Added a selftest to libavutil/display.c

    - Check if av_display_rotation_get() gets the correct degrees
    - Check if av_display_rotation_set() sets the correct matrix
    - Check if av_display_matrix_flip() changes correct the matrix

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 43 insertions, 0 deletions

diff --git a/libavutil/display.c b/libavutil/display.c
index a0076e067b..ceed492756 100644
--- a/libavutil/display.c
+++ b/libavutil/display.c
@@ -71,3 +71,46 @@ void av_display_matrix_flip(int32_t matrix[9], int hflip, int vflip)
         for (i = 0; i < 9; i++)
             matrix[i] *= flip[i % 3];
 }
+
+#ifdef TEST
+
+static void print_matrix(int32_t matrix[9])
+{
+    int i, j;
+
+    for (i = 0; i < 3; ++i) {
+        for (j = 0; j < 3 - 1; ++j)
+            printf("%d ", matrix[i*3 + j]);
+
+        printf("%d\n", matrix[i*3 + j]);
+    }
+}
+
+int main(void)
+{
+    int32_t matrix[9];
+
+    // Set the matrix to 90 degrees
+    av_display_rotation_set(matrix, 90);
+    print_matrix(matrix);
+    printf("degrees: %f\n", av_display_rotation_get(matrix));
+
+    // Set the matrix to -45 degrees
+    av_display_rotation_set(matrix, -45);
+    print_matrix(matrix);
+    printf("degrees: %f\n", av_display_rotation_get(matrix));
+
+    // flip horizontal
+    av_display_matrix_flip(matrix, 1, 0);
+    print_matrix(matrix);
+    printf("degrees: %f\n", av_display_rotation_get(matrix));
+
+    // flip vertical
+    av_display_matrix_flip(matrix, 0, 1);
+    print_matrix(matrix);
+    printf("degrees: %f\n", av_display_rotation_get(matrix));
+
+    return 0;
+
+}
+#endif