Contact person: VoIP/GSM Call Merging for CSipSimple APK

Phone:Show

Email:Show

Location: Sanaa, Yemen

Budget: Recommended by industry experts

Time to start: As soon as possible

Project description:
"Job Posting: Android Developer for CSipSimple VoIP/GSM Call Merging

Project Overview
I am seeking an experienced Android developer to create a custom solution for merging VoIP and GSM calls on a rooted Android device (versions 5 or 6 or 7) using the open-source CSipSimple app (available on GitHub: [login to view URL]). The goal is to enable automatic (not manual) merging of a VoIP call (initiated via a FreePBX SIP account) with a GSM call (using the device's SIM card) to create a seamless conference call. The solution will leverage root access, su commands, and Xposed Framework to access private Android APIs for call management and audio stream merging.
Requirements

Objective: Modify CSipSimple to automatically merge an active VoIP call (e.g., from extension 73 on FreePBX) with a GSM call (initiated to a specified phone number via the SIM card) on Android 5 (Lollipop) or 6 (Marshmallow).
Technical Details:
Use the CSipSimple open-source codebase (GitHub: [login to view URL]) as the base.
Implement automatic call merging (no manual intervention) using:
su commands (e.g., am start -a [login to view URL] tel:<number>) to initiate the GSM call.
Xposed Framework (or LSPosed with Magisk) to hook private APIs such as [login to view URL] (e.g., conference method) or [login to view URL] for call management.
AudioManager, AudioTrack, and AudioRecord to merge VoIP and GSM audio streams seamlessly.


Ensure compatibility with FreePBX SIP accounts (e.g., extension 73 configured in CSipSimple).
Target devices: Rooted Android phones running Android 5 or 6 (specific models to be provided upon hiring).


Deliverables:
A modified CSipSimple APK or a custom plugin that enables automatic VoIP/GSM call merging.
Documentation on setup, including Xposed module installation and configuration.
Test cases to verify merging functionality on Android 5/6.


Constraints:
The solution must work on rooted Android 5 or 6 without requiring external hardware or VoIP providers (e.g., no external trunks like [login to view URL]).
Must leverage the SIM card's free GSM minutes for the external call.
No reliance on Bluetooth, USB connections, or hardware gateways (e.g., GoIP).



Required Skills

Strong experience in Android development (Java/Kotlin) and working with Android private APIs.
Familiarity with Xposed Framework or LSPosed for hooking system APIs (e.g., ITelephony, AudioManager).
Experience with audio stream manipulation (AudioTrack, AudioRecord) for merging VoIP and GSM audio.
Knowledge of SIP/VoIP protocols and FreePBX integration.
Proficiency with root-level development, including su commands and Magisk modules.
Familiarity with CSipSimple codebase or similar open-source VoIP apps is a plus.
Ability to debug and test on Android 5/6 using tools like ADB and logcat.

Preferred Qualifications

Previous projects involving Android call management or audio routing (e.g., call recording, conferencing).
Experience with decompiling/modifying APKs or developing Xposed modules.
Contributions to open-source Android projects on GitHub.




Budget

Please provide a quote with your application.

Application Process

Submit similer projects, showcasing relevant Android/root/Xposed projects.
Include a brief proposal outlining your approach to achieving automatic VoIP/GSM call merging with CSipSimple.
Specify your experience with Android 5/6, Xposed, and audio stream manipulation.
Provide an estimated timeline and quote." (client-provided description)