Is 720 crop to 704 a valid streaming size?

[Barrythecrab]

Hello Forum.
Before I go on, I will just say after many attempts to grasp PAR, SAR and DAR, blessings to all who get it.
Anyway, for simplicity's sake and so my head doesn't explode, I capture lossless at 720x480>Crop and deinterlace in Hybrid (other filters as needed) to 704x480.
Then using I render to lossless 704x480, deliver in PowerDirector as MP4, 704x480 60P bobbed from 29.97 capture. The files play perfectly fine in everything including my LG smarty TV, tablet, PC on Facebook, thumb drive everywhere. No client has ever complained.
Is here any reason that 704 is so uncommon? Should I be cropping to 704 but delivering as 640?
If it doesn't seem to be broke, don't fix it, but am I doing something inadvisable?

[Sharc]

Cropping captured analog video to 704x480, encode and play it as 4:3 is perfectly right.

[Barrythecrab]

Thank you, Sharc, I have been searching and searching here there and everywhere for a definitive answer. Why is it so uncommon? My simple mind just figured capture non-square, deliver non-square, less conversion but I'm certain that reveals my lack of fully understanding, it's probably meaningless. OK, at least I can rest easy I am not doing something terrible.

[Sharc]

Thank you, Sharc, I have been searching and searching here there and everywhere for a definitive answer. Why is it so uncommon?

It's not uncommon. It is the standard (Rec.601) for analog capturing, rounded to practical digital values (704 being mod16 compliant).

[dellsam34]

Resize to 1440x1080 and all your worries go away, If de-interlaced properly, TVs and media players wouldn't have to do anything but display the pixels or double line if you have a 4K TV.

[Gary34]

Cropping captured analog video to 704x480, encode and play it as 4:3 is perfectly right.

For Facebook or YouTube shouldn't he be using square pixels?

[lollo]

For Facebook or YouTube shouldn't he be using square pixels?

Not really; for YouTube we upscale to a HD resolution (i.e. 1440x1080) to get better treatement, which incidentally is a square pixel format.
For Facebook we generally use 1280x720.
In other words, square pixel is not a requirement.
704x576 (or 704x480) are the final resolution to use while staying in SD resolutions, as Sharc proprely said, adding a 4:3 DAR.

[Gary34]

Not really; for YouTube we upscale to a HD resolution (i.e. 1440x1080) to get better treatement, which incidentally is a square pixel format.
For Facebook we generally use 1280x720.
In other words, square pixel is not a requirement.
704x576 (or 704x480) are the final resolution to use while staying in SD resolutions, as Sharc proprely said, adding a 4:3 DAR.

Okay now i'm confused. So for YouTube and Facebook non square pixel aspect ratios are fine?

[dellsam34]

Are fine as long as an AR flag is provided in the encoded video, otherwise YT or FB wouldn't know what shape the pixels are and display them as square pixels with distorted frames, Haven't you seen enough of those distorted videos already online?

[Gary34]

Haven't you seen enough of those distorted videos already online?

Yes, I have. Okay I got what you are saying.