G.711
-----

Introduction
~~~~~~~~~~~~

`G.711 <https://www.itu.int/rec/recommendation.asp?lang=en&parent=T-REC-G.711-198811-I>`__
is an ITU-T standard for audio companding: Pulse code modulation
(PCM) of voice frequencies.

Source Code
~~~~~~~~~~~

This codec is based on the original `G.711 <https://www.itu.int/rec/recommendation.asp?lang=en&parent=T-REC-G.711-198811-I>`__,
25 November 1988, corresponding ANSI-C code is available in the G.711 module of the `ITU-T G.191 <https://www.itu.int/rec/T-REC-G.191/en>`__ Software Tools Library, 13 January 2019, 
and this codec passes the test cases successfully.

Multi-instance and reentrance
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Codec hasn't tested on multi-instance run, for more information about support of
multi-instance run see codec source documentation. Codec supports reentrance
in case if AGU address pointer registers (:exc:`AGU_AUX_APx`), AGU offset registers (:exc:`AGU_AUX_OSx`),
AGU modifier registers (:exc:`AGU_AUX_MODx`), see [1] in :ref:`Refs`, will be saved and restored.

Codec-Specific Build Options
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

:exc:`LTO_BUILD` and :exc:`REMAPITU_T` options are not available for this codec. Use the following command to build the G.711 codec:

.. code:: shell

   mdb -run -cl -nsim -tcf=<default TCF from /rules/common_hw_config.mk> g711demo.elf <number of frames> [u|A] [-r] [lili|loli|lilo] <input_file> <output_file> <BlockSize> <1stBlock> <NoOfBlocks> [-skip n]

The following table lists the G.711 codec parameters 

.. table:: Command-Line Option Descriptions for G.711 Codec
   :align: center
   :widths: 20,130

   +-----------------------------------+-----------------------------------+
   | **Option**                        | **Description**                   |
   +===================================+===================================+
   | :exc:`<input_file>`               | Specifies the input file          |
   +-----------------------------------+-----------------------------------+
   | :exc:`<output_file>`              | Specifies the output file         |
   +-----------------------------------+-----------------------------------+
   | :exc:`-r`                         | Disables even-bit swap by A-law   |
   |                                   | encoding and decoding (DEFAULT)   |
   +-----------------------------------+-----------------------------------+
   | :exc:`A`                          | Input data for encoding and       |
   |                                   | output data for decoding are in   |
   |                                   | α-law (G.711) format              |
   +-----------------------------------+-----------------------------------+
   | :exc:`u`                          | Input data for encoding and       |
   |                                   | output data for decoding are in   |
   |                                   | µ-law (G.711) format              |
   +-----------------------------------+-----------------------------------+
   | :exc:`lili`                       | Convert the input file            |
   |                                   | linear to linear: lin -> (A/u)log |
   |                                   | -> lin                            |
   +-----------------------------------+-----------------------------------+
   | :exc:`lilo`                       | Convert the input file            |
   |                                   | linear to (A/u)-log               |
   +-----------------------------------+-----------------------------------+
   | :exc:`loli`                       | Convert the input file            |
   |                                   | (A/u) log to linear               |
   +-----------------------------------+-----------------------------------+
   | :exc:`<BlockSize>`                | Number of samples per block       |
   |                                   | [256] (optional)                  |
   +-----------------------------------+-----------------------------------+
   | :exc:`<1stBlock>`                 | Number of the first block         |
   |                                   | of the input file to be processed |
   |                                   | (optional)                        |
   +-----------------------------------+-----------------------------------+
   | :exc:`<NoOfBlocks>`               | Number of blocks to               |
   |                                   | process, starting with block      |
   |                                   | <1stBlock>                        |
   +-----------------------------------+-----------------------------------+
   | :exc:`-skip *n*`                  | *n* is the number of samples to   |
   |                                   | skip (optional)                   |
   +-----------------------------------+-----------------------------------+

**Examples**

The following command converts the linear samples to A-law log:

.. code:: shell

   mdb -run -cl -nsim -tcf=em9d_voice_audio g711demo.elf A lilo ../testvectors/Ref/sweep.src ../testvectors/sweep-r.a 256 1 256

The following command converts from A-law log to linear samples:

.. code:: shell

   mdb -run -cl -nsim -tcf=em9d_voice_audio g711demo.elf A loli ../testvectors/Ref/sweep-r.a ../testvectors/sweep.src 256 1 256