Weird Exporting/Playback Issues

Plamen Petrov · February 15th, 2014, 01:01 AM

Has anybody experienced such an issue:

After rendering out a video file with CineForm, DNxHD or other codecs, there is always a huge difference when playing the rendered video file back on different players. For example, just take a look at the attached snapshots below: the 1st is with Windows Media Player and other players; the 2nd is with QuickTime Player. As you can see, the video from QTP looks exactly as edited and graded before rendering out, while the same video from WMP and other players gets highlights overblown and other destructive effects. Is that normal, how to fix this problem? When I put the same (rendered) video file on Sony Vegas or AE timeline, it looks properly as it is and as QTP shows it. Re-rendering this already rendered video file with various codecs and settings goes to the same issues. The same issue I experience with video files converted with 5D2RGB - QTP shows it properly with the 1.8 gamma lifted up, while WMP and the other players show exactly zero difference from the source MTS video file. So, why does this happen? Any idea why the video editors display the video properly and then the other players don't?

Another issue: the WMP snapshot is vertically stretched a little, don't know why and this appears on the TV too as well as the destroyed highlights and other defects; while the QTP snapshot looks exactly as it should. I'm shocked!!! Any help and suggestions? Thanks in advance!

Juris Lielpeteris · February 15th, 2014, 01:27 AM

Quote:

When I put the same (rendered) video file on Sony Vegas or AE timeline, it looks properly as it is and as QTP shows it.

This means that the rendering takes place properly and you need to adjust players.

Plamen Petrov · February 15th, 2014, 01:39 AM

How do you think the players can be adjusted?!?
And even if there is a way for adjusting the players, then how to adjust the TV when it plays the same wrong way as the players, but not properly as QuickTime player only?
I think the problem is in the system. Why is QuickTime player the only one which plays properly?
Sometimes I try watching videos on my TV from YouTube exporting to USB flash and they all look normal as in the browser or even played with WMP and other players(!!!)
So, the problem is in the system, but where?!?

Christopher Young · February 15th, 2014, 04:22 AM

This problem raises its head all the time. Often the case is that ‘broadcast’ type NLE software is working or set up to output SMPTE broadcast ITU 601 or 709 levels and will be working in the studio YUV gamut range of 16-235 levels. Many PCs, can’t comment on Mac as I don’t work with them, have their display output set to computer RGB levels which in most cases is 0-255. This will blow your highlights and crush your blacks on 16-235 level material unless the levels are correctly re-mapped to display at 0-255.

Most of the common media players are only capable of displaying 0-255 levels so this becomes an issue if you want the correct output results. The only way I have found around this is to use Media Player Classic Home Cinema where the output levels can be selected. See attached JPGs. You can distinctly see the differences in the white levels on the vehicles and the difference in the shades of 'blacks' such as the tyres etc when the different output ranges are selected.

If you are using Nvidia or ATI graphics cards you can select the output level the card will put out. 0-255 or 16-235. By setting the output of the card / s to 16-235 this will remap the output of players that are pushing out 0-255.

The trouble with all this is that this might all work nicely on your own systems but you can guarantee that most of your clients won’t have a clue as to output levels. The only way of compensating for this IMHO is to carefully ascertain where and how the material is going to be delivered. If the material is 100% for PC / Web viewing then produce your material using the full RGB gamut of 0-255. If it is for TV distribution then it must comply with the 1v P-P levels required by the SMPTE ITU standards. If editing in 8-bit color space this is 16-235.

If you look at the attached JPGs you will see what happens to a 16-235 video level output to a 0-255 display setting level. They are the Vegas screen shots with the color bars. Pay particular attention to the 16-235 0utput INCORRECT on 0-255 display JPG as you will see the white bar overdrives, clips in other words and the blacks crush.

The TV signals we receive at home from satellite or free to air transmissions etc and the content of DVDs and Blu-Rays is all in the 16-235 level space and most of it in 4:2:0 color space. Set top boxes and displays expect to output and receive 16-235 content by default.

