[FFmpeg-cvslog] doc/protocols/file: document general file protocol URL syntax

[Stefano Sabatini]

ffmpeg | branch: master | Stefano Sabatini <stefasab at gmail.com> | Sat Jan  4 14:48:23 2014 +0100| [98ecbf0093e5a16a91f5d2fede7914cd302d2f09] | committer: Stefano Sabatini

doc/protocols/file: document general file protocol URL syntax

Also drop confusing ff* tools reference about exceptions to the
file:FILENAME syntax, which is not ff* tool specific.

With various edits by Alexander Strasser <eclipse7 at gmx.net>.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=98ecbf0093e5a16a91f5d2fede7914cd302d2f09
---

 doc/protocols.texi |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/doc/protocols.texi b/doc/protocols.texi
index de157f7..d3a6a5c 100644
--- a/doc/protocols.texi
+++ b/doc/protocols.texi
@@ -119,16 +119,24 @@ File access protocol.
 
 Allow to read from or read to a file.
 
+A file URL can have the form:
+ at example
+file:@var{filename}
+ at end example
+
+where @var{filename} is the path of the file to read.
+
+An URL that does not have a protocol prefix will be assumed to be a
+file URL. Depending on the build, an URL that looks like a Windows
+path with the drive letter at the beginning will also be assumed to be
+a file URL (usually not the case in builds for unix-like systems).
+
 For example to read from a file @file{input.mpeg} with @command{ffmpeg}
 use the command:
 @example
 ffmpeg -i file:input.mpeg output.mpeg
 @end example
 
-The ff* tools default to the file protocol, that is a resource
-specified with the name "FILE.mpeg" is interpreted as the URL
-"file:FILE.mpeg".
-
 This protocol accepts the following options:
 
 @table @option