how does HV20 make SD out of HDV?

rayortiz313

rayortiz313

Active member
Hey guys,

Using an hv20 for my next short and can't edit high-def with my current system (looong story). Been shooting tons of tests, and am happy so far, but....

When I shoot in HDV and let the camera downconvert to SD for capture, what exactly is it doing to the HDV image? Is it cropping it? Stretching the pixels? What sorcery is at work here? I tried comparing captured SD footage to the same footage displayed in the on-camera flip-out screen, and I'm tempted to think that HDV footage crops data from off the sensor, but that could just be pipe-dreaming.

Yes I'm also aware its 2017, but I have nowhere else to go with this question!!
 
Love to hear about another HV20 going strong!!

Do you have any possibility of transcoding the footage from HD to SD before you edit? Should improve the image.

I don't have the answer on how it downconverts from the sensor myself.

I used the HV20 recently to get a "slightly" period camcorder look (i.e. meant to look a little dogeared), recorded it out to a Shogun Flame via HDMI and was delighted that I could get the Shogun to recognize the faux-24p live image and record it as 23.98p. Helped a lot with post.
 
I mean, Id love to do that- I'm looking for solutions to make the original m2t file into SD (or an HD avi perhaps for Inverse telecine and/or resizing in virtualdub), but haven't found anything that doesnt hurt my brain (avisynth, ffmpeg, etc)

EDIT:

OK I did it (I think):

Ive also entered the nightmare world of video formats from whence many a traveller has lost their minds.

HDV Split : Gets the HDV into PC as m2t file
Avidemux: Convert to avi but the outputted file only works with Virtualdub when I use HuffYUV output (which is lossless so thats fine right)
virtualdub: For Inverse telecine and resize (by half) to get SD file.

MY BRAIN HURTS

Does this sound OK?
 
Last edited:
In case anyone is curious:

Discovered my most practical workflow is to open the .m2t file in a vegas project scaled to 1/2 size- Vegas seems to do a good job of downscaling, if the project resolution is properly proportional (1/2 size in both width and height). I then output an uncompressed .avi and bring it back in to vegas for editing

looks great as far as I can tell
 
Yes, I found Virtual Dub to be a great option for round-tripping HD to SD from Vegas as uncompressed .avi. I think Vegas' down-rez to SD is very poor; however, I'm happy with its down-rez of UHD to HD.
I have a HV30 that still gets pressed into service, so that's cool to hear about an HV20 still going at it.
 
Id rather do that but I cant find anything to convert the m2t to avi. avidemux doesnt work for me anymore, I get some strange distorted ghost frames. I guess I'm gonna try to learn how to use ffmpeg next.
 
You must log in or register to reply here.
Back
Top