| /* |
| * Copyright (c) 2005 Robert Edele <yartrebo@earthlink.net> |
| * Copyright (c) 2012 Stefano Sabatini |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * Advanced blur-based logo removing filter |
| * |
| * This filter loads an image mask file showing where a logo is and |
| * uses a blur transform to remove the logo. |
| * |
| * Based on the libmpcodecs remove-logo filter by Robert Edele. |
| */ |
| |
| /** |
| * This code implements a filter to remove annoying TV logos and other annoying |
| * images placed onto a video stream. It works by filling in the pixels that |
| * comprise the logo with neighboring pixels. The transform is very loosely |
| * based on a gaussian blur, but it is different enough to merit its own |
| * paragraph later on. It is a major improvement on the old delogo filter as it |
| * both uses a better blurring algorithm and uses a bitmap to use an arbitrary |
| * and generally much tighter fitting shape than a rectangle. |
| * |
| * The logo removal algorithm has two key points. The first is that it |
| * distinguishes between pixels in the logo and those not in the logo by using |
| * the passed-in bitmap. Pixels not in the logo are copied over directly without |
| * being modified and they also serve as source pixels for the logo |
| * fill-in. Pixels inside the logo have the mask applied. |
| * |
| * At init-time the bitmap is reprocessed internally, and the distance to the |
| * nearest edge of the logo (Manhattan distance), along with a little extra to |
| * remove rough edges, is stored in each pixel. This is done using an in-place |
| * erosion algorithm, and incrementing each pixel that survives any given |
| * erosion. Once every pixel is eroded, the maximum value is recorded, and a |
| * set of masks from size 0 to this size are generaged. The masks are circular |
| * binary masks, where each pixel within a radius N (where N is the size of the |
| * mask) is a 1, and all other pixels are a 0. Although a gaussian mask would be |
| * more mathematically accurate, a binary mask works better in practice because |
| * we generally do not use the central pixels in the mask (because they are in |
| * the logo region), and thus a gaussian mask will cause too little blur and |
| * thus a very unstable image. |
| * |
| * The mask is applied in a special way. Namely, only pixels in the mask that |
| * line up to pixels outside the logo are used. The dynamic mask size means that |
| * the mask is just big enough so that the edges touch pixels outside the logo, |
| * so the blurring is kept to a minimum and at least the first boundary |
| * condition is met (that the image function itself is continuous), even if the |
| * second boundary condition (that the derivative of the image function is |
| * continuous) is not met. A masking algorithm that does preserve the second |
| * boundary coundition (perhaps something based on a highly-modified bi-cubic |
| * algorithm) should offer even better results on paper, but the noise in a |
| * typical TV signal should make anything based on derivatives hopelessly noisy. |
| */ |
| |
| #include "libavutil/imgutils.h" |
| #include "libavutil/opt.h" |
| #include "avfilter.h" |
| #include "formats.h" |
| #include "internal.h" |
| #include "video.h" |
| #include "bbox.h" |
| #include "lavfutils.h" |
| #include "lswsutils.h" |
| |
| typedef struct { |
| const AVClass *class; |
| char *filename; |
| /* Stores our collection of masks. The first is for an array of |
| the second for the y axis, and the third for the x axis. */ |
| int ***mask; |
| int max_mask_size; |
| int mask_w, mask_h; |
| |
| uint8_t *full_mask_data; |
| FFBoundingBox full_mask_bbox; |
| uint8_t *half_mask_data; |
| FFBoundingBox half_mask_bbox; |
| } RemovelogoContext; |
| |
| #define OFFSET(x) offsetof(RemovelogoContext, x) |
