Video synchronization problem

Hi,
I am building an application that must play 2 videos in sync.
The videos are streamed using RTMP.
One of the videos is shorter then the other one and it must play/pause when the main video reaches predefined time key points.
The problem is that if the application remains in an idle state for a longer time (the videos are playing, but there is no user interaction) the second video breaks, usualy at my next seek operation, but sometime even if no seek operation is performed.
By "second video breaks", I mean the:
- secondVideo.currentTime propertie returns NaN
- secondVideo.mx_internal::videoPlayer.bufferLength returns NaN
- secondVideo.mx_internal::videoPlayer.state is buffering
- no PLAYBACK_ERROR event is dispatched
- I can't pause/play the secondVideo anynore;
My solution would be to reset the video and seek to correct time, but this operation takes some time and it's not really an option.
What I'm more interested in, is what can cause the videoPlayer to return these values.
I'm using Flex SDK 4.5, tryied with 4.0 also - same problem.
Thanks!

For starters, nice topic you have for a Uni dessertation (which Uni is it? i'm an undergraduate myself :) )
Secondly, fear not :p There is a way of doing this, but it might take a while to get it through. I'll try and give you a basic clue for JMF, and you'll have to go on from there on your own (by trying out stuff and all).
A) Make a list with those check boxes that you want, name them the way you like and make sure to add the additional functionality (if any).
B) When the user wants to play between some players (and checks on some check boxes), find out which check boxes have been checked (if chkBox1.isChecked() bla bla bla). For those checkBoxes, you will manipulate the corresponding players.
C) When it comes to synchronization of the players you will use the TimeBase and TimeFunctions that JMF supports. A simple way of doing this is by saying: player1.setTimeBase(player2.getTimeBase()); and do that for all the players that you have at hand (the ones that have been selected in your case). The thing is that you must control, in this way, each player individually, which might be a difficult thing to do (any of the 6 players might post an event, and you need to find out who was it, by also making sure that other players are informed of the event, in case you need to take some actions).
I would advise you to download the JMF API Guide (downloadable from here: http://java.sun.com/products/java-media/jmf/2.1.1/specdownload.html) and read through the Synchronizing multiple media streams section).
Regards,
George

Similar Messages

Video Synchronization Problems

I am having a major problem with video synchronization. I
have a single FLV that is used throughout the presentation. I have
edited viewer.xml and inserted the correct start and stop times,
and everything works perfectly when run from my local machine.
However, when I publish to my webserver, everything breaks. The
video file is reloaded on every slide, and it starts at the
beginning for every one instead of starting at the proper time. Any
ideas?

Are you republishing to your webserver after you have made
changes in viewer.xml ? If that is true then your xml would be
created again which will not have these changes .
Right method would be to use the published folder(or zipped
folder ) with updated viewer.xml

CS4 to CS5 audio video synchronization problem

Hello,
I have a issue when i am opening CS4 Premiere Projects (Win) with CS5 Premiere (Mac), the problem is that the sound and the video is not in the correct time place.
Everything is not synchronized and even the videos are not appearing like they should be in Premiere CS5.
In CS4 all is perfect but when i open this CS5 they are not.
Any solution?
Thanks in advance

What are the specs. of the Assets in this Project?
The ideal is to address the OOS (Out Of Sync) at the beginning, which you are doing. However, if thing fail, then this ARTICLE might be useful for fixing the problem down the line.
Good luck,
Hunt

Possible "pitch/synchronization" problems when exporting

I have a video that I edited in Adobe Premiere Pro, with a Sequence setting of 23.976fps... in the editor, when I render it and play it back... it plays back beautifully. Just the way I want it to.
I exported it as an MP4 file (with NATIVE fps, 23.976) and uploaded it to Vimeo, and played it there - and I SEE that it's off.
The way my video is edited is very fast, and relies heavily on Audio/Video synchronization, it's the WHOLE point of my video.
In Vimeo - I can SEE that it's off. The video is just a few milliseconds lagging. It's not catastrophical, but spending a month editing and playing it back over and over again in Premiere Pro, I pretty much know how it should play out... and the moment I saw it playback on Vimeo, I spotted this slight un-synchronization. The audio is slightly faster than the image that is supposed to be in synchronization with that audio effect
Is this a frame rate problem or am I exporting it wrong?
My Adobe Premiere Sequence settings are
[quote]Sequence 01
1920 x 1080
00;20;26;11, 23.976 fps
48000 Hz - Stereo[/quote]
when I right click on the actual audio IN the timeline the settings are
[quote]Source Audio Format: 44100 Hz - compressed - Stereo
Project Audio Format: 44100 Hz - 32 bit floating point - Stereo
Total Duration: 00:04:39:37476
Average Data Rate: 39 KB / second[/quote]
Can anyone tell me if there's something I'm doing wrong?
the 44hz, and the Sequence 48Hz are different, yes... but why is it when I play it back rendered in Premiere that it syncs perfectly then? or does the problem lie in something else?
Again for reference, my video is very experimental, the cuts are very fast that sync with the sound.

