[FFmpeg-devel] [PATCH] lavfi: port libmpcodecs remove-logo filter
Stefano Sabatini
stefasab at gmail.com
Sun Mar 11 04:01:32 CET 2012
Address trac issue #249.
---
configure | 1 +
doc/filters.texi | 23 ++
libavfilter/Makefile | 2 +
libavfilter/allfilters.c | 1 +
libavfilter/extutils.c | 121 +++++++++
libavfilter/extutils.h | 53 ++++
libavfilter/vf_removelogo.c | 584 +++++++++++++++++++++++++++++++++++++++++++
7 files changed, 785 insertions(+), 0 deletions(-)
create mode 100644 libavfilter/extutils.c
create mode 100644 libavfilter/extutils.h
create mode 100644 libavfilter/vf_removelogo.c
diff --git a/configure b/configure
index 271ecf4..2f3b798 100755
--- a/configure
+++ b/configure
@@ -1677,6 +1677,7 @@ mptestsrc_filter_deps="gpl"
negate_filter_deps="lut_filter"
ocv_filter_deps="libopencv"
pan_filter_deps="swresample"
+removelogo_filter_deps="avcode avformat swscale"
scale_filter_deps="swscale"
tinterlace_filter_deps="gpl"
yadif_filter_deps="gpl"
diff --git a/doc/filters.texi b/doc/filters.texi
index 62783c0..20d3b97 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2202,6 +2202,29 @@ format=monow, pixdesctest
can be used to test the monowhite pixel format descriptor definition.
+ at section removelogo
+
+Suppress a TV station logo, using an image file to determine which
+pixels comprise the logo. The width and height of the image file must
+match those of the video stream being processed.
+
+This filter requires 1 argument and has no optional arguments. It
+requires a filter bitmap, which must be in any image format.
+
+Pixels with a value of zero are not part of the logo, and non-zero
+pixels are part of the logo. If you use white (255) for the logo and
+black (0) for the rest, you will be safe. For making the filter
+bitmap, it is recommended to take a screen capture of a black frame
+with the logo visible, and then using a threshold filter followed by
+the erode filter once or twice.
+
+If needed, little splotches can be fixed manually. Remember that if
+logo pixels are not covered, the filter quality will be much
+reduced. Marking too many pixels as part of the logo does not hurt as
+much, but it will increase the amount of blurring needed to cover over
+the image and will destroy more information than necessary, and extra
+pixels will slow things down on a large logo.
+
@section scale
Scale the input video to @var{width}:@var{height}[:@var{interl}=@{1|-1@}] and/or convert the image format.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 6a9a3ad..8a214e2 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -8,6 +8,7 @@ FFLIBS-$(CONFIG_AMOVIE_FILTER) += avformat avcodec
FFLIBS-$(CONFIG_ARESAMPLE_FILTER) += swresample
FFLIBS-$(CONFIG_MOVIE_FILTER) += avformat avcodec
FFLIBS-$(CONFIG_PAN_FILTER) += swresample
+FFLIBS-$(CONFIG_REMOVELOGO_FILTER) += swscale avformat avcodec
FFLIBS-$(CONFIG_SCALE_FILTER) += swscale
FFLIBS-$(CONFIG_MP_FILTER) += avcodec postproc
@@ -78,6 +79,7 @@ OBJS-$(CONFIG_OCV_FILTER) += vf_libopencv.o
OBJS-$(CONFIG_OVERLAY_FILTER) += vf_overlay.o
OBJS-$(CONFIG_PAD_FILTER) += vf_pad.o
OBJS-$(CONFIG_PIXDESCTEST_FILTER) += vf_pixdesctest.o
+OBJS-$(CONFIG_REMOVELOGO_FILTER) += bbox.o extutils.o vf_removelogo.o
OBJS-$(CONFIG_SCALE_FILTER) += vf_scale.o
OBJS-$(CONFIG_SELECT_FILTER) += vf_select.o
OBJS-$(CONFIG_SETDAR_FILTER) += vf_aspect.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 6972271..7f6a328 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -86,6 +86,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (OVERLAY, overlay, vf);
REGISTER_FILTER (PAD, pad, vf);
REGISTER_FILTER (PIXDESCTEST, pixdesctest, vf);
