[mythtv-users] Right then....how to tell recording to start xxx minutes in rather then at beginning?

[Mike Perkins]

On 03/08/16 22:32, John Pilkington wrote:
> On 03/08/16 20:09, Another Sillyname wrote:
>> The BBC are now showing the Olympics in a glorious 8 channel Red
>> Button festival....I won't sleep for a month!!!!
>>
>> However I'll explain for non UK based users.
>>
>> The BBC Red Button service in effect turns digital channels on and off
>> as required so if a certain Olympics event is due to start at say
>> 14:00 the programming will start at say 13:45 and the channel will go
>> live literally maybe a minute before the programming starts.
>>
>> In SD this hasn't usually created a problem.
>>
>> However in HD when you try to playback the recording has started
>> early.....the HD decoder tries to play the file and borks (as the
>> channel probably hasn't 'turned on' when the recording started), if
>> you play the file with VLC it's fine...so it's there.
>>
>> I suspect that myth is looking for video info at the start of playback
>> to decide what decode mode it needs to go into and when there isn't
>> any it segfaults.
>>
>> So how can I tell myth to start playback say 4 minutes into a recording?
>>
>> I can't change the recording rules...there's far far to many
>> recordings to want to mess around with (unless I can setup a rule such
>> as "If this recording is on 'BBC RB HD' then start recording 5 minutes
>> later then normal).
>>
>> Thanks
>
> I'm not sure I recognise the problem - but I normally use SD DVB-T, on which the RB services appear
> as normal EIT-schedulable channels 600 (RB 0) and 601 (RB 1), usually at 544x576 resolution.
> There's also 200 (Red Button), for which I don't see EIT data.  All these are in the BBC SD mux.
>
> I don't see RB channels listed in the DVB-T2 HD mux.  mythffprobe on BBC One HD currently shows two
> dsmcc_b data streams with unsupported codecs, using current *buntu ppa/trusty
>
> ...but no doubt things are different via HD DVB-S
>
The problem isn't that the channels are non-scheduleable but that because they come and go there 
often isn't even a carrier until just before the program begins.

This is doubtless difficult for a tuner to cope with. We have this with BBC 4 which starts at 19:00 
each evening (though doubtless it will be 24/7 during the Olympics). Because the channel isn't 
transmitting until just before startup time, it is difficult to record the first program of the 
evening without taking precautions.

-- 

Mike Perkins