Hate to bring up an old thread, but this is EXACTLY the same type of issue I am always having, and rather than be accused of not doing a search, I thought that I'd reply to this and see if any can give some insight.
I'm in the exact same situation where the type of edits that I do are critical in syncing audio and sfx to visual cues in the video. As the OP mentioned, I spend countless hours getting things just right on the Premiere timeline, only to have things be not quite right on export...regardless of format it seems.
The bigges then I'm thinking is the root cause is the fact that many audio sources are different. Most music from CDs or online are in 44kHz whereas default sequences in Premiere are in 48kHz, as well as audio from video cameras.
It's really difficult to understand what is the "proper" workflow when working with 48kHz and 44kHz to ensure that WYHIWYG (what you hear is what you get), on export.
Is there anyone that can explain or point in the right direction to solve this issue?

Intermittent loss of sound (not the video/sound problem)

Hi -
I just got my third ipod (30G ipod with video) two days ago and I've encountered an issue.
Twice so far, after pausing my ipod for 10-15 minutes and then going to resume, I have lost all sound output. The first time it happened, the ipod showed progress in the song - but the second time, although the icon showed that it was playing, there was no movement in the progress bar.
All menu functions work properly and promptly - it's not just a freeze. I tried four different sets of headphones, all with the same result. The only thing I have not yet determined is whether the problem appears when the ipod is docked and audio is not going through the headphone port.
A reset seemed to resolve the problem, but I don't much relish the idea of having to reset the thing every day, especially when I have a 4G color that has NEVER had to be reset. This happens in regular audio mode (I know an issue exists with sound and video synchronization, but that hasn't been my problem).
I am considering rolling the firmware back to 1.0, but I am wondering if the problem might not be either related to the hard disk or even the headphone jack itself (each time the problem manifests, it has been after headphones were removed and later replaced.)
Any ideas, or is this a known issue? A quick search here and at ilounge yielded mostly discussions about the video sync problem. Any help would be appreciated!
Thanks!

Finally... someone with nearly the same problem as I'm having with my 30G 5G ipod. You can read about it here:
http://discussions.apple.com/thread.jspa?messageID=1868779
and here:
http://discussions.apple.com/thread.jspa?messageID=1930370
I say nearly because my problem doesn't exhibit itself every time or I would have taken it to the Apple store and showed them. But this problem of yours sounds alot like mine. I used to think it was related to charging it hence the title on my first thread. But now I too think it's related to the ear plug jack. There is something about the sensor in it and the fact that it is a plug that has like 3 or 4 outputs, I wonder if the seating of the plug has to be right or it shorts out something just enough to screw up the audio. My second thread suggests my problem is related to the case I use which has material around the hole but not covering it. You insert thru the hole in the case and into the hole in the jack. The seating may not be 100% which may cause issues. You didn't mention a case...does yours have one?
Like you, I too had to soft reset the ipod to get it out of this wierd mode. Someone else suggested that when it happens turn off the ipod, pull out the plug, then re-plug it in, turn on the ipod. I have lately found that most of the time if I just unplug and replug the jack it clears the problem. I haven't had it fail enough times to see if this solution will fail or not. See if it helps your situation.
Let me know about the case question.

Audio and video sync problem

Hi,
I have a problem with audio and video synchronization. I'm using Merge class to merge video and audio tracks. But audio track can be shorter then whole video track (for example video length: 2 min., audio length 1 min.). When I merge them everything is OK. After that I'd like to concatenate more tracks (generated from merge) into one final video file. For this purpose I'm using Concat class.
But here is the problem, after I concatenate all these tracks then the result video is OK but audio is synchronized right after the previous audio track ended. (If I have video1- 2min. audio1 - 1min., video2 - 2min., audio2 - 30 seconds, then second audio2 starts in 1,30 min right after the first audio track. But I want to start it when the second video2 starts.) Do you have any ideas??
Merge class http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/solutions/Merge.html
Concat class http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/solutions/Concat.html
Thanks for help in advance.

