Best Quality Hardware or software downconverter?

[conrad gaunt]

Heres a basic GUI for some tests I've been doing into downsampling. It downsizes TIFF images. Output goes into same folder as source images, as do temporary files. I've only enabed TIFF input and output at the moment, and they are read and written as 48bit files. Its the result of a busy night this week. It can read and write most formats either internally, or using external tools, when I enable it.. when I get time. That code is already in there, including encoding to AVI/ MPEG etc, I turned it off until i can test everything. Eventually I intend to allow keyframed imagepans across a sequence of TIFs using splines with continuity (so looping imagepans can be created), and HQ upsampling/super-resolution of sequences... and very soon the ability to choose a different output folder!

There is a large test chart (uncompressed TIFF) in the program folder. If you want to test the downsampling, move it to another folder and process that folder using the default output sizes (273x341 I think, 1/100 the size of the aforementioned TIFF..) and process. No go try the same resample in PhotoshopCS4/ AfterEffects etc and compare results. I did ;) There is a complex mode which yields insignificantly better results..so don't use it.. its just a test mode really, and very slow. best regards

here's the link:

www.northyorkshirecamerahire.com/tds48bit.zip

[Gabriele Turchi]

thanks conrad i will test it tomorrow !

g

[Scott Brown]

I've done a lot of research into high quality down-conversion for our broadcast output and would suggest using a HDCAM SR deck for this or the Snell and Wilcox Alchemist.

The S & W guys are at the top of their game and I believe they are looking at a software solution but I'm not sure when this would be released. I spoke with their R & D guys and they explained that software down-conversion should always be better than hardware as this does not have to work in realtime.

The BBC here in the UK recommend the SR deck option and they are VERY fussy.

After Effects does a good job and Compressor is also decent but slow.

Hope this helps.

Best wishes

Scott

[conrad gaunt]

I've done a lot of research into high quality down-conversion for our broadcast output and would suggest using a HDCAM SR deck for this or the Snell and Wilcox Alchemist.

The S & W guys are at the top of their game and I believe they are looking at a software solution but I'm not sure when this would be released. I spoke with their R & D guys and they explained that software down-conversion should always be better than hardware as this does not have to work in realtime.

The BBC here in the UK recommend the SR deck option and they are VERY fussy.

After Effects does a good job and Compressor is also decent but slow.

Hope this helps.

Best wishes

Scott

They're right! And you're right about After Effects.. especially compared to Photoshop.. but you should try my downsampler, then send a link to the S & W guys and then the BBC ;) ..there's a test chart in the .zip for testing and comparing..



UPDATE: I've re-written it for a fourth time. This one seems to have a stable GUI and can export in different formats (TIF,DPX or J2K, all 48bit). You can also choose a different destination folder, and despite using less memory overall, it now uses double precision floats instead of single precision. same link as above

[Binxu Wang]

Would you kindly repost the link ? the link above is down .

[Alexander Mejia]

I personally use AVISynth's spline36 scaler for downsamples to HD resoltuions, and Lancos4 for Downsamples to SD resolutions. This can be very slow mostly because disk IO isn't as fast a real time on a tape deck.

That being said, most tape decks have very good hardware downsampling. In my experience the BlackMagic Multibridge Pro is a good SD downsampler, but that doesn't get you to mpeg-2, so there is still another step to do it that way.

AviSynth feeds straight into CCP and HCEnc, 2 of the best software Mpeg-2 encoders available. Depending on your comptuer setup, this could be a faster solution.

By the way, scaling methods are a subjective matter. I don't think it's fair to say there is a "best" method.

[Aleksandar Colancevski]

Try Resolve, you will be surprised how good is down conversion.

[Andrew_HD]

Most of the good methods look almost the same if you ask for downscaling. Downscaling progressive is very easy, downscaling interlaced is yet another challenge- it's not as easy as to make it as sharp as possible :)
Upscaling is a different matter and nothing comes close to avisynth- including Teranex etc.