Merge @chapter Introduction and @chapter Description into a single

section, and make the whole rendered in the man output.

Simplify layout, and make it more consistent with that of the other
man pages. Also I cannot see a good reason for keeping split the two
sections.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@23407 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

doc/ffmpeg-doc.texi

@@ -7,8 +7,8 @@
 @sp 3
 @end titlepage
 
-
-@chapter Introduction
+@chapter Description
+@c man begin DESCRIPTION
 
 FFmpeg is a very fast video and audio converter. It can also grab from
 a live audio/video source.
@@ -21,6 +21,35 @@ bitrate you want.
 FFmpeg can also convert from any sample rate to any other, and resize
 video on the fly with a high quality polyphase filter.
 
+As a general rule, options are applied to the next specified
+file. Therefore, order is important, and you can have the same
+option on the command line multiple times. Each occurrence is
+then applied to the next input or output file.
+
+* To set the video bitrate of the output file to 64kbit/s:
+@example
+ffmpeg -i input.avi -b 64k output.avi
+@end example
+
+* To force the frame rate of the output file to 24 fps:
+@example
+ffmpeg -i input.avi -r 24 output.avi
+@end example
+
+* To force the frame rate of the input file (valid for raw formats only)
+to 1 fps and the frame rate of the output file to 24 fps:
+@example
+ffmpeg -r 1 -i input.m2v -r 24 output.avi
+@end example
+
+The format option may be needed for raw input files.
+
+By default, FFmpeg tries to convert as losslessly as possible: It
+uses the same audio and video parameters for the outputs as the one
+specified for the inputs.
+
+@c man end DESCRIPTION
+
 @chapter Quick Start
 
 @c man begin EXAMPLES
@@ -192,34 +221,6 @@ The generic syntax is:
 ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
 @c man end
 @end example
-@c man begin DESCRIPTION
-As a general rule, options are applied to the next specified
-file. Therefore, order is important, and you can have the same
-option on the command line multiple times. Each occurrence is
-then applied to the next input or output file.
-
-* To set the video bitrate of the output file to 64kbit/s:
-@example
-ffmpeg -i input.avi -b 64k output.avi
-@end example
-
-* To force the frame rate of the output file to 24 fps:
-@example
-ffmpeg -i input.avi -r 24 output.avi
-@end example
-
-* To force the frame rate of the input file (valid for raw formats only)
-to 1 fps and the frame rate of the output file to 24 fps:
-@example
-ffmpeg -r 1 -i input.m2v -r 24 output.avi
-@end example
-
-The format option may be needed for raw input files.
-
-By default, FFmpeg tries to convert as losslessly as possible: It
-uses the same audio and video parameters for the outputs as the one
-specified for the inputs.
-@c man end
 
 @c man begin OPTIONS