| .. -*- coding: utf-8; mode: rst -*- |
| |
| .. _V4L2-PIX-FMT-NV12: |
| .. _V4L2-PIX-FMT-NV21: |
| |
| ****************************************************** |
| V4L2_PIX_FMT_NV12 ('NV12'), V4L2_PIX_FMT_NV21 ('NV21') |
| ****************************************************** |
| |
| |
| V4L2_PIX_FMT_NV21 |
| Formats with ½ horizontal and vertical chroma resolution, also known as |
| YUV 4:2:0. One luminance and one chrominance plane with alternating |
| chroma samples as opposed to ``V4L2_PIX_FMT_YVU420`` |
| |
| |
| Description |
| =========== |
| |
| These are two-plane versions of the YUV 4:2:0 format. The three |
| components are separated into two sub-images or planes. The Y plane is |
| first. The Y plane has one byte per pixel. For ``V4L2_PIX_FMT_NV12``, a |
| combined CbCr plane immediately follows the Y plane in memory. The CbCr |
| plane is the same width, in bytes, as the Y plane (and of the image), |
| but is half as tall in pixels. Each CbCr pair belongs to four pixels. |
| For example, Cb\ :sub:`0`/Cr\ :sub:`0` belongs to Y'\ :sub:`00`, |
| Y'\ :sub:`01`, Y'\ :sub:`10`, Y'\ :sub:`11`. ``V4L2_PIX_FMT_NV21`` is |
| the same except the Cb and Cr bytes are swapped, the CrCb plane starts |
| with a Cr byte. |
| |
| If the Y plane has pad bytes after each row, then the CbCr plane has as |
| many pad bytes after its rows. |
| |
| **Byte Order.** |
| Each cell is one byte. |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| - .. row 1 |
| |
| - start + 0: |
| |
| - Y'\ :sub:`00` |
| |
| - Y'\ :sub:`01` |
| |
| - Y'\ :sub:`02` |
| |
| - Y'\ :sub:`03` |
| |
| - .. row 2 |
| |
| - start + 4: |
| |
| - Y'\ :sub:`10` |
| |
| - Y'\ :sub:`11` |
| |
| - Y'\ :sub:`12` |
| |
| - Y'\ :sub:`13` |
| |
| - .. row 3 |
| |
| - start + 8: |
| |
| - Y'\ :sub:`20` |
| |
| - Y'\ :sub:`21` |
| |
| - Y'\ :sub:`22` |
| |
| - Y'\ :sub:`23` |
| |
| - .. row 4 |
| |
| - start + 12: |
| |
| - Y'\ :sub:`30` |
| |
| - Y'\ :sub:`31` |
| |
| - Y'\ :sub:`32` |
| |
| - Y'\ :sub:`33` |
| |
| - .. row 5 |
| |
| - start + 16: |
| |
| - Cb\ :sub:`00` |
| |
| - Cr\ :sub:`00` |
| |
| - Cb\ :sub:`01` |
| |
| - Cr\ :sub:`01` |
| |
| - .. row 6 |
| |
| - start + 20: |
| |
| - Cb\ :sub:`10` |
| |
| - Cr\ :sub:`10` |
| |
| - Cb\ :sub:`11` |
| |
| - Cr\ :sub:`11` |
| |
| |
| **Color Sample Location..** |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - |
| - 0 |
| |
| - |
| - 1 |
| |
| - 2 |
| |
| - |
| - 3 |
| |
| - .. row 2 |
| |
| - 0 |
| |
| - Y |
| |
| - |
| - Y |
| |
| - Y |
| |
| - |
| - Y |
| |
| - .. row 3 |
| |
| - |
| - |
| - C |
| |
| - |
| - |
| - C |
| |
| - |
| |
| - .. row 4 |
| |
| - 1 |
| |
| - Y |
| - |
| |
| - Y |
| |
| - Y |
| |
| - |
| - Y |
| |
| - .. row 5 |
| |
| - |
| |
| - .. row 6 |
| |
| - 2 |
| |
| - Y |
| - |
| |
| - Y |
| |
| - Y |
| |
| - |
| - Y |
| |
| - .. row 7 |
| |
| - |
| - |
| - C |
| |
| - |
| - |
| - C |
| |
| - |
| |
| - .. row 8 |
| |
| - 3 |
| |
| - Y |
| |
| - |
| - Y |
| |
| - Y |
| |
| - |
| - Y |