When displaying 16-235 content on a desktop PC that is feeding a VGA or DVI monitor, the PC should re-map the 16-235 material to 0-255 to ensure blacks are black and whites are white. If the output is not re-mapped you will get those lovely blown highlights and crushed blacks.

If you are displaying 16-235 content on a standard HDMI equipped TV, the PC should ensure 16-235 sources are output as 16-235, and that any 0-255 PC content is also remapped back to 16-235 to maintain the correct levels.

NOTE THE DISTINCTION HERE THOUGH. An HDMI input on a PC monitor is generally expecting a 0-255 level. An HDMI connector on a TV is generally expecting to see a 16-235 level. A lot of later model higher end flat panel monitors and TV displays now have advanced menu selections for selecting whether to accept restricted range 16-235 or full range 0-255. The selection of which range to choose from is of course predicted on you knowing WHAT color space range you are feeding the flat panel.

The cross fertilization of PC 0-255 and TV 0-16-235 color space has complicated matters to such a degree I see many, many cases of incorrect display levels.

Most of my work is for TV so my video and audio levels address those requirements. If clients require the material for web delivery as well... well they get the same levels rendered to MP4 or WebM or whatever they require. No client has yet complained about the restricted gamut 16-235 levels on their web encodes so that’s the way it will stay. Those who have been somewhat technically inclined have been quite happy to go along with this approach when it is explained to them that to deliver two color space requirements is going to cost them a complete re-grade and re-render of their program to the second color space.

Why you have display distortions I wouldn't hazard a guess but I would put it down to player display problems of some kind.

The attached JPG titles are pretty self explanatory.

Chris Young
CYV Productions
Sydney

Plamen Petrov · February 15th, 2014, 04:52 AM

Thank you, Christopher, for all you wrote.
At the same time I'm so sorry that you've spent your time for the big reply, because everything you say is known to me.
Look, the problem is that when I put the rendered video file back on the timeline of Sony Vegas or AE, it looks as in QuickTime player, i.e. exactly as it should, exactly as I edited and graded it, without the mentioned weird issues.
So, in the video editors - ok, in the players and TV (except QT) - not ok.
I still think the problem may be in the codecs somehow or in the encoders of the players. But why only QuickTime player plays the video file properly? Obviously the encoding is different.
Same about the vertical image stretching - when I download videos from YouTube, Vimeo, etc., all the players and TV show them exactly as they are, i.e. no picture or aspect issues.

Christopher Young · February 16th, 2014, 04:36 AM

Exactly as I said. In your NLE is should look ok as hopefully your NLE is working to the correct 601 / 709 levels of 16-235. All your other players, other than maybe QuickTime Player which I hardly ever use so I don't know, will display this as 0-255 as most software players are designed for PC use and therefore your 16-235 video levels will clip on the highlights and crush in the blacks. PC players are designed around full swing 0-255. As I said the only player I know that can put out your 16-235 levels correctly is Media Player Classic Home Cinema. Even then you must select that 16-235 display option because by default it is outputting 0-255 display levels.

Not knowing how you are playing your files on a TV but if it is direct from a PC then you have to use a software PC player that can be switched to correct display levels of 16-235 if showing 16-235 based material. If you plug the PC to an HDMI TV input the TV is expecting to see 16-235 levels. If the player on your PC is putting out 0-255 to the TV then it is no small wonder the picture levels do not look correct.

Chris Young

CYV Productions
Sydney

Plamen Petrov · February 16th, 2014, 06:00 AM

Ok, Chris, what are the levels of my LCD TV?
I copy the rendered video file to USB flash memory which I attach to the USB input of the TV, it can read and playback photos, music files, AVI (xvid, divx, mkv, H264, etc.), mpreg, ...
So that's another question: why do the issues appear on the TV same as in PC players (except QT) when the TV is 16-235 and the players - 0-255? Why when QT player displays 16.235 somehow, the TV doesn't display it the same proper way?!? When all the players show 0-255 with the issue, then why the TV shows it the same way as if as it (the TV) is 0-255? Confusing, right?
I still think and believe that the problem is in the system, in particular in the codecs.

