utils.c

SwsVector *sws_getGaussianVec(double variance, double quality)
{
    const int length = (int)(variance * quality + 0.5) | 1;
    int i;
    double middle  = (length - 1) * 0.5;
    SwsVector *vec;

    if(variance < 0 || quality < 0)
        return NULL;

    vec = sws_allocVec(length);

    if (!vec)
        return NULL;

    for (i = 0; i < length; i++) {
        double dist = i - middle;
        vec->coeff[i] = exp(-dist * dist / (2 * variance * variance)) /
                        sqrt(2 * variance * M_PI);
    }

    sws_normalizeVec(vec, 1.0);

    return vec;
}

/**
 * Allocate and return a vector with length coefficients, all
 * with the same value c.
 */
#if !FF_API_SWS_VECTOR
static
#endif
SwsVector *sws_getConstVec(double c, int length)
{
    int i;
    SwsVector *vec = sws_allocVec(length);

    if (!vec)
        return NULL;

    for (i = 0; i < length; i++)
        vec->coeff[i] = c;

    return vec;
}

/**
 * Allocate and return a vector with just one coefficient, with
 * value 1.0.
 */
#if !FF_API_SWS_VECTOR
static
#endif
SwsVector *sws_getIdentityVec(void)
{
    return sws_getConstVec(1.0, 1);
}

static double sws_dcVec(SwsVector *a)
{
    int i;
    double sum = 0;

    for (i = 0; i < a->length; i++)
        sum += a->coeff[i];

    return sum;
}

void sws_scaleVec(SwsVector *a, double scalar)
{
    int i;

    for (i = 0; i < a->length; i++)
        a->coeff[i] *= scalar;
}

void sws_normalizeVec(SwsVector *a, double height)
{
    sws_scaleVec(a, height / sws_dcVec(a));
}

#if FF_API_SWS_VECTOR
static SwsVector *sws_getConvVec(SwsVector *a, SwsVector *b)
{
    int length = a->length + b->length - 1;
    int i, j;
    SwsVector *vec = sws_getConstVec(0.0, length);

    if (!vec)
        return NULL;

    for (i = 0; i < a->length; i++) {
        for (j = 0; j < b->length; j++) {
            vec->coeff[i + j] += a->coeff[i] * b->coeff[j];
        }
    }

    return vec;
}
#endif

static SwsVector *sws_sumVec(SwsVector *a, SwsVector *b)
{
    int length = FFMAX(a->length, b->length);
    int i;
    SwsVector *vec = sws_getConstVec(0.0, length);

    if (!vec)
        return NULL;

    for (i = 0; i < a->length; i++)
        vec->coeff[i + (length - 1) / 2 - (a->length - 1) / 2] += a->coeff[i];
    for (i = 0; i < b->length; i++)
        vec->coeff[i + (length - 1) / 2 - (b->length - 1) / 2] += b->coeff[i];

    return vec;
}

#if FF_API_SWS_VECTOR
static SwsVector *sws_diffVec(SwsVector *a, SwsVector *b)
{
    int length = FFMAX(a->length, b->length);
    int i;
    SwsVector *vec = sws_getConstVec(0.0, length);

    if (!vec)
        return NULL;

    for (i = 0; i < a->length; i++)
        vec->coeff[i + (length - 1) / 2 - (a->length - 1) / 2] += a->coeff[i];
    for (i = 0; i < b->length; i++)
        vec->coeff[i + (length - 1) / 2 - (b->length - 1) / 2] -= b->coeff[i];

    return vec;
}
#endif

/* shift left / or right if "shift" is negative */
static SwsVector *sws_getShiftedVec(SwsVector *a, int shift)
{
    int length = a->length + FFABS(shift) * 2;
    int i;
    SwsVector *vec = sws_getConstVec(0.0, length);

    if (!vec)
        return NULL;

    for (i = 0; i < a->length; i++) {
        vec->coeff[i + (length    - 1) / 2 -
                       (a->length - 1) / 2 - shift] = a->coeff[i];
    }

    return vec;
}

#if !FF_API_SWS_VECTOR
static
#endif
void sws_shiftVec(SwsVector *a, int shift)
{
    SwsVector *shifted = sws_getShiftedVec(a, shift);
    if (!shifted) {
        makenan_vec(a);
        return;
    }
    av_free(a->coeff);
    a->coeff  = shifted->coeff;
    a->length = shifted->length;
    av_free(shifted);
}

