[mythtv] [mythtv-commits] mythtv commit: r11390 by danielk

[Michael T. Dean]

On 10/03/06 08:38, Daniel Kristjansson wrote:

>On Mon, 2006-10-02 at 22:43 -0400, Michael T. Dean wrote:
>  
>
>>On 10/02/06 19:28, mythtv at cvs.mythtv.org wrote:
>>Daniel, I'm still willing to make a patch for finetuning the frequency 
>>of the digital channels, but I need some input, first.  IRC and standard 
>>cable both allocate 6MHz for each channel while HRC uses 6.0003MHz.  
>>Using this frequency increment, all the appropriate frequencies can be 
>>computed using the already-in-place structure you've defined.
>>
>>So, to modify the HRC frequencies, we'll need to modify the FREQ() 
>>define to allow specifying the frequency increment.  For both, we'll 
>>have to break out the aeronautical radiocommunication bands from the 
>>bands they're currently in (this is only channels 42, 98, and 99, so it 
>>would require 2 new FREQ() calls).
>>
>>Any concerns over this approach?
>>    
>>
>Not really. There is another macro used for DVB frequency tables,
>just make sure you don't grab anything from them that might require
>the DVB headers. We support at least two DTV devices that don't
>require us to compile with the DVB headers, but do require this
>table. It seems unlikely that you would do that anyway though...
>

I uploaded a patch to http://svn.mythtv.org/trac/ticket/2087#comment:17 
.  I modified the existing FREQ define--I couldn't find other macros, so 
please let me know if I should have done it differently.

After this patch, the only other "issues" I see are that our standard 
cable frequency tables go up to channel 159, whereas our HRC and IRC 
tables stop at 125.  I included comments with equations showing how to 
calculate the frequency of any EIA-542 channel over 159 (for standard, 
HRC, and IRC), so we could easily modify it as desired.  I would 
recommend making HRC and IRC go up to 159, also, for the digital 
tables.  While it may take longer to perform scans, it would help more 
people find more channels.  Please let me know if you want a patch.

Also, standard cable's high frequency table starts at channel 78 
(~550MHz), while HRC's and IRC's start at channel 76 (~535MHz).  Do we 
want to make these more consistent?

Finally, we haven't yet made a two frequency tables for standard cable 
(one with a positive offset and one with a negative offset for 
aeronatical radiocommunications/radionavigation bands).  I didn't get 
any useful responses when I asked for information from people who are 
using standard cable and had to specify finetune values, so either a) no 
one is seeing issues because of this or b) no one wanted to help.

The dbcheck patches for updating finetune values will take a bit 
longer--after your commit [11415], I found out that using LEFT JOIN on 
an UPDATE or a DELETE is only valid in MySQL 4.x, so I have to do it the 
hard way.

Mike