Black/Missing Preview Frames when Fast Forwarding

I’ve noticed lately that when we try to fast forward in a recording (like skipping commercials), that sometimes the preview images that typically show up in the frames are gone. We have to stop fast forwarding at that point because we can’t predict when to stop otherwise. Anyone else see this? Most of the time we are fast forwarding at the slowest speed, or the next speed up from that.


Yes, it’s been reported, and confirmed by Tablo Support.
They say it’s an issue with Roku OS v8 memory.
The blank preview thumbnails are actually there, but don’t display sometimes.
If you exit out of the recording playback, and resume from the same point in time, you’ll see the blank preview thumbnails properly populated.

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I have gotten in the habit of counting to 7 while I am forwarding thru a commecial and that gets me close.

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Tablo: It has been a year since the black preview frames srarted on my Roku, and it’s still going on. Will this be corrected in the next revision of the Roku app? It’s getting annoying.

This issue has been going on so long it predates the Amazon Cube fix. And seems to have gotten worse after the Cube fix.

But consider yourself lucky. I have multiple units and no matter which unit or channel or time of day approximately 15%-20% of the recordings don’t generate thumbnails. But they recording do play perfectly.

Yep, I got them on my Roku. Usually not so many that I can’t fast fwd into one that is showing so I can tell where I am. It will be nice once the commercial skip is implemented, then no worries about frames.

Your hope is that the thumbnail generation totally completed with no errors since commercial skip appears to use the thumbnails to remove commercials.

The root issue that we first saw around this was a lack of memory on the Roku. We have optimized as much as possible for that so unless the frames come back after rebooting the Roku and trying that same recording again, it’s likely that the missing frames are due to errors in the broadcast stream.

FFWD preview frames are created by re-processing completed recordings and taking periodic snapshots of the video. If the video is corrupted several frames in a row, you will see black frames.

This can even happen on video that seems to play back fine as the blips can be so short that they aren’t noticed by the naked eye, but it just so happens that the ‘snapshot’ was taken at that time.

That would also explain why Zippy is seeing this…

Although a good guess, this is not true:

Recordings that fail FFWD preview creation aren’t passed to the commercial skip server for processing because we anticipate they’ll be too corrupted to have successful skips.

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Holy cow. You mean my 3 month old 4660 ultra is out memory. Or the fact the blank are seen a 2x and 3x FF but not 1x. Or if you rewind and FF again they appear.

I’ve recently seen the lack of thumbnails on both OG and dual 64 using internal disk on hi-vhf and uhf NBC, ABC, Fox, 9AM, 12 noon, 4PM.

But the reality is since tablo’s commercial is an all or nothing feature, it’s of no use to me. I prefer to use plexs remove commercials from selected recordings feature.

Plex has an automatic commercial removal feature now? Interesting - did not know that.

It uses comskip and also allows bitheads to edit the comskip.ini file.

You have 4 combinations of configuration 1) DVR level on 2) DVR level on specific recordings off 3) DVR level off 4) DVR level off specific recordings on

We’ll see how it works out. My wife turned on the shield and moved some of her recordings over to plex,

So would adding a micro SD card to a Roku help with the black frame issue? Or does Tablo only use internal memory?

Of the seven current Roku player models only the ulta (4660) has a sd card slot.