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# ANSFrame Multi-Resolution Architecture Plan
## Detailed Comparison: Current vs ANSFrame
### Test Configuration
- GPU: RTX 4070 Laptop (8 GB VRAM)
- Cameras: 5 running (3840×2160, 2880×1620, 1920×1080)
- AI Tasks: 12 (subscribing to cameras)
- Engines: 7 TRT engines
- Decode: Software (YUV420P, CPU)
- Frame rate: SetTargetFPS(100) = ~10 FPS per camera
- Baseline: 8.4 hour stable run (ANSLEGION42), 1,048,325 inferences
### Per-Frame Generation (inside GetImage)
| Step | Current | ANSFrame |
|---|---|---|
| Decode YUV420P | ~5ms (CPU) | ~5ms (same) |
| Full res BGR (cvtColor) | ~4-8ms (4K YUV→BGR) | ~4-8ms (same) |
| 640×640 letterbox | Not done here | ~0.8ms (resize YUV planes + cvtColor, done ONCE) |
| 1080p display | Not done (returns 4K) | ~1.5ms (resize YUV planes + cvtColor, done ONCE) |
| **Total GetImage time** | **~4-8ms** | **~6-10ms** (+2ms for 2 extra sizes) |
### Clone & Dispatch to AI (per clone × 12 AI tasks)
| Step | Current (4K clone) | ANSFrame (1080p clone) |
|---|---|---|
| Clone image size | 3840×2160×3 = **24.9 MB** | 1920×1080×3 = **6.2 MB** |
| memcpy time per clone | **3-5ms** | **0.8-1.2ms** |
| 12 clones total size | **299 MB** | **74 MB** |
| 12 clones total time | **36-60ms** | **10-14ms** |
### AI Preprocessing (per AI task)
| Step | Current | ANSFrame |
|---|---|---|
| Receive image | 4K BGR (24.9 MB) | 1080p BGR (6.2 MB) + ANSFrame ref |
| Local clone in engine | 24.9 MB memcpy (~3ms) | 6.2 MB memcpy (~0.8ms) |
| CPU letterbox resize | 4K→640×640 (~2-3ms) | **SKIP** (use ANSFrame.inference, 0ms) |
| BGR→RGB | 640×640 (~0.3ms) | 640×640 (~0.3ms) |
| GPU upload | 1.2 MB (~0.1ms) | 1.2 MB (~0.1ms) |
| **Total preprocess per task** | **~5-6ms** | **~1.2ms** |
| **12 tasks total** | **~60-72ms** | **~14ms** |
### Pipeline Crop Quality (ALPR, Face Recognition)
| Step | Current | ANSFrame |
|---|---|---|
| Detection from | 4K image | 1080p display (detection) → ANSFrame.fullRes (crop) |
| Crop source | Same 4K image | ANSFrame.fullRes (4K original) |
| **Crop quality** | **4K** | **4K** (identical) |
### Total Processing Time Per Frame Cycle
| Phase | Current (4K) | ANSFrame | Savings |
|---|---|---|---|
| GetImage generation | 4-8ms | 6-10ms | -2ms |
| Clone × 12 | 36-60ms | 10-14ms | **+22-46ms** |
| AI preprocess × 12 | 60-72ms | 14ms | **+46-58ms** |
| TRT inference × 12 | 60-600ms | 60-600ms | Same |
| Postprocess × 12 | 12-60ms | 12-60ms | Same |
| **Total CPU overhead** | **112-200ms** | **28-38ms** | **~80-160ms saved** |
| **Total with inference** | **172-800ms** | **88-638ms** | **~80-160ms saved** |
### RAM Usage
| Resource | Current | ANSFrame |
|---|---|---|
| GetImage output (per camera) | 24.9 MB (4K BGR) | 32.3 MB (3 images) |
| Clones in flight (12 tasks) | 12 × 24.9 = **299 MB** | 12 × 6.2 = **74 MB** |
| AI local clone (12 tasks) | 12 × 24.9 = **299 MB** | 12 × 6.2 = **74 MB** |
| ANSFrame shared data | 0 | 32.3 MB (shared, refcounted) |
| **Total RAM per frame cycle** | **~623 MB** | **~213 MB** |
| **Peak RAM (5 cams, 2-3 cycles)** | **~1.2-1.9 GB** | **~0.4-0.6 GB** |
### GPU / VRAM Usage
| Resource | Current | ANSFrame |
|---|---|---|
| VRAM (engines + workspace) | ~5.9 GB | ~5.9 GB (same) |
| GPU upload per inference | 1.2 MB | 1.2 MB (same) |
| PCIe bandwidth | ~300 MB/s | ~300 MB/s (same) |
| SM utilization | 0-34% | 0-34% (same) |
### CPU Usage
| Component | Current | ANSFrame |
