[mythtv-users] OT: NTSC Video synchonization

Patrick Doyle wpdster at gmail.com
Mon Jul 9 13:38:46 UTC 2007

I realize that this off topic for the purpose of this list, so I would
appreciate any pointers folks would care to give me regarding a
list/forum/textbook where questions such as these are the
bread-and-butter of the list and not off topic.

I'm curious how the mpeg-2 video stream gets synchronized to the
display.  From the textbooks I read, NTSC video operates at a frame
rate of 29.97 frames/second, whereas it seems to me that most monitors
operate at a frame rate of 30 frames/second.  If I capture (analog)
broadcast NTSC video and encode it with the hardware encoder on my
video capture card, I presume that it is encoded at the 29.97
frames/second.  If I later decide to play that video on my display, I
presume that it is pulled off the disk at a rate of 30 frames/second.

How is this resolved?  Is the X server configured for 29.97 frames/second?

On what list could I hang out where questions such as this are
considered run-of-the-mill?


More information about the mythtv-users mailing list