INTERACT FORUM

Please login or register.

Login with username, password and session length
Advanced search  
Pages: [1]   Go Down

Author Topic: Video playback and aspect ratio remembering  (Read 2084 times)

Osho

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 1211
Video playback and aspect ratio remembering
« on: April 16, 2007, 07:38:58 pm »

Hi,

When a video file is played, MC12 currently will use the aspect ratio that was used last (for whatever video file playback). I don't know why the correct aspect ratio for the last video file played has anything to do with the aspect ratio that should be used for the new file. This means that as I go changing video files being played I have to constant reassign the right aspect ratio for the video file. Sometimes, I have to do that again and again for some video files.

I would like to request some enhancements to how MC handles aspect ratio selection for video playback:

  • MC remember what was the aspect ratio used for each video file last time it was played.
  • MC should have a "auto select" mode for selecting the right aspect ratio that works 90% of the time which takes into consideration the display resolution and the aspect ratio of the display being played on.
  • There should be "Toggle Aspect ratio" action that just cycles through all the available aspect ratios.
  • It should be possible to map the "Toggle Aspect Ratio" action to a remote control with USBUIRT.

Now that the theater view errors are represented as proper theater view messages (thanks!), aspect ratio selection is the only reason why I have to get up from the couch while using theater view/display view from it.

Yeah probably a lot to ask for :) but I can always hope with MC!

thanks,
Osho
Logged

Yaobing

  • Administrator
  • Citizen of the Universe
  • *****
  • Posts: 10875
  • Dogs of the world unite!
Re: Video playback and aspect ratio remembering
« Reply #1 on: April 16, 2007, 09:06:58 pm »

  • MC should have a "auto select" mode for selecting the right aspect ratio that works 90% of the time which takes into consideration the display resolution and the aspect ratio of the display being played on.

This is available as "Source Aspect Ratio" and is the default.
Logged
Yaobing Deng, JRiver Media Center

glynor

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 19608
Re: Video playback and aspect ratio remembering
« Reply #2 on: April 16, 2007, 10:36:28 pm »

Yeah... If you have a lot of video files that are displaying with the wrong pixel aspect ratio when it's set to "source", then they're really not being encoded properly.  Video files should be encoded with the proper pixel aspect ratio for maximum quality.  Where are these files coming from?  I have a handful that I didn't encode myself that were done improperly and don't display right, but not that many.  Mostly the ones that I see that are bad are encoded at 720x480 with square pixels (which isn't ever right) and should be either 720x540/square or 720x480/0.9PAR (D1).  They forget to take into account that video typically has rectangular pixels and and just encode them as square (which makes them look weird and stretched "wider").  I also sometimes see video messed up due to Anamorphic DVDs.

People who are novices at video formatting and encoding often really don't understand what an "anamorphic" DVD is, so maybe I should explain...

As you're likely fully aware, video displays create pictures by "scanning" video lines onto the screen.  The more horizontal lines used, the higher the resolution.  Standard NTSC Standard Definiton format video is is made up of 525 lines, though some of this is used for "subpicture data" and control information (tracking information, subtitles, alternate audio tracks, and stuff like that), so generally only 468 of those lines are visible on the screen (480 for DV formatted footage).  Each of those scan lines is made up of 720 pixels, so we end up with a "resolution" of roughly 720x480.  When taken into account with the fact that the pixels are not square but rectangular, this gives us the standard 4x3 Display Aspect Ratio (screen shape).



That's all fine and good for source material that was originally shot and edited for use on a 4x3 screen, but when you are repurposing footage originally intended for use on a wide screen in a movie theater (generally either 1.85:1 or 2.35:1 DAR) you have essentially two choices, both nearly equally bad:

1) Chop the video.  This is called Pan & Scan.  Pan & scan is basically moving a 4x3 window back and forth across the wider film frame to capture the action. This is terrible for a couple of reasons.  First off, it changes the aesthetic of the original movie. However, what's worse is that it frequently cuts out important parts of the movie if things are happening on opposite sides of the video frame (you have to choose where to put the smaller box).  43% of the picture is off-screen at all times with this method!  If you've ever watched the original Indiana Jones in Pan & Scan (and you know the original movie at all) you'll know what I mean here!

2) Letterboxing.  This is what was generally used with old laserdiscs, and some high-quality VHS copies of movies.  I'm sure you know what I mean -- it adds the black bars to the top and bottom of the image.  Good because you can now see all the action, but bad because your essentially wasting almost 1/2 of those 468 horizontal scan lines on black bars!  This drastically reduces the visual resolution of the image that is on the screen, because all the content is actually only (roughly) 720x272 resolution now, with the rest wasted on blank black bars!