Ok, do I do it right:
Original .MTS (or original file converted to DNxHD or CineForm 4:2:2 or ProRes) ---> After Effects, Project Settings 16 (or 32) bits per channel, Working space HDTV (Rec. 709) Simulate Output - HDTV (Rec. 709) ---> Render: DNxHD .709 or CineForm 4:2:2.

Do you see anything wrong?

Christopher Young · February 16th, 2014, 07:59 AM

I see nothing wrong with your workflow. The way to check your TV is to encode some PAL SMPTE color bars as per your normal workflow. On the PAL SMPTE bars (shouldn't really say PAL as in truth that is transmission standard but we all say it) there should be three pluge bars under the red bar. The first one is Super Black, -50millivolts, the second one is Black, 0 millivolts, and the third one is +50 millivolts above Black.

Try displaying these bars of a USB on your TV. On a TV that is interpreting the correct levels you should JUST see the +50 millivolt bar. If this is not what you see then you will need to find out just what level and gamma settings your particular TV can handle. Recently I had to set up a large screen Panasonic for a display as all the video shown on it looked terrible. After poking around in its advanced menus I discovered range and gamma settings and was soon able to select the correct settings for the 16-235 video level material that were being shown.

A quick way to check what your flat panel is doing is get hold of a copy of 'Monsters Inc' or, I think it was the last in the series, 'Indiana Jones and the last Crusade.' Both these discs have a pretty comprehensive setup section with most of the test signals and test scenes required to set up virtually any display.

Failing that go to the following site and check what it has to say regarding setups for 709 displays. You can actually download and burn your own setup check discs from this site.

AVS HD 709 - Blu-ray & MP4 Calibration

It's a nasty thing setting up and getting the correct levels on flat panels these days, especially for TV mastering. We still use Sony BVM grade one CRT studio monitors for grading. For eighteen months we were using Sony's latest Trimaster BVM OLED monitors. In my opinion not a patch on correctly set CRTs but then I’m old school. Give me reference glass any day at least then I know my material is correct when delivered.

Chris Young
CYV Productions
Sydney

Nicholas de Kock · February 16th, 2014, 05:26 PM

Plamen I'm going to save you years of agony with a single line of advice...."Stop worrying about it!" :)

You will never get your video to look the way you wanted unless you have full control of the viewing experience aka expensive broadcast calibrated monitor. People will watch your video on phones, tablets, computer monitors, plasma TV's, LCD TV's, LED TV's and every single device will play your video differently. All you can really do is utilise your scopes as a general reference & hope the person viewing your video isn't doing so on a crappy player, in most cases they do so make sure the content is compelling.

Christopher Young · February 16th, 2014, 08:35 PM

Nicholas

My advice was purely so Plamen could satisfy himself that his material looked okay when it left him. You can't tell how it 'looks' regardless of keeping you scope levels correct. As you suggest you can't let it worry you as you have no control whatsoever as to how and where your material is going to be viewed. The only time I know this is when I deliver material to a network and then it must meet 709 spec. If it doesn't they throw it back in my face with a time code print out from there 'Legaliser' hardware listing where the signal is out of bounds and what the problem was and a short note "Please fix."

