Are I-Frames the same as Keyframes?

[leopard]

Are I-Frames the same as Keyframes when using the H264 codec?
Is 300 a satisfactory setting?

[redwudz]

Yes. 'I frame' is the proper term, but same as a keyframe. 300 I frame spacing is the same as Xvid/Divx uses by default, so should be OK, though I'm not sure about that. You can look up 'P, I, B' frames in our Glossary for more info.

[minidv2dvd]

h264 has a range you should stay in - minimum=framerate maximum=10 x framerate. the smaller the number used the larger the file size.

[Flarch]

Doesn't 'I-Frame' frequency dictate how finely one can skip forward or back?

Or is that not the case with newer video formats?

[jagabo]

Doesn't 'I-Frame' frequency dictate how finely one can skip forward or back?

It depends on the playback software/device. Some will skip to the I frame nearest the selected location. Others will skip to the I frame before the selected location, decode all the frames in between, the start displaying at the selected frame. That can take a while with long GOPs, especially with large frame sizes. I usually use I frame intervals of 100 in Divx/Xvid for faster seeking on players that seek to the exact frame.