Using the 8/15 GA build of DVR Server on my Shield I was having an issue with the web player today where any TVE stream I tried to start would show "Transcoder Starting" but would not play. Checking the logs I found that the consistent error message was as follows:
"pipe:: could not find codec parameters"
I tried both the classic and next generation transcoder (option under settings menu) but both had the same result. After this I 'shift' updated to the latest beta build (2019.08.26.0150 as of today) and now the issue appears resolved. Wanted to document this in case others hit the 'pipe' issue. Hoping it remains resolved in the next GA build. Thanks for your efforts as always 