|---|---|---|
| SW decode (5 cameras) | ~3-5 cores | ~3-5 cores (same) |
| YUV→BGR generation | ~0.3 cores | ~0.42 cores (+0.12 for extra sizes) |
| CPU resize per AI task | ~1.5 cores | **0 cores (pre-computed)** |
| Clone memcpy | ~2.4 cores | **~0.5 cores** |
| **Total CPU for pipeline** | **~7-9 cores** | **~4-6 cores** |
| **CPU savings** | — | **~3 cores freed** |
### LabVIEW Thread Scheduling Impact
| Factor | Current | ANSFrame |
|---|---|---|
| Data per task dispatch | 24.9 MB | **6.2 MB** (4x less) |
| Memory allocation pressure | 299 MB in flight | **74 MB** (4x less) |
| Cache efficiency | Poor (24.9 MB > L3) | **Better** (6.2 MB closer to L3) |
| **Processing time (LabVIEW)** | **100-500ms** | **70-300ms (~30-40% faster)** |
### Final Summary
| Metric | Current (8h stable) | ANSFrame (projected) | Improvement |
|---|---|---|---|
| Clone time (12 tasks) | 36-60ms | 10-14ms | **3-4x faster** |
| Preprocess (12 tasks) | 60-72ms | 14ms | **4-5x faster** |
| CPU overhead total | 112-200ms | 28-38ms | **4-5x less** |
| RAM usage (frames) | ~1.2-1.9 GB | ~0.4-0.6 GB | **66% less** |
| CPU cores for pipeline | ~7-9 cores | ~4-6 cores | **3 cores freed** |
| VRAM | No change | No change | — |
| Crop quality (ALPR/FR) | 4K | 4K | Same |
| Processing time | 100-500ms | 70-300ms | **~30-40% faster** |
| Code complexity | Simple | Medium | +~500 lines |
---
## Overview
Replace the single-resolution `cv::Mat**` output from `GetImage` with a multi-resolution `ANSFrame` that contains 3 pre-computed images generated from the YUV420P decoded frame. This eliminates redundant resizing across AI tasks and reduces clone/memcpy overhead by 20x.
## Current Flow (Inefficient)
```
Decoder → YUV420P → cvtColor → 4K BGR (25 MB) → GetImage returns 4K
LabVIEW: clone 4K (25 MB × 12 tasks = 300 MB memcpy)
Each AI task: CPU resize 4K → 640×640 (redundant × 12 tasks)
```
## New Flow (Optimized)
```
Decoder → YUV420P → generate 3 images from YUV planes:
├─ Full resolution BGR (for crop/pipeline)
├─ 640×640 letterbox BGR (for detection inference)
└─ 1080p BGR (for display, configurable)
GetImage returns ANSFrame (contains refs to all 3 images)
LabVIEW: clone 1080p only (6.2 MB × 12 = 74 MB, was 300 MB)
AI task: uses 640×640 directly (0.1 MB clone, no resize needed)
Pipeline crop: uses full resolution image (no upscaling artifacts)
```
## Performance Comparison
### Resize from YUV420P planes (Option A — RECOMMENDED)
```
4K YUV420P frame (12.4 MB in 3 planes)
├─ Full res: cvtColor(Y+U+V → BGR) ~4-8ms
│ Result: 3840×2160 BGR (24.9 MB)
├─ 640×640: resize Y(640×360) + U,V(320×180) ~0.5ms
│ + pad bottom + cvtColor ~0.3ms
│ Result: 640×640 BGR (1.2 MB) Total: ~0.8ms
└─ 1080p: resize Y(1920×1080) + U,V(960×540) ~1.0ms
+ cvtColor ~0.5ms
Result: 1920×1080 BGR (6.2 MB) Total: ~1.5ms
Total generation time: ~6-10ms (all 3 images)
```
### Resize from BGR (Option B — slower)
```
4K YUV420P → cvtColor → 4K BGR (24.9 MB) ~4-8ms
├─ Full res: already done ~0ms
├─ 640×640: cv::resize(4K BGR → 640×640) + letterbox ~2-3ms
└─ 1080p: cv::resize(4K BGR → 1080p) ~1-2ms
Total generation time: ~7-13ms (all 3 images)
```
### Recommendation: Option A (resize YUV planes)
Option A is ~30% faster because YUV420P is 1.5 bytes/pixel vs BGR 3 bytes/pixel — half the data to resize. The YUV plane resize produces identical quality because `cvtColor` is applied after resize (same as how GPU NV12 resize works).
