Using Intel Integrated Performance Primitive (IPP) with PJMEDIA

Table of Contents

1. Requirements
2. Installation
   1. Windows Instructions
3. PJMEDIA Configuration
   1. Enable IPP Support
   2. Enable/Disable? Individual IPP Codec
4. Using in Application
   1. Codec Registration
   2. Codec Settings
5. Open Issues
   1. Bitrate Selection
   2. Bitrate negotiation for G.722.1 and G.726
   3. G.729 Annex B
   4. AMR Options
   5. Linux Support
   6. MacOS X Support

Intel® Integrated Performance Primitives (Intel® IPP) is an extensive library of multi-core-ready, highly optimized software functions for multimedia data processing, and communications applications.

The Intel IPP can be used with PJMEDIA library to provide the following codecs:

Codec	Bitrate (Kbps)	Clock rate/ frame ptime	default frames/pkt	default bitrate	VAD/DTX	PLC	Note
AMR NB	4.75 to 12.2	8000/160	4	5900	internal	internal
AMR WB	6.6 to 23.85	16000/320	1	15850	internal	internal
G.722.1	16, 24, 32, 40	16000/320	1	16000	pjmedia	internal
G.723.1	5.3, 6.3	8000/240	1	5300	internal	internal
G.726	16, 24, 32, 40	8000/80	2	-	pjmedia	pjmedia	The bitrate is negotiated in SDP
G.728	16	8000/80	2	16000	pjmedia	internal
G.729A	8	8000/80	2	8000	pjmedia	internal	1) G.729 VAD (Annex B) is currently disabled. 2) Annex D and Annex E is supported for receive direction.

Requirements

The following are required:

• PJSIP version 1.0-rc1 or above
• Intel IPP library for your platform
• Intel IPP samples

We tested with Intel IPP version 5.3. You may be able to use different Intel IPP version with PJMEDIA, however we have not tested this.

Note that the use of Intel IPP may require license, both from Intel and the parties who own the royalty of the codec.

Installation

Windows Instructions

Download and install IPP and IPP samples

1. Download Intel IPP and Intel IPP samples from ​http://www.intel.com/cd/software/products/asmo-na/eng/302910.htm
2. Run the Intel IPP installer (e.g. w_ipp_ia32_p_5.3.3.082.exe). The default installation will install it to C:\Program Files\Intel\IPP\5.3.3.082 folder, and this is the folder that will be referred to by this tutorial.
3. Unzip the Intel IPP samples (e.g. w_ipp-samples_p_5.3.095.zip) to a folder. This tutorial assumes that the samples are installed in C:\ipp-samples.

Build the IPP samples

1. Go to the IPP samples unzipped folder (e.g. C:\ipp-samples).
2. Go to speech-codecs folder.
3. Open the readme.htm file, and follow the instructions there to build the samples from the source.

Once the build process done, you should have usc.lib file somewhere inside speech-codecs\bin directory (in my case, it's in C:\ipp-samples\speech-codecs\bin\win32_cl9\lib folder).

If you have any problems with installing and/or building the IPP or IPP samples, please read the documentation or contact Intel for support.

Configure Visual Studio

1. Add Intel IPP include and library path to Visual Studio paths. For example if 32bit Intel IPP is installed in C:\Program Files\Intel\IPP\5.3.3.082\ia32 directory:
   • add C:\Program Files\Intel\IPP\5.3.3.082\ia32\include to the include path
   • add C:\Program Files\Intel\IPP\5.3.3.082\ia32\stublib to the library path
2. Add Intel IPP samples include and library path to Visual Studio directory options. For example, if Intel IPP samples are in C:\ipp-samples:
   • add C:\ipp-samples\speech-codecs\core\usc\include to the include path
   • add C:\ipp-samples\speech-codecs\bin\win32_cl9\lib to the library path

PJMEDIA Configuration

Enable IPP Support

By default, IPP support is disabled in PJMEDIA. To enable IPP support, declare the following in your config.site.h:

#define PJMEDIA_HAS_INTEL_IPP	1

Enable/Disable? Individual IPP Codec

Once IPP support is enabled, by default all IPP codecs are enabled. To disable parcular codecs, use the following constructs:

#define PJMEDIA_HAS_INTEL_IPP_CODEC_AMR     0
#define PJMEDIA_HAS_INTEL_IPP_CODEC_AMRWB   0
#define PJMEDIA_HAS_INTEL_IPP_CODEC_G729    0
#define PJMEDIA_HAS_INTEL_IPP_CODEC_G723_1  0
#define PJMEDIA_HAS_INTEL_IPP_CODEC_G726    0
#define PJMEDIA_HAS_INTEL_IPP_CODEC_G728    0
#define PJMEDIA_HAS_INTEL_IPP_CODEC_G722_1  0

Using in Application

Codec Registration

Before application can use any of the IPP codecs above, the IPP codec factory must be registered to the codec manager. If application is using PJSUA-LIB, this will be done automatically by PJSUA-LIB. If application is using PJMEDIA directly, then it must register the IPP codec factory by calling:

    pjmedia_codec_ipp_init(media_endpt);

Or alternatively, to register all codec factories that are enabled at compile time to the codec manager:

    pjmedia_init_all_codecs(media_endpt);

Note that if the use of pjmedia_init_all_codecs to register all codec will result in linking to all codec libraries that are enabled at compile time and this will increase application's footprint/executable size.

Codec Settings

Codec settings are managed by setting the appropriate field in settings part of ​pjmedia_codec_param as usual.

Open Issues

Bitrate Selection

For codecs that support multiple bitrates (such as G.723.1 and AMR), the encoding bitrate is currently selected by setting ​pjmedia_codec_param.info.avg_bps field. This mechanism currently contradicts the normal convention of not modifying pjmedia_codec_param.info part.

Bitrate negotiation for G.722.1 and G.726

SDP negotiation for selecting the appropriate bitrate for these codecs is currently not supported.

G.729 Annex B

This currently is not supported, and instead the usual PJMEDIA VAD/DTX is used. This should be compatible with G.729 though.

AMR Options

Negotiation of various AMR options in SDP is currently not supported. The AMR mode is locked to bandwidth-optimized, and when AMR with octet-aligned packet is received, the behavior is undefined.

Linux Support

Currently IPP integration is not supported by the autoconf script. You must add the appropriate CFLAGS and LDFLAGS in user.mak file in order to use IPP.

MacOS X Support

Although IPP is said to be supported for MacOS X (Intel), we don't know yet how to configure this support.