multiple tuner support

[fuzzard]

How:
CheckTunerAvailable() does a simple CURLOpen, and will fail if a http status code
of >= 400 is returned when connecting. HDHomerun returns a 503 status code when no tuners available. This will then allow _GetChannelStreamURL() to iterate through other tuners to return another url from a different tuner.

Dev Details:
We are not able to find the exact status code to check for a 503 using kodi's CURLOpen provided to addons, as if anything >= 400 is detected, the call fails, and the new GetFilePropertyValue() isnt able to be run with this state. Ive gone down the route of using curl/curl.h to manage status in another branch (https://github.com/fuzzard/pvr.hdhomerun/tree/openlivestream), but build issues for appveyor (building curl on win automatically, without building for all platforms (linux/mac os not needing generally) have been stumping me for a couple of days, and im going to leave that as is for now. I hate cmake, but i digress.

Issues: Using the current codebase, the most glaring issue with this is that between the time of the CheckTunerAvailable method call and the return to GetChannelStreamProperties(), there is potential for change of status (tuner no longer available, failed tuner now available). For now, i think its a viable option for users with multiple tuners.

Discussion:
To implement this in the best case scenario that i can see, we would need to return to implementing our own Open/Read/CloseLivestream functions, and use the libhdhomerun hdhomerun_device_tuner_lockkey_request and release to handle our own locking. I've been fiddling with a branch that goes down this path, but havent fleshed it all out yet.
Interested in comments about traveling down this path to support multiple tuners better. My own personal thoughts are that it would be interesting from my dev point of view, but i dont have multiple tuners, so the testing would be tricky, and i dont know of any users who would be willing to guinea pig for me.
Is a close enough is good enough approach (This PR) good enough for most users, and therefore everything else is pointless?

[fuzzard]

Had another look at the logic of this, and its not going to work as intended. Ill close this and re-evaluate. Was attempting to do it with as little code change as possible to other areas, but i think its going to require a larger core change to the logic to accomodate multiple tuners with the same channel lineups.

[fuzzard]

Found some time to look at this briefly. I think the logic works this time.

It checks for the uniqueId on the channel as a primary search, but if that doesnt work, it will continue looking for a match of the channel, subchannel, channelname all matching the PVR_CHANNEL object.

This should mean it will find the first tuner that tests as available regardless of whether its the specified uniqueId it was searching for. May have to create an option to have a preference for a specific tuner/tuners and/or ability to blacklist tuners.

[fuzzard]

New commit to make hide duplicate channel setting work.

[fuzzard]

Thanks for the comment Matthew. I had wondered why you implemented a blacklist setting.
In conjunction with the earlier commits in this PR, its more of a blanket try any tuner thats discovered and available. The _Getchannelstreamurl() will try the first found tuner that will usually have the corresponding uniquechannelid, and if its full as found by the CheckTunerAvailable() call, it will try for any other tuner that has a lineup with the same channelnumber, subchannel and channelname disregarding the uniquechannelid from the callchain by kodi.

This is all theoretical because i dont have multiple boxes to test with to actually see if it works as im expecting it to. In the long run, i think additional settings as you have done (preffered, and now i understand why the blacklist) would be desired, but this approach gets the basics up and running.

[fuzzard]

Just a reminder for myself.

xbmc/xbmc#14114

peak3d has now made it possible to retrieve the status code >400. Should be able to drop the checktuneravailable function, set the "failonerror" protocol option (CURLAddOption(filehandle, ADDON_CURL_OPTION_PROTOCOL, "failonerror", "false")) and then retrieve using .GetFilePropertyValue(filehandle, FILE_PROPERTY_RESPONSE_PROTOCOL, "")

This would remove the downside to this solution, without the requirement to implement locking using libhdhomerun.

[fuzzard]

I've acquired a second hdhomerun device so ive now been able to test multiple tuner devices. I've updated the commit to now handle acquiring a channel from any available tuner.

Any chance of a review on this @Rechi @ksooo . I know you will both be busy, but i believe it would be a nice addition to the addon that i can now confirm first hand functions as expected.

[ksooo]

addon version bump in addon.xml.in is missing

[fuzzard]

Fixed, sorry about that.

[ksooo]

lgtm, code-wise. Cannot say anything about functionality, though.