#if !FF_API_SWS_VECTOR
static
#endif
void sws_addVec(SwsVector *a, SwsVector *b)
{
    SwsVector *sum = sws_sumVec(a, b);
    if (!sum) {
        makenan_vec(a);
        return;
    }
    av_free(a->coeff);
    a->coeff  = sum->coeff;
    a->length = sum->length;
    av_free(sum);
}

#if FF_API_SWS_VECTOR
void sws_subVec(SwsVector *a, SwsVector *b)
{
    SwsVector *diff = sws_diffVec(a, b);
    if (!diff) {
        makenan_vec(a);
        return;
    }
    av_free(a->coeff);
    a->coeff  = diff->coeff;
    a->length = diff->length;
    av_free(diff);
}

void sws_convVec(SwsVector *a, SwsVector *b)
{
    SwsVector *conv = sws_getConvVec(a, b);
    if (!conv) {
        makenan_vec(a);
        return;
    }
    av_free(a->coeff);
    a->coeff  = conv->coeff;
    a->length = conv->length;
    av_free(conv);
}

SwsVector *sws_cloneVec(SwsVector *a)
{
    SwsVector *vec = sws_allocVec(a->length);

    if (!vec)
        return NULL;

    memcpy(vec->coeff, a->coeff, a->length * sizeof(*a->coeff));

    return vec;
}
#endif

/**
 * Print with av_log() a textual representation of the vector a
 * if log_level <= av_log_level.
 */
#if !FF_API_SWS_VECTOR
static
#endif
void sws_printVec2(SwsVector *a, AVClass *log_ctx, int log_level)
{
    int i;
    double max = 0;
    double min = 0;
    double range;

    for (i = 0; i < a->length; i++)
        if (a->coeff[i] > max)
            max = a->coeff[i];

    for (i = 0; i < a->length; i++)
        if (a->coeff[i] < min)
            min = a->coeff[i];

    range = max - min;

    for (i = 0; i < a->length; i++) {
        int x = (int)((a->coeff[i] - min) * 60.0 / range + 0.5);
        av_log(log_ctx, log_level, "%1.3f ", a->coeff[i]);
        for (; x > 0; x--)
            av_log(log_ctx, log_level, " ");
        av_log(log_ctx, log_level, "|\n");
    }
}

void sws_freeVec(SwsVector *a)
{
    if (!a)
        return;
    av_freep(&a->coeff);
    a->length = 0;
    av_free(a);
}

void sws_freeFilter(SwsFilter *filter)
{
    if (!filter)
        return;

    sws_freeVec(filter->lumH);
    sws_freeVec(filter->lumV);
    sws_freeVec(filter->chrH);
    sws_freeVec(filter->chrV);
    av_free(filter);
}

void sws_freeContext(SwsContext *c)
{
    int i;
    if (!c)
        return;

    for (i = 0; i < 4; i++)
        av_freep(&c->dither_error[i]);

    av_freep(&c->vLumFilter);
    av_freep(&c->vChrFilter);
    av_freep(&c->hLumFilter);
    av_freep(&c->hChrFilter);
#if HAVE_ALTIVEC
    av_freep(&c->vYCoeffsBank);
    av_freep(&c->vCCoeffsBank);
#endif

    av_freep(&c->vLumFilterPos);
    av_freep(&c->vChrFilterPos);
    av_freep(&c->hLumFilterPos);
    av_freep(&c->hChrFilterPos);

