Re: [PATCH v2 1/5] V4L2: I2C: ML86V7667 video decoder driver

[Vladimir Barinov <vladimir.barinov@cogentembedded.com>]

Hi Hans,

Hans Verkuil wrote:
>>>> +	 */
>>>> +	val = i2c_smbus_read_byte_data(client, STATUS_REG);
>>>> +	if (val < 0)
>>>> +		return val;
>>>> +
>>>> +	priv->std = val & STATUS_NTSCPAL ? V4L2_STD_PAL : V4L2_STD_NTSC;
>>>>     
>>>>         
>>> Shouldn't this be 50 Hz vs 60 Hz formats? There are 60 Hz PAL standards
>>> and usually these devices detect 50 Hz vs 60 Hz, not NTSC vs PAL.
>>>   
>>>       
>> In the reference manual it is not mentioned about 50/60Hz input format 
>> selection/detection but it mentioned just PAL/NTSC.
>> The 50hz formats can be ether PAL and NTSC formats variants. The same is 
>> applied to 60Hz.
>>
>> In the ML86V7667 datasheet the description for STATUS register detection 
>> bit is just PAL/NTSC:
>> " $2C/STATUS [2] NTSC/PAL identification 0: NTSC /1: PAL "
>>
>> If you assure me that I must judge their description as 50 vs 60Hz 
>> formats and not PAL/NTSC then I will make the change.
>>     
>
> I can't judge that. Are there no status bits anywhere that tell you something
> about the number of lines per frame or the framerate?
>   
You are right. I've found a relationship table with description of 
number of total H/V pixels vs Video Modes mentioned in datasheet.
It's  "NTSC" has Odd/263 and Even/262 vertical lines. The "PAL" has 
Odd/312 and Even/313.
So I will change the standard per your suggestion.
> Are you able to test with a PAL-M or PAL-N(c) input?
>   
Unfortunately I cannot. I have a couple of different cameras and all of 
them mention PAL output with number of lines in the technical manual. 
All of them are 625 lines.
> Can you ask the manufacturer for more information?
>   
It can take a while for waiting their feedback since OKI was 
significantly reorganized.

Than you very much for your valuable feedback/review.

Regards,
Vladimir