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where sample.mp4 - is the name of the file that should be located in the "media" directory (by default, /usr/local/FlashphonerWebCallServer/media/, or, starting from v. 5.2.687, the directory specified using property media_dir).
If a file with such a name does not exist, the server returns the StreamStatusEvent FAILED message, where the "info" field has the reason: "File not found".
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