QNX Technical Articles

Date of this edition: March 29, 2010

Target OS: This software is compatible with target systems running QNX^® Neutrino^® 6.3.2 or 6.4.0.

Host OS: You must have already installed the QNX^® Momentics^® development suite 6.3.2 or the QNX Software Development Platform 6.4.0 as a self-hosted QNX^® Neutrino^® system, or on one of the following development hosts:

You must also have installed QNX Aviage Acoustic Processing 1.3.

---

This patch doesn't apply to QNX Aviage Acoustic Processing 1.2. For version 1.3, this patch supersedes the QNX Aviage Acoustic Processing 1.2 and 1.3 ARMLE, PPCBE, and SHLE qwa_rcs Libraries Patch (Patch ID 1401). For the most up-to-date version of these notes, go to our website (www.qnx.com), log into your myQNX account, and then go to the Download Center.

---

Contents

• What's in this patch?
• Fixed issues
• Recommendation added
• Known issues
• Technical support

Throughout this document, you may see reference numbers associated with particular issues, changes, etc. When corresponding with our Technical Support staff about a given issue, please quote the relevant reference number. You might also find the reference numbers useful for tracking issues as they become fixed.

What's in this patch?

To get the full effect of this patch, you should also install the QNX^® Aviage^® Acoustic Processing 1.3 QWALive.exe for Windows Patch (Patch ID 1852).

The patch provides updates mainly for the following areas:

• Send/Recv AGC
• Wind Block
• Soft limiter
• Default parameter values

This patch also includes an updated version of the Acoustic Processing User's Guide, packaged as an Eclipse plugin for the QNX Momentics IDE, and in a form suitable for the Photon Helpviewer.

Binaries

The following binary files are installed under $QNX_TARGET/, in subdirectories for each supported target platform:

ARMLE

• armle/lib/libqwa.a
• armle/lib/libqwaS.a
• armle/lib/libqwa-vfp.a
• armle/lib/libqwa-vfpS.a
• armle/lib/libqwa_rcs.a
• armle/lib/libqwa_rcsS.a
• armle/lib/libqwa_rcs-vfp.a
• armle/lib/libqwa_rcs-vfpS.a

PPCBE

• ppcbe/lib/libqwa.a
• ppcbe/lib/libqwaS.a
• ppcbe/lib/libqwa_rcs.a
• ppcbe/lib/libqwa_rcsS.a

SHLE

• shle/lib/libqwa.a
• shle/lib/libqwaS.a
• shle/lib/libqwa_rcs.a
• shle/lib/libqwa_rcsS.a

Header files

• usr/include/qwa_rcs_err.h
• usr/include/qwa_rcs.h
• usr/include/qwa_err.h
• usr/include/qwa_defs.h
• usr/include/qwa.h

Sample source code

The following source code files with examples of how to use QNX Aviage Acoustic Processing 1.3 are installed under $QNX_TARGET/:

• etc/readme/qnxaviage-ap/qwa_hf_example/qwa_hf_example.c
• etc/readme/qnxaviage-ap/qwa_rcs_example/qwa_rcs_example.c
• etc/readme/qnxaviage-ap/qwa_vr_example/qwa_vr_example.c

Documentation

The functionality provided by this package is described in the QNX Aviage Acoustic Processing User's Guide, which you'll find in the IDE's help system on Linux and Windows systems. On self-hosted Neutrino systems, you can find the documentation in the Photon helpviewer.

You'll find the QWALive User's Guide installed as $QNX_CONFIGURATION\bin\QWALive\QWALive.pdf on Windows systems.

You'll find the sample programs and a PDF version of the User's Guide in the $QNX_TARGET/etc/readme/qnxaviage-ap directory.

API Changes

• Changed default value for residual echo suppression (qwaRECSuppress) to 40 from 50 for a better double-talk performance.
• Changed default values for send and receive AGC amplitude targets in hands free mode (qwaSendAGCAmpTgts and qwaRecvAGCAmpTgts) to [-1500 -900] from [-1200 -600] for slightly better send and receive voice quality.
• Changed default value for BWE brightness (qwaRecvBWEBrightness) to 25 from 50 for more natural extension across a larger number of speakers.

Fixed issues

• Fixed issue with the Wind Block algorithm, changed it to make it more effective in both mild and severe wind noise conditions. (Ref# 74510)
• Fixed issue, changed AAP receive & reference Voice Activity Detection (VAD) indicators to be more robust to low level quantized noise, preventing unnecessary increase of receive gain or freezing of send gain. (Ref# 74541)
• Fixed issue with the soft limiter, which occasionally failed to prevent clipping near the beginning of an audio frame. (Ref# 74846)
• Fixed issue with the low-pass filter, the coefficients of which were re-ordered to give as sharp a cut-off, but with less audible ringing. (Ref# 74845)
• Fixed issue in the fixed-point version, where residual echo suppression did not always fully suppress echo, resulting in occasional small echo artifacts. (Ref# 75031)
• Fixed issue where Send AGC gain changes were applied instantaneously, potentially leading to audible discontinuities for high-bit rate wideband telephony. (Ref# 74698)
• Modified send AGC to give a higher perceived output level in high noise. (Ref# 73846)

Recommendation added

• To simulate pass-through mode and have anti-aliasing protection and a decent listening level in mixed mode (16kHz input / 8kHz output), we recommend you turn off all AAP switches using QWALive and apply a fixed gain which can be estimated from the gain value during normal operation.

Known issues

None currently known.

Technical support

If you have any questions, comments, or problems with a QNX product, please contact Technical Support. For more information, see the How to Get Help chapter of the Welcome to QNX Momentics or Welcome to the QNX Software Development Platform guide or visit our website, www.qnx.com.