imgutils: add function to clear an image to black

[ffmpeg] / libavutil / imgutils.h

diff --git a/libavutil/imgutils.h b/libavutil/imgutils.h
index ea083b10f11e3da660789c97e84e5878cff44294..2ab90ac0339eb5149caf4077ebb6428ac253b754 100644 (file)
--- a/libavutil/imgutils.h
+++ b/libavutil/imgutils.h
@@ -238,6 +238,33 @@ int av_image_check_size2(unsigned int w, unsigned int h, int64_t max_pixels, enu
  */
 int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar);
 
+/**
+ * Overwrite the image data with black. This is suitable for filling a
+ * sub-rectangle of an image, meaning the padding between the right most pixel
+ * and the left most pixel on the next line will not be overwritten. For some
+ * formats, the image size might be rounded up due to inherent alignment.
+ *
+ * If the pixel format has alpha, the alpha is cleared to opaque.
+ *
+ * This can return an error if the pixel format is not supported. Normally, all
+ * non-hwaccel pixel formats should be supported.
+ *
+ * Passing NULL for dst_data is allowed. Then the function returns whether the
+ * operation would have succeeded. (It can return an error if the pix_fmt is
+ * not supported.)
+ *
+ * @param dst_data      data pointers to destination image
+ * @param dst_linesize  linesizes for the destination image
+ * @param pix_fmt       the pixel format of the image
+ * @param range         the color range of the image (important for colorspaces such as YUV)
+ * @param width         the width of the image in pixels
+ * @param height        the height of the image in pixels
+ * @return 0 if the image data was cleared, a negative AVERROR code otherwise
+ */
+int av_image_fill_black(uint8_t *dst_data[4], const ptrdiff_t dst_linesize[4],
+                        enum AVPixelFormat pix_fmt, enum AVColorRange range,
+                        int width, int height);
+
 /**
  * @}
  */