## ANSFrame Structure
### Header: `include/ANSFrame.h`
```cpp
#pragma once
#include <opencv2/core/mat.hpp>
#include <atomic>
#include <cstdint>
// ANSFrame holds pre-computed multi-resolution images from a single decoded frame.
// Generated once in avframeYUV420PToCvMat, shared across all AI tasks via registry.
// Eliminates per-task resize and reduces clone size by 20x.
struct ANSFrame {
// --- Pre-computed images (all BGR, CPU RAM) ---
cv::Mat fullRes; // Original resolution (e.g., 3840×2160) — for crop/pipeline
cv::Mat inference; // Model input size (e.g., 640×640 letterbox) — for detection
cv::Mat display; // Display resolution (e.g., 1920×1080) — for LabVIEW UI
// --- Metadata ---
int originalWidth = 0; // Original frame width before any resize
int originalHeight = 0; // Original frame height before any resize
int inferenceWidth = 0; // Inference image width (e.g., 640)
int inferenceHeight = 0;// Inference image height (e.g., 640)
float letterboxRatio = 1.0f; // Scale ratio used for letterbox (for coordinate mapping)
int64_t pts = 0; // Presentation timestamp
// --- Configuration (set per camera) ---
int displayMaxHeight = 1080; // Configurable display resolution
int inferenceSize = 640; // Configurable inference size (default 640)
// --- Lifecycle ---
std::atomic<int> refcount{1};
};
```
### Changes to `ANSFrame` Registry
The existing `ANSGpuFrameRegistry` can be extended or a new `ANSFrameRegistry` created to map `cv::Mat*` (the display image pointer) to its parent `ANSFrame`. When LabVIEW clones the display image and sends it to AI, the AI task can look up the parent `ANSFrame` to access the inference or full-res image.
```cpp
// Registry: maps display cv::Mat* → ANSFrame*
class ANSFrameRegistry {
std::unordered_map<const uchar*, ANSFrame*> m_map; // key = Mat.data pointer
std::mutex m_mutex;
public:
void attach(cv::Mat* displayMat, ANSFrame* frame);
ANSFrame* lookup(const cv::Mat& mat); // lookup by data pointer
void release(cv::Mat* mat);
};
```
## Implementation Steps
### Step 1: Create ANSFrame structure and registry
**Files to create:**
- `include/ANSFrame.h` — ANSFrame struct definition
- `modules/ANSCV/ANSFrameRegistry.h` — Registry mapping display Mat → ANSFrame
- `modules/ANSCV/ANSFrameRegistry.cpp` — Registry implementation
**Key design decisions:**
- ANSFrame is allocated per decoded frame, shared across all clones
- refcount tracks how many clones reference this frame
- When refcount → 0, all 3 images are freed
### Step 2: Generate multi-resolution images in avframeYUV420PToCvMat
**File to modify:** `MediaClient/media/video_player.cpp`
Replace current `avframeYUV420PToCvMat` which returns single BGR with new version that populates ANSFrame with 3 images.
```cpp
ANSFrame* CVideoPlayer::generateANSFrame(const AVFrame* frame) {
auto* ansFrame = new ANSFrame();
const int W = frame->width;
const int H = frame->height;
ansFrame->originalWidth = W;
ansFrame->originalHeight = H;
// --- Resize YUV planes for each resolution ---
// 1. Full resolution: direct cvtColor (no resize)
cv::Mat yuv(H * 3/2, W, CV_8UC1);
// ... copy planes ...
cv::cvtColor(yuv, ansFrame->fullRes, cv::COLOR_YUV2BGR_I420);
// 2. Inference size (640×640 letterbox from YUV planes)
int infSize = ansFrame->inferenceSize; // default 640
float r = std::min((float)infSize / W, (float)infSize / H);
int unpadW = (int)(r * W), unpadH = (int)(r * H);
ansFrame->letterboxRatio = 1.0f / r;
// Resize Y plane
cv::Mat yFull(H, W, CV_8UC1, frame->data[0], frame->linesize[0]);
cv::Mat yResized;
cv::resize(yFull, yResized, cv::Size(unpadW, unpadH));
// Resize U, V planes
cv::Mat uFull(H/2, W/2, CV_8UC1, frame->data[1], frame->linesize[1]);
cv::Mat vFull(H/2, W/2, CV_8UC1, frame->data[2], frame->linesize[2]);
cv::Mat uResized, vResized;
cv::resize(uFull, uResized, cv::Size(unpadW/2, unpadH/2));
cv::resize(vFull, vResized, cv::Size(unpadW/2, unpadH/2));
// Assemble padded I420 buffer
cv::Mat yuvInf(infSize * 3/2, infSize, CV_8UC1, cv::Scalar(114)); // gray padding
yResized.copyTo(yuvInf(cv::Rect(0, 0, unpadW, unpadH)));
// ... copy U, V with padding ...