Ok thanks.
I tried to implement PullBufferDataSource and everything went ok, the audio .wav file was generated, but when I run that file, the length is 0 and not the lenght I wanted (40.00). Where can be a problem?
Here is the code I wrote/changed:
TimeDataSource tds = new TimeDataSource(40.00);
Processor p;
try {
    System.err.println("- create processor for the image datasource ...");
    p = Manager.createProcessor(tds);
} catch (Exception e) {
    System.err.println("Yikes! Cannot create a processor from the data source.");
    return false;
}I set content type to WAVE:
// Set the output content descriptor to QuickTime.
p.setContentDescriptor(new ContentDescriptor(FileTypeDescriptor.WAVE));I use DataSource as the next:
    class TimeDataSource extends PullBufferDataSource {
                 private double duration;
                 TimeSourceStream streams[];
                 public TimeDataSource(double duration) {
                  this.duration = duration;
                  streams = new TimeSourceStream[1];
              streams[0] = new TimeSourceStream(40);
          @Override
          public PullBufferStream[] getStreams() {
               return streams;
          @Override
          public void connect() throws IOException {
          @Override
          public void disconnect() {
          @Override
          public String getContentType() {
               return ContentDescriptor.RAW;
          @Override
          public Object getControl(String arg0) {
               return null;
          @Override
          public Object[] getControls() {
               return new Object[0];
          @Override
          public Time getDuration() {
               return new Time(duration);
          @Override
          public void start() throws IOException {
          @Override
          public void stop() throws IOException {
    class TimeSourceStream implements PullBufferStream {
               private AudioFormat format;
               private boolean ended = false;
               private long duration;
               public TimeSourceStream(long duration) {
                    this.duration = duration;
                    format = new AudioFormat(AudioFormat.LINEAR, 8000, 8, 1);
          @Override
          public Format getFormat() {
               return format;
          @Override
          public void read(Buffer buf) throws IOException {
               buf.setDuration(duration);
               buf.setFormat(format);
               buf.setEOM(true);
               buf.setOffset(0);
               buf.setLength(0);
               ended = true;
          @Override
          public boolean willReadBlock() {
               return false;
          @Override
          public boolean endOfStream() {
               return ended;
          @Override
          public ContentDescriptor getContentDescriptor() {
               return new ContentDescriptor(ContentDescriptor.RAW);
          @Override
          public long getContentLength() {
               return 0;
          @Override
          public Object getControl(String arg0) {
               return null;
          @Override
          public Object[] getControls() {
               return new Object[0];
    }Edited by: mako123 on Feb 22, 2010 2:18 PM
Edited by: mako123 on Feb 22, 2010 2:23 PM

MSI K7N2 Delta-ILSR, Mouse problem & Video off problem solved!!!

I find the following information that I collected very interesting at the very least...
Here goes...
The video off problem that I was having was directly linked to the mouse. Here, let me explain the video off problem. In the BIOS Have the Standby mode set to S3. The problem occurred when I started windows, then went into standby, then started back up, then restarted the computer, the monitor would act as if it were in sleep mode, or rather there was no signal being sent to the monitor. Well the odd way I fixed that is by plugging in a standard 2 button PS/2 mouse. Also this fixed the issue with the mouse sometimes not working in windows.
Here is how I tested.
Logitech MX700 Cordless Optical Mouse, PS/2 & USB= failed.
Logitech iFeel Optical Mouse, USB= failed.
Microsoft Cordless Ball Mouse, PS/2= failed.
Standard Artec (Cheapy brand) Ball Mouse (With no wheel), PS/2= All issues fixed, and passed.
When I said failed I do not mean they didn't work, I mean they sometimes didn't work and also caused the Video off problem after restarting the computer.
Obviously it isn't the ports (PS/2 or USB) that are the problem, it is more like the mouse itself, and the amount of buttons in particular. As you can see above the only mouse that works correctly is the one that only has 2 buttons, the rest has 3 or more buttons along with a Wheel. The MX700 has 8 buttons + wheel, WOW!
Anyways I figure out it was the mouse, and not the memory.
Obviously MSI needs to make a patch for this mouse problem.
I'm still having a hard time believing that the mouse caused the video not to work, but it is true! I spend well over 5 hours testing this crap. Every time with the mice with more then 3 buttons it messed up, and every time with the 2 button old fashion mouse it worked flawlessly!
MSI, get to work on a new BIOS to fix this mess!!! :]
BioHaz

