@VK

If you look up the QP numbers in the table (in the standard, that is) a value of 20 corresponds to a 5:1 compression ratio in I frames. An uncompressed 4:2:0 1080p frame comes to about 3MB. If you divide that by 5 you get about 600K - which is what @driftwood got (almost - but you have to account for overhead).

Assuming that B frames ideally come out to about 1/4 the size of I frames with GOP 3, that means GOP 3 will be about twice as efficient as GOP 1. Given that, the QP should be able to be set at 14. That will result in I frames of about 1.2MB and B frames of about 300KB at a bitrate of 100Mb. Setting AQ at 1-2 should get close to that, or QP can be set manually. Without also raising FB1, FB2, and frame limit about 1.5x, the codec will either not reach 100Mb, or B frames will become artificially large because I frame size will be limited to 1MB. Thus I believe that with GOP3 at 100Mb you pretty much have to increase quality settings to make productive use of the bandwidth.

Anyway, that's how I calculated it. That's why I like this stuff @driftwood is doing.

Chris

100Mbps, GOP3, AQ2, 7~9Mb I-frame... Hmmm... AQ3 is too much to ask? Go for it @driftwood!!!!

I worked out the theoretical numbers. It looks like @driftwood has just about reached the theoretical limit for GOP1 at 100Mb. The detail quality should be equivalent to factory 24H - assuming detail doesn't degrade with P @ B frames - which it shouldn't with static shots (motion is something else altogether). This is very impressive.

Going through the math for GOP 3, I calculate that using a AQ of 1-2 should just about hit the sweet spot, yielding I frames of up to 8-10 Mb at 100Mb bitrate. If that works out it would be spectacular. Now, unless you set FBx and frame limit to 1.5x the original values, you won't get I frames above 8Mb. If that works out - these will become the settings I use personally!

Chris

@cbrandin Ill give it a try on the QP settings. First just finishing off a 100mbps 3 GOP test ;-)

1:11 corresponds to a QP of 27 - that's less than half the detail of the factory 24H settings, which use a QP of 20. That corresponds to a 5:1 compression ratio on I frames best case for factory 24H. The P and B frames compress a lot more, but hopefully retain detail from the I frame.

These I frames are around 300KB - that's pretty low. Don't bother setting AQ to anything above 0 - at these I frame sizes it won't make any difference and setting it to a higher value will probably cause problems. If anything, try setting the QP setting in the tester section higher than 20 - like maybe 26.

Chris

Pappas Death Chart at 100mbps, GOP1 = SUCCESS!

>I've got a problem with playing clips in camera

Try to cut few first seconds using some MTS cutting tool and put it back.
Check how it'll behave.

100mbps GOP 1 Successful. Need to do a Pappa's deathh chart now ;-)

@driftwood
can my card is too slow?
@Vitaliy
I changed the table in 1080p24 T4 testers section and changed it to 1080p24 T1. Here is what I received. I still have a problem with WMP home cinema, which can easily play with the GOP 12 88 Mbits.

@Mihuel

Find 1080p24 T4 table in testers section and set it to 1080p24 T1.
Must help with cadence.

My greed was punished;.) Loaded the settings @ driftwood, but changed the bitrate to 66Mbits and AQ to 3 for 24. Unfortunately, Windows Media Player, Home Cinema, playback is very stuttery.

But wait... wouldn't AQ4 might require higher Mb size for I-frame on highly detailed scene?

So u saying 60Mbs should be good enough for AVC-Intra 4:2:0 8Bit?

Then how to explain better low light performance at 88Mbps?