| #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM |
| static const AVOption removelogo_options[] = { |
| { "filename", "set bitmap filename", OFFSET(filename), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, |
| { "f", "set bitmap filename", OFFSET(filename), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, |
| { NULL } |
| }; |
| |
| AVFILTER_DEFINE_CLASS(removelogo); |
| |
| /** |
| * Choose a slightly larger mask size to improve performance. |
| * |
| * This function maps the absolute minimum mask size needed to the |
| * mask size we'll actually use. f(x) = x (the smallest that will |
| * work) will produce the sharpest results, but will be quite |
| * jittery. f(x) = 1.25x (what I'm using) is a good tradeoff in my |
| * opinion. This will calculate only at init-time, so you can put a |
| * long expression here without effecting performance. |
| */ |
| #define apply_mask_fudge_factor(x) (((x) >> 2) + (x)) |
| |
| /** |
| * Pre-process an image to give distance information. |
| * |
| * This function takes a bitmap image and converts it in place into a |
| * distance image. A distance image is zero for pixels outside of the |
| * logo and is the Manhattan distance (|dx| + |dy|) from the logo edge |
| * for pixels inside of the logo. This will overestimate the distance, |
| * but that is safe, and is far easier to implement than a proper |
| * pythagorean distance since I'm using a modified erosion algorithm |
| * to compute the distances. |
| * |
| * @param mask image which will be converted from a greyscale image |
| * into a distance image. |
| */ |
| static void convert_mask_to_strength_mask(uint8_t *data, int linesize, |
| int w, int h, int min_val, |
| int *max_mask_size) |
| { |
| int x, y; |
| |
| /* How many times we've gone through the loop. Used in the |
| in-place erosion algorithm and to get us max_mask_size later on. */ |
| int current_pass = 0; |
| |
| /* set all non-zero values to 1 */ |
| for (y = 0; y < h; y++) |
| for (x = 0; x < w; x++) |
| data[y*linesize + x] = data[y*linesize + x] > min_val; |
| |
| /* For each pass, if a pixel is itself the same value as the |
| current pass, and its four neighbors are too, then it is |
| incremented. If no pixels are incremented by the end of the |
| pass, then we go again. Edge pixels are counted as always |
| excluded (this should be true anyway for any sane mask, but if |
| it isn't this will ensure that we eventually exit). */ |
| while (1) { |
| /* If this doesn't get set by the end of this pass, then we're done. */ |
| int has_anything_changed = 0; |
| uint8_t *current_pixel0 = data + 1 + linesize, *current_pixel; |
| current_pass++; |
| |
| for (y = 1; y < h-1; y++) { |
| current_pixel = current_pixel0; |
| for (x = 1; x < w-1; x++) { |
| /* Apply the in-place erosion transform. It is based |
| on the following two premises: |
| 1 - Any pixel that fails 1 erosion will fail all |
| future erosions. |
| |
| 2 - Only pixels having survived all erosions up to |
| the present will be >= to current_pass. |
| It doesn't matter if it survived the current pass, |
| failed it, or hasn't been tested yet. By using >= |
| instead of ==, we allow the algorithm to work in |
| place. */ |
| if ( *current_pixel >= current_pass && |
| *(current_pixel + 1) >= current_pass && |
| *(current_pixel - 1) >= current_pass && |
| *(current_pixel + linesize) >= current_pass && |
| *(current_pixel - linesize) >= current_pass) { |
| /* Increment the value since it still has not been |
| * eroded, as evidenced by the if statement that |
| * just evaluated to true. */ |
| (*current_pixel)++; |
| has_anything_changed = 1; |
| } |
| current_pixel++; |
| } |
| current_pixel0 += linesize; |
| } |
| if (!has_anything_changed) |
| break; |
| } |
| |
| /* Apply the fudge factor, which will increase the size of the |