#if HAVE_MMX_INLINE
#if USE_MMAP
    if (c->lumMmxextFilterCode)
        munmap(c->lumMmxextFilterCode, c->lumMmxextFilterCodeSize);
    if (c->chrMmxextFilterCode)
        munmap(c->chrMmxextFilterCode, c->chrMmxextFilterCodeSize);
#elif HAVE_VIRTUALALLOC
    if (c->lumMmxextFilterCode)
        VirtualFree(c->lumMmxextFilterCode, 0, MEM_RELEASE);
    if (c->chrMmxextFilterCode)
        VirtualFree(c->chrMmxextFilterCode, 0, MEM_RELEASE);
#else
    av_free(c->lumMmxextFilterCode);
    av_free(c->chrMmxextFilterCode);
#endif
    c->lumMmxextFilterCode = NULL;
    c->chrMmxextFilterCode = NULL;
#endif /* HAVE_MMX_INLINE */

    av_freep(&c->yuvTable);
    av_freep(&c->formatConvBuffer);

    sws_freeContext(c->cascaded_context[0]);
    sws_freeContext(c->cascaded_context[1]);
    sws_freeContext(c->cascaded_context[2]);
    memset(c->cascaded_context, 0, sizeof(c->cascaded_context));
    av_freep(&c->cascaded_tmp[0]);
    av_freep(&c->cascaded1_tmp[0]);

    av_freep(&c->gamma);
    av_freep(&c->inv_gamma);

    ff_free_filters(c);

    av_free(c);
}

struct SwsContext *sws_getCachedContext(struct SwsContext *context, int srcW,
                                        int srcH, enum AVPixelFormat srcFormat,
                                        int dstW, int dstH,
                                        enum AVPixelFormat dstFormat, int flags,
                                        SwsFilter *srcFilter,
                                        SwsFilter *dstFilter,
                                        const double *param)
{
    static const double default_param[2] = { SWS_PARAM_DEFAULT,
                                             SWS_PARAM_DEFAULT };
    int64_t src_h_chr_pos = -513, dst_h_chr_pos = -513,
            src_v_chr_pos = -513, dst_v_chr_pos = -513;

    if (!param)
        param = default_param;

    if (context &&
        (context->srcW      != srcW      ||
         context->srcH      != srcH      ||
         context->srcFormat != srcFormat ||
         context->dstW      != dstW      ||
         context->dstH      != dstH      ||
         context->dstFormat != dstFormat ||
         context->flags     != flags     ||
         context->param[0]  != param[0]  ||
         context->param[1]  != param[1])) {

        av_opt_get_int(context, "src_h_chr_pos", 0, &src_h_chr_pos);
        av_opt_get_int(context, "src_v_chr_pos", 0, &src_v_chr_pos);
        av_opt_get_int(context, "dst_h_chr_pos", 0, &dst_h_chr_pos);
        av_opt_get_int(context, "dst_v_chr_pos", 0, &dst_v_chr_pos);
        sws_freeContext(context);
        context = NULL;
    }

    if (!context) {
        if (!(context = sws_alloc_context()))
            return NULL;
        context->srcW      = srcW;
        context->srcH      = srcH;
        context->srcFormat = srcFormat;
        context->dstW      = dstW;
        context->dstH      = dstH;
        context->dstFormat = dstFormat;
        context->flags     = flags;
        context->param[0]  = param[0];
        context->param[1]  = param[1];

        av_opt_set_int(context, "src_h_chr_pos", src_h_chr_pos, 0);
        av_opt_set_int(context, "src_v_chr_pos", src_v_chr_pos, 0);
        av_opt_set_int(context, "dst_h_chr_pos", dst_h_chr_pos, 0);
        av_opt_set_int(context, "dst_v_chr_pos", dst_v_chr_pos, 0);

        if (sws_init_context(context, srcFilter, dstFilter) < 0) {
            sws_freeContext(context);
            return NULL;
        }
    }
    return context;
}