_bits(&s->pb, 4, s->mjpeg_hsample[0]); /* H factor */
    put_bits(&s->pb, 4, s->mjpeg_vsample[0]); /* V factor */
    put_bits(&s->pb, 8, 0); /* select matrix */
    
    /* Cb component */
    put_bits(&s->pb, 8, 2); /* component number */
    put_bits(&s->pb, 4, s->mjpeg_hsample[1]); /* H factor */
    put_bits(&s->pb, 4, s->mjpeg_vsample[1]); /* V factor */
#ifdef TWOMATRIXES
    put_bits(&s->pb, 8, lossless ? 0 : 1); /* select matrix */
#else
    put_bits(&s->pb, 8, 0); /* select matrix */
#endif

    /* Cr component */
    put_bits(&s->pb, 8, 3); /* component number */
    put_bits(&s->pb, 4, s->mjpeg_hsample[2]); /* H factor */
    put_bits(&s->pb, 4, s->mjpeg_vsample[2]); /* V factor */
#ifdef TWOMATRIXES
    put_bits(&s->pb, 8, lossless ? 0 : 1); /* select matrix */
#else
    put_bits(&s->pb, 8, 0); /* select matrix */
#endif
    }

    /* scan header */
    put_marker(&s->pb, SOS);
    put_bits(&s->pb, 16, 12); /* length */
    put_bits(&s->pb, 8, 3); /* 3 components */
    
    /* Y component */
    put_bits(&s->pb, 8, 1); /* index */
    put_bits(&s->pb, 4, 0); /* DC huffman table index */
    put_bits(&s->pb, 4, 0); /* AC huffman table index */
    
    /* Cb component */
    put_bits(&s->pb, 8, 2); /* index */
    put_bits(&s->pb, 4, 1); /* DC huffman table index */
    put_bits(&s->pb, 4, lossless ? 0 : 1); /* AC huffman table index */
    
    /* Cr component */
    put_bits(&s->pb, 8, 3); /* index */
    put_bits(&s->pb, 4, 1); /* DC huffman table index */
    put_bits(&s->pb, 4, lossless ? 0 : 1); /* AC huffman table index */

    put_bits(&s->pb, 8, lossless ? s->avctx->prediction_method+1 : 0); /* Ss (not used) */
    put_bits(&s->pb, 8, lossless ? 0 : 63); /* Se (not used) */
    put_bits(&s->pb, 8, 0); /* Ah/Al (not used) */
}

static void escape_FF(MpegEncContext *s, int start)
{
    int size= get_bit_count(&s->pb) - start*8;
    int i, ff_count;
    uint8_t *buf= s->pb.buf + start;
    int align= (-(size_t)(buf))&3;
    
    assert((size&7) == 0);
    size >>= 3;
    
    ff_count=0;
    for(i=0; i<size && i<align; i++){
        if(buf[i]==0xFF) ff_count++;
    }
    for(; i<size-15; i+=16){
        int acc, v;

        v= *(uint32_t*)(&buf[i]);
        acc= (((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
        v= *(uint32_t*)(&buf[i+4]);
        acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
        v= *(uint32_t*)(&buf[i+8]);
        acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
        v= *(uint32_t*)(&buf[i+12]);
        acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;

        acc>>=4;
        acc+= (acc>>16);
        acc+= (acc>>8);
        ff_count+= acc&0xFF;
    }
    for(; i<size; i++){
        if(buf[i]==0xFF) ff_count++;
    }

    if(ff_count==0) return;
    
    /* skip put bits */
    for(i=0; i<ff_count-3; i+=4)
        put_bits(&s->pb, 32, 0);
    put_bits(&s->pb, (ff_count-i)*8, 0);
    flush_put_bits(&s->pb); 

    for(i=size-1; ff_count; i--){
        int v= buf[i];

        if(v==0xFF){
//printf("%d %d\n", i, ff_count);
            buf[i+ff_count]= 0;
            ff_count--;
        }

        buf[i+ff_count]= v;
    }
}

void mjpeg_picture_trailer(MpegEncContext *s)
{
    int pad= (-get_bit_count(&s->pb))&7;
    
    put_bits(&s->pb, pad,0xFF>>(8-pad));
    flush_put_bits(&s->pb);

    assert((s->header_bits&7)==0);
    
    escape_FF(s, s->header_bits>>3);

    put_marker(&s->pb, EOI);
}

static inline void mjpeg_encode_dc(MpegEncContext *s, int val,
				   uint8_t *huff_size, uint16_t *huff_code)
{
    int mant, nbits;

    if (val == 0) {
        put_bits(&s->pb, huff_size[0], huff_code[0]);
    } else {
        mant = val;
        if (val < 0) {
            val = -val;
            mant--;
        }
        
        nbits= av_log2_16bit(val) + 1;
            
        put_bits(&s->pb, huff_size[nbits], huff_code[nbits]);
        
        put_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));
    }
}

static void encode_block(MpegEncContext *s, DCTELEM *block, int n)
{
    int mant, nbits, code, i, j;
    int component, dc, run, last_index, val;
    MJpegContext *m = s->mjpeg_ctx;
    uint8_t *huff_size_ac;
    uint16_t *huff_code_ac;
    
