i420_rgb.c

uclinux 下的vlc播放器源代码

static void Deactivate( vlc_object_t *p_this )
{
    vout_thread_t *p_vout = (vout_thread_t *)p_this;

#if defined (MODULE_NAME_IS_i420_rgb)
    free( p_vout->chroma.p_sys->p_base );
#endif
    free( p_vout->chroma.p_sys->p_offset );
    free( p_vout->chroma.p_sys->p_buffer );
    free( p_vout->chroma.p_sys );
}

#if defined (MODULE_NAME_IS_i420_rgb)
/*****************************************************************************
 * SetGammaTable: return intensity table transformed by gamma curve.
 *****************************************************************************
 * pi_table is a table of 256 entries from 0 to 255.
 *****************************************************************************/
static void SetGammaTable( int *pi_table, double f_gamma )
{
    int i_y;                                               /* base intensity */

    /* Use exp(gamma) instead of gamma */
    f_gamma = exp( f_gamma );

    /* Build gamma table */
    for( i_y = 0; i_y < 256; i_y++ )
    {
        pi_table[ i_y ] = (int)( pow( (double)i_y / 256, f_gamma ) * 256 );
    }
}

/*****************************************************************************
 * SetYUV: compute tables and set function pointers
 *****************************************************************************/
static void SetYUV( vout_thread_t *p_vout )
{
    int          pi_gamma[256];                               /* gamma table */
    volatile int i_index;                                 /* index in tables */
                   /* We use volatile here to work around a strange gcc-3.3.4
                    * optimization bug */

    /* Build gamma table */
    SetGammaTable( pi_gamma, p_vout->f_gamma );

    /*
     * Set pointers and build YUV tables
     */

    /* Color: build red, green and blue tables */
    switch( p_vout->output.i_chroma )
    {
    case VLC_FOURCC('R','G','B','2'):
        p_vout->chroma.p_sys->p_rgb8 = (uint8_t *)p_vout->chroma.p_sys->p_base;
        Set8bppPalette( p_vout, p_vout->chroma.p_sys->p_rgb8 );
        break;

    case VLC_FOURCC('R','V','1','5'):
    case VLC_FOURCC('R','V','1','6'):
        p_vout->chroma.p_sys->p_rgb16 = (uint16_t *)p_vout->chroma.p_sys->p_base;
        for( i_index = 0; i_index < RED_MARGIN; i_index++ )
        {
            p_vout->chroma.p_sys->p_rgb16[RED_OFFSET - RED_MARGIN + i_index] = RGB2PIXEL( p_vout, pi_gamma[0], 0, 0 );
            p_vout->chroma.p_sys->p_rgb16[RED_OFFSET + 256 + i_index] =        RGB2PIXEL( p_vout, pi_gamma[255], 0, 0 );
        }
        for( i_index = 0; i_index < GREEN_MARGIN; i_index++ )
        {
            p_vout->chroma.p_sys->p_rgb16[GREEN_OFFSET - GREEN_MARGIN + i_index] = RGB2PIXEL( p_vout, 0, pi_gamma[0], 0 );
            p_vout->chroma.p_sys->p_rgb16[GREEN_OFFSET + 256 + i_index] =          RGB2PIXEL( p_vout, 0, pi_gamma[255], 0 );
        }
        for( i_index = 0; i_index < BLUE_MARGIN; i_index++ )
        {
            p_vout->chroma.p_sys->p_rgb16[BLUE_OFFSET - BLUE_MARGIN + i_index] = RGB2PIXEL( p_vout, 0, 0, pi_gamma[0] );
            p_vout->chroma.p_sys->p_rgb16[BLUE_OFFSET + BLUE_MARGIN + i_index] = RGB2PIXEL( p_vout, 0, 0, pi_gamma[255] );
        }
        for( i_index = 0; i_index < 256; i_index++ )
        {
            p_vout->chroma.p_sys->p_rgb16[RED_OFFSET + i_index] =   RGB2PIXEL( p_vout, pi_gamma[ i_index ], 0, 0 );
            p_vout->chroma.p_sys->p_rgb16[GREEN_OFFSET + i_index] = RGB2PIXEL( p_vout, 0, pi_gamma[ i_index ], 0 );
            p_vout->chroma.p_sys->p_rgb16[BLUE_OFFSET + i_index] =  RGB2PIXEL( p_vout, 0, 0, pi_gamma[ i_index ] );
        }
        break;

