@Ralph_B gettting the 1080p24 gh2 recordings which record at 30 fps hdmi .mov in the Ninja out of post at 24p, as Its probably different for other hdmi recorders I'm wondering if my solution on the GH2 + Ninja thread is quicker than using your AVIsynth variation/less painless for Ninja users?
@cbrandin is there a danger that in allowing the codec to vary the bitrate on the I frame that it might pick a low bitrate for a low detail I-Frame that can't be improved upon by the following B/P frames - i.e. the quality is now low for the entire GOP?
@sam_stickland It doesn't actually drop that low tbh, also the 66M patch here runs stable on AQ3. I've been shooting with it for a few days with no issues. Wouldn't be surprised to find it was also stable at AQ4. I created an 88M AQ2 the same way as this and it holds a high I-frame size under lots of conditions really well too. As for P and B frames maintaining quality, that really relates to a static shot I think. If there is a lot of movement then they're going to be holding a lot more detail and motion.
I've seen a few times B + P frames climb higher in size than the preceeding I-Frame during fast motion and high detail leading onto a larger I-Frame in the next GOP.
@Stray Cool. I've just finished a 48 Hour Film Project entry on cbrandin's 66M settings, so I should have some more time for some testing myself now. Prior to this stable was very important!
@Stray is right - my original statement about P and B frames only maintaining quality related to static scenes. Big P and B frames can make a huge difference in motion quality. Think about it, if the scene changes a lot there isn't really anything to "maintain".
If detail were improved between I frames you would get a very bad looking detail pulsing between them. most codecs are designed to avoid this.