Playback problems with AVC761

Hello,

I've recently bought and installed an AVC 761 DVR with 2 cameras only. I can see live feed from both cameras in either case where connected remotely or via directly connected monitor. However when I try to playback I'm getting a only scrambled/encoded like picture. I have tried numerous settings CIF mode and Frame mode to resolve this problem.

My question(s) is(are), has anyone else had this problem and if so how did they resolve it? Is it required to have 4 cameras connected to the 761 rather than in my setup where I only have record enabled for the 2 cameras? (note:- I have only enabled recording on 2, also I'm only doing manual records and can see the houry system recorded files from the search option on the OSD.)

Any Help would be appreciated,

Thanks

You do not need to have 4 cameras on the system. It will work with just one camera attached.

As you are looking at live video from your monitor, then I can rule out that you are looking at video via the internet.

You should not be having this problem. I have not seen this problem before.

I would try to remove the wires to the hard drive, and then reattach them. What does your video look like now?

I am wondering if your unit came with a hard drive, or if you installed one of your own?

The DVR can operate without a hard drive (although it will not record), and it appears that you only have video problems when "pulling" the video from the hard drive. You may have a bad hard drive (HD), or you may have one that is not of the manufacture's spec.

I would swap the HD for testing purposes.

If that does not rectify your problem then in may be some "chip" that is supposed to put video to the HD that may be bad.

Other than that I cannot help you.

Thanks for the quick response.

I bought the DVR new online with seagate 250G HD installed.

> I would try to remove the wires to the hard drive, and then reattach them. What does your video look like now?

Yes. I actually tried removing the HD completely and re-connecting yesterday, without any success.

> I would swap the HD for testing purposes.

I will try this, check the HD against the spec. and maybe even reformat for fat32.

> If that does not rectify your problem then in may be some "chip" that is supposed to put video to the HD that may be bad.

I hope not, It never worked, and the machine is new (2 months old).

Thanks again for you time.

Can we confirm also that the live feed looks normal?

I had a problem just yesterday with a camera that created an 'encoded' type image - but the live view also showed the bad image (it was the camera at fault as the image was still bad when I plugged it into my TV directly)

If the OSD shows a list of available recordings - and the time/date of those recordings makes sense (ie today's dat, not 1/1/1898 or something) then I'd go out on a limb and suggest the HD is fine.

Can we try to figure out WHEN the image is being distorted? ie The image follows these steps:

1: Real life ->

2: Camera ->

3: Coax or cat5 ->

4: DVR input ->

5: DVR Image porcessing (ie for motion) ->

6: Saved to HD ->

7: Read from HD ->

8.1: DVD backup as pure data, then converted back to image by player app

or

8.2: USB backup as pure data, then converted back to image by player app

or

8.3: Network backup as pure data, then converted back to image by player app

or

8.4: Converted back to image by DVR and output to screen

or

8.5: Converted back to image by DVR as output to Video Server app

So...

Does the 'list of recordings' show motion events? Do you get the little "motion dude" in the bottom right of the screen when there is motion? If the motion dude appears only when there is actual motion then that suggests the video stream is good up to the component that does motion processing. That would suggest that everything up to & including step 5 is working normally.

So we need to test the rest of the system...

Do you have DVD output? Or USB output? Record a piece of video by noting the time, walking past a camera, noting the time again... Then use the USB backup to output that time range / channel. Play the images back on your computer (doubleclick the playback.exe to install the playback viewer on your cimputer, then select the .787 file for the video that was just backed up, select 'convert', and 'play file'.) Do you get good video or the same garbage? (If you get an error message and the player refuses to install, then try the DVD export. On mine the playback.exe that is saved to USB key is bad but the DVD is good, and once the player was installed by the DVD backup it could read the USB files also.)

You have up to 5 ways of getting video back (depending on DVR model) and if you test each one then you can help isolate the bad component.

1) DVD Backup

2) USB Backup

3) Network Backup through Video Server app

4) Live View via Monitor output (also, live view via call output)

5) Live View via Video Server app

If 1-3 all work and 4 & 5 don't work, then it suggests the video is being converted to data and stored on the HD correctly, but the component in the DVR that renders that data back to a viewable image is not working. (the DVD, USB and Netowrk backups are pure data and the data is rendered back to an image by the software, not the DVR)

If all 5 fail then it likely suggests that the image is not being converted to data correctly before being stored to HD, or there is some processing on the read side that is still common to all 5 vewing methods that is bad.

Again, if you have an apparenlty sensible list of video event stored then I'd suggest the HD is ok - because that event list is gong to be stored on the HD, no?

I've thought of a few things while reading you're reply.