    case VLC_FOURCC('R','V','2','4'):
    case VLC_FOURCC('R','V','3','2'):
        p_vout->chroma.p_sys->p_rgb32 = (uint32_t *)p_vout->chroma.p_sys->p_base;
        for( i_index = 0; i_index < RED_MARGIN; i_index++ )
        {
            p_vout->chroma.p_sys->p_rgb32[RED_OFFSET - RED_MARGIN + i_index] = RGB2PIXEL( p_vout, pi_gamma[0], 0, 0 );
            p_vout->chroma.p_sys->p_rgb32[RED_OFFSET + 256 + i_index] =        RGB2PIXEL( p_vout, pi_gamma[255], 0, 0 );
        }
        for( i_index = 0; i_index < GREEN_MARGIN; i_index++ )
        {
            p_vout->chroma.p_sys->p_rgb32[GREEN_OFFSET - GREEN_MARGIN + i_index] = RGB2PIXEL( p_vout, 0, pi_gamma[0], 0 );
            p_vout->chroma.p_sys->p_rgb32[GREEN_OFFSET + 256 + i_index] =          RGB2PIXEL( p_vout, 0, pi_gamma[255], 0 );
        }
        for( i_index = 0; i_index < BLUE_MARGIN; i_index++ )
        {
            p_vout->chroma.p_sys->p_rgb32[BLUE_OFFSET - BLUE_MARGIN + i_index] = RGB2PIXEL( p_vout, 0, 0, pi_gamma[0] );
            p_vout->chroma.p_sys->p_rgb32[BLUE_OFFSET + BLUE_MARGIN + i_index] = RGB2PIXEL( p_vout, 0, 0, pi_gamma[255] );
        }
        for( i_index = 0; i_index < 256; i_index++ )
        {
            p_vout->chroma.p_sys->p_rgb32[RED_OFFSET + i_index] =   RGB2PIXEL( p_vout, pi_gamma[ i_index ], 0, 0 );
            p_vout->chroma.p_sys->p_rgb32[GREEN_OFFSET + i_index] = RGB2PIXEL( p_vout, 0, pi_gamma[ i_index ], 0 );
            p_vout->chroma.p_sys->p_rgb32[BLUE_OFFSET + i_index] =  RGB2PIXEL( p_vout, 0, 0, pi_gamma[ i_index ] );
        }
        break;
    }
}

static void Set8bppPalette( vout_thread_t *p_vout, uint8_t *p_rgb8 )
{
    #define CLIP( x ) ( ((x < 0) ? 0 : (x > 255) ? 255 : x) << 8 )

    int y,u,v;
    int r,g,b;
    int i = 0, j = 0;
    uint16_t *p_cmap_r=p_vout->chroma.p_sys->p_rgb_r;
    uint16_t *p_cmap_g=p_vout->chroma.p_sys->p_rgb_g;
    uint16_t *p_cmap_b=p_vout->chroma.p_sys->p_rgb_b;

    unsigned char p_lookup[PALETTE_TABLE_SIZE];

    /* This loop calculates the intersection of an YUV box and the RGB cube. */
    for ( y = 0; y <= 256; y += 16, i += 128 - 81 )
    {
        for ( u = 0; u <= 256; u += 32 )
        {
            for ( v = 0; v <= 256; v += 32 )
            {
                r = y + ( (V_RED_COEF*(v-128)) >> SHIFT );
                g = y + ( (U_GREEN_COEF*(u-128)
                         + V_GREEN_COEF*(v-128)) >> SHIFT );
                b = y + ( (U_BLUE_COEF*(u-128)) >> SHIFT );

                if( r >= 0x00 && g >= 0x00 && b >= 0x00
                        && r <= 0xff && g <= 0xff && b <= 0xff )
                {
                    /* This one should never happen unless someone
                     * fscked up my code */
                    if( j == 256 )
                    {
                        msg_Err( p_vout, "no colors left in palette" );
                        break;
                    }

                    /* Clip the colors */
                    p_cmap_r[ j ] = CLIP( r );
                    p_cmap_g[ j ] = CLIP( g );
                    p_cmap_b[ j ] = CLIP( b );

#if 0
		    printf("+++Alloc RGB cmap %d (%d, %d, %d)\n", j,
			   p_cmap_r[ j ] >>8, p_cmap_g[ j ] >>8, 
			   p_cmap_b[ j ] >>8);
#endif

                    /* Allocate color */
                    p_lookup[ i ] = 1;
                    p_rgb8[ i++ ] = j;
                    j++;
                }
                else
                {
                    p_lookup[ i ] = 0;
                    p_rgb8[ i++ ] = 0;
                }
            }
        }
    }

    /* The colors have been allocated, we can set the palette */
    p_vout->output.pf_setpalette( p_vout, p_cmap_r, p_cmap_g, p_cmap_b );

#if 0
    /* There will eventually be a way to know which colors
     * couldn't be allocated and try to find a replacement */
    p_vout->i_white_pixel = 0xff;
    p_vout->i_black_pixel = 0x00;
    p_vout->i_gray_pixel = 0x44;
    p_vout->i_blue_pixel = 0x3b;
#endif

    /* This loop allocates colors that got outside the RGB cube */
    for ( i = 0, y = 0; y <= 256; y += 16, i += 128 - 81 )
    {
        for ( u = 0; u <= 256; u += 32 )
        {
            for ( v = 0; v <= 256; v += 32, i++ )
            {
                int u2, v2, dist, mindist = 100000000;

                if( p_lookup[ i ] || y == 0 )
                {
                    continue;
                }

                /* Heavy. yeah. */
                for( u2 = 0; u2 <= 256; u2 += 32 )
                {
                    for( v2 = 0; v2 <= 256; v2 += 32 )
                    {
                        j = ((y>>4)<<7) + (u2>>5)*9 + (v2>>5);
                        dist = (u-u2)*(u-u2) + (v-v2)*(v-v2);

                        /* Find the nearest color */
                        if( p_lookup[ j ] && dist < mindist )
                        {
                            p_rgb8[ i ] = p_rgb8[ j ];
                            mindist = dist;
                        }

                        j -= 128;

                        /* Find the nearest color */
                        if( p_lookup[ j ] && dist + 128 < mindist )
                        {
                            p_rgb8[ i ] = p_rgb8[ j ];
                            mindist = dist + 128;
                        }
                    }
                }
            }
        }
    }
}

#endif