    /* DC coef */
    component = (n <= 3 ? 0 : n - 4 + 1);
    dc = block[0]; /* overflow is impossible */
    val = dc - s->last_dc[component];
    if (n < 4) {
        mjpeg_encode_dc(s, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance);
        huff_size_ac = m->huff_size_ac_luminance;
        huff_code_ac = m->huff_code_ac_luminance;
    } else {
        mjpeg_encode_dc(s, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
        huff_size_ac = m->huff_size_ac_chrominance;
        huff_code_ac = m->huff_code_ac_chrominance;
    }
    s->last_dc[component] = dc;
    
    /* AC coefs */
    
    run = 0;
    last_index = s->block_last_index[n];
    for(i=1;i<=last_index;i++) {
        j = s->intra_scantable.permutated[i];
        val = block[j];
        if (val == 0) {
            run++;
        } else {
            while (run >= 16) {
                put_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]);
                run -= 16;
            }
            mant = val;
            if (val < 0) {
                val = -val;
                mant--;
            }
            
            nbits= av_log2(val) + 1;
            code = (run << 4) | nbits;

            put_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]);
        
            put_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));
            run = 0;
        }
    }

    /* output EOB only if not already 64 values */
    if (last_index < 63 || run != 0)
        put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);
}

void mjpeg_encode_mb(MpegEncContext *s, 
                     DCTELEM block[6][64])
{
    int i;
    for(i=0;i<6;i++) {
        encode_block(s, block[i], i);
    }
}

static int encode_picture_lossless(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
    MpegEncContext * const s = avctx->priv_data;
    MJpegContext * const m = s->mjpeg_ctx;
    AVFrame *pict = data;
    const int width= s->width;
    const int height= s->height;
    AVFrame * const p= (AVFrame*)&s->current_picture;
    const int predictor= avctx->prediction_method+1;

    init_put_bits(&s->pb, buf, buf_size);

    *p = *pict;
    p->pict_type= FF_I_TYPE;
    p->key_frame= 1;
    
    mjpeg_picture_header(s);

    s->header_bits= get_bit_count(&s->pb);

    if(avctx->pix_fmt == PIX_FMT_RGBA32){
        int x, y, i;
        const int linesize= p->linesize[0];
        uint16_t buffer[2048][4];
        int left[3], top[3], topleft[3];

        for(i=0; i<3; i++){
            buffer[0][i]= 1 << (9 - 1);
        }

        for(y = 0; y < height; y++) {
            const int modified_predictor= y ? predictor : 1;
            uint8_t *ptr = p->data[0] + (linesize * y);

            for(i=0; i<3; i++){
                top[i]= left[i]= topleft[i]= buffer[0][i];
            }
            for(x = 0; x < width; x++) {
                buffer[x][1] = ptr[4*x+0] - ptr[4*x+1] + 0x100;
                buffer[x][2] = ptr[4*x+2] - ptr[4*x+1] + 0x100;
                buffer[x][0] = (ptr[4*x+0] + 2*ptr[4*x+1] + ptr[4*x+2])>>2;

                for(i=0;i<3;i++) {
                    int pred, diff;

                    PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
                        
                    topleft[i]= top[i];
                    top[i]= buffer[x+1][i];
                    
                    left[i]= buffer[x][i];

                    diff= ((left[i] - pred + 0x100)&0x1FF) - 0x100;
                    
                    if(i==0)
                        mjpeg_encode_dc(s, diff, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
                    else
                        mjpeg_encode_dc(s, diff, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
                }
            }
        }
    }else{
        int mb_x, mb_y, i;
        const int mb_width  = (width  + s->mjpeg_hsample[0] - 1) / s->mjpeg_hsample[0];
        const int mb_height = (height + s->mjpeg_vsample[0] - 1) / s->mjpeg_vsample[0];
        
        for(mb_y = 0; mb_y < mb_height; mb_y++) {
            for(mb_x = 0; mb_x < mb_width; mb_x++) {
                if(mb_x==0 || mb_y==0){
                    for(i=0;i<3;i++) {
                        uint8_t *ptr;
                        int x, y, h, v, linesize;
                        h = s->mjpeg_hsample[i];
                        v = s->mjpeg_vsample[i];
                        linesize= p->linesize[i];