| * mask a little to reduce jitter at the cost of more blur. */ |
| for (y = 1; y < h - 1; y++) |
| for (x = 1; x < w - 1; x++) |
| data[(y * linesize) + x] = apply_mask_fudge_factor(data[(y * linesize) + x]); |
| |
| /* As a side-effect, we now know the maximum mask size, which |
| * we'll use to generate our masks. */ |
| /* Apply the fudge factor to this number too, since we must ensure |
| * that enough masks are generated. */ |
| *max_mask_size = apply_mask_fudge_factor(current_pass + 1); |
| } |
| |
| static int query_formats(AVFilterContext *ctx) |
| { |
| static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE }; |
| AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts); |
| if (!fmts_list) |
| return AVERROR(ENOMEM); |
| return ff_set_common_formats(ctx, fmts_list); |
| } |
| |
| static int load_mask(uint8_t **mask, int *w, int *h, |
| const char *filename, void *log_ctx) |
| { |
| int ret; |
| enum AVPixelFormat pix_fmt; |
| uint8_t *src_data[4], *gray_data[4]; |
| int src_linesize[4], gray_linesize[4]; |
| |
| /* load image from file */ |
| if ((ret = ff_load_image(src_data, src_linesize, w, h, &pix_fmt, filename, log_ctx)) < 0) |
| return ret; |
| |
| /* convert the image to GRAY8 */ |
| if ((ret = ff_scale_image(gray_data, gray_linesize, *w, *h, AV_PIX_FMT_GRAY8, |
| src_data, src_linesize, *w, *h, pix_fmt, |
| log_ctx)) < 0) |
| goto end; |
| |
| /* copy mask to a newly allocated array */ |
| *mask = av_malloc(*w * *h); |
| if (!*mask) |
| ret = AVERROR(ENOMEM); |
| av_image_copy_plane(*mask, *w, gray_data[0], gray_linesize[0], *w, *h); |
| |
| end: |
| av_freep(&src_data[0]); |
| av_freep(&gray_data[0]); |
| return ret; |
| } |
| |
| /** |
| * 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); |
| } |
| |
| static av_cold int init(AVFilterContext *ctx) |
| { |
| RemovelogoContext *s = ctx->priv; |
| int ***mask; |
| int ret = 0; |
| int a, b, c, w, h; |
| int full_max_mask_size, half_max_mask_size; |
| |
| if (!s->filename) { |
| av_log(ctx, AV_LOG_ERROR, "The bitmap file name is mandatory\n"); |
| return AVERROR(EINVAL); |
| } |
| |
| /* Load our mask image. */ |
| if ((ret = load_mask(&s->full_mask_data, &w, &h, s->filename, ctx)) < 0) |
| return ret; |
| s->mask_w = w; |
| s->mask_h = h; |
| |
| convert_mask_to_strength_mask(s->full_mask_data, w, w, h, |
| 16, &full_max_mask_size); |
| |
| /* Create the scaled down mask image for the chroma planes. */ |
| if (!(s->half_mask_data = av_mallocz(w/2 * h/2))) |
| return AVERROR(ENOMEM); |
| generate_half_size_image(s->full_mask_data, w, |
| s->half_mask_data, w/2, |
| w, h, &half_max_mask_size); |
| |
| s->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_array(s->max_mask_size + 1, sizeof(int **)); |
| if (!mask) |
| return AVERROR(ENOMEM); |
| |
| for (a = 0; a <= s->max_mask_size; a++) { |
| mask[a] = (int **)av_malloc_array((a * 2) + 1, sizeof(int *)); |
| if (!mask[a]) { |
| av_free(mask); |
| return AVERROR(ENOMEM); |
| } |
| for (b = -a; b <= a; b++) { |
| mask[a][b + a] = (int *)av_malloc_array((a * 2) + 1, sizeof(int)); |
| if (!mask[a][b + a]) { |
| av_free(mask); |
| 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; |
| } |
| } |
| } |
| s->mask = mask; |
| |
| /* Calculate our bounding rectangles, which determine in what |
| * region the logo resides for faster processing. */ |
| ff_calculate_bounding_box(&s->full_mask_bbox, s->full_mask_data, w, w, h, 0); |
| ff_calculate_bounding_box(&s->half_mask_bbox, s->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", \ |
| s->mask_type##_mask_bbox.x1, s->mask_type##_mask_bbox.x2, \ |
| s->mask_type##_mask_bbox.y1, s->mask_type##_mask_bbox.y2, \ |
| mask_type##_max_mask_size); |
| SHOW_LOGO_INFO(full); |
| SHOW_LOGO_INFO(half); |
| |
| return 0; |
| } |
| |