Chris Young
CYV Productions
Sydney

February 15th, 2014, 01:01 AM	#1
Plamen Petrov Regular Crew Join Date: Feb 2005 Location: Sofia Bulgaria Posts: 147	Weird Exporting/Playback Issues - Look At The Snapshots! Has anybody experienced such an issue: After rendering out a video file with CineForm, DNxHD or other codecs, there is always a huge difference when playing the rendered video file back on different players. For example, just take a look at the attached snapshots below: the 1st is with Windows Media Player and other players; the 2nd is with QuickTime Player. As you can see, the video from QTP looks exactly as edited and graded before rendering out, while the same video from WMP and other players gets highlights overblown and other destructive effects. Is that normal, how to fix this problem? When I put the same (rendered) video file on Sony Vegas or AE timeline, it looks properly as it is and as QTP shows it. Re-rendering this already rendered video file with various codecs and settings goes to the same issues. The same issue I experience with video files converted with 5D2RGB - QTP shows it properly with the 1.8 gamma lifted up, while WMP and the other players show exactly zero difference from the source MTS video file. So, why does this happen? Any idea why the video editors display the video properly and then the other players don't? Another issue: the WMP snapshot is vertically stretched a little, don't know why and this appears on the TV too as well as the destroyed highlights and other defects; while the QTP snapshot looks exactly as it should. I'm shocked!!! Any help and suggestions? Thanks in advance! Attached Thumbnails

February 15th, 2014, 01:39 AM	#3
Plamen Petrov Regular Crew Join Date: Feb 2005 Location: Sofia Bulgaria Posts: 147	Re: Weird Exporting/Playback Issues - Look At The Snapshots! How do you think the players can be adjusted?!? And even if there is a way for adjusting the players, then how to adjust the TV when it plays the same wrong way as the players, but not properly as QuickTime player only? I think the problem is in the system. Why is QuickTime player the only one which plays properly? Sometimes I try watching videos on my TV from YouTube exporting to USB flash and they all look normal as in the browser or even played with WMP and other players(!!!) So, the problem is in the system, but where?!?

February 15th, 2014, 04:22 AM	#4
Christopher Young Trustee Join Date: Apr 2008 Location: Sydney Australia Posts: 1,527	Re: Weird Exporting/Playback Issues - Look At The Snapshots! This problem raises its head all the time. Often the case is that ‘broadcast’ type NLE software is working or set up to output SMPTE broadcast ITU 601 or 709 levels and will be working in the studio YUV gamut range of 16-235 levels. Many PCs, can’t comment on Mac as I don’t work with them, have their display output set to computer RGB levels which in most cases is 0-255. This will blow your highlights and crush your blacks on 16-235 level material unless the levels are correctly re-mapped to display at 0-255. Most of the common media players are only capable of displaying 0-255 levels so this becomes an issue if you want the correct output results. The only way I have found around this is to use Media Player Classic Home Cinema where the output levels can be selected. See attached JPGs. You can distinctly see the differences in the white levels on the vehicles and the difference in the shades of 'blacks' such as the tyres etc when the different output ranges are selected. If you are using Nvidia or ATI graphics cards you can select the output level the card will put out. 0-255 or 16-235. By setting the output of the card / s to 16-235 this will remap the output of players that are pushing out 0-255. The trouble with all this is that this might all work nicely on your own systems but you can guarantee that most of your clients won’t have a clue as to output levels. The only way of compensating for this IMHO is to carefully ascertain where and how the material is going to be delivered. If the material is 100% for PC / Web viewing then produce your material using the full RGB gamut of 0-255. If it is for TV distribution then it must comply with the 1v P-P levels required by the SMPTE ITU standards. If editing in 8-bit color space this is 16-235. If you look at the attached JPGs you will see what happens to a 16-235 video level output to a 0-255 display setting level. They are the Vegas screen shots with the color bars. Pay particular attention to the 16-235 0utput INCORRECT on 0-255 display JPG as you will see the white bar overdrives, clips in other words and the blacks crush. The TV signals we receive at home from satellite or free to air transmissions etc and the content of DVDs and Blu-Rays is all in the 16-235 level space and most of it in 4:2:0 color space. Set top boxes and displays expect to output and receive 16-235 content by default. When displaying 16-235 content on a desktop PC that is feeding a VGA or DVI monitor, the PC should re-map the 16-235 material to 0-255 to ensure blacks are black and whites are white. If the output is not re-mapped you will get those lovely blown highlights and crushed blacks. If you are displaying 16-235 content on a standard HDMI equipped TV, the PC should ensure 16-235 sources are output as 16-235, and that any 0-255 PC content is also remapped back to 16-235 to maintain the correct levels. NOTE THE DISTINCTION HERE THOUGH. An HDMI input on a PC monitor is generally expecting a 0-255 level. An HDMI connector on a TV is generally expecting to see a 16-235 level. A lot of later model higher end flat panel monitors and TV displays now have advanced menu selections for selecting whether to accept restricted range 16-235 or full range 0-255. The selection of which range to choose from is of course predicted on you knowing WHAT color space range you are feeding the flat panel. The cross fertilization of PC 0-255 and TV 0-16-235 color space has complicated matters to such a degree I see many, many cases of incorrect display levels. Most of my work is for TV so my video and audio levels address those requirements. If clients require the material for web delivery as well... well they get the same levels rendered to MP4 or WebM or whatever they require. No client has yet complained about the restricted gamut 16-235 levels on their web encodes so that’s the way it will stay. Those who have been somewhat technically inclined have been quite happy to go along with this approach when it is explained to them that to deliver two color space requirements is going to cost them a complete re-grade and re-render of their program to the second color space. Why you have display distortions I wouldn't hazard a guess but I would put it down to player display problems of some kind. The attached JPG titles are pretty self explanatory. Chris Young CYV Productions Sydney Attached Thumbnails

