Lowest Resolutions For Phones & Tablets

[goldensun87]

I don't have a smartphone yet, but I currently have a Nexus 7. Any tablets I buy in the future, I will not buy anything bigger than a 7" screen. So, since tablets have much less storage capacity, I was wondering, what's the smallest resolution I can compress down to, without sacrificing video quality? I'm thinking 480p, but can I go lower than that? How much lower?

I would also like to know the ideal minimum resolutions for the different smartphone screen sizes.

[wonkey_monkey]

what's the smallest resolution I can compress down to, without sacrificing video quality?

You literally can't do that; you can only balance one against the other.

That said, for watchability, I personally wouldn't go below 480p. I'd target a certain filesize that seems reasonable - 1Gb an hour, perhaps, for a modest tablet, but it all depends how much you want to store - then find settings that give you roughly the right size for a given resolution and see how they compare with each other.

Then, there's also the matter of what your source is. If it's a DVD rip, well, you'd probably get away with 1/4 of the original bitrate for an MKV without noticing anything untoward (particularly if viewed on a tablet), but again your mileage may vary.

I would also like to know the ideal minimum resolutions for the different smartphone screen sizes.

There isn't one; anything below a particular screen's native resolution is by definition less than ideal. There's only what you find acceptable, which is completely subjective.

[Blue_MiSfit]

It all depends on how much you care, so nobody will be able to tell you how low is too low.

For most content that I'm only going to watch once, I'm more concerned about how much video I can cram on the device, not so much what the quality is. In practice, I'll still try to target the device's native screen resolution, but will go as low as 360p in a crunch.

[goldensun87]

"Native screen resolution"

See, that can get tricky with mobile devices. On a 15" laptop screen with max internal resolution of 1080p, there is no question. For someone who cares about quality, no lower than 480p for DVD sources, and no lower than 720p for Bluray sources. A smartphone with a 4.7" screen and the first Nexus 7 with its 7" screen, both have an internal resolution of 720p. Now, the 2nd Nexus 7 still has its 7" screen, but 1080p internal resolution. This is why I asked for suggestions based on screen size, as opposed to internal resolution. On the first Nexus 7, a 480p encode from a Bluray source looks ok(to me). But, how will this 480p encode look on a 7" screen with 1080p internal resollution? Would there be visible artifacting/pixelation? Btw, I prefer to use CRF mode, and I start out with 18. If the resulting bitrate is too high for me, I try out higher values until I hit a bitrate range which I prefer. And since my tablet has only 16 GB, I do not put any full-length movies on it, just music videos.