cv::cvtColor(yuvInf, ansFrame->inference, cv::COLOR_YUV2BGR_I420);
ansFrame->inferenceWidth = infSize;
ansFrame->inferenceHeight = infSize;
// 3. Display resolution (1080p from YUV planes)
int dispH = ansFrame->displayMaxHeight;
float dispScale = (float)dispH / H;
int dispW = (int)(W * dispScale);
cv::Mat yDisp, uDisp, vDisp;
cv::resize(yFull, yDisp, cv::Size(dispW, dispH));
cv::resize(uFull, uDisp, cv::Size(dispW/2, dispH/2));
cv::resize(vFull, vDisp, cv::Size(dispW/2, dispH/2));
cv::Mat yuvDisp(dispH * 3/2, dispW, CV_8UC1);
// ... assemble I420 ...
cv::cvtColor(yuvDisp, ansFrame->display, cv::COLOR_YUV2BGR_I420);
return ansFrame;
}
```
### Step 3: Modify GetImage to return display image + attach ANSFrame
**File to modify:** `modules/ANSCV/ANSRTSP.cpp` (and other ANSCV classes)
```cpp
cv::Mat ANSRTSPClient::GetImage(int& width, int& height, int64_t& pts) {
// ... existing logic to get frame from player ...
// GetImage returns the DISPLAY image (1080p)
// ANSFrame is attached to the Mat via registry
ANSFrame* frame = _currentANSFrame;
width = frame->display.cols;
height = frame->display.rows;
pts = frame->pts;
// Register: display Mat's data pointer → ANSFrame
ANSFrameRegistry::instance().attach(&frame->display, frame);
return frame->display; // 1080p, ~6.2 MB (was 25 MB for 4K)
}
```
### Step 4: Modify ANSCV_CloneImage_S to link clone to ANSFrame
**File to modify:** `modules/ANSCV/ANSOpenCV.cpp`
```cpp
int ANSCV_CloneImage_S(cv::Mat** imageIn, cv::Mat** imageOut) {
*imageOut = anscv_mat_new(**imageIn); // clone display image (6.2 MB, was 25 MB)
// Link clone to same ANSFrame (refcount++)
ANSFrame* frame = ANSFrameRegistry::instance().lookup(**imageIn);
if (frame) {
frame->refcount++;
ANSFrameRegistry::instance().attach(*imageOut, frame);
}
return 1;
}
```
### Step 5: Modify engine Preprocess to use ANSFrame inference image
**Files to modify:** All engine Preprocess functions
```cpp
// In ANSRTYOLO::DetectObjects (and all other engines):
std::vector<std::vector<cv::cuda::GpuMat>> ANSRTYOLO::Preprocess(
const cv::Mat& inputImage, ImageMetadata& outMeta) {
// Try to get pre-resized inference image from ANSFrame
ANSFrame* frame = ANSFrameRegistry::instance().lookup(inputImage);
cv::Mat srcForInference;
if (frame && !frame->inference.empty() &&
inputImage.cols <= frame->inferenceWidth) {
// Use pre-computed 640×640 — ZERO resize needed
srcForInference = frame->inference;
outMeta.imgHeight = frame->originalHeight;
outMeta.imgWidth = frame->originalWidth;
outMeta.ratio = frame->letterboxRatio;
} else if (frame && !frame->fullRes.empty() &&
inputImage.cols > frame->inferenceWidth) {
// Need larger than inference size — use full resolution
srcForInference = frame->fullRes;
// ... resize to model input from full res ...
} else {
// Fallback: use input image directly (backward compat)
srcForInference = inputImage;
}
// Convert BGR → RGB
cv::Mat cpuRGB;
cv::cvtColor(srcForInference, cpuRGB, cv::COLOR_BGR2RGB);
// Upload small image to GPU
cv::cuda::GpuMat gpuResized;
gpuResized.upload(cpuRGB, stream);
// ...
