[mythtv-users] multi-camera TV recordings?

[José Oliver Segura]

On Sun, Jun 21, 2015 at 12:07 AM, Mike Perkins <mikep at randomtraveller.org.uk
> wrote:

> On 20/06/15 22:30, John Pilkington wrote:
>
>> On 17/06/15 13:37, Andre Newman wrote:
>>
>>>
>>> On 16 Jun 2015, at 22:45, José Oliver Segura <primijos at gmail.com> wrote:
>>>
>>>  Hi all,
>>>>
>>>> Does anybody know if it's possible to record and play files with more
>>>> than
>>>> one video stream in them?
>>>>
>>>> I'm trying to figure out how to record and play "multi-camera" shows
>>>> (mainly
>>>> sports/motor events). I receive them via IPTV, each camera has its own
>>>> multicast address and I've done some experiments in order to use avconv
>>>> + the
>>>> external recorder option (through a custom script) available in mythtv
>>>> to
>>>> make all those independent channels look like a single channel with
>>>> multiple
>>>> video streams in it.
>>>>
>>>> The problem is that the final step would be to be able to cycle among
>>>> those
>>>> video streams when playing back the recorded file, but I can't find any
>>>> information about whether tha'ts possible or not in mythtv. I know
>>>> dvd/blueray playback has some sort of multi-angle support, but I can't
>>>> find
>>>> nothing similar regarding recorded TV.
>>>>
>>>
>>> I’ve used VLC for playback of full transport streams, they can have many
>>> channels within the same file. VLC allows you to select which channel to
>>> watch
>>> by name, even decodes subtitles and multiple audio streams. I’ve never
>>> found a
>>> way to do this with the same file in MythTV.
>>>
>>> I do have some multi angle DVDs, I just tried one from an iso file and
>>> there’s
>>> an angle menu which allows selection of the four video angles, maybe you
>>> could
>>> mux together the video streams in the same way a multi angle dvd does?
>>> Maybe
>>> ffmpeg can be persuaded to do this?
>>>
>>> I just tried a transport stream with several video channels in it and
>>> MythTV
>>> just plays the first one and there’s no select video stream menu like the
>>> select audio one.
>>>
>>> Andre
>>>
>>>
>>>
>>>> Any hint?
>>>>
>>>> Best,
>>>> Jose
>>>>
>>>
>> I thought this query rang a bell but I didn't at the time find out
>> where.  Just
>> came across an option in master in
>>
>> Backend setup > Recording Profiles > Hardware DVB Encoders > Default >
>> Normal >
>> Record Full .ts
>>
>> "If set, extra files will be created for each recording with the name of
>> the
>> recording followed by .ts.raw.  These extra files represent the full
>> contents of
>> the transport stream used to generate the recording.
>> (For debugging purposes.)"
>>
>> I haven't tried this and I can't say how it might fit into the OP's
>> scenario. I
>> suppose one could set up a non-default profile and a new recording rule.
>>
>> It sounds as if this could provide a way of bypassing the fairly
>> arbitrary limit
>> on the number of virtual tuners per physical DVB tuner, but without the
>> scheduling and metadata facilities, and at the cost of extra
>> post-processing.
>>
>>  Well, the obvious next step to me is to use that .ts to drive a "video
> wall". It seems to me that dividing the screen up into 4, 9 or 16 and using
> a similar method to picture-in-picture could accomplish this.


I'm not sure this is so trivial. We're talking about 6-9 HD streams. I
mean: I don't know if there's enough horse power in most of the hardware
setups used as mythtv frontends to do that in realtime. In fact, I'm almost
sure that would be too much also for the IPTV original decoder (the one
that you get installed when subscribing to the service), so my guess is
that the PIP or videowall setup must be done with some IPTV stream that
gets generated by the broadcaster company, I mean: it has to be a specific
"channel" and the decoder gets information about which "camera channel" is
shown in each area of the videowall channel in order to highlight it and
zap to it when user presses the "OK" button.

I've not checked this, that's one of the next steps...

Best,
Jose
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