[FFmpeg-cvslog] lavu/tx: mention FFT output is not normalized

[Lynne]

ffmpeg | branch: master | Lynne <dev at lynne.ee> | Sat Feb  8 23:06:09 2020 +0000| [d500eff3cce7ab0c6f7101860b633ca955a9f85e] | committer: Lynne

lavu/tx: mention FFT output is not normalized

Not even FFTW's output is normalized.
This should prevent at least some users from complaining that doing a forward
transform followed by an inverse transform has a mismatching output to the
original input.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d500eff3cce7ab0c6f7101860b633ca955a9f85e
---

 libavutil/tx.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavutil/tx.h b/libavutil/tx.h
index d6cdfdf9f2..8b405c0021 100644
--- a/libavutil/tx.h
+++ b/libavutil/tx.h
@@ -35,7 +35,7 @@ typedef struct AVComplexDouble {
 enum AVTXType {
     /**
      * Standard complex to complex FFT with sample data type AVComplexFloat.
-     * Scaling currently unsupported
+     * Output is not 1/len normalized. Scaling currently unsupported.
      */
     AV_TX_FLOAT_FFT = 0,
     /**