[FFmpeg-user] Chroma subsampling formats

[Mark Filipak]

On 15/07/2025 16.04, Paul B Mahol wrote:
> On Tue, Jul 15, 2025 at 7:57 PM Mark Filipak <markfilipak.imdb at gmail.com>
> wrote:
> 
>> On 15/07/2025 15.40, Paul B Mahol wrote:
>>> On Tue, Jul 15, 2025 at 7:34 PM Mark Filipak <markfilipak.imdb at gmail.com
>>>
>>> wrote:
>>
>>>>            Y element, pixels 0..3
>>>>           /    Cb element, pixels 0..3
>>>>          /    /    Cr element, pixels 0..3
>>>>         /    /    /
>>>> 4:4:1  ¤¤¤¤ ¤¤¤¤ ¤¤¤¤ —— lines in field 0
>>>>        ¤¤¤¤ ¤••• ¤••• —— lines in field 1
>>>>
>>>> 4:2:1  ¤¤¤¤ ¤•¤• ¤•¤•
>>>>        ¤¤¤¤ ¤••• ¤•••
>>
>> Well, Paul, you're the expert. Are those two correct? If they are, then
>> I'm right about how the
>> tokens work and the folks at wikipedia are wrong. I don't care whether the
>> wikipedia folks are right
>> or wrong because I don't pay wikipedia any mind because I think wikipedia
>> is a train wreck. I want
>> to be right because I want to be knowledgeable so I can help myself and so
>> I can help other people.
>>
> 
> For 4:2:0
> 
> its for 4x4 luma block you have 2x2 block chroma

No, no, not 4:2:0. Is my 4:4:1 correct? Is my 4:2:1 correct?

> Your attempts to explain it with ascii are comical.

How so, Paul? Pictures is how I think.

--Mark.