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<blockquote data-quote="Huge" data-source="post: 70096" data-attributes="member: 23832">Hi, I have had some experience writing a video player and we came up with the following ideas.1. Output (screen) pixel aspect ratio is fixed.&nbsp; Set this once, and forget.2. Source pixel aspect ratio can be found from direct-show, or assumed from video rect (pal, ntsc etc).&nbsp; *may* require some overrride, but probably not.3. black-bar detection in the source is a topic of its own - handle it a) automatically detect, b) let user specify (per channel ?) c) ignore.So, once the above (constant for given hardware setup, ie, do not need to be dynamically addressable) considerations have been taken into account, the problem reduces to the problem of fitting one rectangle inside another.&nbsp; A simple scheme is this:Have 2 controls, &quot;allowable crop&quot; and &quot;allowable stretch&quot;.It works like this:&nbsp; say you have 3% allowable stretch. First thing you do is expand the video rect in the &quot;unused&quot; direction by up to this fraction.&nbsp; If that is all you need to do, then you are done.Otherwise, look at your &quot;allowable crop&quot;.&nbsp; Say this is 20%.&nbsp; zoom the image (1:1) until either 20% of the image has gone, or the black bars on the side are all taken up.&nbsp; Whatever left over is black-barred.This works so well because for a given user, these numbers are pretty much constant.&nbsp; ie.Person A&nbsp; is a video-phile and requires a 1:1 aspect ratio, and can not tollerate losing the edge of the screen = allowable crop=0%, allowable stetch=0%.Person B (me!) does not like to &quot;waste&quot; room on the telly, does not really like stretching, and can handle a bit of the image missing at the edges: allowable stretch=2%, allowable crop=10%.etc.You do not really need to change these dynamically, so you could use the spot in the video menu to correct for source-black-bar detection/lack of.&nbsp; These are more subtle, and if you consider the allowable stretch, these changes wont violate peoples aspect-ratio expectations.</blockquote>

[QUOTE="Huge, post: 70096, member: 23832"] Hi, I have had some experience writing a video player and we came up with the following ideas. 1. Output (screen) pixel aspect ratio is fixed. Set this once, and forget. 2. Source pixel aspect ratio can be found from direct-show, or assumed from video rect (pal, ntsc etc). *may* require some overrride, but probably not. 3. black-bar detection in the source is a topic of its own - handle it a) automatically detect, b) let user specify (per channel ?) c) ignore. So, once the above (constant for given hardware setup, ie, do not need to be dynamically addressable) considerations have been taken into account, the problem reduces to the problem of fitting one rectangle inside another. A simple scheme is this: Have 2 controls, "allowable crop" and "allowable stretch". It works like this: say you have 3% allowable stretch. First thing you do is expand the video rect in the "unused" direction by up to this fraction. If that is all you need to do, then you are done. Otherwise, look at your "allowable crop". Say this is 20%. zoom the image (1:1) until either 20% of the image has gone, or the black bars on the side are all taken up. Whatever left over is black-barred. This works so well because for a given user, these numbers are pretty much constant. ie. Person A is a video-phile and requires a 1:1 aspect ratio, and can not tollerate losing the edge of the screen = allowable crop=0%, allowable stetch=0%. Person B (me!) does not like to "waste" room on the telly, does not really like stretching, and can handle a bit of the image missing at the edges: allowable stretch=2%, allowable crop=10%. etc. You do not really need to change these dynamically, so you could use the spot in the video menu to correct for source-black-bar detection/lack of. These are more subtle, and if you consider the allowable stretch, these changes wont violate peoples aspect-ratio expectations. [/QUOTE]

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