+ REGISTER_FILTER (REMOVELOGO, removelogo, vf);
REGISTER_FILTER (SCALE, scale, vf);
REGISTER_FILTER (SELECT, select, vf);
REGISTER_FILTER (SETDAR, setdar, vf);
diff --git a/libavfilter/extutils.c b/libavfilter/extutils.c
new file mode 100644
index 0000000..25474e8
--- /dev/null
+++ b/libavfilter/extutils.c
@@ -0,0 +1,121 @@
+/*
+ * 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
+ */
+
+#include "extutils.h"
+#include "libavutil/imgutils.h"
+
+int ff_load_image(uint8_t *data[4], int linesize[4],
+ int *w, int *h, enum PixelFormat *pix_fmt,
+ const char *filename, void *log_ctx)
+{
+ AVInputFormat *iformat = NULL;
+ AVFormatContext *format_ctx;
+ AVCodec *codec;
+ AVCodecContext *codec_ctx;
+ AVFrame *frame;
+ int frame_decoded, ret = 0;
+ AVPacket pkt;
+
+ av_register_all();
+
+ iformat = av_find_input_format("image2");
+ if ((ret = avformat_open_input(&format_ctx, filename, iformat, NULL)) < 0) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Failed to open input file '%s'\n", filename);
+ return ret;
+ }
+
+ codec_ctx = format_ctx->streams[0]->codec;
+ codec = avcodec_find_decoder(codec_ctx->codec_id);
+ if (!codec) {
+ av_log(log_ctx, AV_LOG_ERROR, "Failed to find codec\n");
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+
+ if ((ret = avcodec_open2(codec_ctx, codec, NULL)) < 0) {
+ av_log(log_ctx, AV_LOG_ERROR, "Failed to open codec\n");
+ goto end;
+ }
+
+ if (!(frame = avcodec_alloc_frame()) ) {
+ av_log(log_ctx, AV_LOG_ERROR, "Failed to alloc frame\n");
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+
+ ret = av_read_frame(format_ctx, &pkt);
+ if (ret < 0) {
+ av_log(log_ctx, AV_LOG_ERROR, "Failed to read frame from file\n");
+ goto end;
+ }
+
+ ret = avcodec_decode_video2(codec_ctx, frame, &frame_decoded, &pkt);
+ if (ret < 0 || !frame_decoded) {
+ av_log(log_ctx, AV_LOG_ERROR, "Failed to decode image from file\n");
+ goto end;
+ }
+ ret = 0;
+
+ *w = frame->width;
+ *h = frame->height;
+ *pix_fmt = frame->format;
+
+ if ((ret = av_image_alloc(data, linesize, *w, *h, *pix_fmt, 16)) < 0)
+ goto end;
+ ret = 0;
+
+ av_image_copy(data, linesize, frame->data, frame->linesize, *pix_fmt, *w, *h);
+
+end:
+ if (codec_ctx)
+ avcodec_close(codec_ctx);
+ if (format_ctx)
+ avformat_close_input(&format_ctx);
+ av_freep(&frame);
+
+ if (ret < 0)
+ av_log(log_ctx, AV_LOG_ERROR, "Error loading image file '%s'\n", filename);
+ return ret;
+}
+
+int ff_scale_image(uint8_t *dst_data[4], int dst_linesize[4], int dst_w, int dst_h, enum PixelFormat dst_pix_fmt,
+ uint8_t * const src_data[4], int src_linesize[4], int src_w, int src_h, enum PixelFormat src_pix_fmt,
+ void *log_ctx)
+{
+ int ret;
+ struct SwsContext *sws_ctx = sws_getContext(src_w, src_h, src_pix_fmt,
+ dst_w, dst_h, dst_pix_fmt,
+ SWS_BILINEAR, NULL, NULL, NULL);
+ if (!sws_ctx) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Impossible to create scale context for the conversion fmt:%s s:%dx%d -> fmt:%s s:%dx%d\n",
+ av_get_pix_fmt_name(src_pix_fmt), src_w, src_h, av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h);
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+
+ if ((ret = av_image_alloc(dst_data, dst_linesize, dst_w, dst_h, dst_pix_fmt, 16)) < 0)
+ goto end;
+ ret = 0;
+ sws_scale(sws_ctx, src_data, src_linesize, 0, src_h, dst_data, dst_linesize);
+
+end:
+ sws_freeContext(sws_ctx);
+ return ret;
+}
diff --git a/libavfilter/extutils.h b/libavfilter/extutils.h
new file mode 100644
index 0000000..ac51b19
--- /dev/null
+++ b/libavfilter/extutils.h
@@ -0,0 +1,53 @@
+/*
+ * 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
+ * Miscellaneous utilities which make use of the other libav* libraries.