| static int config_props_input(AVFilterLink *inlink) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| RemovelogoContext *s = ctx->priv; |
| |
| if (inlink->w != s->mask_w || inlink->h != s->mask_h) { |
| av_log(ctx, AV_LOG_INFO, |
| "Mask image size %dx%d does not match with the input video size %dx%d\n", |
| s->mask_w, s->mask_h, inlink->w, inlink->h); |
| return AVERROR(EINVAL); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * Blur image. |
| * |
| * It takes a pixel that is inside the mask and blurs it. It does so |
| * by finding the average of all the pixels within the mask and |
| * outside of the mask. |
| * |
| * @param mask_data the mask plane to use for averaging |
| * @param image_data the image plane to blur |
| * @param w width of the image |
| * @param h height of the image |
| * @param x x-coordinate of the pixel to blur |
| * @param y y-coordinate of the pixel to blur |
| */ |
| static unsigned int blur_pixel(int ***mask, |
| const uint8_t *mask_data, int mask_linesize, |
| uint8_t *image_data, int image_linesize, |
| int w, int h, int x, int y) |
| { |
| /* Mask size tells how large a circle to use. The radius is about |
| * (slightly larger than) mask size. */ |
| int mask_size; |
| int start_posx, start_posy, end_posx, end_posy; |
| int i, j; |
| unsigned int accumulator = 0, divisor = 0; |
| /* What pixel we are reading out of the circular blur mask. */ |
| const uint8_t *image_read_position; |
| /* What pixel we are reading out of the filter image. */ |
| const uint8_t *mask_read_position; |
| |
| /* Prepare our bounding rectangle and clip it if need be. */ |
| mask_size = mask_data[y * mask_linesize + x]; |
| start_posx = FFMAX(0, x - mask_size); |
| start_posy = FFMAX(0, y - mask_size); |
| end_posx = FFMIN(w - 1, x + mask_size); |
| end_posy = FFMIN(h - 1, y + mask_size); |
| |
| image_read_position = image_data + image_linesize * start_posy + start_posx; |
| mask_read_position = mask_data + mask_linesize * start_posy + start_posx; |
| |
| for (j = start_posy; j <= end_posy; j++) { |
| for (i = start_posx; i <= end_posx; i++) { |
| /* Check if this pixel is in the mask or not. Only use the |
| * pixel if it is not. */ |
| if (!(*mask_read_position) && mask[mask_size][i - start_posx][j - start_posy]) { |
| accumulator += *image_read_position; |
| divisor++; |
| } |
| |
| image_read_position++; |
| mask_read_position++; |
| } |
| |
| image_read_position += (image_linesize - ((end_posx + 1) - start_posx)); |
| mask_read_position += (mask_linesize - ((end_posx + 1) - start_posx)); |
| } |
| |
| /* If divisor is 0, it means that not a single pixel is outside of |
| the logo, so we have no data. Else we need to normalise the |
| data using the divisor. */ |
| return divisor == 0 ? 255: |
| (accumulator + (divisor / 2)) / divisor; /* divide, taking into account average rounding error */ |
| } |
| |
| /** |
| * Blur image plane using a mask. |
| * |
| * @param source The image to have it's logo removed. |
| * @param destination Where the output image will be stored. |
| * @param source_stride How far apart (in memory) two consecutive lines are. |
| * @param destination Same as source_stride, but for the destination image. |
| * @param width Width of the image. This is the same for source and destination. |
| * @param height Height of the image. This is the same for source and destination. |
| * @param is_image_direct If the image is direct, then source and destination are |
| * the same and we can save a lot of time by not copying pixels that |
| * haven't changed. |
| * @param filter The image that stores the distance to the edge of the logo for |
| * each pixel. |
| * @param logo_start_x smallest x-coordinate that contains at least 1 logo pixel. |
| * @param logo_start_y smallest y-coordinate that contains at least 1 logo pixel. |
| * @param logo_end_x largest x-coordinate that contains at least 1 logo pixel. |
