OpenIMP is an open implementation of Ingenic's libimp video API. It runs against the stock ISP, sensor, FrameSource, and AVPU kernel drivers.

The public encoder graph is shared by T23, T30, T31, T40, and T41. The hardware backend is selected only where the SoC ABI actually differs:

• src/t40/openimp_p2_encoder.c owns the public encoder lifecycle.
• src/t40/codec-t40.c owns the shared AVPU codec backend.
• include/openimp/openimp_avc.h exposes that backend independently of the IMP graph for physically contiguous NV12 producers such as V4L2 DMA-BUF.
• include/openimp/openimp_tuning.h and openimp-tuningd keep image policy and gain feedback independent of capture/encoder ownership. See docs/TUNING_DAEMON.md.
• src/al_avpu.c, src/device_pool.c, src/fifo.c, and src/hw_encoder.c provide the common hardware path.
• src/t30/ provides the native T30 Helix descriptor and legacy /dev/soc_vpu channel adapter.
• src/t31/, src/framesource/framesource_tseries.c, src/isp/isp_tseries.c, src/kernel_interface.c, and src/dma_alloc.c are the T31 stock-driver ABI seam.
• src/t40/openimp_p1.c and src/t40/openimp_p2_dma.c are the corresponding T4 stock-driver seam, with explicit T40/T41 ABI branches.

T31 does not carry a separate scheduler, rate-control graph, or codec implementation. Platform conditionals are restricted to real ABI differences such as public structure sizes, ioctl layouts, device behavior, and cache maintenance.

Audio processing belongs to libaudioProcess-neo. Logging and system support libraries belong to ingenic-system-libs-neo. OpenIMP provides the native IMP audio I/O layer on T31 and T40/T41. HPF, noise suppression, and AGC are loaded at runtime from the installed libaudioProcess-neo; OpenIMP does not replace that effects library or build replacement libsysutils/libalog libraries.

# T23
./build-for-device.sh T23
# or
make t23

# T30/T30X
./build-for-device.sh T30
# or
make t30

# T31 (default)
./build-for-device.sh
# or
make t31

# T40/T40XP
./build-for-device.sh T40
# or
make t40

# T41/T41NQ
./build-for-device.sh T41
# or
make t41

Outputs:

• build/t23/libimp.so
• build/t30/libimp.so
• build/t31/libimp.so
• build/t40/libimp.so
• build/t41/libimp.so

Each target build rejects a produced library that depends on an OEM libimp.so. Target builds record RVD import coverage where a matching Raptor binary is available.

• T30: source-only native Helix H.264 through the stock 3.10.14 /dev/soc_vpu ABI. A T30X VDB1 streams both configured channels over RTSP; main and sub rings sustain 25 fps with decoder-clean I/P GOPs, ping-pong reconstruction, and feedback rate control. The 1920x1080 Main stream runs near the OEM bitrate under the same Raptor configuration.
• T40: decoder-clean, resolution-independent H.264 streaming through the stock T40XP ISP and AVPU drivers.
• T31: the shared T40-derived encoder ran for more than 1,000 hardware frames on a stock-driver GC2053 camera. Main 1920x1080 H.264 and AAC probed and decoded without H.264 errors during the device smoke cycle. The T31 FrameSource seam now preserves the kernel DQBUF completion timestamp in the OEM frameInfo.timeStamp slot at offset 0x20; the shared encoder copies that capture timestamp into each public pack instead of substituting encoder-start wall time. A 30-second live decode completed 721 frames with zero duplicate/non-monotonic DTS warnings, compared with 11 warnings in the prior 12-second checkpoint.
• Capture ownership is an explicit platform policy: T31 returns a frame after AVPU completion, while T40 returns it immediately after submission. This preserves full-rate capture on both stock-driver ABIs.
• T41: active correctness bring-up. The build covers every RVD/RAD IMP import, the shared pipeline runs dual-channel FrameSource capture, and the native AVPU backend emits decoder-clean High-profile H.264 at both configured geometries. Raptor currently uses embedded-ring copy mode for correctness; its cross-process cached-rmem reference path is not yet coherent. ISP parity and configured-rate delivery remain in progress.
• T41's standalone V4L2 path exports capture buffers as DMA-BUF and submits their bus addresses directly to the shared OpenIMP AVC backend. A 250-frame 2560x1440 High-profile sample completed in 10.20 seconds, reported 25/1 fps, and decoded without warnings or pixel copies.
• Sensor configuration and tuning remain owned by the stock ISP driver, so the userspace encoder is sensor-independent.

See docs/T40_STATUS.md and docs/T41_STATUS.md for the corresponding runtime gates. See docs/T30_STATUS.md for the legacy Helix bring-up and its current limitations. See docs/PROFILING.md for the opt-in on-device stage profiler, the current T41 QHD hotspot data, and the MXU2/MXU3 assessment.