B-frames at high bitrates (4Mbit/sec)

[Stereodude]

I'm encoding 960x540 (1/4HD) stuff and I've been trying out data rates of 4Mbit/sec. I've tried turning B-frames on and off. They don't seem to help anything. The average Quantizer increases and the data rates go up. So, what is their benefit, or does the resolution and bitrate I'm using preclude them from being of any use?

[Koepi]

Erm.

Ok, bframes are there to minimize the bitrate used - or in a fixed bitrate scenario, offer more bits for i- and p-frames.

So they _do help_ quality.

Koepi

[Stereodude]

So I shouldn't be worried that the total average quantizer degraded after enabling b frames?

[CruNcher]

@Stereodude that is absolutely normal, because b-frames can use higher quantization but still look the same then lower quantized i or p frames.

[zx50]

I don't really get this, @4mbit the quality should be stunning, if not a tad off DVD, why on earth would you want to use b-frames, the quality you will get off that bitrate should be well sufficent.

P.S not telling you what to do just puzzled that's all:)

[Stereodude]

@zx50: Well I am encoding stuff beyond DVD size. I'm just playing around really. I think I've decided to do a quality based 1 pass setup instead.