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IQ-9075-EVKIQ-8275-EVKStable

4

Cameras (IQ-9075-EVK)

3

Cameras (IQ-8275-EVK)

1

IFE Hardware Used

SFE

Bus Fetch Engine
Platform Scope:
This feature is applicable for IQ-9075-EVK and IQ-8275-EVK only.
Both platforms have two IFEs that natively support real-time de-bayering of bayer camera images.

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01 · What Is It?

The Offline IFE feature allows a single IFE hardware instance to process bayer images from multiple cameras by running in offline mode. Instead of real-time de-bayering, frames are first stored in DDR via IFE-Lite’s RDI port, then fetched by the IFE using the SFE Lite bus engine for bayer-to-YUV conversion. 
Real-Time Path:    Sensor → IFE-Lite (RDI) → DDR
Offline Path:      DDR → SFE Lite (Fetch) → IFE Offline → YUV Output

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02 · What Does It Control?

Controls how many concurrent bayer cameras can stream simultaneously by reusing a single IFE in offline mode rather than requiring dedicated IFE instances per camera.
CapabilityWithout Offline IFEWith Offline IFE
Concurrent bayer cameras2 cameras max4 cameras (IQ-9075-EVK)
IFE instances required1 per 2 cameras1 shared (offline)
Frame routingDirect sensor → IFESensor → IFE-Lite → DDR → IFE
SFE Lite usageNot usedUsed as bus fetch engine
IQ-8275-EVK camera count2 cameras max3 cameras

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03 · Feature Validation

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

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Platform Reference Configurations

Ensure you have connected one of the following camera configurations:
  • IQ-9075-EVK: Four OV9282 MIPI cameras connected to four MIPI CSI slots (0, 1, 2, and 3).
  • IQ-8275-EVK: Three OV9282 MIPI cameras connected to three MIPI CSI slots (0, 1, and 2).

IQ-9075-EVK Config

KeyValue
Camera count4
SensorOV9282 MIPI
MIPI CSI slots0, 1, 2, 3
FormatNV12 1280×720

IQ-8275-EVK Config

KeyValue
Camera count3
SensorOV9282 MIPI
MIPI CSI slots0, 1, 2
FormatNV12 1280×720
1

Collect user log

Collect User Log
# On device console
journalctl -f > /opt/user_log.txt
2

Collect kernel log

Collect Kernel Log
dmesg -w  > /opt/kernel_log.txt
3

Run GStreamer pipeline with multicamera-hint=true

Run the following for each camera (change camera=0 to 1, 2, 3 accordingly):
GStreamer Pipeline
gst-launch-1.0 -e qtiqmmfsrc name=camsrc camera=0 multicamera-hint=true ! \
video/x-raw,format=NV12,width=1280,height=720,framerate=30/1,\
interlace-mode=progressive,colorimetry=bt601 ! v4l2h264enc \
capture-io-mode=4 output-io-mode=5 extra-controls="controls,video_bitrate=6000000,\
video_bitrate_mode=0;" ! h264parse ! mp4mux ! filesink location=/opt/mux_avc.mp4
Repeat for each camera
Run similarly for camera=1, camera=2, and camera=3 (IQ-9075-EVK) or up to camera=2 (IQ-8275-EVK) with multicamera-hint=true on each.
4

Verify log output

After running the pipeline, confirm the feature is active by checking these exact log entries:User log — CamX pipeline status:
User Log Trace
CamX: [CORE_CFG]3509 3556 [CORE   ] camxpipeline.h:4222 SetPipelineStatus() RealTimeFeatureZSLPreviewRawOfflineIFE_0_cam_0 status is now PipelineStatus::STREAM_ON
Kernel log — IFE acquisition confirmation:
Kernel Log Trace
CAM_INFO: CAM-ISP: cam_ife_hw_mgr_print_acquire_info: 1733: 0:4:11.835 Acquired Single IFE[0] SFE[0] OFFLINE: Y with [9 pix] [0 pd] [0 rdi] ports for ctx:1
OFFLINE: Y in the kernel log confirms the IFE is running in offline mode. STREAM_ON in the user log confirms the CamX pipeline is live.

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🛠️ Troubleshooting

IssueCauseFix
Only 2 cameras stream; 3rd/4th droppedmulticamera-hint=true not set on all streamsEnsure every gst-launch call includes multicamera-hint=true
OFFLINE: N in kernel logOffline IFE not acquired — possible resource conflictRestart camera service; verify no other pipeline is holding IFE
Pipeline stalls or drops framesDDR bandwidth saturation at 4-camera loadReduce framerate to 24fps or lower resolution to 720p