}
```
### Step 6: Pipeline crop uses full resolution
```cpp
// In ANSLPR or any pipeline that crops detected objects:
// Instead of cropping from display image (1080p, upscaling artifacts):
ANSFrame* frame = ANSFrameRegistry::instance().lookup(inputImage);
cv::Mat cropSource = (frame && !frame->fullRes.empty())
? frame->fullRes // Full 4K quality for face/plate recognition
: inputImage; // Fallback
// Scale bbox from display coords to full-res coords
float scaleX = (float)cropSource.cols / displayImage.cols;
float scaleY = (float)cropSource.rows / displayImage.rows;
cv::Rect fullResBbox(bbox.x * scaleX, bbox.y * scaleY,
bbox.width * scaleX, bbox.height * scaleY);
cv::Mat crop = cropSource(fullResBbox).clone();
```
### Step 7: Configuration API
```cpp
// Set inference size (default 640) — before StartRTSP
void SetRTSPInferenceSize(ANSRTSPClient** Handle, int size); // 640, 320, 1280
// Set display resolution (default 1080) — before StartRTSP
void SetRTSPDisplayResolution(ANSRTSPClient** Handle, int width, int height);
// Check if ANSFrame is available for a cloned image
int HasANSFrame(cv::Mat** image); // returns 1 if ANSFrame attached
// Get specific resolution from ANSFrame
int GetANSFrameInference(cv::Mat** displayImage, cv::Mat** inferenceImage);
int GetANSFrameFullRes(cv::Mat** displayImage, cv::Mat** fullResImage);
```
## Memory & Performance Impact
### Per-Frame Memory
| Image | Resolution | Size | Before (single 4K) |
|---|---|---|---|
| Full resolution | 3840×2160 | 24.9 MB | 24.9 MB |
| Inference | 640×640 | 1.2 MB | (generated per AI task) |
| Display | 1920×1080 | 6.2 MB | (was part of 4K) |
| **Total per frame** | | **32.3 MB** | **24.9 MB** |
+7.4 MB per frame for pre-computed images, BUT:
### Clone Savings (12 AI tasks)
| | Before | After |
|---|---|---|
| Clone size per task | 24.9 MB | 6.2 MB (display only) |
| 12 clones total | 299 MB | 74 MB |
| Clone time | 36-60ms | 8-12ms |
| Resize per task | 2-3ms × 12 = 24-36ms | 0ms (pre-computed) |
| **Total savings** | | **~250 MB RAM, ~50ms CPU** |
### Generation Time (one-time per frame)
| Step | Time |
|---|---|
| Full res: cvtColor YUV→BGR | ~4-8ms |
| 640×640: resize YUV planes + cvtColor | ~0.8ms |
| 1080p: resize YUV planes + cvtColor | ~1.5ms |
| **Total** | **~6-10ms** |
vs Current: cvtColor 4K = ~4-8ms + resize per task = ~2-3ms × 12 = ~28-44ms total
**Net savings: ~20-35ms per frame cycle across all tasks.**
## Files to Create/Modify
### New files:
1. `include/ANSFrame.h` — ANSFrame struct
2. `modules/ANSCV/ANSFrameRegistry.h` — Registry header
3. `modules/ANSCV/ANSFrameRegistry.cpp` — Registry implementation
### Modified files:
4. `MediaClient/media/video_player.h` — Add generateANSFrame declaration
5. `MediaClient/media/video_player.cpp` — Implement generateANSFrame, modify getImage
6. `modules/ANSCV/ANSRTSP.h` — Add ANSFrame member, SetInferenceSize
7. `modules/ANSCV/ANSRTSP.cpp` — Modify GetImage to return display + attach ANSFrame
8. `modules/ANSCV/ANSOpenCV.cpp` — Modify CloneImage_S to link to ANSFrame
9. `modules/ANSCV/ANSMatRegistry.h` — Optional: integrate ANSFrame into mat registry
10. `modules/ANSODEngine/ANSRTYOLO.cpp` — Use ANSFrame inference image
11. `modules/ANSODEngine/ANSTENSORTRTOD.cpp` — Same
12. `modules/ANSODEngine/ANSTENSORRTPOSE.cpp` — Same
13. `modules/ANSODEngine/ANSTENSORRTSEG.cpp` — Same
14. `modules/ANSODEngine/ANSTENSORRTCL.cpp` — Same
15. `modules/ANSODEngine/ANSYOLOV12RTOD.cpp` — Same
16. `modules/ANSODEngine/ANSYOLOV10RTOD.cpp` — Same
17. `modules/ANSODEngine/SCRFDFaceDetector.cpp` — Same
18. `modules/ANSODEngine/dllmain.cpp` — Set tl_currentANSFrame for pipeline lookup
19. `modules/ANSLPR/ANSLPR_OD.cpp` — Use fullRes for plate crop
20. `modules/ANSFR/ARCFaceRT.cpp` — Use fullRes for face crop
21. `modules/ANSFR/ANSFaceRecognizer.cpp` — Use fullRes for face crop
### Apply to other ANSCV classes:
22. `modules/ANSCV/ANSFLV.h/.cpp` — Same pattern as ANSRTSP
23. `modules/ANSCV/ANSMJPEG.h/.cpp` — Same
24. `modules/ANSCV/ANSRTMP.h/.cpp` — Same
25. `modules/ANSCV/ANSSRT.h/.cpp` — Same
## Clone-to-ANSFrame Mapping (Critical Design)
### The Problem
LabVIEW calls `ANSCV_CloneImage_S` to create a deep copy of the 1080p display image. The clone has a **different `data` pointer** than the original — so a simple pointer lookup won't find the ANSFrame.
