.. -*- 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 * - start + 0: - Y'\ :sub:`00` - Y'\ :sub:`01` - Y'\ :sub:`02` - Y'\ :sub:`03` * - start + 4: - Y'\ :sub:`10` - Y'\ :sub:`11` - Y'\ :sub:`12` - Y'\ :sub:`13` * - start + 8: - Y'\ :sub:`20` - Y'\ :sub:`21` - Y'\ :sub:`22` - Y'\ :sub:`23` * - start + 12: - Y'\ :sub:`30` - Y'\ :sub:`31` - Y'\ :sub:`32` - Y'\ :sub:`33` * - start + 16: - Cb\ :sub:`00` - Cr\ :sub:`00` - Cb\ :sub:`01` - Cr\ :sub:`01` * - 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 * - - 0 - - 1 - 2 - - 3 * - 0 - Y - - Y - Y - - Y * - - - C - - - C - * - 1 - Y - - Y - Y - - Y * - * - 2 - Y - - Y - Y - - Y * - - - C - - - C - * - 3 - Y - - Y - Y - - Y