Quote
Originally posted by Raven_
hi
its possible to use an ps/2 mouse AND a usb mouse at the same time.
i used the ps/2 mouse in windows and the usb mouse when playing games.
you can get some trouble if you do it the way i did it.
i was in windows surfing and the pointer just jumped all over the screen.
when i looked on the other side under a table a friends little kid played with the usn mouse. )
bye
LOL, that isn't what I'm talking about.
There seems to be a problem with my motherboard accepting mice with more then 2 buttons. It works the first time, but if you restart the computer, the video goes off. If you have both installed, it still messed up.
BioHaz

'Source play' and 'audio-video sync' problems with PE8 on fast WIN7 64 bit computer

I am transferring Hi8 videos, about 2 hours long, to my WIN7 64 bit computer with PE8. [Dell Mobile Precision M4400 Computer Workstation (Intel Core 2 Duo T9900 500GB/4GB); NVIDIA Quadro FX 770M, 512MB] I seem to have several problems:
First, after importing the file (.avi), I get a message about ‘dropped frames.’
Secondly, when I try to play the video in the source monitor, the audio plays but the video doesn’t; it only shows the first frame [this is after waiting until the video is ?recognized? ] I can use the shift-arrow key and see that the video is there.
Thirdly, I can play the .avi file in other players, e.g., avidemux or PE pro CS5 on another computer. There, I see that the audio and video are not in sync; the audio can be up to 300 ms ahead of the video (as determined using avidemux).
Questions:
1. Why doesn’t the source monitor play the video? Is this a problem with PE8 (latest update as of 3 March 2011) on aWIN7 64 bit computer (intel duo core. 3 GHz).
2. Is the audio-video sync problem the result of the ‘dropped frames?’ How can PE8 correct this? Avoid this? Or, is it coincidence?

"I think you're telling me you're using a backwards compatible Digital8 camcorder to capture your video as DV-AVIs. Is that right?" YES
"Are you using Premiere Elements to do this capturing?" YES, AS ABOVE PE8
"Go to the File menu and select Properties. It should show a standard DV codec being used for your video and audio."
WMP v12 is dumb. Under properties, media, it says 'video.' However, avidemux gave me the information state above: video -- Codec 4CC: dvsd, frame rate: 29.971 fps; audio -- codec: PCM, channels: Stereo, frequency: 48 kHz.
So, back to the Questions:
1. Why doesn’t the source monitor play the video? Is this a problem with PE8 (latest update as of 3 March 2011) on aWIN7 64 bit computer (intel duo core. 3 GHz).
2. Is the audio-video sync problem the result of the ‘dropped frames?’ How can PE8 correct this? Avoid this? Or, is it coincidence?

MacBook Pro 15" video card problems (i think)

