cv181x-media

name	cv181x-media
description	Expert guide for CV181X/CV182X/CV180X (SG200X) multimedia development using CVI MPI API. Use this skill when working with: VI (video input/camera/ISP), VPSS (video processing/scaling/crop), VENC (H.264/H.265/JPEG encoding), VDEC (decoding), VB (video buffer pools), SYS binding, or any CVI_* API calls. Covers camera pipeline setup, offline VPSS processing, VB pool planning, and error diagnosis (ERR_VPSS_NOBUF, ERR_VB_NOBUF). API details in references/.
compatibility	Best used with access to the target SDK headers or samples, the target chip or board model, and relevant runtime logs when debugging.
version	2.3.0

CV181X/CV182X/CV180X Multimedia Skill

Instructions

Step 1: Confirm the missing context before giving exact API guidance

When the user asks about exact API behavior, limits, struct fields, or error diagnosis, first confirm the available context:

• Target chip or board model
• SDK version or SDK source tree path
• Relevant code snippet, pipeline stage, or runtime log

If required context is missing:

• State that the answer is limited or provisional
• Ask for the specific missing artifact needed to verify the claim
• Do not present SDK-version-specific behavior as universal unless it is confirmed in the available references

Step 2: Prefer authoritative sources

Use the source order already defined in this skill: SDK headers first, SDK samples second, external material only if it is verified against the headers or samples

Complete Reference Index

All 18 reference files with searchable keywords:

File	Keywords	Key APIs
references/vi.md	camera, sensor, ISP, MIPI, DEV, PIPE, CHN, video input	CVI_VI_*, CVI_ISP_*, CVI_MIPI_*
references/vpss.md	scaling, crop, resize, rotate, cvtColor, format conversion, group, channel	CVI_VPSS_*, SendFrame, GetChnFrame
references/venc.md	encode, H.264, H.265, HEVC, JPEG, MJPEG, bitrate, GOP	CVI_VENC_*, SendFrame, GetStream
references/vdec.md	decode, JPEG decode, H.264 decode, bitstream	CVI_VDEC_*, SendStream, GetFrame
references/vb.md	buffer pool, VB, memory, block, pool sizing, CommonPool	CVI_VB_*, GetBlock, ReleaseBlock
references/sys.md	bind, unbind, init, exit, VI_VPSS_MODE, VPSS_MODE	CVI_SYS_*, Bind, SetVIVPSSMode
references/vo.md	display, output, LCD, HDMI, layer, framebuffer	CVI_VO_*, SendFrame, ChnShow
references/rgn.md	OSD, overlay, region, text, graphics, privacy mask	CVI_RGN_*, AttachToChn, SetBitMap
references/gdc.md	distortion, fisheye, LDC, rotation, mesh, warp	CVI_GDC_*, AddCorrectionTask
references/audio.md	audio, microphone, speaker, AI, AO, AENC, ADEC, VQE	CVI_AI_*, CVI_AO_*, CVI_AENC_*

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Quick Lookup

By Task

Task	Reference
Camera capture	references/vi.md
Video scaling/crop/rotate	references/vpss.md
H.264/H.265/JPEG encode	references/venc.md
JPEG/H.264 decode	references/vdec.md
Buffer pool planning	references/vb.md
Module binding	references/sys.md
Video display	references/vo.md
OSD/overlay	references/rgn.md
Fisheye correction	references/gdc.md
Audio capture/playback	references/audio.md
DMA memory	references/ion.md
Debugging	references/debug.md
Error diagnosis	references/troubleshooting.md

By Error Code

Error	Reference
ERR_VPSS_NOBUF (0xc006800e)	references/troubleshooting.md
ERR_VB_NOBUF	references/vb.md
ERR_VENC_NOBUF	references/venc.md
ERR_VI_NOTREADY	references/vi.md
Bind failure	references/sys.md

By Pipeline

Pipeline	References
Camera -> VPSS (online)	vi.md, vpss.md, sys.md
File -> VPSS (offline)	vpss.md, vb.md
JPEG decode -> VPSS	vdec.md, vpss.md
VPSS -> VENC	venc.md, sys.md
Dual pipeline	references/binding-cookbook.md

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Private Operating Procedures

1. Authoritative Source Order

1. SDK headers in cvi_mpi/include/
2. SDK samples in cvi_mpi/sample/
3. Never: external repos without header verification

2. VPSS Input Ownership

• VPSS group for ONE input type: ISP or MEM
• Never switch between Bind and SendFrame at runtime
• Concurrent ISP + MEM: separate groups and VB pools

3. VI-VPSS Mode Selection

Mode	Use Case
VI_OFFLINE_VPSS_ONLINE	Camera pipeline (recommended)
VI_OFFLINE_VPSS_OFFLINE	Maximum flexibility
VI_ONLINE_VPSS_ONLINE	Lowest latency

4. Binding Requirements

• Control plane: CVI_SYS_Bind establishes relationship
• Data plane: Mode setting determines data flow
• Binding required even in ISP direct mode
• Unbind before stop; bind after start

5. Camera Readiness

• Warm up pipeline after start
• Discard first few frames before capture

6. VENC SendFrame Memory

• Must use VB pool, not raw ION
• Use CVI_VB_GetBlock(), set frame.u32PoolId

7. Diagnostics

On failure: /proc/cvitek/{sys,vb,vi,vpss,vdec,venc}

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Module Init Order

1. CVI_VB_SetConfig + CVI_VB_Init
2. CVI_SYS_Init
3. CVI_SYS_SetVIVPSSMode
4. CVI_SYS_SetVPSSModeEx
5. VI: sensor -> mipi -> dev -> pipe -> isp -> chn
6. VPSS: CreateGrp -> SetChnAttr -> EnableChn -> StartGrp
7. CVI_SYS_Bind
8. Warmup

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VPSS Mode Reference

VPSS_MODE_DUAL

DEV0 = VPSS_INPUT_MEM   -> Offline (SendFrame)
DEV1 = VPSS_INPUT_ISP   -> Camera (Bind)

VpssDev Selection

Input	VpssDev
Camera (ISP)	1
File/Memory	0

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VB Pool Sizing

Size = COMMON_GetPicBufferSize(w, h, fmt, DATA_BITWIDTH_8, COMPRESS_MODE_NONE, 0)

Counts: Camera=4-6, VPSS=3-4, Encode=2-3, Decode=4-6

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Debug Commands

cat /proc/cvitek/sys | grep -A 10 "BIND RELATION"
cat /proc/cvitek/vb | grep -A 20 "PoolId"
cat /proc/cvitek/vi | grep -A 5 "VI CHN STATUS"
cat /proc/cvitek/vpss | grep -A 20 "WORK STATUS"
echo "VI=7" > /proc/cvitek/log

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Version: 2.4.0 | Updated: 2026-01-20 | Platform: SG200X