Audio and Video out of Sync on Church WebCast system

I have noticed over the past month that the longer a webcast broadcast goes on, the audio and video always gets out of sync and refreshing the browser causes the audio and video to go back in sync.

• We are getting the same information reported to us in our webcast feedback surveys from individual sites (multiple surveys every week)
• We are able to see the problem ourselves as we monitor the broadcasts
• We see the problem on both Teradek and J-Tech encoders
• We don't see the problem when using the WebCast App on Android TV NVidia Devices
• Our current theory is it is a problem with the Browser Webpage Client for playing meetings

I've submitted the problem to a friend I have that works on the WebCast team, but I'm posting it here to gather more detail to see if other Stake Technology Specialist or Broadcast Specialists have noticed the same thing in their local units? If so, are there any more details you can provide from your own observations of the problem?

Thanks!

I have seen the same thing, except that if I stay on the browser page receiving the webcast, the problem is not apparent unless the meeting lasts longer than an hour, and usually not even then.

If I switch from the receiving browser page to do something else on my computer, the problem noticeably appears. The longer I am away from the streaming tab of the browser, the worse it gets, and it becomes obnoxious quickly. This happens whether I am viewing a different browser tab, a browser tab in another instance of the browser, or if I am doing something else on my computer while the webcast is running in the background (like checking on other concurrent webcasts, monitoring the servers, working on a LibreOffice word processing or spreadsheet file, taking meeting notes in a text file, etc.).

The audio is always delayed after the video, never the other way around.

The same solution works for me. Reloading the page syncs the video and audio again.

I suspect that it has something to do with the way my browser and my computer process the video and audio signals. I suspect that part of the problem is that the servers provide a video signal separate from the audio signal that starts in sync, but that there is nothing further from the server to keep them in sync if the receiving system does not process both video and audio in a timely manner. I believe my browser/computer is introducing a delay in the audio in some of the circumstances described above.

Whether it is the lack of a synchronizing signal from the server, or an issue with the codec specifications, or a computer/browser issue, I do not know. Occasionally (but very rarely) I see it on other streaming services besides the servers the Church uses.

That will be 2 cents, please. [grin]

Thank goodness it is not just me. But I would like to resolve the issue. Are there setting on the J-Tech encoders that would help the sync issue, like encode the audio at a lower bit rate?

Bill Gage
Neah-Kah-Nie Branch
Rockaway, OR

hicksticks2001 wrote:I have noticed over the past month that the longer a webcast broadcast goes on, the audio and video always gets out of sync and refreshing the browser causes the audio and video to go back in sync.

• We are getting the same information reported to us in our webcast feedback surveys from individual sites (multiple surveys every week)
• We are able to see the problem ourselves as we monitor the broadcasts
• We see the problem on both Teradek and J-Tech encoders
• We don't see the problem when using the WebCast App on Android TV NVidia Devices
• Our current theory is it is a problem with the Browser Webpage Client for playing meetings

I've submitted the problem to a friend I have that works on the WebCast team, but I'm posting it here to gather more detail to see if other Stake Technology Specialist or Broadcast Specialists have noticed the same thing in their local units? If so, are there any more details you can provide from your own observations of the problem?

Thanks!

@hicksticks2001: Any update from your friend?

I have many reports in my stake of this issue too. There will be push to go back to Youtube because it doesn't have this sync issue. Yes, a refresh can fix it, but from a user's perspective it bites to have to refresh mid meeting. Youtube simply doesn't have that issue.

garnsb wrote:@hicksticks2001: Any update from your friend?
I have many reports in my stake of this issue too.

The problem was bad for me today on one of the four meetings I monitored, and I could not fix it even with a refresh. Oddly, the other three meetings were just fine.

After a lot more research, the issue seems to be with the embedded player. We're able to play the chunks without any sync issue and we can play the m3u8 in VLC without any sync issue either. Playing via the embedded bitmovin player, the stream goes out of sync within a minute. After a whole sacrament meeting, the sync is waaay off (10-15 seconds). We can make this happen everytime on more than one device, on different internet connections. Anyone know if a change was recently made to the player that would cause this? I had seen it before, but a refresh would resolve it. The last two weeks, after multiple refreshes, the stream still goes out of sync within a minute. It is so bad that I have people calling and emailing from several different wards about how distracting it is...hoping it can be addressed.

