Re: [PATCH 1/5] tm6000: add mts parameter

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Em 20-04-2011 12:27, Stefan Ringel escreveu:
> Am 20.04.2011 17:17, schrieb Mauro Carvalho Chehab:
>> Em 20-04-2011 11:19, Stefan Ringel escreveu:
>>> Am 20.04.2011 14:37, schrieb Mauro Carvalho Chehab:
>>>> Em 20-04-2011 05:14, Stefan Ringel escreveu:
>>>>> Am 19.04.2011 23:21, schrieb Mauro Carvalho Chehab:
>>>>>> Em 04-04-2011 17:18, stefan.ringel@arcor.de escreveu:
>>>>>>> From: Stefan Ringel<stefan.ringel@arcor.de>
>>>>>>>
>>>>>>> add mts parameter
>>>>>> Stefan,
>>>>>>
>>>>>> The MTS config depends on the specific board design (generally present on
>>>>>> mono NTSC cards). So, it should be inside the cards struct, and not
>>>>>> provided as an userspace parameter.
>>>>>>
>>>>>> Mauro.
>>>>> No. It wrong. I think edge board must work under all region and TV standards and if I set MTS, it doesn't work in Germany (PAL_BG and DVB-T). The best is to set outside region specific params.
>>>> Stefan,
>>>>
>>>> Not all boards have MTS wired.
>>> standard option that param is not auto.
>>> MTS = 0 or not set means load firmware without MTS.
>>> MTS = 1 means load firmware with MTS.
>>> That means, if you MTS then add a param MTS=1.
>>> Have you other method to detect norm BTSC and EIAJ and set it? I have not that.
>> Yes. Audio standard is related to video standard. So, it is easy to map on what
>> standards you have BTSC or EIAJ.
>>
>> You could find that info listed on some places, like:
>>     http://www.videouniversity.com/articles/world-wide-tv-standards
>>     http://en.wikipedia.org/wiki/BTSC
>> and on good analog TV books.
>>
>> Basically, BTSC/EIAJ applies only to PAL/M, PAL/N and NTSC/M. So, if the standard is
>> not PAL/MN, mts should always be equal to 0. We may have a patch at tuner-xc2028 for that.
>>
>> If standard is V4L_STD_MN, we have:
>>
>> For NTSC standards:
>>     if standard == V4L2_STD_NTSC_M_KR, audio is A2 (Korea) and mts should be 0.
>>     if standard == V4L2_STD_NTSC_M_JP, audio is EIAJ (Japan).
>>     All the rest use BTSC (or are mono, but the BTSC decoder is designed to be
>> backward compatible with NTSC mono FM transmission).
>>
>> For PAL:
>>     V4L2_STD_PAL_M - always BTSC
>>     V4L2_STD_PAL_Nc (only Argentina) - always BTSC
>>     V4L2_STD_PAL_N  (Paraguay/Uruguay) - they also use FM for audio. I think it is also BTSC.
>>
>> So, basically, assuming that some device could potentiallt have both SIF and MTS baseband
>> wired and that the audio decoder is not capable of decoding EIAJ/BTSC, it makes sense to
>> add something like this at tuner-xc2028:
>>
>> /* MTS is only valid for M/N standars, except in Korea */
>> if (!(std&  V4L2_STD_MN) || (std == V4L2_STD_NTSC_M_KR))
>>     mts = 0;
>>
>> and, for such device, specify xc2028 with mts = 1.
>>
>> For devices that support only mts, it makes sense to change the supported standards to
>> just V4L2_STD_MN.
>>
>> However, we cannot assume that (std&  V4L2_STD_MN)&&  (std != V4L2_STD_NTSC_M_KR) is always
>> mts, as it will depend on how xc2028/xc3028 is wired to the bridge/audio demod.
>>
> Is that better to use no mts parameter and always mts = 0?

No. The better is to use a per-board mts parameter, as we have on all other drivers
that use xc2028/xc3028.

Mauro.