FORUMS: list search recent posts

720p@30fps Possible with Main Profile Level 3.0?

COW Forums : Compression Techniques

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Norman Greenwood
720p@30fps Possible with Main Profile Level 3.0?
on Mar 17, 2015 at 8:39:52 pm

I thought I would enlist the help of some experts on this as I have been a bit confused...

I have a software program called PlayLater. It is essentially time-shifting software that allows you to legally record shows and movies from the likes of Hulu, Netflix, Amazon, etc. There is a SD and HD version. The HD version boasts 720p recording. You login to your account of whichever media streaming site you have and then search for an episode or movie you would like to record and view later. The recording happens in real-time, so you have to wait the full-length of the episode or movie before it finishes.

I have recorded a couple of different shows in 720p. I bought a few HD shows off of Amazon, and have recorded a couple of Elmo videos for my daughter through Netflix. What I have noticed is that the videos have sub-par quality. They are recording with H.264 in a MP4 container. They normally average between 3100-3300Kbps. Needless to say, they are hefty files.

My qualm is that these shows are not being recorded, or at least recorded properly, in 720p. They all indicate that they use the Main Profile (MP) level 3.0 at 29.97fps. From what I have read MP level 3.0 does not support 720p, but MP level 3.1 does. I did some basic calculations, and even if level 3.0 could do 720p, it would be at a drastically reduced frame rate closer to 11fps. I am wondering if and how it is possible to get a 720p recording at MP level 3.0? And would doing so greatly reduce the quality of a 720p recording in comparison to MP level 3.1?

Doing a bit of research I know that I cannot achieve this with a NLE like Adobe Premiere Pro, it just won't allow it unless I change the profile (or the frame rate as it states). I came across only one other media site that stated they had used MP level 3.0 for 720p in the past, but are now using MP level 3.2 for 720p recordings. I have also seen a couple of Chinese IP cameras that state they use MP level 3.0 for 720p recording. There is of course the chance that these sites are incorrectly stating the specifications actually being used...

The only thought I have had is that PlayLater could be recording the source at something like 480p then re-encoding at 1280x720 so that it seems like 720p, just without the actual quality. Again, is there a way to get true 720p from MP level 3.0?

Thanks, and I apologize if this is the wrong forum for this thread, I just did not see another area where it might fit.

Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2020 All Rights Reserved