What server are you using? Perhaps try a different server?

I've been using US West 2 with no complaints.

Keep in mind the test for server should be run from the chapel. I'd pick one that has consistently good results during the test - not a "come from way behind" winner.

Ok...after a ton of testing, I've solved the sync issues found when using the J-Tech Encoders! (This doesn't address any issues with Teradek encoders, but then I've never personally seen a sync issue with the Teradeks.) The sync issues mostly affected Chromium-based browsers, but it has been observed from time to time on Safari as well. Additionally, with the new static encode URL from the Church, we can all remove a bit of load from the Church's systems by reverting back to the stock firmware (No offense bretep! Your firmware rocked while we needed it!) as we no longer need the auto configuration. Without the auto configuration in bretep's modified firmware, the encoder will still boot quickly, and try about every minute to connect to the "Enabled" URL (as defined below). Once it connects, it streams beautifully! I used this configuration for two 1-hour tests and five Sacrament Meetings yesterday...and it never went out of sync! Here's the steps I recommend taking asap:

1. Download the latest firmware from J-Tech: https://jtechdigital.com/product/jtech-ench4-0220/ (Scroll down and click on "Firmware Upgrade")
   • Extract the zip file and you'll have an up.rar file.
   • If you'd like a custom splash screen when the encoder first begins to stream or when the HDMI is disconnected, follow their link for "Tech Digital JTECH-ENCH4 (JTD-220) H.264 Encoder - How to change the "No Signal" image": https://jtechdigital.com/?p=126976
   • Alternatively, if you'd like their V2.89 firmware with the blue church logo, you can download the up.rar file attached to this post. (I followed their instructions above.)
2. Login to the J-Tech Encoder and upload the firmware:
   1. On the left side, click on "System", then "Upgrade".
   2. Click "Choose file" and find the up.rar file you downloaded to your computer.
   3. Click "Upload", and wait until the status bar shows it has completed the upload.
3. Reboot the encoder:
   • On the left side, under the "System" section, click "Reboot" and then click the "Reboot" button.
4. Configure for the new static URL:
   1. On the left side, click "Encoder", then "Main stream"
   2. Set the following settings:
      • Encoding type: H.264
      • FPS: 30
      • GOP: 15 <-- this will make the encoder create 2 keyframes per second which helps with the audio/video sync
      • Bitrate(kbit): your desired bitrate -- 1536 (1.5Mbps) or 2048 (2Mbps) is sufficient for 1280x720 video
      • Encoded Size: 1280x720 -- if you're using the tiny RCA spycam suggested by bretep in other posts
      • H.264 Level: high profile
      • Bitrate control: vbr
      • Disable all URLs and "Multicast IP" except for "RTMP/RTMPS/RTSP PUSH URL".
      • Login to webcast.churchofjesuschrist.org and get the "Encoder URL" for your specific encoder. Paste it in the box for "RTMP/RTMPS/RTSP PUSH URL" and set it to "Enable"
   3. Click "Apply"
5. Configure Audio Settings:
   1. On the left side, click "Encoder", then click "Audio"
   2. Set the following settings:
      • Audio Input: HDMI
      • Sampling rate: 48000 <-- this will also be paramount to keep the video and audio in sync. The default from J-Tech is 44100.
      • Encoder: AAC
      • Audio Channel: If you are only supplying mono to the encoder, set this to match where you're inserting it into the HDMI (L or R) and the encoder will make it stereo. If you are using a mono splitter to feed both L & R into the HDMI, then select "L+R".
      • Bitrate: 96000 - 128000 should be sufficient
      • Digital Volume: 0 is probably sufficient for most cases, but if viewers are having to turn up the volume a lot to hear the webcast, then this number can be increased to help boost the volume in the stream. For example, in a non-Stake Center with a QSC amplifier, I use 30. In the Stake Center with an old Ivie, I use 10. (Good idea to set a value and test with a test event.)
      • G711A Over PTE: Enabled
   3. Click "Apply"
6. Reboot the encoder:
   • On the left side, click "System", then click "Reboot", then click the "Reboot" button.