video stuttering once tuner (HDHR) configured with no transcoding

Mike Gideons

Here's my HW/SW configuration:
- RPi2
- running 2015.06-1 OSMC
- TVheadend with the hdhomerun packages/libraries/DVB wrappers (i can get version info if neccessary, but it was all installed within the last 2 months)
- Kodi PVR addon frontend
- both MPEG2 and VC-1 licenses
- ASUS RT-N16 router with latest firmware
- HDHR EXTEND (HDTC-2US) ATSC tuner with latest firmware
- everything connected together with CAT6 ethernet cable

- all other network loads are idle or VERY low activity

Problem:

Thanks to the guys on the OSMC forum, i was able to get TVheadend up and running, but was having issues with HORRIBLE resolution. A few times, i would get a field or matrix of colored cubes rotating while hearing the audio from the HDHR feed (i think this is a Pi hardware graphics image that is displayed when something goes bad, but, let's move past this....). After some digging, turns out that TVheadend doesn't force the transcode mode of these tuners. So, i manually configured it to 'none', so the video stream was untouched as decoded from the broadcaster. From that point on, i have experienced stuttering and complete stream dropout with very periodic disconnect of the PVR front end to TVheadend (some message about HTS this or that). I've rescaned the muxes and this didn't help.

Other info:

I've since loaded the Kodi addon from Silicondust. It's a frontend of sorts with no PVR capability. The video feed is beautiful and stutter free. So, it's not an issue with my hardware or my network capability/bandwidth. Silicondust is comming out with a PVR server, but it's not here yet. Furthermore, both the frontend and the PVR backend "may" not be open, so maintenance and future enhancements may be slow in coming or not at all (the guys at Silicondust weren't sure of the status of the openess for linux based code... Windows and Mac based code are out due to licensing issues).

Any ideas? Any sort of log file that i can generate and share?

Saen Acro

Why using transcoding when watching locally?
pi pi2 pi3 haven't potential to transcode to something else then low resolution phone

Mike Gideons

To start, the transcoding in and of itself is not my issue. My issue is with stuttering of the stream when using TVheadend as the backend and the Kodi PVR Addon as the frontend. Since i have used the EXACT same hardware successfully with the HDHomeRun Live TV Addon, i know it is isolated to TVheadendOR** Kodi PVR Addon.

Addressing the previous reply... yes, as in my previous post, TVheadend was not changing the transcode mode of the tuner, so... i had to do it manually, and as previously stated, i set it to 'none', meaning no transcoding ;) Also, it wouldn't be the pi that is transcoding, it would be the tuner, which was built to transcode.

The first attempt was with the tuner transcode mode set to 'Internet240' which spits out a highly compressed stream. It might be an MPEG2 stream (don't recall), but it is highly compressed and the resolution looked like crap. I'm not sure when or how it got set to that mode, but TVheadend was not (and would not) change it (confirmed in another post). Setting the tuner transcode mode to 'none' passes the raw stream from the broadcaster. Most broadcasters use MPEG2, but a few might use other compression schemes. The rpi2/OSMC can handle many different compression formats, so if a broadcaster uses something other than MPEG2, the rpi2/OSMC will probably play it with no problem since it has the codecs built in (no transcoding in that case as well).

Now, if i'm playing the stream on a roku, i MUST transcode to garauntee that whatever comes to the roku is in H.264 format as the roku will not play any other format. In that case, the 'Heavy' or 'Mobile' tuner transcode mode should transcode to H.264 (unless the broadcaster is transmitting an H.264 format, which means that there would be no transcoding occurring, even though the tuner transcode mode is set to something other than 'none').

Hope this helps clarify the issue.

Saen Acro

I'm not sure what "tuner to transcode" are you talking about
attach some pictures or video of setup
see debug log of tvheadend and htop during transcode