So, when the DVD specification was being designed, the engineers came up with a third (and much better) option -- Anamorphic!  This essentially takes the full widescreen image and squishes the sides of the image together into the 720x486 box.  This makes everyone on screen look very tall and skinny, but it allows you to encode at the full possible NTSC resolution that can be stored!  What the DVD consortium did then to address the tall and skinny issue was provided a "flag" in the video stream that the DVD player would recognize that says "this video is supposed to be 2.35:1, or 1.85:1, or whatever other weird widescreen format it might be in Japan and the DVD player fixes it during playback by adding the black bars in.  This allows you to still see the full frame of the video, but (even though the elements are smaller on screen) the resolution of those elements remains 486 lines high so the resolution isn't terrible.  That's why after DVDs came out, the TV manufacturers started putting out the so-called "enhanced Standard Def" format TVs, that provided more lines of resolution than the NTSC spec called for (usually 570-620 lines)!  Those TVs really look no better with regular TV content, but with Anamorphic DVDs,  they can more accurately display those full 480-some lines!

So, what happens with some "badly ripped" videos is that the encoder fails to "listen" to this flag when it's ripping the content off of the disc!  If it doesn't listen, and you don't fix it manually in the encoding software, you'll end up with encodes that show up stretched on the display (tall and skinny).  The best solution if this is happening to your own encodes a lot is to use a newer/better encoding package that knows how to really encode the video properly.  If you describe in more detail what exactly you're doing to make the videos, I might be able to help (if I happen to know the package).  MC has the Aspect Ratio tools so that you can force content that was encoded improperly to display right, but it would really be best to stop making bad files in the first place!

In a perfect world, instead of the "hack" of Anamorphic DVDs, they would have simply changed the standard to offer a true widescreen format.  And they did!  It's called 720p/1080p HD, which is 16x9 native!  Of course, 16x9 isn't even perfect because 16 divided by 9 is still only 1.7778 and the "real" format is generally 1.85:1 (and some movies also use the ultra-wide 2.35:1 format -- which is why sometimes the black bars are wider than others on a 4x3 screen and why sometimes you still get black bars on a widescreen TV).  Alas, the world was no where near ready to throw out all their TVs back when the DVD standard was designed, and the TV manufacturers weren't ready to build and sell new widescreen ones for cheap enough prices for people to actually buy them!
Logged
"Some cultures are defined by their relationship to cheese."

Visit me on the Interweb Thingie: http://glynor.com/

glynor

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 19608
Re: Video playback and aspect ratio remembering
« Reply #3 on: April 16, 2007, 10:43:00 pm »

PS.  Interestingly, the reason NTSC was originally designed as 4x3 rather than widescreen in the first place was because way back then most movies and movie theater screens were also roughly 4x3 shaped!  After TVs came out and became popular they started "stealing" market share from the movie theater owners, who fought back by making the movie theater "experience" better by making the screen big and wide.  So, the NTSC engineers did try to do it right -- the movies just changed in response.

Now, we'll likely have the same thing happen.  As you well know, most movie theaters are having a terrible time lately.  They keep blaming it on piracy and short DVD release windows, but the real problem is that no one wants to go to a movie theater and pay $10 + popcorn and get gum on their shoes and annoying people coughing on them (or talking on cell phones) when they spent thousands to build a beautiful home high-def theater system.  Why should they?

Well... I'm here to tell you, I'm sitting in meetings all day this week with people who edit those feature films, and the theater companies (and studios) aren't just going to take it.  A lot of them are betting on 3D and iMax style theaters saving the day.  The studios hope that by the end of 2008 there will be 600-1000 3D capable, huge-screen, theaters across the country (there's already about 500 worldwide and they're building them with reckless abandon), and most big-budget studios are starting to plan the blockbusters of the future with those theaters in mind.  As soon as enough theaters exist to make it cost effective (worth it) to produce the movies all in super-high def 3D, they're gonna move to it.  There's also new 3D tech available (I watched a demo today) that doesn't even require glasses!  Very cool stuff indeed, but it's going to lead to the same sort of issues even for HD home theater systems that you may have just finished building.

Ah well, such is life!   ::)

(PS. This is a separate post because I hit the character limit with the previous one when I added the picture.  Oops!)
Logged
"Some cultures are defined by their relationship to cheese."

Visit me on the Interweb Thingie: http://glynor.com/

Osho

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 1211
Re: Video playback and aspect ratio remembering
« Reply #4 on: April 16, 2007, 11:08:18 pm »

This is available as "Source Aspect Ratio" and is the default.

