Question about Bit Pixel Frame

[hardy]

I guess my question pertains to the quality of the BPF and settings

I have two encodes of the same movie.
1080p resolution with Bits/(Pixel*Frame) : 0.074
720p resolution with Bits/(Pixel*Frame) : 0.192

They are both 2pass, the 720p does have a higher bit rate, which may be the reason for the higher BPF.

My question is: Does the higher BPF hold better detail per frame? Even though the higher BPF has lower resolution.

[smrpix]

720p does have a higher bit rate, which may be the reason for the higher BPF.

By definition.

All it tells you is that one file is bigger than the other.

[hardy]

So it's nothing really important? I thought it had a little to do with quality.

[smrpix]

Higher bitrate generally implies higher quality, but there are a lot of variables.

As an example, a static shot of text would likely be much clearer at 1080 than 720 even with a lower bitrate.

[hardy]

The only issue I have with the lower bitrate is banding/blocking. When you take a Full BD and encode down to 1080p w/ 3500 bitrate for example. Or the 720p w/ 4500 bitrate. Upscaling on my 42' TV sometimes look better with a 720p and higher bitrate. I know the encode settings and filters used play a big part as well

[davexnet]

BPF is some number derived from the formula (as can be seen above) taking into account
the bitrate AND resolution. For example, a video @ 2000 kbps:
A 720p encode using this bitrate would look better than a 1080p encode using this bitrate
all things being equal (source, encode parameters, etc,etc)

The 720p would have a higher BPF. The problem with it is that it can't really be used as an indicator
of quality in general, too many other factors involved.

[hardy]

I understand. Thank you for the quick responses.

[jagabo]

Don't forget that reducing the frame size is a loss of quality too. You're trading off resolution in order to get less blocking artifacts.

[hardy]

I prefer 1080p resolution but then again it's all about the viewing experience.