... & Exact search (accurate to second), Smart search6. Support multi-channel playback simultaneously,7. Live, recording, playback, backup & remote ... access8. Provide single / 4 channel audio function9. Support picture in picture display, OSD interfaces, ... Lines 50 Field/secSync System Internal SynchronizationGamma Characteristic 0.45S/N Ratio ≥65dB (AGC OFF) ≥54dB (AGC OFF) ...