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.