Yes but it doesn't stay as default one for each new video file playback. Let me elaborate. If I play file1.flv then the aspect ratio is "Source Aspect Ratio". Now, suppose I need to change the aspect ratio to Letterbox (1:85 : 1) to properly view file1.flv. I change the aspect ratio to Letterbox. Now, if I play some other file, say file2.flv then the aspect ratio for file2.flv is still Letterbox (whereas there is no reason that the second file will need the same aspect ratio as the first file). Even if I quit MC12 and restart it and then play file2.flv - the aspect ratio is still Letterbox.

I think anytime a new video file is played, it's aspect ratio should be "Source Aspect Ratio". If I change the aspect ratio for a particular file, say file1.flv to Letterbox then MC should remember it and next time I play file1.flv it should use that aspect ratio for file1.flv always.

Osho
Logged

Osho

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 1211
Re: Video playback and aspect ratio remembering
« Reply #5 on: April 16, 2007, 11:17:54 pm »

Where are these files coming from? 

Youtube and google video :). I tell you it's a mess out there with those files.

But thanks a lot for the wonderful explanation and the inside information. And, I agree. I and my wife have stopped going to theaters. We just wait for the DVDs. The last movie we saw out together in theater was Superman returns and that was because it was in Imax 3D - which actually was much more entertaining.

Osho
Logged

glynor

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 19608
Re: Video playback and aspect ratio remembering
« Reply #6 on: April 16, 2007, 11:40:12 pm »

I think anytime a new video file is played, it's aspect ratio should be "Source Aspect Ratio". If I change the aspect ratio for a particular file, say file1.flv to Letterbox then MC should remember it and next time I play file1.flv it should use that aspect ratio for file1.flv always.

I agree wholeheartedly here!!  This would be a fantastic feature actually, and it would make me less likely to manually re-encode the random video I have that's been done improperly.  Especially if this "memory" was just saved as a tag in the database.  All the files could normally have the tag set to "Source AR" but if you change it to one of the others, it'd play it with that DAR.  Actually -- it'd be super dooper nice if you could also specify your own arbitrary AR for that random badly-encoded anime file that came out of North Korea or some other nonsense so none of MCs options would really work.  This might require some serious scaling power that MC doesn't have, but if so.... It'd be just one more amazingly cool feature!

Oh, and...

Youtube and google video :). I tell you it's a mess out there with those files.

Yeah... That explains it.  I don't even bother to try to fix most of those.  You really want to see some bad stuff?   Try Delutube out for a little while...  So bad YouTube won't even let it on there.   ::)

It's funny though... Being at this NAB conference with a bunch of professional video editors, animators, cameramen and whatnot... YouTube keeps coming up.  People seem to hate it, because it offends their "elite sensibilities" (just like most of them look down their noses at the DV Camcorders and HDV camcorders) and because they seem to be a little afraid that it's going to hurt the marketability of their talents.

It makes me laugh.  Yes, it's bad out there on YouTube for the most part (though there's really also some really well done content on there too).  But is that a bad thing?  Doesn't it just make content that is done well look more valuable by comparison?  Doesn't the fact that novices can see in real terms, personally, just how difficult it is to put out something that is really nice quality give the general public a better respect for what we do?  I mean... One of the problems I have all the time with clients is the "well can't you just do it like this?" mentality.  Not realizing that what they're asking requires millions and millions of dollars of equipment, and teams of hundreds of highly-skilled, highly-paid people.  The fact that some of those people have now tried to do some stuff using iMovie and whatnot gives them a better understanding of exactly how little they do know about the process.
Logged
"Some cultures are defined by their relationship to cheese."

Visit me on the Interweb Thingie: http://glynor.com/

ThoBar

  • Citizen of the Universe
  • *****
  • Posts: 992
  • Was confishy
Re: Video playback and aspect ratio remembering
« Reply #7 on: April 17, 2007, 12:13:27 am »

Quote
I think anytime a new video file is played, it's aspect ratio should be "Source Aspect Ratio". If I change the aspect ratio for a particular file, say file1.flv to Letterbox then MC should remember it and next time I play file1.flv it should use that aspect ratio for file1.flv always.

Let me (once again) add my support to very useful request.

C.
Logged

Osho

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 1211
Re: Video playback and aspect ratio remembering
« Reply #8 on: April 18, 2007, 04:04:14 am »


Quote
I think anytime a new video file is played, it's aspect ratio should be "Source Aspect Ratio". If I change the aspect ratio for a particular file, say file1.flv to Letterbox then MC should remember it and next time I play file1.flv it should use that aspect ratio for file1.flv always.

Let me (once again) add my support to very useful request.

JimH, any luck thrown our way? :)

Osho
Logged
Pages: [1]   Go Up