Merge commit 'd336bfcf'

* commit 'd336bfcf':
  pixdesc: fix and extend doxy for av_pix_fmt_get_chroma_sub_sample()
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

libavutil/pixdesc.h

@@ -292,8 +292,8 @@ enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc);
  * 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
  */