Support software TNR/MCTF - Qualcomm Dragonwing Documentation

IQ-9075-EVKIQ-8275-EVKGPU Accelerated

GPU

Processing Engine

NV12_Q08C

Input Format

MCTF

Noise Reduction

Platform Scope:
SW TNR / MCTF is enabled only for IQ-9075-EVK and IQ-8275-EVK.

01 · What Is It?

Motion Compensated Temporal Filtering - a software-based video quality filter that reduces noise across frames — runs on the GPU where IPE hardware MCTF is unavailable. MCTF improves preview and video quality by reducing temporal noise and enhancing motion clarity. The SW implementation runs on the GPU, performing inter-frame blending in static regions and applying global motion compensation transforms.

02 · What It Controls

SW MCTF Workflow Pipeline:
Current Frame  →  ME Matrix  →  Warp (prev frame)  →  Alpha Mask  →  Blend  →  Output Frame
Previous Output →  Noise Calc  →  Blend Input  ↗

Stage	What it does	Impact if skipped
Motion Estimation (ME)	Calculates transform matrix between current and previous frame	No motion compensation → ghosting artifacts
Warp	Warps previous output frame using ME matrix	Misaligned blend → smearing
Alpha Mask	Classifies background vs. local motion regions	Static noise not reduced, moving areas over-blended
Blend	Merges current + previous frames using alpha mask + noise estimate	Temporal noise visible in output video

For high-motion scenarios (robotics, automotive), reducing MCTF blend strength prevents temporal ghosting on fast-moving objects.

03 · Validation

Connect to the device console using SSH. See How To SSH? for instructions.

Collect user log

Monitor the CamX core configuration status in real-time.

Log Collection

# On device console
journalctl -f > /opt/user_log.txt

Collect kernel log

Capture ISP hardware manager events and acquisition info.

Kernel Logging

dmesg -w > /opt/kernel_log.txt

Run GStreamer pipeline with sw-tnr=true

Execute the pipeline using the NV12_Q08C format and enable the software TNR flag.

GStreamer (SW MCTF Enablement)

gst-launch-1.0 -e qtiqmmfsrc name=camsrc video_0::type=preview sw-tnr=true ! \
video/x-raw,format=NV12_Q08C,width=1280,height=720,framerate=30/1 ! \
v4l2h264enc capture-io-mode=4 output-io-mode=5 \
extra-controls="controls,video_bitrate=6000000,video_bitrate_mode=0;" ! \
h264parse ! mp4mux ! filesink location=/opt/cam_prev.mp4

Verify log output

Confirm the feature is active by checking these exact log entries in the user log:CamX pipeline status:

User Log Verification

CamX: [CORE_CFG] 3509 3556 [CORE] camxpipeline.h:4222 SetPipelineStatus()
RealTimeFeatureZSLPreviewRawSWMCTF_0_cam_0 status is now PipelineStatus::STREAM_ON

MCTF library initialization:

User Log Verification

CamX: [ INFO] 3509 3556 [CHI ] camxchimoduleswmctf.cpp:328 Initialize()
libmctf Version: 1.0.0

STREAM_ON confirms the CamX pipeline is live with MCTF enabled. The libmctf Version string confirms the software library is initialized on the GPU.

🛠️ Troubleshooting / Known Issues — SW TNR/MCTF

Issue / Observation	Details / Notes
Ghosting artifacts on fast-moving objects	High-motion scenarios (robotics, automotive) can cause temporal ghosting — reduce MCTF blend strength to mitigate
`STREAM_ON` status not seen in user log	CamX pipeline may not be live with MCTF enabled — verify log entry: `SetPipelineStatus() ... status is now PipelineStatus::STREAM_ON`
`libmctf` library not initialized	If `libmctf Version: 1.0.0` is absent from user log, the SW MCTF library failed to initialize on the GPU — check `camxchimoduleswmctf.cpp:328 Initialize()`

GPU

NV12_Q08C

MCTF

​01 · What Is It?

​02 · What It Controls

​03 · Validation

​🛠️ Troubleshooting / Known Issues — SW TNR/MCTF

01 · What Is It?

02 · What It Controls

03 · Validation

🛠️ Troubleshooting / Known Issues — SW TNR/MCTF