                        for(y=0; y<v; y++){
                            for(x=0; x<h; x++){
                                int pred;

                                ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
                                if(y==0 && mb_y==0){
                                    if(x==0 && mb_x==0){
                                        pred= 128;
                                    }else{
                                        pred= ptr[-1];
                                    }
                                }else{
                                    if(x==0 && mb_x==0){
                                        pred= ptr[-linesize];
                                    }else{
                                        PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
                                    }
                                }
                                
                                if(i==0)
                                    mjpeg_encode_dc(s, (int8_t)(*ptr - pred), m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
                                else
                                    mjpeg_encode_dc(s, (int8_t)(*ptr - pred), m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
                            }
                        }
                    }
                }else{
                    for(i=0;i<3;i++) {
                        uint8_t *ptr;
                        int x, y, h, v, linesize;
                        h = s->mjpeg_hsample[i];
                        v = s->mjpeg_vsample[i];
                        linesize= p->linesize[i];
                             
                        for(y=0; y<v; y++){
                            for(x=0; x<h; x++){
                                int pred;

                                ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
//printf("%d %d %d %d %8X\n", mb_x, mb_y, x, y, ptr); 
                                PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);

                                if(i==0)
                                    mjpeg_encode_dc(s, (int8_t)(*ptr - pred), m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
                                else
                                    mjpeg_encode_dc(s, (int8_t)(*ptr - pred), m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
                            }
                        }
                    }
                }
            }
        }
    }

    emms_c();
    
    mjpeg_picture_trailer(s);
    s->picture_number++;

    flush_put_bits(&s->pb);
    return pbBufPtr(&s->pb) - s->pb.buf;
//    return (get_bit_count(&f->pb)+7)/8;
}

#endif //CONFIG_ENCODERS

/******************************************/
/* decoding */

#define MAX_COMPONENTS 4

typedef struct MJpegDecodeContext {
    AVCodecContext *avctx;
    GetBitContext gb;
    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */

    int start_code; /* current start code */
    int buffer_size;
    uint8_t *buffer;

    int16_t quant_matrixes[4][64];
    VLC vlcs[2][4];
    int qscale[4];      ///< quantizer scale calculated from quant_matrixes

    int org_width, org_height;  /* size given at codec init */
    int first_picture;    /* true if decoding first picture */
    int interlaced;     /* true if interlaced */
    int bottom_field;   /* true if bottom field */
    int lossless;
    int rgb;
    int rct;            /* standard rct */  
    int pegasus_rct;    /* pegasus reversible colorspace transform */  
    int bits;           /* bits per component */

    int width, height;
    int mb_width, mb_height;
    int nb_components;
    int component_id[MAX_COMPONENTS];
    int h_count[MAX_COMPONENTS]; /* horizontal and vertical count for each component */
    int v_count[MAX_COMPONENTS];
    int comp_index[MAX_COMPONENTS];
    int dc_index[MAX_COMPONENTS];
    int ac_index[MAX_COMPONENTS];
    int nb_blocks[MAX_COMPONENTS];
    int h_scount[MAX_COMPONENTS];
    int v_scount[MAX_COMPONENTS];
    int h_max, v_max; /* maximum h and v counts */
    int quant_index[4];   /* quant table index for each component */
    int last_dc[MAX_COMPONENTS]; /* last DEQUANTIZED dc (XXX: am I right to do that ?) */
    AVFrame picture; /* picture structure */
    int linesize[MAX_COMPONENTS];                   ///< linesize << interlaced
    uint8_t *qscale_table;
    DCTELEM block[64] __align8;
    ScanTable scantable;
    void (*idct_put)(uint8_t *dest/*align 8*/, int line_size, DCTELEM *block/*align 16*/);

    int restart_interval;
    int restart_count;

    int buggy_avid;
    int interlace_polarity;
} MJpegDecodeContext;

static int mjpeg_decode_dht(MJpegDecodeContext *s);

static int build_vlc(VLC *vlc, const uint8_t *bits_table, const uint8_t *val_table, 
                      int nb_codes)
{
    uint8_t huff_size[256];
    uint16_t huff_code[256];

    memset(huff_size, 0, sizeof(huff_size));
    build_huffman_codes(huff_size, huff_code, bits_table, val_table);
    
    return init_vlc(vlc, 9, nb_codes, huff_size, 1, 1, huff_code, 2, 2);
}

static int mjpeg_decode_init(AVCodecContext *avctx)
{
    MJpegDecodeContext *s = avctx->priv_data;
    MpegEncContext s2;

    s->avctx = avctx;