1) the Cameras are wireless. But of good quality without "vloss".

2) I have noticed that on the playback of the scrambled (s) recordings the date will be incorrect giving 2000-1-1. In the list given by the search menu the dates seem to be 2 days behind the current date.(and I believe these (s)ystem files are hourly generated. So there should be ones in the list for Eg. Now - 1 hour)

Maybe something in the above will strike you as a known issue and eliminate my need for any other troubleshooting. Otherwise I appreciate the list you''ve sent me and I will start working my way through them. This will take some time.

Thanks agian

I've thought of a few things while reading you're reply.

 

1) the Cameras are wireless. But of good quality without "vloss".

2) I have noticed that on the playback of the scrambled (s) recordings the date will be incorrect giving 2000-1-1. In the list given by the search menu the dates seem to be 2 days behind the current date.(and I believe these (s)ystem files are hourly generated. So there should be ones in the list for Eg. Now - 1 hour)

 

Maybe something in the above will strike you as a known issue and eliminate my need for any other troubleshooting. Otherwise I appreciate the list you''ve sent me and I will start working my way through them. This will take some time.

 

Thanks agian

Did you change the date/time while the DVR was recording?

If it was me I'd check the date/time is correct then have the DVR clear the HD and start again. Then check the time/date of the playback files. Make sure you let it record for a couple of hours before you try to playback because the manual states that it needs a minimum number of recorded images before you can play back otherwise the playback will not work correctly.

Hi Scruit,

I did what you said regarding resetting date, wiping disk, restarting recording and waiting over 12 hours before playback but unfortunately without success.

However, I did attempt the USB Backup that you suggected and got the following error message:-

Cannot find file CH01

->OK

followed by

Cannot find file CH02

->OK

followed by Backup successful.

When I check the USB Key(formatted for FAT32) which was empty to start with, it's still empty afterwards.

Maybe this information can indicate what may be going wrong.

Thanks in adv.

Hi Scruit,

 

 

I did what you said regarding resetting date, wiping disk, restarting recording and waiting over 12 hours before playback but unfortunately without success.

 

However, I did attempt the USB Backup that you suggected and got the following error message:-

 

Cannot find file CH01

->OK

followed by

Cannot find file CH02

->OK

followed by Backup successful.

 

When I check the USB Key(formatted for FAT32) which was empty to start with, it's still empty afterwards.

 

Maybe this information can indicate what may be going wrong.

 

Thanks in adv.

Definitely sounds like a hard drive problem - if it can't even get the data off the HD. Have you tried a different HD?

I am interested to find out if that is the problem.

Hello,

 

I've recently bought and installed an AVC 761 DVR with 2 cameras only. I can see live feed from both cameras in either case where connected remotely or via directly connected monitor. However when I try to playback I'm getting a only scrambled/encoded like picture. I have tried numerous settings CIF mode and Frame mode to resolve this problem.

 

My question(s) is(are), has anyone else had this problem and if so how did they resolve it? Is it required to have 4 cameras connected to the 761 rather than in my setup where I only have record enabled for the 2 cameras? (note:- I have only enabled recording on 2, also I'm only doing manual records and can see the houry system recorded files from the search option on the OSD.)

 

Any Help would be appreciated,

Thanks

It's most probably a problem of DSP conerning your playback like encode image. You'd better contact with your supplier for a help.

As for the time that is 2 days later the current time, it might be a problem of system time setup, pls try to set it right.

Tmvideo,Jasmine

I've tried several more things suggested in this thread.

1) Network backup of recored files. In this case the recorded files can be searched and selected from the AP software. Upon download selection of any of these files and after 97% is downloaded an error indicating that the file dowload failed. However, there is a file stored on the specified path on my laptop that can be converted into a .vse file that can be opened in the AP software player. The file plays with a tiny, scrambled strip of colours in the top left of the viewer display.

2) Regarding the date, The system date setup is working fine and I can set it to todays date. It's just the date on the playback (from either the web interface or monitor) is incorrect and no mater which file I try to play the same single datetime value is always shown for that file.

If I re-format the hd as fat32 reinstall in the DVR could this work? Can we eliminate the possibility that some DSP processing is failling as there is some other problem given that the file date is incorrect in playback and the file can't be retrieved during network backup?

Thanks for your help.

Well... since it's a new unit, you should just bring it back to your supplier for them to find out the problem.

Few other things you could try.

1. NTSC or PAL, are you using the right system ? Your camera, your dvr and your DVR, are they all on the same system ?

2. Used a WIRED Camera instead of a Wireless Camera. The interference from wireless cause havoc with a lot of compression codec.