+ */
+
+#ifndef AVFILTER_EXTUTILS_H
+#define AVFILTER_EXTUTILS_H
+
+#include "libavcodec/avcodec.h"
+#include "libavformat/avformat.h"
+#include "libswscale/swscale.h"
+
+/**
+ * Load image from filename and put the resulting image in dst_data
+ * and dst_linesize.
+ *
+ * @param w pointer to the width of the loaded image
+ * @param h pointer to the height of the loaded image
+ * @param pix_fmt pointer to the pixel format of the loaded image
+ * @param filename the name of the image file to load
+ * @param log_ctx log context
+ * @return 0 in case of success, a negative error code otherwise.
+ */
+int ff_load_image(uint8_t *data[4], int linesize[4],
+ int *w, int *h, enum PixelFormat *pix_fmt,
+ const char *filename, void *log_ctx);
+
+/**
+ * Scale image using libswscale.
+ */
+int ff_scale_image(uint8_t *dst_data[4], int dst_linesize[4], int dst_w, int dst_h, enum PixelFormat dst_pix_fmt,
+ uint8_t *const src_data[4], int src_linesize[4], int src_w, int src_h, enum PixelFormat src_pix_fmt,
+ void *log_ctx);
+
+#endif /* AVFILTER_EXTUTILS_H */
diff --git a/libavfilter/vf_removelogo.c b/libavfilter/vf_removelogo.c
new file mode 100644
index 0000000..49a9dab
--- /dev/null
+++ b/libavfilter/vf_removelogo.c
@@ -0,0 +1,584 @@
+/*
+ * Copyright (c) 2005 Robert Edele <yartrebo at 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.
+ */
+
+/**
+ * Hello and welcome. 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 filter requires 1 argument and has no optional arguments. It requires a
+ * filter bitmap, which must be in any image format. A sample invocation would
+ * be -vf remove_logo=/home/username/logo_bitmaps/xyz.pgm. The image file is
+ * converte to a gray image, and pixels with a value lesser than the minimum
+ * value are not part of the logo, and other pixels are part of the logo. If you
+ * use white (255) for the logo and black (0) for the rest, you will be
+ * safe. For making the filter bitmap, I recommend taking a screen capture of a
+ * black frame with the logo visible, and then using The GIMP's threshold filter
+ * followed by the erode filter once or twice. If needed, little splotches can
+ * be fixed manually. Remember that if logo pixels are not covered, the filter
+ * quality will be much reduced. Marking too many pixels as part of the logo
+ * doesn't hurt as much, but it will increase the amount of blurring needed to
+ * cover over the image and will destroy more information than
+ * necessary. Additionally, this blur algorithm is O(n) = n^4, where n is the
+ * width and height of a hypothetical square logo, so extra pixels will slow
+ * things down on a large logo.
