NextNVR/snapshot.go

133 lines
3.5 KiB
Go

// NextNVR v0.3.3 — Snapshot engine
// Writes latest.jpg every 2s (live wall) and snap_{timestamp}.jpg every 60s (archive/thumbnails).
// All files go into the per-camera directory: /mnt/recordings/{cam-name}/
package main
import (
"fmt"
"log"
"os"
"os/exec"
"path/filepath"
"sync"
"time"
)
// SnapshotEngine manages per-camera snapshot goroutines.
type SnapshotEngine struct {
mu sync.Mutex
stopChs map[string]chan struct{}
config StorageConfig
}
// NewSnapshotEngine creates a new snapshot engine.
func NewSnapshotEngine(cfg StorageConfig) *SnapshotEngine {
return &SnapshotEngine{
stopChs: make(map[string]chan struct{}),
config: cfg,
}
}
// StartAll launches a snapshot goroutine for each enabled camera.
func (se *SnapshotEngine) StartAll(cameras []CameraConfig) {
for _, cam := range cameras {
if !cam.Enabled {
continue
}
stopCh := make(chan struct{})
se.mu.Lock()
se.stopChs[cam.ID] = stopCh
se.mu.Unlock()
go se.snapshotLoop(cam, stopCh)
}
log.Printf("snapshot: %d cameras started", len(se.stopChs))
}
// StopAll terminates all snapshot goroutines.
func (se *SnapshotEngine) StopAll() {
se.mu.Lock()
defer se.mu.Unlock()
for id, ch := range se.stopChs {
close(ch)
log.Printf("snapshot: stopped camera %s", id)
}
se.stopChs = make(map[string]chan struct{})
}
// snapshotLoop grabs a JPEG frame every 2 seconds and writes latest.jpg.
// Every 60 seconds, copies latest.jpg to snap_{timestamp}.jpg for archival.
func (se *SnapshotEngine) snapshotLoop(cam CameraConfig, stopCh chan struct{}) {
rtspURL := cam.RTSPSub
if rtspURL == "" {
rtspURL = fmt.Sprintf("rtsp://%s:%s@%s:554/Streaming/Channels/102",
cam.Username, cam.Password, cam.IP)
}
camDirName := cam.Name
if camDirName == "" {
camDirName = cam.ID
}
outDir := filepath.Join(se.config.RecordingsPath, camDirName)
if err := os.MkdirAll(outDir, 0755); err != nil {
log.Printf("snapshot: %s — mkdir %s failed: %v", cam.ID, outDir, err)
return
}
latestFile := filepath.Join(outDir, "latest.jpg")
tmpFile := latestFile + ".tmp"
lastArchive := time.Time{} // track when we last wrote an archival snapshot
log.Printf("snapshot: %s → %s (live every 2s, archive every 60s)", cam.ID, outDir)
// Grab first frame immediately.
se.grabFrame(rtspURL, tmpFile, latestFile, outDir, cam.ID, &lastArchive)
fastTicker := time.NewTicker(2 * time.Second)
defer fastTicker.Stop()
for {
select {
case <-stopCh:
return
case <-fastTicker.C:
se.grabFrame(rtspURL, tmpFile, latestFile, outDir, cam.ID, &lastArchive)
}
}
}
// grabFrame launches ffmpeg to capture a JPEG. Updates latest.jpg every call,
// and copies to snap_*.jpg once per minute.
func (se *SnapshotEngine) grabFrame(rtspURL, tmpFile, latestFile, outDir, camID string, lastArchive *time.Time) {
cmd := exec.Command("ffmpeg",
"-hide_banner", "-loglevel", "error",
"-rtsp_transport", "tcp",
"-i", rtspURL,
"-vframes", "1",
"-q:v", "5",
"-f", "image2",
"-y", tmpFile,
)
cmd.Run()
if _, err := os.Stat(tmpFile); err != nil {
return // ffmpeg failed — camera may be offline
}
os.Rename(tmpFile, latestFile)
// Archive: once per minute, copy latest.jpg to snap_{timestamp}.jpg
now := time.Now()
if now.Sub(*lastArchive) >= 60*time.Second {
archiveFile := filepath.Join(outDir, "snap_"+now.Format("2006-01-02-15-04-05")+".jpg")
copyFile(latestFile, archiveFile)
*lastArchive = now
}
}
// copyFile copies a file from src to dst.
func copyFile(src, dst string) {
data, err := os.ReadFile(src)
if err != nil {
return
}
os.WriteFile(dst, data, 0644)
}