Can anyone tell me if this is indeed a video card problem?
MBP 15" info (Dec. 2011)
Processor 2.4 GHz Intel Core i7
Memory 4GB 1333 MHz DDR3
Graphics Intel HD Graphics 3000 384 MB
OS X Lion 10.7.5
This is what happened:
I use my mbp heavily because I edit a lot of videos with Premiere. I also use lightroom / photoshop alot + games. I also installed Parallels desktop late 2013. I don't know if that is relevant but anyway. Everything started late 2013 (a little after installing parallels actually) when there are moments when the audio wouldn't work and I couldn't adjust the volume. It would come back anyway so i didn't mind it. Then the fans were on high speed for little activity. After that the keyboard backlight couldn't be adjusted and wouldnt work. I ignored all of these cuz i wasn't troubling me at the time. In January i left for france to study - I use bike all the time and once stupidly placed my laptop on the basket going to school (rough roads). I had a class with html so I had to open Parallels, my teacher pointed out the fans and how loud they were. That day, parallels desktop said i must upgrade to windows 9 or it will restart every 2hours. I didn't of course. I didn't have time to.
After that (a few days later i think) my laptop would randomly turn into a black screen but it's still on (the power LED is on) I tried turning it off by pressing down the power button and then turning it back on. It worked the first time. During the first week, the frequency of it happening grew. It would do it almost 3 times a day. during that same week I tried to do an SMC reset. It fixed the keyboard light, fans and audio but not the black screen thing. It just keeps on happening around 1-3 times a day. It only happens when I'm using it btw, never when I just leave it. ALSO, after a few days, it would take longer hours to open my mbp again. I mean, the screen would turn black. i would turn it off, then on again. I will ONLY hear the hard drive moving but no startup sound and no grey screen and apple logo. nothing.
The following weeks after that, I asked a friend to help me out. He suggested that I install gfxCardStatus because he said it might be my video card. He instructed that I keep it on intergrated only. So I installed that and did what he said I thought it worked for a while because the black screens stopped happening (even when gfx keeps on going back to dynamic) BUT NOW, MY LAPTOP WOULD FREEZE (not turn black). I'd shut it down using the power button but it still takes me hours to open it again. Sometimes, I'd wait for the battery to drain because it would startup when i charge it (sometimes)
I tried doing AHT as well to confirm the video card problem, but the results are no problems found. I really don't want to replace my logicboard here in france. everything is more expensive here. ;__;
Today I uninstalled parallels to see if that might have had anything to do with my problem now but i think that's just wishful thinking.
Can somebody tell me if this is really about the video card? Thank you

Your appointment at the genius Bar in an Apple Store (anywhere in the world) for an evaluation is FREE, in warranty or out. Those guys put their hands on these Macs all day every day, and they are especially good at Physical and Power problems.
Ask them.

Has anyone not working with .dv files had synchronization problems?

Has anyone not working with .dv files had sound synchronization problems? I'm not exactly sure what the alternatives to DV are, but I think one of them is HD.
The reason for asking this question is to help isolate the nature and cause of a very serious flaw in iMovie '11. In the original release of iMovie '11 (version 9.0) there was a small--but serious--synchronization problem. In the 9.01 there is a large synchronization problem. We know of one person who has not experienced the problem, and he is not working with DV files (media). So we want to find out if anyone who is using something other than .dv files is experiencing a lack of synchronization between sound and picture. Knowing the answer to this will help with figuring out where the cause lies. For the initial iMovie '11 release (9.0), you probably would not notice a problem unless you had very long event-clips, e.g., two hours long. Events get this long if you are transferring from analog 8 mm tapes. Even then, it would have to be in scenes in which the connection between event and sound is obvious, e.g., close ups of people talking. It isn't until the 9.01 release that most people would notice anything. All we need to do is establish one case of a synchronization problem in which the person is using something other than DV.
Message was edited by: Paul Bullen

Hopefully, the 9.0.2 release will make my question moot. Zyfert must have posted the announcement of the release just as I was formulating my question. Still, if you have information on the subject, it would be interesting to hear.

Video signaling problem caused by 1.9, 2.0 BIOS (pointing out a BIOS problem)

Hi, i have a problem with the video signal. At random times when i boot up my computer, the computer would power up but there is no signal to the monitor. there is no hdd activity (via the hdd led) and nothing seems to be happening just that the fans are whirring. i have to unplug the computer then plug it again then turn it up again which sometimes repeats the problem. This is very irritating! So i did a little bit of troubleshooting:
1. I changed video cards. I used a SAPPHIRE ati radeon 9600XT fireblade and a LEADTEK GF4 ti4200. Both cards were causing the same problem and when i used both cards to another computer, there is no problem. = NOT A video card problem
2. used differnt kinds of drivers Cat 3.10, 4.10, 4.20 (omega and official) does not seem to do anything (which also i believe the drivers are OS dependent and its the bios of the vid card that starts up the vid card)
3. upgraded from 1.9 to 2.0 BIOS. still the same problem
4. reverted from 2.0 to 1.7 BIOS. the problem ended.
BTW, the board is 865PE-Neo2 - S. on a Intel 2.6Ghz C, 512MB TwinMos ram with m-tec chips, 80gb hdd, enermax 300w psu
so ive' solved the problem, and i just wanted to point out that there is a problem with 1.9, 2.0 BIOS. (havnt tried the 1.8 tho)

Wish I had seen this thread 2 weeks ago, but you did save me from buying a new graphics card. That was the last step (before chucking this mobo completely) in my attempts to fix the same problem. It didn't bother me too much, except I also couldn't get any DVD player (tried 3) to work. Would boot sometimes and at others gave a blue screen video error.
Flashing to bios 1.7 was the only thing that fixed it. Tried different memory, updating software, various combinations of drives, etc. For the record I tried bios 1.8, 1.9, 2.0, and 2.1. Not sure what about those updates causes problems but there definitely is something wrong.
Thanks.

