.. _nvjpeg2kintroduction-label:

Introduction
#############

The nvJPEG2000 library accelerates the decoding and encoding of JPEG2000 images on NVIDIA GPUs. The library is built on the CUDA platform and is 
supported on Pascal+ GPU architectures.

.. note:: Throughout this document, the terms "CPU" and "Host" are used synonymously. Similarly, the terms "GPU" and "Device" are synonymous.


nvJPEG2000 Decoder
^^^^^^^^^^^^^^^^^^

The library utilizes both CPU and GPU for decoding. Tier 2 decode stage (first stage of decode; please refer to the JPEG2000 specification for details)
is run on the CPU. All other stages of the decoding process are offloaded to the GPU.

The nvJPEG2000 decoder supports the following:

**JPEG2000 Options:**

- Up to 16 bits per component
- No of components : 4
- Reversible(5-3) and irreversible(9-7) wavelet transforms
- Multiple tiles per image
- Up to 32 layers per image
- Chroma sub-sampling types - 444, 422, and 420
- All progression orders
- Image and tile start coordinates should be 0
- Tile/Resolution based decoding
- Partial decoding of tiles and images
- jp2 file format and jpeg2000 codestream
- High throughput jpeg2000(All code-blocks have to be HT code-blocks with one HT set and no refinement)

**Features:**

- Decode multiple images in pipeline mode. Refer to  `nvJPEG2000-Decoder-Pipelined <https://github.com/NVIDIA/CUDALibrarySamples/tree/master/nvJPEG2000/nvJPEG2000-Decoder-Pipelined>`__ sample for details.
- Color conversion to RGB.
- Both planar and interleaved outputs are supported.

.. _nvjpeg2kintroencoder-label:

nvJPEG2000 Encoder
^^^^^^^^^^^^^^^^^^
The library utilizes both GPU and CPU to create JPEG2000 bitstreams. The encode APIs require that the input image is on device memory,
and the compressed bitstream will be written  to host memory. 

The nvJPEG2000 encoder supports the following:

**JPEG2000 options**

- Up to 16 bits per component
- No of components : 4
- Reversible(5-3) and irreversible(9-7) wavelet transforms
- Multiple tiles per image
- Single layer per image
- All progression orders
- Chroma sub-sampling types - 444, 422, and 420
- jp2 file format and jpeg2000 codestream
- PSNR based rate control

**Features**

- Both planar and interleaved inputs are supported.

Prerequisites
^^^^^^^^^^^^^^
- CUDA Toolkit version 11.0 and above
- CUDA Driver version r450 and above


Platforms Supported
^^^^^^^^^^^^^^^^^^^^

* **Linux versions:**

+-------------+------------------------------------------------+
|             | Distribution Information                       |
+             +-------------+--------+-------+------+----------+
|Architecture |Name         |Version |Kernel |GCC   |GLIBC     |
+=============+=============+========+=======+======+==========+
|             |             |9.1     |5.14   |11.3.1|2.34      |
|             |             +--------+-------+------+----------+
| x86_64      |RHEL/Rocky   |8.3     |4.18   |8.5.0 |2.28      |
|             +-------------+--------+-------+------+----------+
|             |             |24.04   |6.8.0  |13.2.0|2.39      |
|             |             +--------+-------+------+----------+
|             |Ubuntu       |22.04   |5.15.0 |11.4.0|2.34      |
|             |             +--------+-------+------+----------+
|             |             |20.04   |5.13.0 |9.4.0 |2.31      |
|             +-------------+--------+-------+------+----------+
|             |OpenSUSE Leap|15.5    |5.14.21|7.5.0 |2.31      |
|             +-------------+--------+-------+------+----------+
|             |SUSE SLES    |15.5    |5.14.21|7.5.0 |2.31      |
|             +-------------+--------+-------+------+----------+
|             |Debian       |12.7    |6.1.0  |12.2.0|2.36      |
|             |             +--------+-------+------+----------+
|             |             |11.10   |5.10.0 |10.2.1|2.31      |
|             +-------------+--------+-------+------+----------+
|             |Fedora       |39      |6.5.6  |13.2.1|2.38      |
+-------------+-------------+--------+-------+------+----------+
|             |             |9.2     |5.14   |11.3.1|2.34      |
|             |RHEL         +--------+-------+------+----------+
| arm64-sbsa  |             |8.3     |4.18   |8.5.0 |2.28      |
|             +-------------+--------+-------+------+----------+
|             |             |24.04   |6.8.0  |13.2.0|2.39      |
|             |             +--------+-------+------+----------+
|             |Ubuntu       |22.04   |5.15.0 |11.4.0|2.35      |
|             |             +--------+-------+------+----------+
|             |             |20.04   |5.4.0  |9.4.0 |2.31      |
|             +-------------+--------+-------+------+----------+
|             |SUSE SLES    |15.5    |5.14.21|7.5.0 |2.31      |
+-------------+-------------+--------+-------+------+----------+

* **Windows Versions**

  * Windows 10/11.

* **Tegra**

  * Supported on Jetpack v5.1.3 and above.



Thread Safety
^^^^^^^^^^^^^

Not all nvJPEG2000 types are thread safe. The following should be instantiated separately for each thread: :ref:`nvjpeg2kDecodeState_t<nvjpeg2kdecodestate-label>`,
:ref:`nvjpeg2kStream_t<nvjpeg2kbitstreamhandle-label>`, and :ref:`nvjpeg2kEncodeState_t<nvjpeg2kencodestate-label>`.