imgconvert.c

现在关于h.264的源码很多

                              int width, int height)
{
    int w, h;
    uint8_t *line1, *line2, *linesrc = dst->data[0];
    uint8_t *lum1, *lum2, *lumsrc = src->data[0];
    uint8_t *cb1, *cb2 = src->data[1];
    uint8_t *cr1, *cr2 = src->data[2];

    for(h = height / 2; h--;) {
        line1 = linesrc;
        line2 = linesrc + dst->linesize[0];

        lum1 = lumsrc;
        lum2 = lumsrc + src->linesize[0];

        cb1 = cb2;
        cr1 = cr2;

        for(w = width / 2; w--;) {
                *line1++ =          *line2++ = *cb1++;
                *line1++ = *lum1++; *line2++ = *lum2++;
                *line1++ =          *line2++ = *cr1++;
                *line1++ = *lum1++; *line2++ = *lum2++;
        }

        linesrc += dst->linesize[0] * 2;
        lumsrc += src->linesize[0] * 2;
        cb2 += src->linesize[1];
        cr2 += src->linesize[2];
    }
}

#define SCALEBITS 10
#define ONE_HALF  (1 << (SCALEBITS - 1))
#define FIX(x)    ((int) ((x) * (1<<SCALEBITS) + 0.5))

#define YUV_TO_RGB1_CCIR(cb1, cr1)\
{\
    cb = (cb1) - 128;\
    cr = (cr1) - 128;\
    r_add = FIX(1.40200*255.0/224.0) * cr + ONE_HALF;\
    g_add = - FIX(0.34414*255.0/224.0) * cb - FIX(0.71414*255.0/224.0) * cr + \
            ONE_HALF;\
    b_add = FIX(1.77200*255.0/224.0) * cb + ONE_HALF;\
}

#define YUV_TO_RGB2_CCIR(r, g, b, y1)\
{\
    y = ((y1) - 16) * FIX(255.0/219.0);\
    r = cm[(y + r_add) >> SCALEBITS];\
    g = cm[(y + g_add) >> SCALEBITS];\
    b = cm[(y + b_add) >> SCALEBITS];\
}

#define YUV_TO_RGB1(cb1, cr1)\
{\
    cb = (cb1) - 128;\
    cr = (cr1) - 128;\
    r_add = FIX(1.40200) * cr + ONE_HALF;\
    g_add = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;\
    b_add = FIX(1.77200) * cb + ONE_HALF;\
}

#define YUV_TO_RGB2(r, g, b, y1)\
{\
    y = (y1) << SCALEBITS;\
    r = cm[(y + r_add) >> SCALEBITS];\
    g = cm[(y + g_add) >> SCALEBITS];\
    b = cm[(y + b_add) >> SCALEBITS];\
}

#define Y_CCIR_TO_JPEG(y)\
 cm[((y) * FIX(255.0/219.0) + (ONE_HALF - 16 * FIX(255.0/219.0))) >> SCALEBITS]

#define Y_JPEG_TO_CCIR(y)\
 (((y) * FIX(219.0/255.0) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)

#define C_CCIR_TO_JPEG(y)\
 cm[(((y) - 128) * FIX(127.0/112.0) + (ONE_HALF + (128 << SCALEBITS))) >> SCALEBITS]

/* NOTE: the clamp is really necessary! */
static inline int C_JPEG_TO_CCIR(int y) {
    y = (((y - 128) * FIX(112.0/127.0) + (ONE_HALF + (128 << SCALEBITS))) >> SCALEBITS);
    if (y < 16)
        y = 16;
    return y;
}


#define RGB_TO_Y(r, g, b) \
((FIX(0.29900) * (r) + FIX(0.58700) * (g) + \
  FIX(0.11400) * (b) + ONE_HALF) >> SCALEBITS)

#define RGB_TO_U(r1, g1, b1, shift)\
(((- FIX(0.16874) * r1 - FIX(0.33126) * g1 +         \
     FIX(0.50000) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)

#define RGB_TO_V(r1, g1, b1, shift)\
(((FIX(0.50000) * r1 - FIX(0.41869) * g1 -           \
   FIX(0.08131) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)

#define RGB_TO_Y_CCIR(r, g, b) \
((FIX(0.29900*219.0/255.0) * (r) + FIX(0.58700*219.0/255.0) * (g) + \
  FIX(0.11400*219.0/255.0) * (b) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)

#define RGB_TO_U_CCIR(r1, g1, b1, shift)\
(((- FIX(0.16874*224.0/255.0) * r1 - FIX(0.33126*224.0/255.0) * g1 +         \
     FIX(0.50000*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)

#define RGB_TO_V_CCIR(r1, g1, b1, shift)\
(((FIX(0.50000*224.0/255.0) * r1 - FIX(0.41869*224.0/255.0) * g1 -           \
   FIX(0.08131*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)

static uint8_t y_ccir_to_jpeg[256];
static uint8_t y_jpeg_to_ccir[256];
static uint8_t c_ccir_to_jpeg[256];
static uint8_t c_jpeg_to_ccir[256];