| * @param logo_end_y largest y-coordinate that contains at least 1 logo pixel. |
| * |
| * This function processes an entire plane. Pixels outside of the logo are copied |
| * to the output without change, and pixels inside the logo have the de-blurring |
| * function applied. |
| */ |
| static void blur_image(int ***mask, |
| const uint8_t *src_data, int src_linesize, |
| uint8_t *dst_data, int dst_linesize, |
| const uint8_t *mask_data, int mask_linesize, |
| int w, int h, int direct, |
| FFBoundingBox *bbox) |
| { |
| int x, y; |
| uint8_t *dst_line; |
| const uint8_t *src_line; |
| |
| if (!direct) |
| av_image_copy_plane(dst_data, dst_linesize, src_data, src_linesize, w, h); |
| |
| for (y = bbox->y1; y <= bbox->y2; y++) { |
| src_line = src_data + src_linesize * y; |
| dst_line = dst_data + dst_linesize * y; |
| |
| for (x = bbox->x1; x <= bbox->x2; x++) { |
| if (mask_data[y * mask_linesize + x]) { |
| /* Only process if we are in the mask. */ |
| dst_line[x] = blur_pixel(mask, |
| mask_data, mask_linesize, |
| dst_data, dst_linesize, |
| w, h, x, y); |
| } else { |
| /* Else just copy the data. */ |
| if (!direct) |
| dst_line[x] = src_line[x]; |
| } |
| } |
| } |
| } |
| |
| static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref) |
| { |
| RemovelogoContext *s = inlink->dst->priv; |
| AVFilterLink *outlink = inlink->dst->outputs[0]; |
| AVFrame *outpicref; |
| int direct = 0; |
| |
| if (av_frame_is_writable(inpicref)) { |
| direct = 1; |
| outpicref = inpicref; |
| } else { |
| outpicref = ff_get_video_buffer(outlink, outlink->w, outlink->h); |
| if (!outpicref) { |
| av_frame_free(&inpicref); |
| return AVERROR(ENOMEM); |
| } |
| av_frame_copy_props(outpicref, inpicref); |
| } |
| |
| blur_image(s->mask, |
| inpicref ->data[0], inpicref ->linesize[0], |
| outpicref->data[0], outpicref->linesize[0], |
| s->full_mask_data, inlink->w, |
| inlink->w, inlink->h, direct, &s->full_mask_bbox); |
| blur_image(s->mask, |
| inpicref ->data[1], inpicref ->linesize[1], |
| outpicref->data[1], outpicref->linesize[1], |
| s->half_mask_data, inlink->w/2, |
| inlink->w/2, inlink->h/2, direct, &s->half_mask_bbox); |
| blur_image(s->mask, |
| inpicref ->data[2], inpicref ->linesize[2], |
| outpicref->data[2], outpicref->linesize[2], |
| s->half_mask_data, inlink->w/2, |
| inlink->w/2, inlink->h/2, direct, &s->half_mask_bbox); |
| |
| if (!direct) |
| av_frame_free(&inpicref); |
| |
| return ff_filter_frame(outlink, outpicref); |
| } |
| |
| static av_cold void uninit(AVFilterContext *ctx) |
| { |
| RemovelogoContext *s = ctx->priv; |
| int a, b; |
| |
| av_freep(&s->full_mask_data); |
| av_freep(&s->half_mask_data); |
| |
| if (s->mask) { |
| /* Loop through each mask. */ |
| for (a = 0; a <= s->max_mask_size; a++) { |
| /* Loop through each scanline in a mask. */ |
| for (b = -a; b <= a; b++) { |
| av_freep(&s->mask[a][b + a]); /* Free a scanline. */ |
| } |
| av_freep(&s->mask[a]); |
| } |
| /* Free the array of pointers pointing to the masks. */ |
| av_freep(&s->mask); |
| } |
| } |
| |
| static const AVFilterPad removelogo_inputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .config_props = config_props_input, |
| .filter_frame = filter_frame, |
| }, |
| { NULL } |
| }; |
| |
| static const AVFilterPad removelogo_outputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| }, |
| { NULL } |
| }; |
| |
| AVFilter ff_vf_removelogo = { |
| .name = "removelogo", |
| .description = NULL_IF_CONFIG_SMALL("Remove a TV logo based on a mask image."), |
| .priv_size = sizeof(RemovelogoContext), |
| .init = init, |
| .uninit = uninit, |
| .query_formats = query_formats, |
| .inputs = removelogo_inputs, |
| .outputs = removelogo_outputs, |
| .priv_class = &removelogo_class, |
| .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, |
| }; |
