[PATCH 2/3] Add dilate libopencv filter.

[Stefano Sabatini]

---
 libavfilter/vf_libopencv.c |  131 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 131 insertions(+), 0 deletions(-)

diff --git a/libavfilter/vf_libopencv.c b/libavfilter/vf_libopencv.c
index 0e3da4d..4f787ad 100644
--- a/libavfilter/vf_libopencv.c
+++ b/libavfilter/vf_libopencv.c
@@ -127,6 +127,136 @@ static void smooth_end_frame_filter(AVFilterContext *ctx, IplImage *inimg, IplIm
     cvSmooth(inimg, outimg, smooth->type, smooth->param1, smooth->param2, smooth->param3, smooth->param4);
 }
 
+static int read_shape_from_file(int *cols, int *rows, int **values, const char *filename, void *log_ctx)
+{
+    char *p, *buf;
+    size_t size;
+    int i, j, w;
+    FILE *f = fopen(filename, "rb");
+    char *line;
+
+    *cols = *rows = 0;
+
+    if (!f) {
+        av_log(log_ctx, AV_LOG_ERROR, "Cannot read file '%s': %s\n", filename, strerror(errno));
+        return AVERROR(errno);
+    }
+    fseek(f, 0, SEEK_END);
+    size = ftell(f);
+    fseek(f, 0, SEEK_SET);
+    buf = av_malloc(size + 1);
+    if (!buf) {
+        fclose(f);
+        return AVERROR(ENOMEM);
+    }
+    fread(buf, 1, size, f);
+    buf[size++] = 0;
+    fclose(f);
+
+    /* prescan file to get the number of lines and the maximum width */
+    w = 0;
+    for (i = 0; i < size; i++) {
+        if (buf[i] == '\n') {
+            (*rows)++;
+            *cols = FFMAX(*cols, w); w = 0;
+        } else
+            w++;
+    }
+    av_log(log_ctx, AV_LOG_DEBUG, "rows:%d cols:%d\n", *rows, *cols);
+
+    if (*rows > INT_MAX / *cols) {
+        av_log(log_ctx, AV_LOG_ERROR, "File with size %dx%d is too big\n",
+               *rows, *cols);
+        return AVERROR_INVALIDDATA;
+    }
+    if (!(*values = av_mallocz(sizeof(int) * *rows * *cols)))
+        return AVERROR(ENOMEM);
+
+    /* fill *values */
+    p = buf;
+    for (i = 0; i < *rows; i++) {
+        for (j = 0;; j++) {
+            /* av_log(log_ctx, AV_LOG_DEBUG, "%d:%d -> '%c'\n", i, j, *p == '\n' ? 'N' : *p); */
+            if (*p == '\n') {
+                p++; break;
+            } else
+                (*values)[*cols*i + j] = !!isgraph(*(p++));
+        }
+    }
+
+    if (!(line = av_malloc(*cols + 1)))
+        return AVERROR(ENOMEM);
+    for (i = 0; i < *rows; i++) {
+        for (j = 0; j < *cols; j++)
+            line[j] = (*values)[i * *cols + j] ? '@' : ' ';
+        line[j] = 0;
+        av_log(log_ctx, AV_LOG_DEBUG, "%3d: %s\n", i, line);
+    }
+    av_free(line);
+
+    return 0;
+}
+
+static int parse_iplconvkernel(IplConvKernel **kernel, char *buf, void *log_ctx)
+{
+    char values_file_str[128], shape_str[128];
+    int cols, rows, anchor_x, anchor_y, shape = CV_SHAPE_RECT;
+    int *values = NULL, ret;
+
+    sscanf(buf, "%dx%d+%dx%d/%127[^=]=%127s", &cols, &rows, &anchor_x, &anchor_y, shape_str, values_file_str);
+    if      (!strcmp(shape_str, "rect"   )) shape = CV_SHAPE_RECT;
+    else if (!strcmp(shape_str, "cross"  )) shape = CV_SHAPE_CROSS;
+    else if (!strcmp(shape_str, "ellipse")) shape = CV_SHAPE_ELLIPSE;
+    else if (!strcmp(shape_str, "custom" )) {
+        shape = CV_SHAPE_CUSTOM;
+        if ((ret = read_shape_from_file(&cols, &rows, &values, values_file_str, log_ctx)) < 0)
+            return ret;
+    } else {
+        av_log(log_ctx, AV_LOG_ERROR, "Shape type '%s' unknown\n.", shape_str);
+        return AVERROR(EINVAL);
+    }
+
+    *kernel = cvCreateStructuringElementEx(cols, rows, anchor_x, anchor_y, shape, values);
+    av_freep(&values);
+    if (!*kernel)
+        return AVERROR(ENOMEM);
+
+    av_log(log_ctx, AV_LOG_INFO, "Structuring element: w:%d h:%d x:%d y:%d shape:%s\n",
+           rows, cols, anchor_x, anchor_y, shape_str);
+    return 0;
+}
+
+typedef struct {
+    int iterations_nb;
+    IplConvKernel *kernel;
+} DilateContext;
+
+static av_cold int dilate_init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+    OCVContext *ocv = ctx->priv;
+    DilateContext *dilate = ocv->priv;
+    char kernel_str[256] = "3x3+0x0/rect";
+    int ret;
+
+    dilate->iterations_nb = 1;
+
+    if (args)
+        sscanf(args, "%d:%255c", &dilate->iterations_nb, kernel_str);
+
+    if ((ret = parse_iplconvkernel(&dilate->kernel, kernel_str, ctx)) < 0)
+        return ret;
+
+    av_log(ctx, AV_LOG_INFO, "iterations_nb:%d\n", dilate->iterations_nb);
+    return 0;
+}
+
+static void dilate_end_frame_filter(AVFilterContext *ctx, IplImage *inimg, IplImage *outimg)
+{
+    OCVContext *ocv = ctx->priv;
+    DilateContext *dilate = ocv->priv;
+    cvDilate(inimg, outimg, dilate->kernel, dilate->iterations_nb);
+}
+
 typedef struct {
     const char *name;
     size_t priv_size;
@@ -137,6 +267,7 @@ typedef struct {
 
 static OCVFilterEntry ocv_filter_entries[] = {
     { "smooth", sizeof(SmoothContext), smooth_init, NULL, smooth_end_frame_filter },
+    { "dilate", sizeof(DilateContext), dilate_init, NULL, dilate_end_frame_filter },
 };
 
 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
-- 
1.7.1


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