/* init various conversion tables */
static void img_convert_init(void)
{
    int i;
    uint8_t *cm = cropTbl + MAX_NEG_CROP;

    for(i = 0;i < 256; i++) {
        y_ccir_to_jpeg[i] = Y_CCIR_TO_JPEG(i);
        y_jpeg_to_ccir[i] = Y_JPEG_TO_CCIR(i);
        c_ccir_to_jpeg[i] = C_CCIR_TO_JPEG(i);
        c_jpeg_to_ccir[i] = C_JPEG_TO_CCIR(i);
    }
}

/* apply to each pixel the given table */
static void img_apply_table(uint8_t *dst, int dst_wrap,
                            const uint8_t *src, int src_wrap,
                            int width, int height, const uint8_t *table1)
{
    int n;
    const uint8_t *s;
    uint8_t *d;
    const uint8_t *table;

    table = table1;
    for(;height > 0; height--) {
        s = src;
        d = dst;
        n = width;
        while (n >= 4) {
            d[0] = table[s[0]];
            d[1] = table[s[1]];
            d[2] = table[s[2]];
            d[3] = table[s[3]];
            d += 4;
            s += 4;
            n -= 4;
        }
        while (n > 0) {
            d[0] = table[s[0]];
            d++;
            s++;
            n--;
        }
        dst += dst_wrap;
        src += src_wrap;
    }
}

/* XXX: use generic filter ? */
/* XXX: in most cases, the sampling position is incorrect */

/* 4x1 -> 1x1 */
static void shrink41(uint8_t *dst, int dst_wrap,
                     const uint8_t *src, int src_wrap,
                     int width, int height)
{
    int w;
    const uint8_t *s;
    uint8_t *d;

    for(;height > 0; height--) {
        s = src;
        d = dst;
        for(w = width;w > 0; w--) {
            d[0] = (s[0] + s[1] + s[2] + s[3] + 2) >> 2;
            s += 4;
            d++;
        }
        src += src_wrap;
        dst += dst_wrap;
    }
}

/* 2x1 -> 1x1 */
static void shrink21(uint8_t *dst, int dst_wrap,
                     const uint8_t *src, int src_wrap,
                     int width, int height)
{
    int w;
    const uint8_t *s;
    uint8_t *d;

    for(;height > 0; height--) {
        s = src;
        d = dst;
        for(w = width;w > 0; w--) {
            d[0] = (s[0] + s[1]) >> 1;
            s += 2;
            d++;
        }
        src += src_wrap;
        dst += dst_wrap;
    }
}

/* 1x2 -> 1x1 */
static void shrink12(uint8_t *dst, int dst_wrap,
                     const uint8_t *src, int src_wrap,
                     int width, int height)
{
    int w;
    uint8_t *d;
    const uint8_t *s1, *s2;

    for(;height > 0; height--) {
        s1 = src;
        s2 = s1 + src_wrap;
        d = dst;
        for(w = width;w >= 4; w-=4) {
            d[0] = (s1[0] + s2[0]) >> 1;
            d[1] = (s1[1] + s2[1]) >> 1;
            d[2] = (s1[2] + s2[2]) >> 1;
            d[3] = (s1[3] + s2[3]) >> 1;
            s1 += 4;
            s2 += 4;
            d += 4;
        }
        for(;w > 0; w--) {
            d[0] = (s1[0] + s2[0]) >> 1;
            s1++;
            s2++;
            d++;
        }
        src += 2 * src_wrap;
        dst += dst_wrap;
    }
}

/* 2x2 -> 1x1 */
void ff_shrink22(uint8_t *dst, int dst_wrap,
                     const uint8_t *src, int src_wrap,
                     int width, int height)
{
    int w;
    const uint8_t *s1, *s2;
    uint8_t *d;

    for(;height > 0; height--) {
        s1 = src;
        s2 = s1 + src_wrap;
        d = dst;
        for(w = width;w >= 4; w-=4) {
            d[0] = (s1[0] + s1[1] + s2[0] + s2[1] + 2) >> 2;
            d[1] = (s1[2] + s1[3] + s2[2] + s2[3] + 2) >> 2;
            d[2] = (s1[4] + s1[5] + s2[4] + s2[5] + 2) >> 2;
            d[3] = (s1[6] + s1[7] + s2[6] + s2[7] + 2) >> 2;
            s1 += 8;
            s2 += 8;
            d += 4;
        }
        for(;w > 0; w--) {
            d[0] = (s1[0] + s1[1] + s2[0] + s2[1] + 2) >> 2;
            s1 += 2;
            s2 += 2;
            d++;
        }
        src += 2 * src_wrap;
        dst += dst_wrap;
    }
}

/* 4x4 -> 1x1 */
void ff_shrink44(uint8_t *dst, int dst_wrap,
                     const uint8_t *src, int src_wrap,
                     int width, int height)
{
    int w;
    const uint8_t *s1, *s2, *s3, *s4;
    uint8_t *d;

    for(;height > 0; height--) {
        s1 = src;
        s2 = s1 + src_wrap;
        s3 = s2 + src_wrap;
        s4 = s3 + src_wrap;
        d = dst;
        for(w = width;w > 0; w--) {
            d[0] = (s1[0] + s1[1] + s1[2] + s1[3] +
                    s2[0] + s2[1] + s2[2] + s2[3] +
                    s3[0] + s3[1] + s3[2] + s3[3] +
                    s4[0] + s4[1] + s4[2] + s4[3] + 8) >> 4;
            s1 += 4;
            s2 += 4;
            s3 += 4;
            s4 += 4;
            d++;
        }
        src += 4 * src_wrap;
        dst += dst_wrap;
    }
}

