/**
* Generate a scaled down image with half width, height, and intensity.
*
* This function not only scales down an image, but halves the value
* in each pixel too. The purpose of this is to produce a chroma
* filter image out of a luma filter image. The pixel values store the
* distance to the edge of the logo and halving the dimensions halves
* the distance. This function rounds up, because a downwards rounding
* error could cause the filter to fail, but an upwards rounding error
* will only cause a minor amount of excess blur in the chroma planes.
*/
static void generate_half_size_image(const uint8_t *src_data, int src_linesize,
uint8_t *dst_data, int dst_linesize,
int src_w, int src_h,
int *max_mask_size)
{
int x, y;
/* Copy over the image data, using the average of 4 pixels for to
* calculate each downsampled pixel. */
for (y = 0; y < src_h/2; y++) {
for (x = 0; x < src_w/2; x++) {
/* Set the pixel if there exists a non-zero value in the
* source pixels, else clear it. */
dst_data[(y * dst_linesize) + x] =
src_data[((y << 1) * src_linesize) + (x << 1)] ||
src_data[((y << 1) * src_linesize) + (x << 1) + 1] ||
src_data[(((y << 1) + 1) * src_linesize) + (x << 1)] ||
src_data[(((y << 1) + 1) * src_linesize) + (x << 1) + 1];
dst_data[(y * dst_linesize) + x] = FFMIN(1, dst_data[(y * dst_linesize) + x]);
}
}
convert_mask_to_strength_mask(dst_data, dst_linesize,
src_w/2, src_h/2, 0, max_mask_size);
}
/**
* \brief Initializes our filter.
*
* \param args The arguments passed in from the command line go here. This
* filter expects only a single argument telling it where the PGM
* or PPM file that describes the logo region is.
*
* This sets up our instance variables and parses the arguments to the filter.
*/
static int vf_open(vf_instance_t *vf, char *args)
{
vf->priv = safe_malloc(sizeof(vf_priv_s));
vf->uninit = uninit;
/* Load our filter image. */
if (args)
vf->priv->filter = load_pgm(args);
else
{
mp_msg(MSGT_VFILTER, MSGL_ERR, "[vf]remove_logo usage: remove_logo=/path/to/filter_image_file.pgm\n");
free(vf->priv);
return 0;
}
if (vf->priv->filter == NULL)
{
/* Error message was displayed by load_pgm(). */
free(vf->priv);
return 0;
}
/* Create the scaled down filter image for the chroma planes. */
convert_mask_to_strength_mask(vf, vf->priv->filter);
vf->priv->half_size_filter = generate_half_size_image(vf, vf->priv->filter);
/* Now that we know how many masks we need (the info is in vf), we can generate the masks. */
initialize_masks(vf);
/* Calculate our bounding rectangles, which determine in what region the logo resides for faster processing. */
calculate_bounding_rectangle(&vf->priv->bounding_rectangle_posx1, &vf->priv->bounding_rectangle_posy1,
&vf->priv->bounding_rectangle_posx2, &vf->priv->bounding_rectangle_posy2,
vf->priv->filter);
calculate_bounding_rectangle(&vf->priv->bounding_rectangle_half_size_posx1,
&vf->priv->bounding_rectangle_half_size_posy1,
&vf->priv->bounding_rectangle_half_size_posx2,
&vf->priv->bounding_rectangle_half_size_posy2,
vf->priv->half_size_filter);
vf->config=config;
vf->put_image=put_image;
vf->query_format=query_format;
return 1;
}
static av_cold int init(AVFilterContext *ctx, const char *args)
{
RemovelogoContext *removelogo = ctx->priv;
int ***mask;
int ret = 0;
int a, b, c, w, h;
int full_max_mask_size, half_max_mask_size;
if (!args) {
av_log(ctx, AV_LOG_ERROR, "An image file must be specified as argument\n");
return AVERROR(EINVAL);
}
/* Load our mask image. */
if ((ret = load_mask(&removelogo->full_mask_data, &w, &h, args, ctx)) < 0)
return ret;
removelogo->mask_w = w;
removelogo->mask_h = h;
convert_mask_to_strength_mask(removelogo->full_mask_data, w, w, h,
16, &full_max_mask_size);
/* Create the scaled down mask image for the chroma planes. */
if (!(removelogo->half_mask_data = av_mallocz(w/2 * h/2)))
return AVERROR(ENOMEM);
generate_half_size_image(removelogo->full_mask_data, w,
removelogo->half_mask_data, w/2,
w, h, &half_max_mask_size);
removelogo->max_mask_size = FFMAX(full_max_mask_size, half_max_mask_size);
/* Create a circular mask for each size up to max_mask_size. When
the filter is applied, the mask size is determined on a pixel
by pixel basis, with pixels nearer the edge of the logo getting
smaller mask sizes. */
mask = (int ***)av_malloc(sizeof(int **) * (removelogo->max_mask_size + 1));
if (!mask)
return AVERROR(ENOMEM);
for (a = 0; a <= removelogo->max_mask_size; a++) {
mask[a] = (int **)av_malloc(sizeof(int *) * ((a * 2) + 1));
if (!mask[a])
return AVERROR(ENOMEM);
for (b = -a; b <= a; b++) {
mask[a][b + a] = (int *)av_malloc(sizeof(int) * ((a * 2) + 1));
if (!mask[a][b + a])
return AVERROR(ENOMEM);
for (c = -a; c <= a; c++) {
if ((b * b) + (c * c) <= (a * a)) /* Circular 0/1 mask. */
mask[a][b + a][c + a] = 1;
else
mask[a][b + a][c + a] = 0;
}
}
}
removelogo->mask = mask;
/* Calculate our bounding rectangles, which determine in what
* region the logo resides for faster processing. */
ff_calculate_bounding_box(&removelogo->full_mask_bbox, removelogo->full_mask_data, w, w, h, 0);
ff_calculate_bounding_box(&removelogo->half_mask_bbox, removelogo->half_mask_data, w/2, w/2, h/2, 0);
#define SHOW_LOGO_INFO(mask_type) \
av_log(ctx, AV_LOG_VERBOSE, #mask_type " x1:%d x2:%d y1:%d y2:%d max_mask_size:%d\n", \
removelogo->mask_type##_mask_bbox.x1, removelogo->mask_type##_mask_bbox.x2, \
removelogo->mask_type##_mask_bbox.y1, removelogo->mask_type##_mask_bbox.y2, \
mask_type##_max_mask_size);
SHOW_LOGO_INFO(full);
SHOW_LOGO_INFO(half);
return 0;
}