The Video Out Problem...Fixed?

I know Wikipedia can be edited by virtually anyone with membership and an opinion, but I had to know.
It said that an itunes update 1.0.2 fixed the video out problem...does that mean that videos can now be connected to a TV and play on the TV? They fixed that?
I am still ever in the market for the nano, just waiting until the right ammount of money to purchase one. Thanks

I think it is currently working according to this knowledgebase article: http://docs.info.apple.com/article.html?artnum=300233
That is, for the new Nano, you can use the older iPod Universal Dock (ie the normal one that has been available for a couple of years) together with an iPod composite video cable or an SVideo cable (ie all currently-available stuff you may have already bought for a previous-series video iPod), OR you can use the brand new "Apple Universal Dock" with the brand new Apple Composite AV Cable or with the (new) Apple Component AV Cable, OR you can use one of those brand new Apple AV Cables directly with the Nano (without the new Apple Universal Dock).
What you cannot do is connect an old video cable or accessory, which was expecting to get composite video from the RCA/audio jack on the Nano, because it looks like (on the new Nano and the Classic) the audio out jack is now just for audio out and video is only available via the dock connector on the iPod.
ted.h.

Aperture Video Import Problem - from Lumix GH4: Imported clips have their dates changed to the import date. The files show up on the hard drive but many are not showing up in Aperture.

Aperture Video Import Problem - from Lumix GH4: Imported clips have their dates changed to the import date. The files show up on the hard drive with import date not created date, but many of these same files are not showing up in Aperture. Sometimes the clips actually show up with the current import but take on the video information from a previously imported file.

It was suggested I move this question to IPhoto or IMovie which I did.
Well moving to a different discussion group did not provide an answer to this question either. But what I finally did was import one batch of photos and videos into IPhoto for a given day at a time. Working with these I could change the date and times in order to get them in the original sequench taken. Then I would create an album with that batch. These would all be on the same day (IMove was closed for this phase). Then I would open IMovie, generate the thumbnails for that album, and select the album I had created. This was necessary because the importing process in IPhoto was using incorrect dates for my video so it was a real struggle finding them in IMove until I developed this approach.
I believe that this whole process was so screwy because I was importing from an external hard drive not a camera. I had these photos on a PC and did not have the original cameras to use to import directly which I am fairly sure would have made this easier!

Video import problem from iphone5 to PC giving error

Hi evereyone,
I have iphone 5. I try to import my videos but am not able to import all, its giving error. I tried also using windows live photo still same prob. the imported videos have problem in playing. I tried with vlc, quick time, the frames are broken and audio video lag. Please help me how i can import all and rum smoothly.

Ilan_B wrote:
Every time I plug my iphone 5 into the laptop (using windows 7) the easiest way is to right click on the portable device (iphone icon) and import to my pictures, BUT every time I do this it wants to import ALL photos and videos.
And when you do this, it should ask if you want to import the pictures that have already been imported. Select No.
Then, after you import, the photos should be deleted from the Camera Roll.
After the photos are imported and deleted from the Camera Roll, you can import using iTunes, only the photos you want on the iPhone.

Hello to all: My iMac has developed a video display problem. It displays everything in cartoon like colors - purple, green, blue. Can this be repaired? Is there a way to output to a different monitor? Thanks in advance! isplays

Hello -
My iMac has developed a video display problem. Everything now appears in a strange, cartoonish way. Purples, greens, blues. Can this be fixed, and if so, any idea how much it might cost? Also, could I output to a seperate monitor? I plan to replace the unit , but cannot right now. Thanks!

Go to System Preferences > Universal Access > Seeing.
In the Display area, reset it to "Black on white" by clicking that checkbox.
You can also reset it by pressing Command-Option-Control-8

Video synchronization problem

Similar Messages

Maybe you are looking for