/* 8x8 -> 1x1 */
void ff_shrink88(uint8_t *dst, int dst_wrap,
                     const uint8_t *src, int src_wrap,
                     int width, int height)
{
    int w, i;

    for(;height > 0; height--) {
        for(w = width;w > 0; w--) {
            int tmp=0;
            for(i=0; i<8; i++){
                tmp += src[0] + src[1] + src[2] + src[3] + src[4] + src[5] + src[6] + src[7];
                src += src_wrap;
            }
            *(dst++) = (tmp + 32)>>6;
            src += 8 - 8*src_wrap;
        }
        src += 8*src_wrap - 8*width;
        dst += dst_wrap - width;
    }
}

static void grow21_line(uint8_t *dst, const uint8_t *src,
                        int width)
{
    int w;
    const uint8_t *s1;
    uint8_t *d;

    s1 = src;
    d = dst;
    for(w = width;w >= 4; w-=4) {
        d[1] = d[0] = s1[0];
        d[3] = d[2] = s1[1];
        s1 += 2;
        d += 4;
    }
    for(;w >= 2; w -= 2) {
        d[1] = d[0] = s1[0];
        s1 ++;
        d += 2;
    }
    /* only needed if width is not a multiple of two */
    /* XXX: veryfy that */
    if (w) {
        d[0] = s1[0];
    }
}

static void grow41_line(uint8_t *dst, const uint8_t *src,
                        int width)
{
    int w, v;
    const uint8_t *s1;
    uint8_t *d;

    s1 = src;
    d = dst;
    for(w = width;w >= 4; w-=4) {
        v = s1[0];
        d[0] = v;
        d[1] = v;
        d[2] = v;
        d[3] = v;
        s1 ++;
        d += 4;
    }
}

/* 1x1 -> 2x1 */
static void grow21(uint8_t *dst, int dst_wrap,
                   const uint8_t *src, int src_wrap,
                   int width, int height)
{
    for(;height > 0; height--) {
        grow21_line(dst, src, width);
        src += src_wrap;
        dst += dst_wrap;
    }
}

/* 1x1 -> 2x2 */
static void grow22(uint8_t *dst, int dst_wrap,
                   const uint8_t *src, int src_wrap,
                   int width, int height)
{
    for(;height > 0; height--) {
        grow21_line(dst, src, width);
        if (height%2)
            src += src_wrap;
        dst += dst_wrap;
    }
}

/* 1x1 -> 4x1 */
static void grow41(uint8_t *dst, int dst_wrap,
                   const uint8_t *src, int src_wrap,
                   int width, int height)
{
    for(;height > 0; height--) {
        grow41_line(dst, src, width);
        src += src_wrap;
        dst += dst_wrap;
    }
}

/* 1x1 -> 4x4 */
static void grow44(uint8_t *dst, int dst_wrap,
                   const uint8_t *src, int src_wrap,
                   int width, int height)
{
    for(;height > 0; height--) {
        grow41_line(dst, src, width);
        if ((height & 3) == 1)
            src += src_wrap;
        dst += dst_wrap;
    }
}

/* 1x2 -> 2x1 */
static void conv411(uint8_t *dst, int dst_wrap,
                    const uint8_t *src, int src_wrap,
                    int width, int height)
{
    int w, c;
    const uint8_t *s1, *s2;
    uint8_t *d;

    width>>=1;

    for(;height > 0; height--) {
        s1 = src;
        s2 = src + src_wrap;
        d = dst;
        for(w = width;w > 0; w--) {
            c = (s1[0] + s2[0]) >> 1;
            d[0] = c;
            d[1] = c;
            s1++;
            s2++;
            d += 2;
        }
        src += src_wrap * 2;
        dst += dst_wrap;
    }
}

/* XXX: add jpeg quantize code */

#define TRANSP_INDEX (6*6*6)

/* this is maybe slow, but allows for extensions */
static inline unsigned char gif_clut_index(uint8_t r, uint8_t g, uint8_t b)
{
    return ((((r)/47)%6)*6*6+(((g)/47)%6)*6+(((b)/47)%6));
}

static void build_rgb_palette(uint8_t *palette, int has_alpha)
{
    uint32_t *pal;
    static const uint8_t pal_value[6] = { 0x00, 0x33, 0x66, 0x99, 0xcc, 0xff };
    int i, r, g, b;

    pal = (uint32_t *)palette;
    i = 0;
    for(r = 0; r < 6; r++) {
        for(g = 0; g < 6; g++) {
            for(b = 0; b < 6; b++) {
                pal[i++] = (0xff << 24) | (pal_value[r] << 16) |
                    (pal_value[g] << 8) | pal_value[b];
            }