+ *
+ * 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 "avfilter.h"
+#include "bbox.h"
+#include "extutils.h"
+
+typedef struct {
+ /* 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;
+ BoundingBox full_mask_bbox;
+ uint8_t *half_mask_data;
+ BoundingBox half_mask_bbox;
+} RemovelogoContext;
+
+/**
+ * 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, *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 + w) >= current_pass &&
+ *(current_pixel - w) >= 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)
+{
+ enum PixelFormat pix_fmts[] = { PIX_FMT_YUV420P, PIX_FMT_NONE };
+ avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
+ return 0;
+}
+
+static int load_mask(uint8_t **mask, int *w, int *h,
+ const char *filename, void *log_ctx)
+{
+ int ret;
+ enum PixelFormat 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, 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_free(src_data[0]);
+ av_free(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, const char *args, void *opaque)
+{
+ 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. */
+ calculate_bounding_rectangle(&removelogo->full_mask_bbox, removelogo->full_mask_data, w, w, h, 0);
+ calculate_bounding_rectangle(&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_INFO, #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;
+}
+
+static int config_props_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ RemovelogoContext *removelogo = ctx->priv;
+
+ if (inlink->w != removelogo->mask_w || inlink->h != removelogo->mask_h) {
+ av_log(ctx, AV_LOG_INFO,
+ "Mask image size %dx%d does not match with the input video size %dx%d\n",
+ removelogo->mask_w, removelogo->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,
+ BoundingBox *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 void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
+{
+ AVFilterLink *outlink = inlink->dst->outputs[0];
+ AVFilterBufferRef *outpicref;
+
+ if (inpicref->perms & AV_PERM_PRESERVE) {
+ outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE,
+ outlink->w, outlink->h);
+ avfilter_copy_buffer_ref_props(outpicref, inpicref);
+ outpicref->video->w = outlink->w;
+ outpicref->video->h = outlink->h;
+ } else
+ outpicref = inpicref;
+
+ outlink->out_buf = outpicref;
+ avfilter_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0));
+}
+
+static void end_frame(AVFilterLink *inlink)
+{
+ RemovelogoContext *removelogo = inlink->dst->priv;
+ AVFilterLink *outlink = inlink->dst->outputs[0];
+ AVFilterBufferRef *inpicref = inlink ->cur_buf;
+ AVFilterBufferRef *outpicref = outlink->out_buf;
+ int direct = inpicref == outpicref;
+
+ blur_image(removelogo->mask,
+ inpicref ->data[0], inpicref ->linesize[0],
+ outpicref->data[0], outpicref->linesize[0],
+ removelogo->full_mask_data, inlink->w,
+ inlink->w, inlink->h, direct, &removelogo->full_mask_bbox);
+ blur_image(removelogo->mask,
+ inpicref ->data[1], inpicref ->linesize[1],
+ outpicref->data[1], outpicref->linesize[1],
+ removelogo->half_mask_data, inlink->w/2,
+ inlink->w/2, inlink->h/2, direct, &removelogo->half_mask_bbox);
+ blur_image(removelogo->mask,
+ inpicref ->data[2], inpicref ->linesize[2],
+ outpicref->data[2], outpicref->linesize[2],
+ removelogo->half_mask_data, inlink->w/2,
+ inlink->w/2, inlink->h/2, direct, &removelogo->half_mask_bbox);
+
+ avfilter_draw_slice(outlink, 0, inlink->h, 1);
+ avfilter_end_frame(outlink);
+ avfilter_unref_buffer(inpicref);
+ if (!direct)
+ avfilter_unref_buffer(outpicref);
+}
+
+static void uninit(AVFilterContext *ctx)
+{
+ RemovelogoContext *removelogo = ctx->priv;
+ int a, b;
+
+ av_freep(&removelogo->full_mask_data);
+ av_freep(&removelogo->half_mask_data);
+
+ if (removelogo->mask) {
+ /* Loop through each mask. */
+ for (a = 0; a <= removelogo->max_mask_size; a++) {
+ /* Loop through each scanline in a mask. */
+ for (b = -a; b <= a; b++) {
+ av_free(removelogo->mask[a][b + a]); /* Free a scanline. */
+ }
+ av_free(removelogo->mask[a]);
+ }
+ /* Free the array of pointers pointing to the masks. */
+ av_freep(&removelogo->mask);
+ }
+}
+
+static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
+
+AVFilter avfilter_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 = (const AVFilterPad[]) {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .get_video_buffer = avfilter_null_get_video_buffer,
+ .config_props = config_props_input,
+ .draw_slice = null_draw_slice,
+ .start_frame = start_frame,
+ .end_frame = end_frame,
+ .min_perms = AV_PERM_WRITE | AV_PERM_READ,
+ .rej_perms = AV_PERM_PRESERVE },
+ { .name = NULL }
+ },
+ .outputs = (const AVFilterPad[]) {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO, },
+ { .name = NULL }
+ },
+};
--
1.7.5.4
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