* Utility function to access log2_chroma_w log2_chroma_h from
* the pixel format AVPixFmtDescriptor.
*
+ * See av_get_chroma_sub_sample() for a function that asserts a
+ * valid pixel format instead of returning an error code.
+ * Its recommended that you use avcodec_get_chroma_sub_sample unless
+ * you do check the return code!
+ *
* @param[in] pix_fmt the pixel format
- * @param[out] h_shift store log2_chroma_w
- * @param[out] v_shift store log2_chroma_h
+ * @param[out] h_shift store log2_chroma_w (horizontal/width shift)
+ * @param[out] v_shift store log2_chroma_h (vertical/height shift)
*
* @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format
*/