Blu-ray's resolution for 2.35 video

[Chengbin]

In Blu-rays, what is the resolution used for 2.35 video (which is the most common aspect ratio for movies)? Is it 1920x1080 with black bars on top and bottom or 1920x816? If it is the former, wouldn't that be a huge waste of bits? If it is the latter, wouldn't it become 816p?

[Gokumon]

It's a 2.35:1 frame that is letterboxed into a 16x9 frame just like any content that has an aspect ratio that is wider than 16x9.

[Manao]

If it is the former, wouldn't that be a huge waste of bits ?Not really. h264 can encode those black borders with a few bits (per border, not even per mb). I'd be surprised if the bit cost was higher than 50 bits per frame, which makes it add at most 1.5 kbps to the video bitrate (and 1 MB for a whole movie), so not even 0.1% of the overall bitrate of a very low bitrate encode.

[ocal5]

wouldn't it become 816p?

Right :-/

It's called "how to do the same stupid things as it was for video-DVD"

[Blue_MiSfit]

Well... it's not like masters are any different...

At least there's no anamorphic confusion going on...

[ocal5]

You're right, and I have the same point of view regarding video content.
But regarding film content, picture is stored anamorphic on the rolls, in order to loss less informations. Why not on encodings ? It's progressive, so, easy to resize. And aspect ratio flags are here to be use, no ?

[Chengbin]

I just realized that I could have answered that question myself. My Blu-ray is giving me 1920x1080 with black borders.

I'm asking because I once encoded a 24 minute 4:3 1080p video with 2000Kbps, with 1920x1080 with black border on left and right, and 1440x1080 with no border. The 1440x1080 came out almost 50MB less. I will encode it again to give you a more detailed report.

[poisondeathray]

I just realized that I could have answered that question myself. My Blu-ray is giving me 1920x1080 with black borders.

I'm asking because I once encoded a 24 minute 4:3 1080p video with 2000Kbps, with 1920x1080 with black border on left and right, and 1440x1080 with no border. The 1440x1080 came out almost 50MB less. I will encode it again to give you a more detailed report.


Those are different frame sizes. Anamorphic is not the same thing.

Your original question dealt with same frame size, but letterbox vs. no letterbox. The black borders take <1% extra to encode (more if the edges are ratty, less if they are clean)

[Chengbin]

Those are different frame sizes. Anamorphic is not the same thing.

Your original question dealt with same frame size, but letterbox vs. no letterbox. The black borders take <1% extra to encode (more if the edges are ratty, less if they are clean)

I don't understand what you're saying. Do you mind clarifying?

[Chengbin]

Never mind, black borders are not that bit hogging. I don't know how I got my results before.

[poisondeathray]

Chengbin - I was referring to your original scenario, but sorry, I misread your 2nd scenario for anamorphic with 4:3 PAR flag (16:9 AR) , but you were referring to a pillarbox encoded vs. cropped 4:3 - so I can't explain your observations, maybe your encoding settings?