Is lack of AVCHD 1080P on settings list of concern when burning

raoul-beaman wrote on 6/23/2019, 10:14 AM

Hi Everybody. I am editing footage on VPX originally recorded on a Sony AX100 (PAL) 4K @ 25FPS. When initially 'creating project' I am choosing the setting applicable to PAL ULTRA HDTV 25P 16/9 3840x2160 25FPS' as this seems the most suitable on the VPX list - which is slightly different to MEPP listings. After editing, and confirming the AVCHD burn, and then requesting the burn dialogue page, I have gone further into Advanced settings, to try and find a 1080 'P' setting but there doesn't seem to be one that corresponds to a 1920x1080 requirement. However, what is automatically presented in the settings window is 'AVCHD 1920x1080 i (default) PAL. Should I be concerned about this or not? My uncertain understanding of this tells me that I am editing 'progressive' frame footage but when going forward to burn the project, the system wants, or is, defaulting to 1080 'i' and finalising and producing a burn as if the software was reading 'interlaced' footage. The results are not that bad but is there something I am overlooking, or am I selecting the wrong setting at the 'create project' stage? Surely I need to burn at 1080'P' not 1080'i'. If anyone can increase my understanding of this and telI me I'm either doing the right or wrong thing, I'd be grateful. Thanks. RB Herefordshire.

Comments

johnebaker wrote on 6/23/2019, 2:01 PM

@raoul-beaman

AVCHD only supports interlaced video, 1080i, for 25 fps video, for 1080p the framerate has to be dropped to 24 fps, however you may get issues with pulldown, eg additional jerkiness on pan shots or where there s fast movement across the screen, that you may already see in the 4K progressive 25fps footage depending on the pan speed.

In my experience there is little to worry about exporting progressive as interlaced.

. . . . as if the software was reading 'interlaced' footage . . . .

You will notice there is no setting in the Projects setting to specify interlaced or progressive. The software does not care whether the footage is progressive or interlaced - I often mix both in the same project - my Sony camera is 4K progressive, however my Sony sportscam is interleaved and I output 1080i for AVCHD video.

HTH

John EB

Scenestealer wrote on 6/24/2019, 5:49 AM

@raoul-beaman

Please see this post:- https://www.magix.info/uk/forum/cant-find-a-template-for-avchd-transport-stream-1080-25p-ac3--1224856/

As I said in the other post it is odd that there is a template that appears via the disc burn screen that gives me a 25p Transport Stream option with AC-3 Surround sound that is not available via the MPEG4 export file option.

Interlaced footage has technically lower vertical resolution than progressive especially if there is horizontal camera or subject movement across the frame because the image from one line to the next is slightly displaced, but as your camera has recorded the lines progressively one after the other, the two half fields will be identical and should not cause a noticeable difference if subsequently encoded as interlaced.

Peter

raoul-beaman wrote on 6/24/2019, 11:15 AM

Many thanks to John (JohnEB) and Peter (Scenestealer) for thier informative input. John - that explains everything. Peter - your post to Magix 13/4/19 and John's response is interesting and echoes my situation. I also note Ben Pitts' comment in 'Video Editing Review' (on line), where he talks about VPX, and comments 'we were perplexed to find no 1080 25P options among the project templates but the software automatically matched the project settings to the imported media'. Interesting. Thank you both again. Raoul B.

Scenestealer wrote on 6/25/2019, 6:25 PM

@raoul-beaman

".....the software automatically matched the project settings to the imported media". Interesting.

That is interesting because I believe that is what happens but have never got around to proving it for certain.Thanks for the info.

Peter