doc: correct AC-3 option subsection placement

Floating-Point-Only section was added after the video encoders chapter
in 034fc7bf merge.

doc/encoders.texi

@@ -369,6 +369,49 @@ is highly recommended that it be left as enabled except for testing purposes.
 
 @end table
 
+@subsection Floating-Point-Only AC-3 Encoding Options
+
+These options are only valid for the floating-point encoder and do not exist
+for the fixed-point encoder due to the corresponding features not being
+implemented in fixed-point.
+
+@table @option
+
+@item -channel_coupling @var{boolean}
+Enables/Disables use of channel coupling, which is an optional AC-3 feature
+that increases quality by combining high frequency information from multiple
+channels into a single channel. The per-channel high frequency information is
+sent with less accuracy in both the frequency and time domains. This allows
+more bits to be used for lower frequencies while preserving enough information
+to reconstruct the high frequencies. This option is enabled by default for the
+floating-point encoder and should generally be left as enabled except for
+testing purposes or to increase encoding speed.
+@table @option
+@item -1
+@itemx auto
+Selected by Encoder (default)
+@item 0
+@itemx off
+Disable Channel Coupling
+@item 1
+@itemx on
+Enable Channel Coupling
+@end table
+
+@item -cpl_start_band @var{number}
+Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
+value higher than the bandwidth is used, it will be reduced to 1 less than the
+coupling end band. If @var{auto} is used, the start band will be determined by
+the encoder based on the bit rate, sample rate, and channel layout. This option
+has no effect if channel coupling is disabled.
+@table @option
+@item -1
+@itemx auto
+Selected by Encoder (default)
+@end table
+
+@end table
+
 @c man end AUDIO ENCODERS
 
 @chapter Video Encoders
@@ -433,48 +476,3 @@ For more information about libx264 and the supported options see:
 @url{http://www.videolan.org/developers/x264.html}
 
 @c man end VIDEO ENCODERS
-
-@subheading Floating-Point-Only AC-3 Encoding Options
-
-These options are only valid for the floating-point encoder and do not exist
-for the fixed-point encoder due to the corresponding features not being
-implemented in fixed-point.
-
-@table @option
-
-@item -channel_coupling @var{boolean}
-Enables/Disables use of channel coupling, which is an optional AC-3 feature
-that increases quality by combining high frequency information from multiple
-channels into a single channel. The per-channel high frequency information is
-sent with less accuracy in both the frequency and time domains. This allows
-more bits to be used for lower frequencies while preserving enough information
-to reconstruct the high frequencies. This option is enabled by default for the
-floating-point encoder and should generally be left as enabled except for
-testing purposes or to increase encoding speed.
-@table @option
-@item -1
-@itemx auto
-Selected by Encoder (default)
-@item 0
-@itemx off
-Disable Channel Coupling
-@item 1
-@itemx on
-Enable Channel Coupling
-@end table
-
-@item -cpl_start_band @var{number}
-Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
-value higher than the bandwidth is used, it will be reduced to 1 less than the
-coupling end band. If @var{auto} is used, the start band will be determined by
-the encoder based on the bit rate, sample rate, and channel layout. This option
-has no effect if channel coupling is disabled.
-@table @option
-@item -1
-@itemx auto
-Selected by Encoder (default)
-@end table
-
-@end table
-
-@c man end AUDIO ENCODERS