Update README.md

clarify EMOTyDA origin and update MELD-DA/IEMOCAP-DA source details

README.md

@@ -52,8 +52,8 @@ Dataset statistics for each dimension in the MMLA benchmark. #C, #U, #Train, #Va
 - **MELD**: Collected from TV series (released in 2019/05).
 - **UR-FUNNY-v2**: Collected from publicly available TED talks (released in 2019/11).
 - **MUStARD**: Collected from TV series (released in 2019/07).
-- **MELD-DA**: Dialogue act annotations added to MELD in 2020/07.
-- **IEMOCAP-DA**: Dialogue act annotations added to IEMOCAP (released in 2020/07).
+- **MELD-DA**: Dialogue act annotations added to MELD in 2020/07. Derived from the EMOTyDA dataset, which re-annotated the original MELD training set videos without collecting new video data.
+- **IEMOCAP-DA**: Dialogue act annotations added to IEMOCAP (released in 2020/07).  Derived from the EMOTyDA dataset, which re-annotated all original IEMOCAP videos without collecting new video data.
 - **MOSI**: Collected from YouTube opinion videos (released in 2016/06).
 - **IEMOCAP**: Collected from scripted improvisational acting (released in 2008/12).
 - **Anno-MI**: Collected from publicly available YouTube and Vimeo videos (released in 2023/03).