February 15th, 2014, 04:52 AM	#5
Plamen Petrov Regular Crew Join Date: Feb 2005 Location: Sofia Bulgaria Posts: 147	Re: Weird Exporting/Playback Issues - Look At The Snapshots! Thank you, Christopher, for all you wrote. At the same time I'm so sorry that you've spent your time for the big reply, because everything you say is known to me. Look, the problem is that when I put the rendered video file back on the timeline of Sony Vegas or AE, it looks as in QuickTime player, i.e. exactly as it should, exactly as I edited and graded it, without the mentioned weird issues. So, in the video editors - ok, in the players and TV (except QT) - not ok. I still think the problem may be in the codecs somehow or in the encoders of the players. But why only QuickTime player plays the video file properly? Obviously the encoding is different. Same about the vertical image stretching - when I download videos from YouTube, Vimeo, etc., all the players and TV show them exactly as they are, i.e. no picture or aspect issues.

February 16th, 2014, 04:36 AM	#6
Christopher Young Trustee Join Date: Apr 2008 Location: Sydney Australia Posts: 1,527	Re: Weird Exporting/Playback Issues - Look At The Snapshots! Exactly as I said. In your NLE is should look ok as hopefully your NLE is working to the correct 601 / 709 levels of 16-235. All your other players, other than maybe QuickTime Player which I hardly ever use so I don't know, will display this as 0-255 as most software players are designed for PC use and therefore your 16-235 video levels will clip on the highlights and crush in the blacks. PC players are designed around full swing 0-255. As I said the only player I know that can put out your 16-235 levels correctly is Media Player Classic Home Cinema. Even then you must select that 16-235 display option because by default it is outputting 0-255 display levels. Not knowing how you are playing your files on a TV but if it is direct from a PC then you have to use a software PC player that can be switched to correct display levels of 16-235 if showing 16-235 based material. If you plug the PC to an HDMI TV input the TV is expecting to see 16-235 levels. If the player on your PC is putting out 0-255 to the TV then it is no small wonder the picture levels do not look correct. Chris Young CYV Productions Sydney

