FLV Playback / Keyframes and Interframes

[ekpyr]

Not sure if anyone knows this one.

How are interframes related to keyframes in the FLV file during playback?

Are keyframes loaded into the viewer and then interframes displayed on top of the keyframe or is there more processing that goes on in the background before the interframe is rendered?

[Nyst]

interframes=intraframes and they are between keyframes on the so called timeline.

in FLV you can seek only to keyframes without eating up the CPU. Seeking to an interaframe requires the player to seek to the closest previous keyframe and render the image of that interaframe using all the interaframes up to the required interaframe - this uses lots of CPU power.

In Flix products you can let you decide where to insert the keyframes (Fixed) mode or let Flix decide (Max) mode and then (Max) there are more interaframes and less keyframes and the FLV will be of the smallest size and not very smooth-seekable. You can set the distance in interaframes between keyframes by using the Fixed mode and supplying a number (interaframes between). The Fixed mode will produce a movie which will be less or more seekable in relation to the distance between keyframes - larger distance = less seekable and the opposite. Remember: More keyframes = more size because keyframes are the heaviest frames in the movie, interaframes just contain the difference from the keyframe to that time.

Hope this helps.