| .. -*- coding: utf-8; mode: rst -*- |
| |
| .. _V4L2-SDR-FMT-PCU18BE: |
| |
| ****************************** |
| V4L2_SDR_FMT_PCU18BE ('PC18') |
| ****************************** |
| |
| Planar complex unsigned 18-bit big endian IQ sample |
| |
| Description |
| =========== |
| |
| This format contains a sequence of complex number samples. Each complex |
| number consist of two parts called In-phase and Quadrature (IQ). Both I |
| and Q are represented as a 18 bit unsigned big endian number stored in |
| 32 bit space. The remaining unused bits within the 32 bit space will be |
| padded with 0. I value starts first and Q value starts at an offset |
| equalling half of the buffer size (i.e.) offset = buffersize/2. Out of |
| the 18 bits, bit 17:2 (16 bit) is data and bit 1:0 (2 bit) can be any |
| value. |
| |
| **Byte Order.** |
| Each cell is one byte. |
| |
| .. flat-table:: |
| :header-rows: 1 |
| :stub-columns: 0 |
| |
| * - Offset: |
| - Byte B0 |
| - Byte B1 |
| - Byte B2 |
| - Byte B3 |
| * - start + 0: |
| - I'\ :sub:`0[17:10]` |
| - I'\ :sub:`0[9:2]` |
| - I'\ :sub:`0[1:0]; B2[5:0]=pad` |
| - pad |
| * - start + 4: |
| - I'\ :sub:`1[17:10]` |
| - I'\ :sub:`1[9:2]` |
| - I'\ :sub:`1[1:0]; B2[5:0]=pad` |
| - pad |
| * - ... |
| * - start + offset: |
| - Q'\ :sub:`0[17:10]` |
| - Q'\ :sub:`0[9:2]` |
| - Q'\ :sub:`0[1:0]; B2[5:0]=pad` |
| - pad |
| * - start + offset + 4: |
| - Q'\ :sub:`1[17:10]` |
| - Q'\ :sub:`1[9:2]` |
| - Q'\ :sub:`1[1:0]; B2[5:0]=pad` |
| - pad |
