# \[Working PoC\] AMB82 Mini — Local WebRTC H.264 Streaming to Firefox Without AWS **URL:** \ **Category:** SDK\ **Tags:** evb-amb82\ **Created:** [October 19, 2026, 2:40am UTC](https://forum.amebaiot.com/t/working-poc-amb82-mini-local-webrtc-h-264-streaming-to-firefox-without-aws/5168 "2026-10-19T02:40:06Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Oleksii\_Semenenko](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/oleksii_semenenko/32/3561_2.png) [@Oleksii\_Semenenko](https://forum.amebaiot.com/u/Oleksii_Semenenko)\ **Post date:** [October 19, 2026, 2:40am UTC](https://forum.amebaiot.com/t/working-poc-amb82-mini-local-webrtc-h-264-streaming-to-firefox-without-aws/5168/1 "2026-10-19T02:40:06Z")
Hello everyone! I would like to share the results of an experiment with the **Realtek AMB82 Mini (RTL8735B)**. My goal was to stream Full HD H.264 video directly to a web browser over WebRTC, without AWS Kinesis, external signaling services, or a separate video transcoding server. After adapting the official FreeRTOS SDK, I managed to establish a working local WebRTC connection between the AMB82 Mini and Firefox. **Confirmed result: 1920×1080 H.264 video, approximately 110–120 ms end-to-end latency in preliminary local tests.** ## 1. Why I Started This Project I initially used the Arduino SDK with H.264 streaming over TCP/WebSocket. The video worked, but occasional freezes and delays, especially around large keyframes and network stalls, motivated me to investigate UDP-based real-time transport. I decided to try the existing FreeRTOS WebRTC implementation, replacing its AWS-dependent signaling layer with a small local signaling server. ## 2. Hardware and Software **Hardware:** - Realtek AMB82 Mini (RTL8735B) - Stock JXF37/JXF37P camera module - Wi-Fi network - Windows PC **Software:** - Official Ameba Pro2 FreeRTOS SDK - GCC ARM toolchain 10.4.1 - CMake with MSYS2/MinGW build environment - mbedTLS 2.28.1 - Node.js signaling server - Mozilla Firefox Official SDK: [GitHub - Ameba-AIoT/ameba-rtos-pro2: Realtek Official IoT Software Development Kit for Ameba Series SoC: (Ameba Pro2) · GitHub](https://github.com/Ameba-AIoT/ameba-rtos-pro2) The base SDK example is `kvs_webrtc_v2_mmf`. ## 3. Architecture The system uses two separate channels. **Signaling:** Firefox → WebSocket → Node.js → HTTP → AMB82 Mini The browser connects to `/signal` using WebSocket. The AMB82 uses a small HTTP client to exchange SDP and ICE messages with the Node.js server. **Video:** AMB82 Mini → H.264 → RTP/SRTP → UDP → Firefox Video is transmitted directly between the AMB82 and the browser. Node.js does not receive, decode, transcode, or relay the video stream. ## 4. FreeRTOS SDK Modifications I used the official `kvs_webrtc_v2_mmf` example as the starting point. The main modifications were: 1. Introduced an `ASC_LOCAL_SIGNALING` CMake option to select a custom local signaling controller instead of the original AWS signaling implementation. 2. Added a lightweight HTTP signaling adapter for the AMB82. 3. Implemented a small Node.js server to bridge WebSocket browser messages and HTTP device messages. 4. Adapted portions of the DTLS/mBedTLS integration for the SDK’s mbedTLS 2.28.1 configuration. 5. Applied IPv4-only compatibility fixes to ICE-related source files. 6. Disabled the unused SCTP library during this experiment. 7. Bypassed the blocking SNTP wait in the experimental local mode. This is a laboratory workaround, not a production-ready solution. The WebRTC media implementation itself remains based on the Realtek SDK. **Important:** These are real source modifications, not just CMake options. A clean upstream SDK requires the corresponding adapter and compatibility patches before it can build this configuration. ## 5. Important: Configure the Camera Sensor This was the most significant hardware-related problem during the experiment. Initially, the WebRTC connection was established successfully, but Firefox received no video RTP packets. The UART output included: `VOE command 0x206 fail ret 0x0` I discovered that the FreeRTOS SDK was configured for the GC2053 sensor, while my AMB82 Mini uses the stock JXF37 camera. The sensor configuration is located at: `project/realtek_amebapro2_v0_example/inc/sensor.h` For my board, I used: - `SENSOR_MAX = 2` - `sen_id = { SENSOR_DUMMY, SENSOR_F37 }` - `USE_SENSOR = SENSOR_F37` - `manual_iq = { "iq", "iq_f37" }` - `MANUAL_SENSOR_IQ = 0xFF` The SDK already contained the necessary binary files: - `sensor_f37.bin` - `iq_f37.bin` - `fcs_data_f37.bin` After modifying `sensor.h`, I performed a clean build and verified the generated `amebapro2_sensor_set.json`. The selected `SENSOR_SET1` correctly referenced all three F37 binary files. **After flashing the new F37 configuration, video streaming started working.