February 16th, 2014, 06:00 AM	#7
Plamen Petrov Regular Crew Join Date: Feb 2005 Location: Sofia Bulgaria Posts: 147	Re: Weird Exporting/Playback Issues - Look At The Snapshots! Ok, Chris, what are the levels of my LCD TV? I copy the rendered video file to USB flash memory which I attach to the USB input of the TV, it can read and playback photos, music files, AVI (xvid, divx, mkv, H264, etc.), mpreg, ... So that's another question: why do the issues appear on the TV same as in PC players (except QT) when the TV is 16-235 and the players - 0-255? Why when QT player displays 16.235 somehow, the TV doesn't display it the same proper way?!? When all the players show 0-255 with the issue, then why the TV shows it the same way as if as it (the TV) is 0-255? Confusing, right? I still think and believe that the problem is in the system, in particular in the codecs. Ok, do I do it right: Original .MTS (or original file converted to DNxHD or CineForm 4:2:2 or ProRes) ---> After Effects, Project Settings 16 (or 32) bits per channel, Working space HDTV (Rec. 709) Simulate Output - HDTV (Rec. 709) ---> Render: DNxHD .709 or CineForm 4:2:2. Do you see anything wrong?

February 16th, 2014, 07:59 AM	#8
Christopher Young Trustee Join Date: Apr 2008 Location: Sydney Australia Posts: 1,527	Re: Weird Exporting/Playback Issues - Look At The Snapshots! I see nothing wrong with your workflow. The way to check your TV is to encode some PAL SMPTE color bars as per your normal workflow. On the PAL SMPTE bars (shouldn't really say PAL as in truth that is transmission standard but we all say it) there should be three pluge bars under the red bar. The first one is Super Black, -50millivolts, the second one is Black, 0 millivolts, and the third one is +50 millivolts above Black. Try displaying these bars of a USB on your TV. On a TV that is interpreting the correct levels you should JUST see the +50 millivolt bar. If this is not what you see then you will need to find out just what level and gamma settings your particular TV can handle. Recently I had to set up a large screen Panasonic for a display as all the video shown on it looked terrible. After poking around in its advanced menus I discovered range and gamma settings and was soon able to select the correct settings for the 16-235 video level material that were being shown. A quick way to check what your flat panel is doing is get hold of a copy of 'Monsters Inc' or, I think it was the last in the series, 'Indiana Jones and the last Crusade.' Both these discs have a pretty comprehensive setup section with most of the test signals and test scenes required to set up virtually any display. Failing that go to the following site and check what it has to say regarding setups for 709 displays. You can actually download and burn your own setup check discs from this site. AVS HD 709 - Blu-ray & MP4 Calibration It's a nasty thing setting up and getting the correct levels on flat panels these days, especially for TV mastering. We still use Sony BVM grade one CRT studio monitors for grading. For eighteen months we were using Sony's latest Trimaster BVM OLED monitors. In my opinion not a patch on correctly set CRTs but then I’m old school. Give me reference glass any day at least then I know my material is correct when delivered. Chris Young CYV Productions Sydney

February 16th, 2014, 05:26 PM	#9
Nicholas de Kock Major Player Join Date: May 2007 Location: KLD, South Africa Posts: 983	Re: Weird Exporting/Playback Issues - Look At The Snapshots! Plamen I'm going to save you years of agony with a single line of advice...."Stop worrying about it!" :) You will never get your video to look the way you wanted unless you have full control of the viewing experience aka expensive broadcast calibrated monitor. People will watch your video on phones, tablets, computer monitors, plasma TV's, LCD TV's, LED TV's and every single device will play your video differently. All you can really do is utilise your scopes as a general reference & hope the person viewing your video isn't doing so on a crappy player, in most cases they do so make sure the content is compelling.

February 16th, 2014, 08:35 PM	#10
Christopher Young Trustee Join Date: Apr 2008 Location: Sydney Australia Posts: 1,527	Re: Weird Exporting/Playback Issues - Look At The Snapshots! Nicholas My advice was purely so Plamen could satisfy himself that his material looked okay when it left him. You can't tell how it 'looks' regardless of keeping you scope levels correct. As you suggest you can't let it worry you as you have no control whatsoever as to how and where your material is going to be viewed. The only time I know this is when I deliver material to a network and then it must meet 709 spec. If it doesn't they throw it back in my face with a time code print out from there 'Legaliser' hardware listing where the signal is out of bounds and what the problem was and a short note "Please fix." Chris Young CYV Productions Sydney