Record
12th July 2006, 19:41
Hi,
Only a certain amount of frames (I-Frames) of a video sequence is compressed in a MPEG-4 file. Between them only motionvectors are computed (P- and B-Frames). The question is whether these keyframes (I-Frames) have a fixed sequence (e.g. every 8th frame is a I-Frame and can be changed by the user) or are they dynamically (the encoder decides when to put an I-Frame based on some algorithms).
If it is dynamically, what criterias (algorithms) exist to choose a frame as keyframe?
Thanks in advance.
Peter
Only a certain amount of frames (I-Frames) of a video sequence is compressed in a MPEG-4 file. Between them only motionvectors are computed (P- and B-Frames). The question is whether these keyframes (I-Frames) have a fixed sequence (e.g. every 8th frame is a I-Frame and can be changed by the user) or are they dynamically (the encoder decides when to put an I-Frame based on some algorithms).
If it is dynamically, what criterias (algorithms) exist to choose a frame as keyframe?
Thanks in advance.
Peter