```
GetImage returns display Mat: data = 0xAAAA → registry: 0xAAAA → ANSFrame #1
CloneImage creates deep copy: data = 0xBBBB → registry: ??? (not registered)
AI task tries lookup(0xBBBB): NOT FOUND — fallback to slow path
```
### The Solution
Register the clone's `data` pointer to the same ANSFrame during `ANSCV_CloneImage_S`:
```
GetImage: data = 0xAAAA → registry: 0xAAAA → ANSFrame #1 (refcount=1)
CloneImage: data = 0xBBBB → registry: 0xBBBB → ANSFrame #1 (refcount=2)
CloneImage: data = 0xCCCC → registry: 0xCCCC → ANSFrame #1 (refcount=3)
ReleaseImage: remove 0xBBBB → ANSFrame #1 (refcount=2)
ReleaseImage: remove 0xCCCC → ANSFrame #1 (refcount=1)
Next GetImage: remove 0xAAAA → ANSFrame #1 (refcount=0) → FREE all 3 images
```
### Implementation in ANSCV_CloneImage_S (ANSOpenCV.cpp)
```cpp
int ANSCV_CloneImage_S(cv::Mat** imageIn, cv::Mat** imageOut) {
*imageOut = anscv_mat_new(**imageIn); // deep copy display (6.2 MB)
gpu_frame_addref(*imageIn, *imageOut); // existing: link GpuFrameData
ANSFrameRegistry::instance().addRef(*imageIn, *imageOut); // NEW: link ANSFrame
return 1;
}
```
### Implementation in ANSCV_ReleaseImage_S (ANSOpenCV.cpp)
```cpp
int ANSCV_ReleaseImage_S(cv::Mat** imageIn) {
ANSFrameRegistry::instance().release(*imageIn); // NEW: refcount--, free if 0
anscv_mat_delete(imageIn); // existing: free Mat
return 1;
}
```
### Implementation in ANSFrameRegistry
```cpp
class ANSFrameRegistry {
std::unordered_map<const uchar*, ANSFrame*> m_map; // Mat.data → ANSFrame
std::mutex m_mutex;
public:
// Register original display Mat → ANSFrame
void attach(const cv::Mat* mat, ANSFrame* frame) {
std::lock_guard<std::mutex> lock(m_mutex);
// Remove old mapping if exists
auto it = m_map.find(mat->data);
if (it != m_map.end() && it->second != frame) {
if (--it->second->refcount <= 0) delete it->second;
}
m_map[mat->data] = frame;
}
// Link clone to same ANSFrame (called from CloneImage)
void addRef(const cv::Mat* src, const cv::Mat* dst) {
std::lock_guard<std::mutex> lock(m_mutex);
auto it = m_map.find(src->data);
if (it == m_map.end()) return;
ANSFrame* frame = it->second;
frame->refcount++;
m_map[dst->data] = frame;
}
// Lookup by any Mat (original or clone)
ANSFrame* lookup(const cv::Mat& mat) {
std::lock_guard<std::mutex> lock(m_mutex);
auto it = m_map.find(mat.data);
return (it != m_map.end()) ? it->second : nullptr;
}
// Release mapping (called from ReleaseImage)
void release(const cv::Mat* mat) {
std::lock_guard<std::mutex> lock(m_mutex);
auto it = m_map.find(mat->data);
if (it == m_map.end()) return;
ANSFrame* frame = it->second;
m_map.erase(it);
if (--frame->refcount <= 0) delete frame;
}
};
```
### Thread Safety
- Registry uses `std::mutex` — same pattern as `ANSGpuFrameRegistry`
- ANSFrame images (fullRes, inference, display) are **immutable after creation** — safe to read from any thread
- Only `refcount` is modified concurrently — uses `std::atomic<int>`
- ANSFrame is freed only when refcount reaches 0 (all clones released)
### Lifecycle Diagram
```
Camera Thread: AI Task 1: AI Task 2:
generateANSFrame()
→ fullRes, inference, display
→ refcount = 1
→ registry: display.data → AF
GetImage returns display
CloneImage(display, &clone1) ─────► clone1
→ registry: clone1.data → AF
→ refcount = 2
CloneImage(display, &clone2) ──────────────────────────► clone2
→ registry: clone2.data → AF
→ refcount = 3
lookup(clone1) → AF
use AF->inference
use AF->fullRes (crop)
ReleaseImage(clone1)
→ refcount = 2
lookup(clone2) → AF
use AF->inference
ReleaseImage(clone2)
→ refcount = 1
Next GetImage:
→ new ANSFrame
→ old display.data removed
→ refcount = 0 → FREE old AF
```
## Leak Prevention (Critical)
### Leak Scenarios
| Scenario | What leaks | Size per leak |
|---|---|---|
| LabVIEW forgets to call ReleaseImage | ANSFrame (fullRes + inference + display) | ~32 MB |
| Camera reconnect while clones exist | Old ANSFrame stays alive until clones released | ~32 MB |
| LabVIEW crash/abort | All ANSFrames in registry | ~32 MB × N frames |
| AI task throws exception, skips Release | ANSFrame refcount never reaches 0 | ~32 MB |
### Protection 1: TTL-Based Auto-Eviction
Same pattern as `ANSGpuFrameRegistry::evictStaleFrames()` — periodically scan for old ANSFrames and force-free them.