3. Change a harddisk. So far, had used a lot of harddisk, never really got any problem with any harddisk with any of the DVR. No matter if they are specificed in the manual or not. You might just have a spoiled harddisk drive.

Considering the cost of postage I would try to resolve the problem locally first -> the problem with buying such stuff online I Guess.

Another thing that may help -> I cant switch between NTSC and PAL on rebutting the machine using the instructions in the guide (via << and >> buttons). It always reverts to PAL regardless. Does this indicate any obvious problems?

Thanks

Just a note.

The dvr requires a blank HDD, ie unformatted.

use fdisk to remove any partitions before popping any spare hard drive in for testing purposes.

Regards,

Snoogs

I've tried re-formatting the disk using fat32format(I'm working with XP) but the problem remains. I'm attaching a screenshot of what I see on playback. Any Ideas, Should I purchace a new HD? format seemed to work ok.

Did you say that you formatted the hard drive with Fat 32?

Another few questions that I have:

Is this a computer that is off site, and it is using the internet to watch your video, or is the computer local to where the DVR is located?

How did you bring up this screen that you have given us a screen shot of??

Did you go into a menu, and did you bring up motion search, or some other search request? The reason I ask is this: If you are not recording video due to a hard drive problem then you should not have any search options available in the search menu. Is this a screen shot of live video, or am I confused, and this is the file error that you said that you were getting?

Did you say that you formatted the hard drive with Fat 32?

> Yes. Using FAT32Format utility. only way to format such a large disk for > fat32 in XP.

> please see information below:-

Another few questions that I have:

Is this a computer that is off site, and it is using the internet to watch your video, or is the computer local to where the DVR is located?

> The computer is on my own local network.

How did you bring up this screen that you have given us a screen shot of??

> I can do this from either remote access via the lan pc or with dvr monitor(dvr panal control buttons) access.

> the steps are.

> i) select all recordings

> ii) select any from the list of recordings. one with

> iii) I select, for example, one with (s) beside it coming from the manual recording.

> iv) I hit enter on and the screen shot shown is displayed.

Did you go into a menu, and did you bring up motion search, or some other search request? The reason I ask is this: If you are not recording video due to a hard drive problem then you should not have any search options available in the search menu. Is this a screen shot of live video, or am I confused, and this is the file error that you said that you were getting?

> I get a list when I press search so I guess something is being recorded.

> This is not a live display. It is a playback of a selected item from search.

> Yes, it would appear to me that what is being recorded is corrupt and the consequences include 1) incorrect playback date, 2) no playback shown, 3) can't backup stored recorded files.

I believe i hava the latest firmware 2020...v18.

Hope this information helps.

>the computer is on my own local network<

This rules out any router, firewall (SonicWall), port, and internet issues.

The fact that you do have items listed in the search menu means to me that the machine is at least "talking" and "listening" to the hard drive.

You have said in your post that you bought this DVR online with a 250GB hard drive installed. You have said that this problem has been happening since day one when you received it.

If it worked normally, and then you made a change then I could bring it back up, but since it was like this when you received it, then there is a problem with the DVR itself.

Since you have formatted the Hard Drive with Fat 32 there is a possiblility that the online company will declare a void of warranty. The hard drive is not supposed to be formatted Fat 32, as others in this post have said.

Before you send the DVR back you will need to get that hard drive back to a blank Hard Drive unformatted. I would do a hardware reset also. What the company does not know will not hurt them.

I am sorry that I can not help you further.

Thanks for this information. one last thing - have you any idea how to unformat a disk of size 250 G with XP.?

(Also, the manual that came with the dvr said that the dvr only recognises fat32 formatted hds.)

What page is the Fat 32 info for the hard drive on?

Thanks!

Page 55

APPENDIX #5 – COMPATIBLE USB FLASH DRIVE BRAND

Please upgrade the firmware of the DVR to the latest version to ensure the accuracy of the

following table. If the USB flash drive is not supported by the DVR, the "USB ERROR" message will be shown on the screen.

NOTE: Please use PC to format the USB flash drive as "FAT 32".<<<<

TROUBLESHOOTING Page 48

6.1 FAQ

Please refer to the FAQ table below for easy troubleshooting. The table below

describes some typical problems and also their solutions. Please check them before

calling your DVR dealer.

Error Code in “SYSTEM LOGâ€

4.15 ADVANCE MENU ___EVENT LOG Page 27

You can get all the information (event type, time, and channel) on the event list,

including video loss list, net list and other lists (such as power on / off, key unlock,

reset to default). Select the event list you want to see and press “ENTERâ€

Anyone any idea what format a new disk should be before installing in the 761?

Do not format the hard drive at all.

Just buy a hard drive, and pop it in, and you are good to go!