On 5/15/06, chris clepper cgc@humboldtblvd.com wrote:
On 5/11/06, Chuckk Hubbard badmuthahubbard@gmail.com wrote:
Wanting to automate opening videos in GEM. Is there any library with a function to check a movie header for fps?
This really varies by platform and API. For example, Quicktime doesn't really have the concept of a frame per second in the container format. That might sound odd, but it allows for frames of different lengths in the same container and multiple frame rate tracks of media to work alongside each other.
Right now with QT we sort of guess at the framerate because it helps to open the movie file faster. It is not a very accurate number though and I would not use it for controlling playback. The 'auto' and 'rate' messages do allow for accurate control of playback based on any media of any framerate.
But the speed of "auto" depends on the "frame" message sent to gemwin. I want to score films with Pure Data. The only way it will line up correctly is if the fps is correct. As of now I have to open the file in Quicktime or Media Player to check, and manually change it in Pd.
I also have to be able to send specific frame messages, because I'm not going to start at the beginning of a 15 minute movie file every time I want to check a passage. I'm still working out exactly how it's going to work; the tempo control in my patch is exponential and so a little strange to calculate beforehand.
-Chuckk