Android VoIP SDK speeds development of custom mobile VoIP apps Android VoIP SDK enables rapid development of mobile apps using our Android VoIP software with standard algorithms easily configured for Android VoIP client and server applications. \tNative Android library with API \tOptimized performance for DSP and ARM platforms \tNarrowband and wideband voice codecs available \tEcho and noise solutions for superior speech \tFull featured VoIP telephony VOCAL's Android VoIP SDK library is modular with source code optimized for DSPs and ARM processors from TI, ADI and other leading vendors. Our Android software development kit and library supports a range of ETSI ITU IEEE compliant algorithms including VoIP codecs, echo cancellation and noise reduction algorithms to develop a variety of internet calling apps. Our expertise in development and configuration of mobile, network and telephony products will speed your Android VoIP software application to market. Contact us to discuss your specific Android VoIP application development requirements. Custom solutions are also available. Features \tMobile SIP stack supports Android VoIP client server applications \tSupports G.711, G.722, G.729, Silk, Opus and other wideband voice codecs \tAcoustic echo cancellation, noise reduction, dereverberation and beamforming available \tDevice configuration and provisioning using TR-069 management protocols available \tSupports multi-tasking and multichannel operations \tTTY / TDD option available \tSupports full and half duplex modes \tSupports multiple VoIP internet services Applications \tAndroid VoIP client \tMobile VoIP internet calling \tAudio and video conferencing \tVoIP game communications \tTTY / TDD calling \tFax over IP \tPTT and Radio over IP Android Library VOCAL's Android Library allows mobile VoIP developers to quickly implement interactive games and apps using standard algorithms easily configured for Android VoIP client server applications. Our Android software development kit is easily installed in a standard IDE as a native Android library. The Android VoIP SDK is provided as a C/C++ Android library with support for: \tAndroid API class library interface \tNative SIP stack with adaptive jitter \tVoIP codecs for narrowband and wideband speech and audio \tVoice quality enhancement with acoustic echo cancellation, noise reduction and dereverberation \tAcoustic beamforming for microphone noise reduction Android API For those that require maximum performance for custom Android applications, such as games and conferencing, our software development kit includes an Android API Class with the JNI (Java Native Interface) which provides ready access to the optimized code in VOCAL's Android vocoder library. Our Android library and API Class have been implemented using the Android NDK for building compatible libraries in C or C++. The Android SDK provides development tools to include our optimized C code in your custom apps via the Java API class. VOCAL's API Class enables access to the Android Library via the JNI Android SIP Stack The native Android SIP stack provides access to the vocoders in the Android Library and incorporates an adaptive jitter algorithm to further enhance voice quality. The proprietary jitter algorithm adapts rapidly to packet loss or delays from congested networks and is exceptional at maintaining constant voice output for the listener. Our native SIP stack and VoIP protocols implement an Android SIP client with full support for VoIP Internet calling services using SIP and RTP. Video conferencing and streaming are also supported with RTP. In addition, VoIP encryption using SRTP or TCP with SSL / TLS is available to ensure secure communication between Android SIP client server applications. Android Vocoders Although the Android platform includes basic GSM telephony capabilities, VOCAL’s Android library includes a range of standard ITU and GSM, Wideband and other standard Android vocoders. In addition, the low bit rate MELP / MELPe (Mixed-Excitation Linear Predictive / enhanced) vocoders and the OPUS Audio Codec are available. Developers should evaluate the characteristics of each Android voice codec algorithm and its suitability for a particular custom Android application and/or platform. Please contact VOCAL to discuss other Android VoIP codec options that are available for Android SIP client custom applications development. Android vocoders may be selected and configured to tailor an Android SIP client for different user requirements and operating environments. The native library structure allows the developer to include only the desired Android vocoder and support packages, thus minimizing memory requirements for the application package files (.apks) ultimately deployed to targeted mobile devices. The following Android vocoder modules are currently available for mobile Android VoIP client applications. \tG.711 - 64k bps PCM (A-law or μ-law form) \tG.722 - 7 kHz audio coding within 64 kbit/s (SB-ADPCM) \tG.722.1 - 24k and 32k bps, 7 kHz audio \tG.722.2 - Adaptive Multi-Rate Wideband (GSM AMR-WB) \tG.729AB - 8k bps CS-ACELP \tMELPe – 600 bps / 1200 bps / 2400 bps \tSpeex – 8 kHz, 16 kHz, and 32 kHz CELP \tSILK – Variable Bitrate Wideband Speech Codec \tOPUS - 8kHz to 48kHz audio with dual layer LP and MDCT encoding Voice Quality Enhancement The Native Android VoIP software library includes VOCAL's voice quality enhancement system with Android echo cancellation, noise reduction, and speech dereverberation algorithms optimized for the architecture. In hands-free voice communications using Android, echo cancellation removes reflected copies of a direct path wave from the acoustic/mechanical coupling between the speaker and microphone in the device; dereverberation handles speech reverberation or reflections from surfaces in an enclosed environment; while noise reduction reduces additive noise sources. All of these techniques contribute to significantly improved speech enhancement and intelligibility for the end user's listening experience. Acoustic Beamforming The native Android library supports acoustic beamforming algorithms to capture the speaker’s voice in dynamic and challenging environments. Mobile devices are often used as hands-free systems with the speaker located some distance from the microphone. Newer Android devices with microphone arrays can use adaptive acoustic beamforming to enhance the speaker’s voice while rejecting interferes and background noise from other sources.