Video Quility Help

[esullivan]

I have 2 videos of the same episode of a show, one is 1080p and the other is 720p. The obvious answer is the 1080p copy is better, but I was looking at them with MetaInfo and I am not sure, looking for help from someone who is in the know.

The 1080 copies bit rate is 5,817 Kbps, but the 720 copies is 10.7 Mbps. Is that going to make a noticeable difference? It is double.

Also the audio on the 1080 copy is 384 Kbps at 16 bits vs the 720 copy is 1,509 Kbps 24 bits.

I am thinking the 720p copy is better here, am I wrong?

Thanks for any help.

[esullivan]

Sorry, screens of MetaInfo

ATTACH]31239[/ATTACH]

[smrpix]

Numbers are only part of the story and yours are contradictory. Which one looks better under the conditions you normally watch?

[newpball]

It depends, a 900Mbs 720p may still be worse than a 15Mbs 1080p.

I'd say unless the 1080p encoding was really crappy it will win always over a 720p.

Note that many will disagree, some make it a national sport to find the minimum resolution/bitrate for videos in order to show something 'acceptable' while others do not like to take compromises with quality and expect maximum resolution with reasonable bitrates.

[Cornucopia]

@newpball, statistically you would be very wrong.

In general, there would need to be a concurrent rise in bitrate in order to accomodate/maintain the PER PIXEL quality of a rise in resolution. However, this is not necessarily linear. So, for example, if you have 4Mbps for 480p, you would need more (say ~7Mbps) for 720p and maybe ~12Mbps for 1080p. This all assumes coming from the same very high resolution master (>=1080p) at same framerate, etc.

Put another way, if your 480p is 4Mbps, a 480p-cropped subset of the 720p version would also need to be ~4Mbps, as would a 480p-cropped subset of the 1080p version, in order for them to have equivalent quality.

That is why the "bitrate/pixel" item in MediaInfo is helpful at gauging quality (though there can often be variation depending on content complexity).

A 480p version that has 4Mbps vs. a 1080p version that has 4Mbps will have differences thusly: the 1080p version will undoubtedly be of higher resolution/detail, but that detail will be soured by the (greatly?) increased artifacting. So depending upon the completeness of one's definition of "quality", the 480p version could look better.

@esullivan, there is no "obvious" answer. One has to take into account the source, the codec & settings chosen, the bitrate, the resolution, etc. Even one's display size & viewing distance could/would make a difference in your case.

Scott

[esullivan]

Thanks guys.

I am streaming with Plex to a Roku and a 1080p TV.

I put the same episode one at 720 one at 1080 and honestly I could not tell the difference. In that case I think I will go with the 1080p, since the size is smaller and it matches the resolution of my TV.

[newpball]

A 480p version that has 4Mbps vs. a 1080p version that has 4Mbps will have differences thusly: the 1080p version will undoubtedly be of higher resolution/detail, but that detail will be soured by the (greatly?) increased artifacting. So depending upon the completeness of one's definition of "quality", the 480p version could look better.

Which brings me to my prior statement.

If a 480p looks better than a 1080p the 1080p encoding was obviously really crappy.
You disagree with that?

What is wrong with: do not compromise resolution and use a reasonably good bitrate?

Jim: Hey Paul look at this video, I worked for days on the encoding, doesn't it look great?
Paul: Well I don't know Jim, got to be honest see a lot of artifacts and not much resolution detail.
Jim: Yes, but wait till you hear how extreme the compression really is and how much it is downscaled! I am sure you will be amazed!
Paul:
Jim: No seriously Paul I am proud of the results! Given the extreme compression it looks pretty good!
Paul: But Jim don't you want to see a good looking video?
Jim: What?
Paul: Oh boy, is it that late already, darn, time to go home.

Point being:

When you watch a a video it has a certain quality based on resolution and bitrate. A viewer of a movie does not give a rat's ass how efficient the compression is. It's good when it looks good!

[Cornucopia]

As I stated before, but you still don't seem to get: NOTHING is "obvious" in this business. If you think it is, you're deluding yourself and/or have too simplistic an understanding.

There ARE times when resolution can/should be compromised, as well as times when it shouldn't. And "reasonably good" is too amorphous a term to be a learning tool.

Scott

[racer-x]

Another thing that greatly effects compessability is dept of field since a shallow one usually only has the object in focus. Take for example this 4k (3840x2160) clip encoded with VP9 @ 1300 kbps: