Capture Live GSM Call Voice Packets

@C0RETECHIES

Hi there, You're looking to build an application that taps into the live, two-way audio of a GSM call on Android. This requires capturing both the microphone input (uplink) and the remote party's audio (downlink) simultaneously, bypassing the typical OS restrictions that isolate this stream from third-party apps. Technical approach: We'll develop a native Kotlin app. On non-rooted devices (Android 10+), the most viable method is using an Accessibility Service to capture system audio output (downlink) while an AudioRecord instance captures the microphone (uplink). A foreground service will manage, synchronize, and mix these two raw PCM streams. Core modules: - Call State Monitor: Uses TelephonyManager to automatically start/stop capture when a call becomes active or ends. - Dual-Stream Capture Service: A persistent service handling the accessibility and microphone audio sources concurrently. - Audio Mixer & Encoder: Merges the two streams into a single, coherent audio file (e.g., WAV). Relevant systems: We previously built an Android Call Management Software with a custom dialer, call recording capabilities, and direct integration with a FreeSWITCH call server, giving us direct experience with low-level audio and call handling on Android. Implementation strategy: We'll start with a proof-of-concept on a target Android version to validate the dual-stream capture technique. The critical challenge is ensuring proper stream synchronization, which we will test across different manufacturer devices as their audio routing implementations can differ significantly. Regards, Rohit

@farooqtahir2013

With over a decade in the Network and Cybersecurity field, I have ample experience working with the tools and technologies necessary to successfully deliver on this project. My familiarity with GSM telephony, Android, and VoIP systems are assets essential for capturing live voice stream for active phone calls. The emphasis of my career has been on planning, designing, and implementing network infrastructures for various organisations; this project provides the perfect opportunity to utilise my skills at the right pace. My proficiency expands beyond Android as I have worked extensively with Asterisk PBX,Linux environment and its related technologies. These experiences mean that I can not only capture the live voice packets as needed for this project but can also remain aware of any limitations or device-specific requirements that might come up. In short, from my expertise in networking to cybersecurity to Voice over IP systems, I possess a unique set of skills tailor-made for this project. Quite simply, no one understands the task at hand better than I do and you can be sure that I will deliver nothing less than 100% satisfaction in a timely manner. Thank you for considering my candidacy and I look forward to working together on this impactful task!

@softsolution2000

I have extensive experience in telecom and Android development, making me well-equipped to handle the task of capturing live GSM call voice packets. My technical approach involves utilizing Linux, Android, and Asterisk PBX to access both incoming and outgoing audio streams during the call. I understand the complexities of mobile voice processing and have worked on similar projects in the past. I am confident in my ability to meet the requirements and provide a high-quality solution for this project. See the above links please.