```cpp
class ANSFrameRegistry {
static constexpr int FRAME_TTL_SECONDS = 5; // Max lifetime of any ANSFrame
static constexpr int EVICT_INTERVAL_MS = 1000; // Check every 1 second
struct Entry {
ANSFrame* frame;
std::chrono::steady_clock::time_point createdAt;
};
void evictStale() {
auto now = std::chrono::steady_clock::now();
// Throttle: only run every EVICT_INTERVAL_MS
if (now - m_lastEvict < std::chrono::milliseconds(EVICT_INTERVAL_MS)) return;
m_lastEvict = now;
std::lock_guard<std::mutex> lock(m_mutex);
for (auto it = m_frames.begin(); it != m_frames.end(); ) {
double ageSec = std::chrono::duration<double>(now - it->createdAt).count();
if (ageSec > FRAME_TTL_SECONDS) {
// Force-free: remove all Mat* mappings to this frame
ANSFrame* frame = it->frame;
for (auto mit = m_map.begin(); mit != m_map.end(); ) {
if (mit->second == frame) mit = m_map.erase(mit);
else ++mit;
}
delete frame;
it = m_frames.erase(it);
} else {
++it;
}
}
}
};
```
Call `evictStale()` from `GetImage()` (piggybacked on camera thread activity — same as `gpu_frame_evict_stale()`).
### Protection 2: Max ANSFrame Pool Size
Limit total number of live ANSFrames. If pool is full, force-free the oldest before creating a new one.
```cpp
static constexpr int MAX_ANSFRAMES = 100; // Max live frames across all cameras
ANSFrame* createANSFrame(...) {
evictStale(); // Clean up expired frames first
// If still over limit, force-free oldest
while (m_frames.size() >= MAX_ANSFRAMES) {
auto oldest = m_frames.begin();
// ... force-remove all mappings + delete ...
}
auto* frame = new ANSFrame();
// ... populate ...
m_frames.push_back({frame, std::chrono::steady_clock::now()});
return frame;
}
```
### Protection 3: Camera-Scoped Cleanup
When a camera is stopped or destroyed, force-free ALL ANSFrames belonging to that camera (regardless of refcount).
```cpp
// In ANSRTSPClient::Stop() and Destroy():
ANSFrameRegistry::instance().releaseByOwner(this);
// In ANSFrameRegistry:
void releaseByOwner(void* owner) {
std::lock_guard<std::mutex> lock(m_mutex);
for (auto it = m_frames.begin(); it != m_frames.end(); ) {
if (it->frame->owner == owner) {
// Remove all Mat* mappings
for (auto mit = m_map.begin(); mit != m_map.end(); ) {
if (mit->second == it->frame) mit = m_map.erase(mit);
else ++mit;
}
delete it->frame;
it = m_frames.erase(it);
} else {
++it;
}
}
}
```
### Protection 4: One ANSFrame Per Camera (Ring Buffer)
Each camera keeps only the **latest** ANSFrame. When a new frame arrives, the previous ANSFrame is marked for cleanup (refcount decremented). This bounds memory to 1 ANSFrame per camera.
```cpp
class ANSRTSPClient {
ANSFrame* _currentANSFrame = nullptr;
void onNewFrame(AVFrame* decoded) {
ANSFrame* newFrame = generateANSFrame(decoded);
newFrame->owner = this;
// Replace old frame — decrement refcount
if (_currentANSFrame) {
ANSFrameRegistry::instance().detachOwner(_currentANSFrame);
// If refcount reaches 0, freed immediately
// If clones still hold refs, freed when they release
}
_currentANSFrame = newFrame;
ANSFrameRegistry::instance().attach(&newFrame->display, newFrame);
}
};
```
### Protection 5: ANSFrame Struct with Owner Tracking
```cpp
struct ANSFrame {
// ... existing fields ...
