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Choppy playback

I purchased a BrightSign LS445 recently for a single channel video art installation. My 6-minute video file was formatted based on the supported codecs: 1920 x 1080 pixels, 30fps, H.265/HEVC, mp4, CBR with a target bitrate of 25mbps. Stereo audio, AAC, 256kbps. I used a class 10 micro SD card. The screen that displays the video is in a unique square format at 1920 x 1920 pixels and is connected with the BrightSign player via a Display port to HDMI cable. The playback was fine for the first few minutes. However, the video became really choppy when it started to loop the second time and continued for about one minute. This kind of choppy playback occurs every time when I turn the screen back on (audio had no problem). Does anyone know a solution to fix this? Many thanks in advance. 

9 comments

  • 0
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    Monica Knutson

    1) Are you using BrightAuthor to publish a presentation or just putting the video on the card and letting the player sort it out?  I'd recommend using BrightAuthor if you're not already doing that.

    2) Are you able to output and test at a lower bitrate to see if it's the compression?  Drop it down to 18mpbs and go up from there to find the right recipe for the video/player/screen combo.

    3) Does it do the same choppiness if you output at the HD codec H.264/AVC?  

    4) One other thing to check is on your output settings for the profiles.  Sometimes when we output from Media Encoder (any Adobe product really) it adjusts the profile.  Make sure you're using this:

    • Bit Depth: 8 and 10 bit 
    • Profile: Main and Main10
    • Level: 5.1 and below

    5) Confirm that your HDMI to DisplayPort cable is bidirectional or specific to HDMI -> DisplayPort direction.  Some are only made for DisplayPort - > HDMI and are unidirectional.

    6) What's the rating on your cable?  HDMI 1.4 or HDMI 2.0+?  That makes a difference.  We have had cable failures because someone was using an HDMI 1.4 cable on a 4K system.

    7) You are already using a good class card so no issues there.  What was the format of your card?  FAT32 or exFAT?  We use exFAT to handle larger video files because of the limits of FAT32.

    That's all I can think of right now.  :o)  Keep us posted!

    Cheers,
    Monica Knutson, UXC
    Digital Design Services Inc.

  • 0
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    Yuge Zhou

    Thanks so much for the detailed feedback. I really appreciate it. So I updated the video file today based on some of your suggestions, but after about an hour of smooth playback, it became choppy again, the choppiness lasted for about 30 seconds and then back to normal...please see below: 

    1) I published the presentation via BrightAuthor:connected with the up-to-date firmware

    2) I dropped the bitrate down to 18mpbs 

    3) Yes, it does the same choppiness when using H.264 codec 

    4) Made sure the bit depth, profile and level are set correctly

    5) I can't tell if my cable is 1.4 or 2.0+, it seems to work fine but I'm going to order a new one and try again just in case

    6) The card is formatted as exFAT

    I have to ship this work out to the venue next week so at this point, I'm contemplating using a Mac mini instead. If you have any other suggestions, please let me know. I spent so much time trying to make the BrightSign player work this past week, it'd be such a waste if I had to return it...

    Thank you. - Yuge

     

     

  • 0
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    Monica Knutson

    Hello Yuge,

    Thanks for the updates.  I have a few more questions and suggestions for you, so don't give up yet on the BrightSign.  

    1) You mentioned your screen size is 1920x1920.  What is your Presentation resolution?

    2) The 1920x1920 presentation size actually scales the zones to 960x960.  See attached image.  Could you upload a screenshot of what your zone layout is and resolution please?  The video playback in my example to remain 16:9 is actually sized to 960x540.  Perhaps the decoding of the resolution gets stuck  For a test, maybe output it at 960x540 and see if it still chatters.

    3) Having a six minute video on loop will undoubtedly lead to card fatigue.  Try outputting the video as a series of the video on your editing software's timeline and output that.  For example... [ ][ ][ ][ ][ ] = five iterations in the single video would lead to a 6min x 5 = 30 minute video.  This will lessen card fatigue because you're not accessing the same databits over and over and over again.

    4) The cable could be critical, especially if it's not an HDMI to DisplayPort directional cable (versus DisplayPort to HDMI).

