Reduced quality in a clip.

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Peter Stedman
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Reduced quality in a clip.

Post by Peter Stedman »

A friend in distant parts has a short clip of video from a mob phone - unfortunately taken in portrait format and not landscape. He got a friend to turn the clip to the correct format in an editing suite but sadly the result is very blurred. He has sent me both clips and I can see what he means.

Any explanation in layman's terms that I can tell him. I might have a go at it myself in Prem C6 and see how I get on.
Cheers.
Pete.
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Dave Watterson
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Re: Reduced quality in a clip.

Post by Dave Watterson »

On the face of it ...

If the change was made simply by cropping the top and bottom off the portrait images, then the resulting picture would contain far fewer pixels.

____
| |
| |
|___| If the phone, like many these days, produces images 540wide x960high
And it is cropped to the normal 16x9 size the width would remain 540 but the height would be about 304 pixels

So the original portrait format would use 518,400 pixels to form an image
but the cropped version would use just 164,160 pixels which is roughly one third of the number of pixels.

That is not allowing for any extra dilution of quality introduced by the editing process.

Why do people shoot in this portrait format? I can only imagine they are holding the phone in one hand and need to balance it. When held with two hands it seems perfectly easy to shoot landscape films on my phone.
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Peter Stedman
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Re: Reduced quality in a clip.

Post by Peter Stedman »

Oh Lord Dave. At this time of the morning all that tech. jargon leaves me somewhat breathless . . .

The complete video clip was just rotated, not cropped at all. The result was then that the expected black bars appeared either side. However the chap that did it, overlaid the video clip onto a suitable background and it looks OK apart from the blurriness.

Thanks for answering. I think an aspirin sandwich is called for.
Cheers.
Pete.
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Dave Watterson
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Re: Reduced quality in a clip.

Post by Dave Watterson »

If the clip was just rotated ... all the people would look as if they were lying down ! Surely that is not what happened.

And why would any black bars be needed? Most phones record a 16*9 aspect ratio these days.

What part of the story am I missing?
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Peter Stedman
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Re: Reduced quality in a clip.

Post by Peter Stedman »

Oh Lord (again!) My fault I'm sure. My friend phoned to say that he had this bit of video that was taken with mob phone in portrait mode. When he play it on his PC it was shown landscape with people laying on their sides. (OK so far). His friend took it and did - what ever he did - and the clip the now played on his PC properly in portrait mode within the 16x9 frame, but of course with excess black bands either side but was dreadfully fuzzy.

He sent me the original and the edited copy (Ghastly) I have just put it on my timeline where it showed in portrait mode with the black bars but the quality was fine. I added some background so that black bars didn't show. Stuck it on You Tube and my friend is now chuffed. Why the other chaps result was so fuzzy is a mystery.

As he is now pleased so thanks for the replies and sorry to have confused you. My stock answer is, as always, "IT'S MY AGE YOU KNOW!". Pete.
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Dave Watterson
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Re: Reduced quality in a clip.

Post by Dave Watterson »

Or maybe your video editor is just much better at handling such transformations than the first chap's.

Glad the result is what was wanted ... who cares how we get there so long as we arrive safely.
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TimStannard
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Re: Reduced quality in a clip.

Post by TimStannard »

Dave Watterson wrote: who cares how we get there so long as we arrive safely.
That sounds like the cue for a very long philosophical argument ...
Tim
Proud to be an amateur film maker - I do it for the love of it
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