// Leak protection
void* owner = nullptr; // Camera that created this frame
std::chrono::steady_clock::time_point createdAt;
std::atomic<int> refcount{1};
~ANSFrame() {
// Images are cv::Mat — automatically freed by OpenCV refcount
// No manual cleanup needed for fullRes, inference, display
}
};
```
### Memory Budget Analysis
With all protections:
| Cameras | Max ANSFrames | Memory (worst case) |
|---|---|---|
| 5 running | 5 current + ~10 in-flight clones | 5 × 32 MB = 160 MB |
| 20 running | 20 current + ~40 in-flight clones | 20 × 32 MB = 640 MB |
| 100 created, 5 running | 5 current + ~10 in-flight | 5 × 32 MB = 160 MB |
| 100 created, 95 stopped | 0 (stopped cameras free ANSFrame) | 0 MB |
**Worst case bounded by:** `running_cameras × 32 MB` — predictable, no growth over time.
### TTL Guarantee
Even if ALL protections fail, the 5-second TTL eviction ensures:
- Maximum leak duration: 5 seconds
- Maximum leaked memory: `cameras × 5 seconds × 10 FPS × 32 MB / frame` — but with ring buffer (1 per camera), it's just `cameras × 32 MB`
- Periodic cleanup on every `GetImage` call ensures no accumulation
## Replacing GpuFrameRegistry
### Current State (wasteful with NV12 disabled)
With `_useNV12FastPath = false` (current default), `GpuFrameRegistry` is never populated — no `gpu_frame_attach` is called. But `gpu_frame_addref`, `gpu_frame_remove`, and `gpu_frame_evict_stale` still run on every clone/release/replace — doing empty lookups that waste CPU cycles.
```
Current code paths that run but do nothing:
ANSCV_CloneImage_S → gpu_frame_addref → lookup → NOT FOUND → no-op
ANSCV_ReleaseImage_S → gpu_frame_remove → lookup → NOT FOUND → no-op
anscv_mat_replace → gpu_frame_remove → lookup → NOT FOUND → no-op
anscv_mat_replace → gpu_frame_evict_stale → scans empty registry → no-op
```
### Plan: ANSFrameRegistry replaces GpuFrameRegistry
ANSFrameRegistry serves the same purpose (mapping `cv::Mat*` → frame metadata) but without GPU complexity:
| Feature | GpuFrameRegistry | ANSFrameRegistry |
|---|---|---|
| Maps Mat* to | GpuFrameData (NV12 GPU pointers) | ANSFrame (3 CPU images) |
| Used when | NV12 fast path enabled | Always (SW or HW decode) |
| GPU dependency | CUDA, pool slots, D2D copy | None |
| Thread safety | mutex + atomic refcount | mutex + atomic refcount |
| Cleanup | TTL eviction + pool cooldown | TTL eviction (simpler) |
### Migration Path
1. **Phase 1 (implement ANSFrame):** ANSFrameRegistry runs alongside GpuFrameRegistry
- `CloneImage`: calls both `gpu_frame_addref` + `ansframe_addref`
- `ReleaseImage`: calls both `gpu_frame_remove` + `ansframe_release`
- Safe: both registries handle NOT FOUND gracefully
2. **Phase 2 (NV12 disabled permanently):** Remove GpuFrameRegistry calls
- Remove `gpu_frame_addref` from `CloneImage`
- Remove `gpu_frame_remove` from `ReleaseImage` and `anscv_mat_replace`
- Remove `gpu_frame_evict_stale` from `anscv_mat_replace`
- Keep GpuFrameRegistry code for future NV12 re-enablement
3. **Phase 3 (optional, if NV12 re-enabled):** Merge into single registry
- ANSFrame struct gains optional GPU fields (yPlane, uvPlane, poolSlot)
- Single registry, single refcount, single lookup
### Recommended: Implement Phase 1 first, Phase 2 after testing
## Backward Compatibility
- If ANSFrame is not available (e.g., old camera module), engines fall back to current behavior (resize input image)
- The `cv::Mat**` API stays the same — LabVIEW doesn't need changes
- ANSFrame is transparent to LabVIEW — it only sees the display image
- The `GetANSFrameInference` / `GetANSFrameFullRes` APIs are optional for advanced use
## Risk Assessment
| Risk | Mitigation |
|---|---|
| Extra 7.4 MB RAM per frame | Negligible vs 250 MB clone savings |
| ANSFrame lifecycle (refcount) | Same pattern as GpuFrameData — proven |
| Coordinate mapping errors | letterboxRatio stored in ANSFrame — deterministic |
| YUV plane resize quality | Same as GPU NV12 resize — proven equivalent |
| Thread safety | ANSFrame is immutable after creation — safe to share |