    Cheers,
    Monica

  • 0
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    Yuge Zhou

    Hello Monica, many thanks again for these suggestions. I really appreciate your expertise. To answers your questions: 

    1) My presentation resolution is 1920 x 1080. I'm using a EIZO FlexScan square monitor, it takes the HD video and transform it into a square video that fills up the screen automatically. See below the screenshot of my zone layout and resolution. 

    2) Thank you for pointing out the card fatigue issue, I didn't know that will test a 30 minute version today. But even if the video is longer, won't the card still get fatigued overtime? Except it may take a few hours rather than a few minute for it to happen? The installation will be playing non-stop for at least seven hours per day, we want to make sure the playback is smooth the whole time. 

    3) I tested the cable on a Micca media player connected to the same monitor, using the same HD video, and the playback was fine. So I don't think the cable is the culprit. Another thing I did yesterday is that I tried to use a USB-C to display port cable to output the video from BrightSign to the monitor, but nothing showed up except that I could hear the audio.

    4) Speaking about audio, do you think if I make the video silent, it will help or fix the issue with the playback? 

    - Yuge 

     
  • 0
    Avatar
    Monica Knutson

    1) + 3) Interesting.  So the Micca output doesn't get choppy but the BrightSign output does get choppy?  Definitely sounds like the issue is stemming from the BrightSign player then.  Does the monitor scale to fill the height at 1920 or does it enlarge and crop the sides?  What happens if you make a 1920x1920 presentation size and choose the "Scale to Fill" option for the video mode.  That way the BrightSign is doing the upscale and not the monitor.  

    2) Card fatigue usually takes awhile to happen.  We've seen some fatigue quicker than others, depending on the brand of microSD card.  We have standardized using SanDIsk Industrial cards (they're white) with great reliability.

    3) The USB-C on the LS445 doesn't output video.

    4) You can test this for sure.  I don't think audio would affect video playback, but stranger things have happened!

    Cheers,
    Monica

  • 0
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    Yuge Zhou

    Monica, so I did more research today and saw some notes about streaming buffer on the BrightSign support site...Even though I’m not streaming (I’m playing the video directly from the player without wifi connection), do you think the choppiness could be a latency issue? I'm asking because most times the choppiness occurs when the video loops the second time (right after the initial playback after the monitor's turned on) and the video stays choppy for about a minute before it smooths out. If it's a latency issue, might it help to increase the size of the buffer of the BrightSign player? If so, how would I do it on the BrightSign software? I also noticed that BrightSign has specific sizes for latency and jitter, do you know what these mean and could changing these values remedy the choppiness of my video?

    1) I found it odd too that the Micca output was fine, but the venue and I decided to not use it due to concerns of longevity of Micca player. The monitor scales to fill the height at 1920. I did try a 1920 x 1920 presentation, and a 4K presentation, but the image would get cropped. So far I think the monitor only works well with 1920 x 1080 signals. 

    2) The card I'm using is from SanDisk but not the industrial one. I didn't get a chance to test the 30 minute version of video today, I plan to do that tomorrow as well as test a silent version, will let you know if any of these works. 

    Thank you - Yuge

     

  • 0
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    Doug

    I am having similar issues with my LS445. Im going to try some different compression, different chip, etc. Will update with finding. I am also noticing that when I click from my still menu to a video i get a little flash of black at the start of the video.

     

    Thanks, Doug

  • 1
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    Yuge Zhou

    Hi Doug, 

    I'm not sure if you've resolved the issue. I just wanted to give you an update in case it's helpful to you. A friend of mine who's a time-based media conservator investigated my installation. So turned out that the LS445 and my Eizo monitor have different refresh rates, hence the occasionally choppy playback. My friended recommended me to use a media player that art museums have been implementing called LattePanda 3 Delta and she helped me set it up. The issue was resolved after we replaced the player. After this experience, I personally think LattePanda is a much more versatile player, however it needs someone with a bit of programming/coding knowledge to set up.  Hope this helps and good luck with your install! - Yuge

  • 0
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    Doug

    Yuge -

    Thank You for sharing your information. My problem resolved when I compressed all my video files at their native frame rate. My framerates were 24fps and 60 fps, I had exported and compressed all the files at the 30 fps rate. After creating a 24fps and a 60fps group the videos played back inside the project they played smoothly and the Brightsign had no trouble jumping back and forth. Doug

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