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| author | Tim Nicholson <Tim.Nicholson@bbc.co.uk> | 2012-09-19 09:02:01 +0100 |
|---|---|---|
| committer | Stefano Sabatini <stefasab@gmail.com> | 2012-09-19 11:50:09 +0200 |
| commit | b90210e9c5ea365befef61b10b9a34ce37f9e679 (patch) | |
| tree | 1fb6afabc89de8fe42bc0e02fe7cb21e5d12d5a1 /doc | |
| parent | f398617b197d9a44b27d3313df8cd6c72b6a168a (diff) | |
doc/filters: clarify use of graph2dot
The GRAPH_DESCRIPTION string supplied to graph2dot must include explicitly
defined inputs and outputs which are not normally part of the command line
used in a real invocation.
This clarifies that requirement, and provides an example.
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/filters.texi | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 60b240d5d4..e202d383d9 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -79,7 +79,18 @@ display graph.png @end example can be used to create and display an image representing the graph -described by the @var{GRAPH_DESCRIPTION} string. +described by the @var{GRAPH_DESCRIPTION} string. Note that this string must be +a complete self-contained graph, with its inputs and outputs explicitly defined. +For example if your command line is of the form: +@example +ffmpeg -i infile -vf scale=640:360 outfile +@end example +your @var{GRAPH_DESCRIPTION} string will need to be of the form: +@example +nullsrc,scale=640:360,nullsink +@end example +you may also need to set the @var{nullsrc} parameters and add a @var{format} +filter in order to simulate a specific input file. @c man end GRAPH2DOT |