[FFmpeg-user] Chroma subsampling formats

[Mark Filipak]

Are these correct? Or, is there some official reference I can consult?
--Mark.

KEY:
¤ —— Element exists in the field and is sampled
• —— Element exists in the field but is not sampled
   —— (blank) Element doesn't exist in the field

Reference: https://en.wikipedia.org/wiki/Chroma_subsampling

            Y element, pixels 0..3
           /    Cb element, pixels 0..3
          /    /    Cr element, pixels 0..3
         /    /    /
4:4:4  ¤¤¤¤ ¤¤¤¤ ¤¤¤¤ —— lines in field 0
        ¤¤¤¤ ¤¤¤¤ ¤¤¤¤ —— lines in field 1

4:4:2  ¤¤¤¤ ¤¤¤¤ ¤¤¤¤
        ¤¤¤¤ ¤•¤• ¤•¤•

4:4:2  ¤¤¤¤ ¤¤¤¤ ¤¤¤¤  // JPEG variant according to the reference
        ¤¤¤¤      ¤¤¤¤

4:4:1  ¤¤¤¤ ¤¤¤¤ ¤¤¤¤
        ¤¤¤¤ ¤••• ¤•••

4:4:0  ¤¤¤¤ ¤¤¤¤ ¤¤¤¤
        ¤¤¤¤

4:2:2  ¤¤¤¤ ¤•¤• ¤•¤•
        ¤¤¤¤ ¤•¤• ¤•¤•

4:2:1  ¤¤¤¤ ¤•¤• ¤•¤•
        ¤¤¤¤ ¤••• ¤•••

4:2:1  ¤¤¤¤ ¤•¤• ¤•¤•  // JPEG variant according to the reference
        ¤¤¤¤      ¤•••

4:2:0  ¤¤¤¤ ¤•¤• ¤•¤•
        ¤¤¤¤

4:1:1  ¤¤¤¤ ¤••• ¤•••
        ¤¤¤¤ ¤••• ¤•••

4:1:0  ¤¤¤¤ ¤••• ¤•••
        ¤¤¤¤

4:0:0  ¤¤¤¤            // My conjecture
        ¤¤¤¤

3:1:1  ¤¤¤  ¤••  ¤••   // Sony variant according to the reference
        ¤¤¤  ¤••  ¤••