imgconvert.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

            lum += 2;
            cb++;
            cr++;
        }
        if (w) {
            lum[0] = p[1];
            cb[0] = p[0];
            cr[0] = p[2];
            cb++;
            cr++;
        }
        p1 += src->linesize[0];
        lum1 += dst->linesize[0];
        if (height>1) {
            p = p1;
            lum = lum1;
            for(w = width; w >= 2; w -= 2) {
                lum[0] = p[1];
                lum[1] = p[3];
                p += 4;
                lum += 2;
            }
            if (w) {
                lum[0] = p[1];
            }
            p1 += src->linesize[0];
            lum1 += dst->linesize[0];
        }
        cb1 += dst->linesize[1];
        cr1 += dst->linesize[2];
    }
}


static void uyvy422_to_yuv422p(AVPicture *dst, const AVPicture *src,
                              int width, int height)
{
    const uint8_t *p, *p1;
    uint8_t *lum, *cr, *cb, *lum1, *cr1, *cb1;
    int w;

    p1 = src->data[0];
    lum1 = dst->data[0];
    cb1 = dst->data[1];
    cr1 = dst->data[2];
    for(;height > 0; height--) {
        p = p1;
        lum = lum1;
        cb = cb1;
        cr = cr1;
        for(w = width; w >= 2; w -= 2) {
            lum[0] = p[1];
            cb[0] = p[0];
            lum[1] = p[3];
            cr[0] = p[2];
            p += 4;
            lum += 2;
            cb++;
            cr++;
        }
        p1 += src->linesize[0];
        lum1 += dst->linesize[0];
        cb1 += dst->linesize[1];
        cr1 += dst->linesize[2];
    }
}


static void yuyv422_to_yuv422p(AVPicture *dst, const AVPicture *src,
                              int width, int height)
{
    const uint8_t *p, *p1;
    uint8_t *lum, *cr, *cb, *lum1, *cr1, *cb1;
    int w;

    p1 = src->data[0];
    lum1 = dst->data[0];
    cb1 = dst->data[1];
    cr1 = dst->data[2];
    for(;height > 0; height--) {
        p = p1;
        lum = lum1;
        cb = cb1;
        cr = cr1;
        for(w = width; w >= 2; w -= 2) {
            lum[0] = p[0];
            cb[0] = p[1];
            lum[1] = p[2];
            cr[0] = p[3];
            p += 4;
            lum += 2;
            cb++;
            cr++;
        }
        p1 += src->linesize[0];
        lum1 += dst->linesize[0];
        cb1 += dst->linesize[1];
        cr1 += dst->linesize[2];
    }
}

static void yuv422p_to_yuyv422(AVPicture *dst, const AVPicture *src,
                              int width, int height)
{
    uint8_t *p, *p1;
    const uint8_t *lum, *cr, *cb, *lum1, *cr1, *cb1;
    int w;

    p1 = dst->data[0];
    lum1 = src->data[0];
    cb1 = src->data[1];
    cr1 = src->data[2];
    for(;height > 0; height--) {
        p = p1;
        lum = lum1;
        cb = cb1;
        cr = cr1;
        for(w = width; w >= 2; w -= 2) {
            p[0] = lum[0];
            p[1] = cb[0];
            p[2] = lum[1];
            p[3] = cr[0];
            p += 4;
            lum += 2;
            cb++;
            cr++;
        }
        p1 += dst->linesize[0];
        lum1 += src->linesize[0];
        cb1 += src->linesize[1];
        cr1 += src->linesize[2];
    }
}

static void yuv422p_to_uyvy422(AVPicture *dst, const AVPicture *src,
                              int width, int height)
{
    uint8_t *p, *p1;
    const uint8_t *lum, *cr, *cb, *lum1, *cr1, *cb1;
    int w;

    p1 = dst->data[0];
    lum1 = src->data[0];
    cb1 = src->data[1];
    cr1 = src->data[2];
    for(;height > 0; height--) {
        p = p1;
        lum = lum1;
        cb = cb1;
        cr = cr1;
        for(w = width; w >= 2; w -= 2) {
            p[1] = lum[0];
            p[0] = cb[0];
            p[3] = lum[1];
            p[2] = cr[0];
            p += 4;
            lum += 2;
            cb++;
            cr++;
        }
        p1 += dst->linesize[0];
        lum1 += src->linesize[0];
        cb1 += src->linesize[1];
        cr1 += src->linesize[2];
    }
}

static void uyyvyy411_to_yuv411p(AVPicture *dst, const AVPicture *src,
                              int width, int height)
{
    const uint8_t *p, *p1;
    uint8_t *lum, *cr, *cb, *lum1, *cr1, *cb1;
    int w;

    p1 = src->data[0];
    lum1 = dst->data[0];
    cb1 = dst->data[1];
    cr1 = dst->data[2];
    for(;height > 0; height--) {
        p = p1;
        lum = lum1;
        cb = cb1;
        cr = cr1;
        for(w = width; w >= 4; w -= 4) {
            cb[0] = p[0];
            lum[0] = p[1];
            lum[1] = p[2];
            cr[0] = p[3];
            lum[2] = p[4];
            lum[3] = p[5];
            p += 6;
            lum += 4;
            cb++;
            cr++;
        }
        p1 += src->linesize[0];
        lum1 += dst->linesize[0];
        cb1 += dst->linesize[1];
        cr1 += dst->linesize[2];
    }
}


static void yuv420p_to_yuyv422(AVPicture *dst, const AVPicture *src,
                              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++ = *lum1++; *line2++ = *lum2++;
                *line1++ =          *line2++ = *cb1++;
                *line1++ = *lum1++; *line2++ = *lum2++;
                *line1++ =          *line2++ = *cr1++;
        }

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

static void yuv420p_to_uyvy422(AVPicture *dst, const AVPicture *src,
                              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];
    }
}

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 = ff_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;