Playback audio desynchronization
Completed
Hi there!
Repeated request regarding audio desynchronization.
The audio codecs supported by Nx are 711, AAC and MP2L2. In some cameras, the 711 codec has a low sampling rate, so the codec MP2L2 is almost always used to obtain high-quality audio. Now the crux of the matter. We have two cameras: one is physically connected to the audio (with wires), and the second is linked programmatically. When archive viewing, events in both cameras occur synchronously, but in the second camera (after a few minutes of viewing) the audio is delayed by a 1second and more (camera synchronization is always on - does not help). I described this defect more than six months ago. But the question remained unanswered. Please pay attention to this repeated request: the problem was repeated in a casino with 500 Nx licenses, and this is serious.
BR.
V.
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Follow-up clarification. After a minute or more of viewing the archive, a lag not only in audio, but also in video begins to accumulate. Synchronization is enabled, and it is ineffective; turning it off and on does not change the situation. Closing the client completely and then opening it resolves the problem, but as viewing time increases, the effect repeats
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Hi Victor Kravchuk,
I tried to reproduce the issue, but failed:
I tarted to play back a midnight at a random date (June 1st), and made the second screenshot one hour later.
The top camera has no audio, and the bottom two-way audio (AAC).
As you can see, not even a second difference between both devices after the hour.
The mentioned codec, MP2L2, isn't listed as a formally supported codecs. It seems like a proprietary codec used by Hikvison. Could you change it to one of the supported codecs, as listed HERE, to confirm if this resolves the issue?0 -
Hi, Norman! Thank you for your quick feedback and payed attention. :) What cameras did you use (we use Hikvision 4 and 8 Mp cameras with a stream up to 12 MBps)? Did you added to the top camera the sound from the sounded camera programmatically? I mean, did you exactly reproduce the situation I have described - problem was on the camera with a programmatically added sound? I will try to change an audio codec to AAC and check if the issue will disappear. But, PCM and Mp3 codecs from Hikvision are not supported in Nx.
BR
V.
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Hi Victor Kravchuk,
I used a 4 MP Dahua device as the source audio, and added this audio to an HD Axis device.
Now you mention the Hikvision camera with 12 Mbps, I recall we discussed this before, however I can't find the conversation. Could you share a link to the community topic or support ticket number?0 -
Hi, Norman! I cannot find it too. Earlier (maybe two or more years ago) it was a problem between Avigilon and Hikvision cameras (sound from Hik was added to Avigilon) - there were the same lags: video and sound on Avigilon appeared on the scereen 1-3 seconds later. Then the same situation was in another casino in Batumi. As for 12 Mbps - such streams are used in current conditions. In what area the mismatch (delay) occurs - during the preparation of content by the server, during the transmission of content by the network, or during unpacking and display on the screen on a workstation - we need to find out. At the same time, software-attached audio may also lag behind the video.
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Hi Victor,
Are you using Nx Witness 5.1.3 or 5.1.4?
Currently, you are seeing the issue with 2 Hikvision devices, right?
I'll try to see if I can connect to a 12 Mbps stream somewhere with and without audio.
What video codec do you use?0 -
Yes, all CCTV system in their casino is built on Hikvision cameras with from 4 till 8 Mp resolution. Guys are using the latest Nx version - 5.1.4.38659. In my casino (for test) I have checked this issue on 6.0.0.38488 version, with Pelco cameras (IME329 and D6230 models, about 8 Mbps from each camera) - the same result: the delay between the same clients' moves in cameras is about a second or a bit more (but for test I used only 2 cameras). For now - H264 for video, and MP2L2 for sound, but I have asked guys to change it to AAC.
But in my case, the server and client are installed on my workstation (version 6.0, for test), so the influence of the network is completely eliminated - all that remains is the process of preparing content by the server and the process of unpacking and displaying it on the screen by the workstation.
for reference: the same cameras in another software work without delay between cameras. Seems, this suggests that the reason is either content preparation or unpacking
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Hi Victor Kravchuk,
I grabbed some Hikvision devices I got and tried to reproduce it, but again, without the desired result. No lag in my system.
And one hour later:
Unfortunately, I don't have access to devices that produce such high bandwidth by itself.
Could you either forward the devices so we can add it to our test environment or for an initial check, add nx.verify@gmail.com as an administrator user to your workstation system?
In case of forwarding, I'll transfer this topic into a support ticket to enable you to share the credentials privately.0 -
Unfortunately, the casino cannot provide access to its cameras. What threads were used in the experiment? In our case, a lag in the movement of the same object (a person, a player’s hand or a dealer’s hand) in different cameras occurs only when using software-attached audio and with streams of at least 8 Mbit. And it is precisely these conditions that need to be reproduced: look and listen to one of the cameras, while the second lags behind. In any case, thanks for the response.
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Hi Victor Kravchuk,
I thought you had the cameras in an isolated environment, and hoped therefore access was possible.
Can you offer the following:
- Start the client through the command line with the --show-full-info parameter, as explained HERE.
- Enable VERBOSE logs on the client and server, as explained HERE, and set the logs to 1 GB and 100 MB each.
- Start a screen recording (if you use the in-client recorder, assure the native resolution is set in the local client settings)
- Open the affected cameras in the layout, select 'i' so the resolution and Mbps show.
- Reproduce the issue
- Close the devices in the layout once the issue was reproduced.
- Download the VERBOSE logs for the client and server
- Default the log settings
- Stop the screen recording
- Share the logs and the screen recording for further analysis (I'll open a ticket on your behalf once you're ready).
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I will send you an E-mail address of their system administrator - he promised to give you an access to their cameras. Connect with him, pls.
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Hi Victor Kravchuk,
I created a support ticket on his behalf, and have put you in CC.
I'll close this topic, and let's continue the conversation in the ticket.0 -
ok, thank you, Norman!
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