Frame rate

Frame rate is very important. It is used for converting frame and time values. It means the number of movie frames played per second. It determines the sampling rate for the timer responsible for rendering subtitles.

The frame rate is determined from movie. If no movie loaded, a default value of 25.0 is selected. The user can select the rate freely. If a movie is loaded, the frame rate is determined from the movie and the user can't change it. If the movie doesn't support frame mode (ASF or OGG for example), the default value of 25.0 is used for rendering subtitles (25 per second is quite enough and gives nice numbers in time mode) and the program can't be switched to the frame mode.

All subtitles have dual timestamps, one in frames an the other in seconds. One is calculated from the other, depending on the subtitles type (frame based or time based). The frame rate is used for converting them. If you save the subtitles in the same format as when they were loaded, the won't have corrupted timing if bad frame rate was selected.

Note: You can't change the subtitles speed by selecting frame rate in this box. If you want for example change the speed of subtitles that were designed for 25,000 fps to run correctly with movie that has 23,976 fps, see editor functions, section Move / Scale.