I’ ## Freelancer Task: Magisk Module for SIP ⇄ SIM Audio Bridge (Jack-Only) ### Project Type Android system / audio engineering (Magisk, AudioPolicy, rooted devices) ### Target Devices Xiaomi Redmi 6 ** Android **8–9** (6A) * **Rooted with Magisk** * **NO custom ROM building** --- ## Objective Create a **Magisk module** that **forces all SIP and SIM call audio through the 3.5 mm wired headset jack only**, enabling **physical TRRS loopback audio bridging**, with **DSP fully disabled**. ## Technical Requirements ### Audio Routing (Critical) * Force **wired headset / wired headphone** as the **only valid**: * Audio **output** device * Audio **input** device * Disable or deprioritize: * Speaker * Earpiece * Bluetooth SCO / A2DP * USB audio (if it steals routing) **Files to override (systemless via Magisk):** * `/vendor/etc/audio_policy_configuration.xml` * OR `/vendor/etc/audio_policy.conf` (older builds) --- ### DSP / Audio Effects (Critical) Disable **all voice processing** that interferes with loopback audio: * Acoustic Echo Cancellation (AEC) * Noise Suppression (NS) * Automatic Gain Control (AGC) **Files to override (systemless):** * `/vendor/etc/audio_effects.conf` or `.xml` * `/system/etc/audio_effects.conf` (if referenced) DSP must be **completely off** for: * `STREAM_VOICE_CALL` * `MODE_IN_CALL` * `VOICE_COMMUNICATION` --- ### Magisk Module Structure Deliver a standard Magisk module with: ``` SIP_SIM_JackOnly/ ├─ module.prop ├─ post-fs-data.sh ├─ service.sh └─ system/ ├─ vendor/ │ └─ etc/ │ ├─ audio_policy_configuration.xml (or .conf) │ └─ audio_effects.conf / .xml └─ etc/ └─ audio_effects.conf (if needed) ``` --- ### Boot-Time Enforcement (Required) In `service.sh`: * Disable Bluetooth audio routing (SCO/A2DP) * Ensure wired headset is preferred at boot * Optional but preferred: * Restart `audioserver` once after boot * Watchdog to re-enforce routing if audio stack restarts --- ### SIP App Compatibility * SIP apps must be able to use: * `STREAM_MUSIC` for playback * Do **not** rely on SIP apps using `VOICE_COMMUNICATION` --- ## Validation & Testing (Mandatory) The freelancer must provide: * `dumpsys audio` output **before vs after** * Proof that: * Calls **never route to speaker** * Wired headset remains active throughout calls * DSP does not suppress injected loopback audio * Test with: * One SIP app (e.g., Linphone or similar) * One SIM call --- ## Deliverables 1. **Flashable Magisk module** (zip or folder) 2. All modified config files with comments 3. Short README: * Install steps * Test procedure * Known limitations 4. Confirmation: --- ## Skillset Required * Android audio policy & routing * Magisk systemless modules * Rooted device debugging * `dumpsys audio`, `logcat`, `audioserver` * Xiaomi / Qualcomm audio stack familiarity --- ## Timeline * 3–days for first working version * --- ## Clarifying Notes for Freelancer * Physical **TRRS loopback cable is already designed** * Your job is **software enforcement only** * This is a **telecom bridge**, not a consumer phone * Stability > elegance --- ## Success Criteria (Simple) > During SIP ⇄ SIM calls, **audio only flows through the wired headset jack**, with **no DSP**, **no speaker**, and **no ROM build**. ### the freelancer do not have a redmi 6 in his hand so the job have to be done remote using anydesk and a redmi 6 connected to it 1. we will need to test it by A.. have a sip server ready with a sip client that is located at the freelancer location B. the redmi 6 will dial a local number to party 2 C. now freelancer can talk with the sip client to party 2 2. we will build the loopback audio jack based on the diagram provided 3. . if the test is good we need to method how to implement the magisk module to 200 redmi 6 phone