** For anyone experiencing a successful WebRTC handshake but no video packets, I strongly recommend checking the actual sensor model and generated ISP configuration before debugging RTP. ## 6. Building the Firmware I created a separate CMake build directory to preserve the original AWS example. The important configuration options were: - `EXAMPLE:STRING=kvs_webrtc_v2_mmf` - `ASC_LOCAL_SIGNALING:BOOL=ON` - `BUILD_USRSCTP_LIBRARY:BOOL=OFF` - `CMAKE_C_USE_RESPONSE_FILE_FOR_INCLUDES=ON` - `CMAKE_CXX_USE_RESPONSE_FILE_FOR_INCLUDES=ON` The build also uses the SDK’s `toolchain.cmake`. For Windows, I recommend keeping the SDK path short. I used `D:\rtk` because very long compiler command lines caused problems in my environment. After configuring the project, the final build command was: `cmake --build . --target flash --parallel 1` The generated firmware image was: `flash_ntz.bin` I flashed it using the official Realtek UART programming tool. Make sure the programming tool, flash image, and boot mode match your board. Back up your working firmware before replacing it. ## 7. Connecting the Browser The Node.js server listens on port `8080`. The AMB82 connects to the server over the local network. Once the board is online, the browser can open: `http://localhost:8080/` The browser sends a WebRTC SDP Offer. The AMB82 generates the SDP Answer, and both peers exchange ICE candidates. For the initial Firefox LAN tests, I temporarily disabled mDNS host candidate obfuscation using: `about:config` → `media.peerconnection.ice.obfuscate_host_addresses` → `false` This was necessary because the embedded ICE implementation did not resolve Firefox’s `.local` host candidates. This is only a testing workaround and should not be considered a production solution. I also needed a compatibility fix in the Node.js server to recover an incorrectly formatted SDP Answer generated by the experimental signaling adapter. The correct long-term solution is to fix JSON encoding in the embedded adapter. ## 8. Results The following were confirmed on real hardware: - Wi-Fi connection established successfully. - Custom local signaling operational without AWS. - SDP Offer/Answer exchanged successfully. - ICE connection established. - WebRTC PeerConnection reached `connected`. - Firefox received and decoded H.264 video. - Full HD video displayed successfully. In one diagnostic snapshot, Firefox reported: | Metric | Value | | --- | --- | | RTP packets received | 4,589 | | Frames received | 2,239 | | Frames decoded | 2,238 | | Keyframes decoded | 75 | | ICE state | connected | | Peer connection | connected | Preliminary end-to-end latency measurements using a visible stopwatch were approximately **110–120 ms**. These measurements are indicative, not a controlled latency or packet-loss benchmark. ## 9. Current Limitations This implementation is still an experimental proof of concept. - Tested successfully on a trusted local Wi-Fi network. - Currently supports one viewer. - Does not provide authentication or HTTPS/WSS. - Does not provide STUN/TURN NAT traversal. - Opening the signaling port from the internet is not sufficient for remote video playback. - Session teardown and reconnect behavior require further work. - SNTP handling and production security need to be restored and validated. - Long-term stability and packet-loss behavior have not yet been benchmarked. I also tested the signaling server through an external internet connection. SDP exchange worked, but ICE failed because the peers did not have a usable UDP route through NAT. This is expected with the current host-candidate-only configuration. ## 10. Source Code and Reproduction The working experiment consists of a local signaling adapter, a Node.js signaling server, a browser viewer, and several compatibility patches for the official SDK. I am preparing these modifications for sharing separately from the Realtek SDK, so that users can apply them to their own SDK checkout. I intend to share the patch bundle and a clean build procedure after reviewing the dependencies and redistribution terms. In the meantime, I hope these findings are useful to anyone experimenting with local WebRTC on AMB82 Mini, especially the JXF37 sensor configuration. I would also be interested to hear whether Realtek has a recommended implementation for private-network WebRTC signaling without AWS, and whether there is a preferred way to support local ICE and future TURN integration. Thanks to the Realtek developers and community for maintaining the SDK and making this kind of experimentation possible! ---
**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/ameba/original/2X/7/7009caf971627f868f3de3d34312aff2d14c61e3.png) [@system](https://forum.amebaiot.com/u/system)\ **Post date:** [October 19, 2026, 2:40am UTC](https://forum.amebaiot.com/t/working-poc-amb82-mini-local-webrtc-h-264-streaming-to-firefox-without-aws/5168/2 "2026-10-19T02:40:15Z")
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