Restoration tips: Andrea’s Corollary to the Kush Gauge™

prologue: DON’T (always) TRUST COMPANIES!

Following many HDTV and internet broadcaster advices, a “studio quality” transmission for an H.264 1080p transmission could be achieved with a bitrate of a mere 6mbps; if we use the Kush Gauge formula, we can see that this is true only if the motion factor is lower than medium… for 16/9 sport material at 29.97fps, for example, a 17.4mbps bitrate is needed!

 

ANDREA’S COROLLARY TO THE KUSH GAUGE

To calculate video bitrate for a codec different from H.264, the Kush Gauge costant value should be changed accordingly to the codec used.

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Restoration tips: Kush Gauge™

KUSH GAUGE™ -> new Kush Gauge calculator

What is the Kush Gauge™?

It’s a rule of thumb to calculate the needed bitrate for H.264 encoded video; it was written by Kush Amerasinghe, a computer scientist. In this context, the word “gauge” means “a device used to make measurements

How does it work?

Quoting Kush’s document:

to estimate the optimal H.264 bit rate value that would give what is considered “good quality” results for a given video, you could multiply the target pixel count by the frame rate; then multiply the result by a factor of 1, 2 or 4, depending on its motion rank; and then multiply that result by 0.07 (the constant, Ed.) to get the bit rate in bps (divide that by 1,000 to get a kbps estimate or by 1,000,000 to get a Mbps estimate).

The Kush Gauge™ formula:

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Restoration tips: Overlap matching

OVERLAP MATCHING

What is the Overlap matching?

When two images of different sizes are used to improve the final result.

Could you be more specific?

Usually this is used when two different versions of the same movie are available at different aspect ratios.

Let’s say you want to restore a movie that is not available in high definition, and you want to upscale a DVD or a laserdisc capture. If you are lucky, an anamorphic DVD is available, so a theoretical 720×576 (PAL) or 720×480 (NTSC) max resolution could be achievable. But, if the original aspect ratio of the movie is 2.35:1, then you have only 720×432 (PAL) or 720×360 (NTSC). Well, enough resolution left to do a decent upscale. However, if the DVD is not anamorphically enhanced, actual resolution drops to 720×324 (PAL) or 720×252 (NTSC).

But what if the only (or the best) available low definition sources are analog? In this case, a 2.35:1 original resolution in laserdisc could be at maximum 576×324 (PAL) or 576×262 (NTSC), while VHS could be 328×324 (PAL) or 328×262 (NTSC)… pretty poor…

So, how it’s possible to improve the quality of such low resolution sources? Continue reading

Restoration tips: the Slice Technique™

Restoration tips: the “Slice technique”

THE SLICE TECHNIQUE™

What’s about this so-called “Slice Technique™”?

In few words: achieve the widest (highest) image possible adding a “slice” of another video clip.

Be more specific…

Well, sometimes there are two editions of the same movie, where one has more image on one side, while less on the other side, and vice versa. So I thought to use the missing “slice” of one joined together with all the other, to obtain the widest image possible. Indeed, it could be only (e.g.) 3% wider than any each version, but I much prefer a 100% wide image Vs a “mere” 97%… (^^,)

Of course, it’s quite difficult – sometimes impossible – to use this technique with every movie, because what must be taken in account are the dimensions (eventual image rotation, width and heigth of sources and chosen slice, eventual resizing and cropping, exact point of matching), colors (both versions should have the same color grading, or one should color match the other), video quality (grain, resolution/definition, different compression used in the sources, frame whobbling in a version not present in the other – in particular at the beginning and ending of a shot), etc.

In these examples, I used a vertical slice and two sources, Continue reading

PaNup™: or, how to upscale PAL + NTSC capture and live (quite) happy…

Today I was thinkering with the “pyramid” LD capture, and, when I was looking for the files, I encountered an old test script for upscaling, abandoned two years ago. Idea was good, so I managed to improve it – as now I have more knowledge than at that time – and results are quite good.

The idea is simple: take two captures of the same content, one PAL, one NTSC, then merge them to “squeeze” every bit of details from it… everyone knows that a PAL capture has 576 horizontal lines, while NTSC has 480… now, when a movie was transferred to video, usually original resolution was higher than that (not all the times, but often); so, the PAL and NTSC “received” different lines of image… see the next image (obviously intentionally exagerated…):


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Restoration, Preservation, Fan Edit – definitions

I’m into this hobby (movie restoration) for two years now, and still not got a complete, final, ultimate definitions of what Restorations, Preservations, Fan Edits (and so on) are, according to everyone… I tried to write down them here, based on what I have understood in this time, what are my personal thought, what other members think about them, and also on the FAQ of this forum and fanedits.com.

Obviously someone will agree with some or all definition completely, someone will agree partially, and others will strongly disagree… and it’s the meaning of this post: trying to find a common thought about WHAT precisely we are doing here!
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