GraphEdit File Format

When the GraphEdit utility saves a DirectShow filter graph, it creates a storage files with a .grf extension. The storage file contains a single stream called ActiveMovieGraph. This stream contains information about all of the filters, filter names, file names, connections, and so forth.

The following grammar describes the syntax of the graph within the stream, using a modified BNF (Backus-Naur Form) syntax:



<graph> ::= 
0003\r\n<filters><connections><clock>
END | 
0002\r\n<filters><connections>
END
<filters> ::= 
FILTERS<b> 
[<filter list><b>
]
<filter list> ::= <filter><b> 
[<filter list>
]
<filter> ::= <filter id><b><name><b><class id><b>
[<file>
]<length><b1><filter data>
<class id> ::= <guid>
<file> ::= 
SOURCE <name><b> | 
SINK <name><b>
<connections> ::= 
CONNECTIONS<b> 
{<connection><b>
}
<connection> ::= <filter id><b><pin id><b><filter id><b><pin id><b><media type>
<filter id> ::= <id>
<pin id> ::= <name>
<media type> ::= <sample size><major type><b><subtype><b><flags><format>
<major type> ::= <guid>
<subtype> ::= <guid>
<flags> ::= <fixed sample size><b><temporal compression><b>
<fixed sample size> ::= 1 
| 0
<temporal compression> ::= 1 
| 0
<format> ::= <length><b1><format type><b><length><b1><format data>
<format type> ::= <guid>
<format data> ::= 
{ binary_data 
}
<clock> ::= 
CLOCK <b><required><b><clockid>
\r\n
<required> ::= 1 
| 0
<clockid> ::= <filter id> 
| <class id>
<name> ::= quote_symbol 
{ any_non_quote_character 
} quote_symbol
<length> ::= unsigned decimal number (as a string), indicating the number 
             of bytes of data in the following token.
<guid> ::= GUID in string format. for example: {CF49D4E0-1115-11CE-B03A-0020AF0BA770}
<b> ::= 
{ space_character 
} 
{ \t 
} 
{ \r 
} 
{ \n 
} { <b> 
}
<b1> ::= space_character
<id> ::= integer (as a string), such as 0001


On output there will be a new line ("\r\n") per filter, one per connection, and one for each of the keywords FILTERS and CONNECTIONS. Each other case of <b> will be a single space. The keywords FILTERS, CONNECTIONS, and END are not localizable. Note also that the filter data and the format data are binary, so they might contain incorrect line breaks, null values, and so on. The stream uses wide characters.

The following shows a typical graph. (The connection lines have been broken for clarity, and the binary data omitted.)



003
FILTERS
0001 "C:\SomeFile.avi" {E436EBB5-524F-11CE-9F53-0020AF0BA770} SOURCE "C:\SomeFile.avi" 0000000000 
0002 "AVI Splitter" {1B544C20-FD0B-11CE-8C63-00AA0044B51E} 0000000000 
0003 "AVI Decompressor" {CF49D4E0-1115-11CE-B03A-0020AF0BA770} 0000000000
0004 "Video Renderer" {70E102B0-5556-11CE-97C0-00AA0055595A} 0000000000
CONNECTIONS
0001 "Output" 0002 "input pin" 0000000288 
   {E436EB83-524F-11CE-9F53-0020AF0BA770} 
   {E436EB88-524F-11CE-9F53-0020AF0BA770} 1 0 0000000001 
   {00000000-0000-0000-0000-000000000000} 0000000000  
0002 "Stream 00" 0003 "In" 0000000376 
   {73646976-0000-0010-8000-00AA00389B71} 
   {64697663-0000-0010-8000-00AA00389B71} 0 0 0000000001 
   {05589F80-C356-11CE-BF01-00AA0055595A} 0000000088 <binary data>
0003 "Out" 0004 "In" 0000000376 
    {73646976-0000-0010-8000-00AA00389B71} 
    {E436EB7D-524F-11CE-9F53-0020AF0BA770} 1 0 0000129600 
    {05589F80-C356-11CE-BF01-00AA0055595A} 0000000088 <binary data> 
CLOCK 1 0000
END


Related topics

Simulating Graph Building with GraphEdit

 

 

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