VirtualDub help - Capture: Information panel
  Processing: Main UI Editing Filtering Rendering/saving Artifacts The pipeline Direct mode Display panes Frameserver Video filter reference Video shader reference Video capture Hardware setup Driver selection Audio setup Pipeline Filtering Info panel Multi-segment mode Timing dialog Performance Troubleshooting Dialogs: Video filters Video frame rate control Video color depth Video range Video compression Audio filters Audio interleaving Audio compression Audio conversion Audio volume Capture settings Preferences On a crash... | The information panel shows current disk, video, and audio status during a video capture. It is toggled through the Option > Show information panel menu command. Frames captured The total number of video frames captured. Total time The amount of time the capture has been running, in days:hours:minutes:seconds. Time left The estimated amount of time the capture can continue, based on available disk space, video frame rate, and current compression ratios. Total file size The total amount of data written to disk in the current capture session. Disk space free How much disk space is left on the capture drive(s). CPU usage Estimated CPU utilization during the video capture. This includes CPU usage by processes other than VirtualDub.
  Note | On a system with multiple logical CPUs (SMP, dual core, or hyperthreading), this value may rise above 100%, up to 100% times the number of CPUs. Video capture is mostly single-threaded, so approaching 100% in these situations may still indicate CPU overload.
Video: Size Total amount of video data written to disk. Video: Average rate The overall rate at which video frames are arriving from the video capture device. The more this diverges from nominal, the more likely sync and frame drop problems are to appear. Video: Data rate The overall rate at which video data is being written to disk, in bytes/kilobytes/megabytes per second. When video compression is in use, this statistic refers to compressed video data. Video: Compression The overall video compression ratio. Ratios greater than 1.0:1 indicate shrinkage in video size, whereas less than 1.0:1 means enlargement (i.e. the "compression" is making the video bigger). Lossless algorithms typically range from 1:1 to 3:1, whereas lossy compression can go much higher. Video: Avg frame size The average size, in bytes, of each video frame written to disk. When video compression is in use, this statistic refers to compressed video frames. Video: Frames dropped This refers to the number of aberrations in the video stream, caused by video frames that were dropped by the video capture device (too many frames), or placeholder frames inserted by VirtualDub to stand in for missing ones (too few frames). Fewer is better. Audio: Size Total amount of audio data written to disk. Audio: Relative rate The average rate of the raw PCM data in the audio stream, relative to the corrected video stream. This is thus the frequency of the audio if the video stream were perfectly timed, as it is assumed in the on-disk video. Discrepancies between this value and the ideal frequency indicate overall sync error. Small errors are expected due to measurement issues. Audio: Data rate Average bandwidth of audio data written to disk. When audio compression is active, this refers to the compressed result. Audio: Compression The overall audio compression ratio; larger ratios mean smaller audio on disk. Audio: VT adjust Amount of adjustment, in milliseconds, applied to the video stream caused by detected differences from audio timing. This is only pertinent if the timing setting is "sync video to audio." Positive values mean the video stream is being sped up; negative values mean it is being slowed down. It is normal for this value to increment or decrement occasionally over the course of a video capture session. Audio: Resample Stretch factor applied to the audio stream, in semitones, in order to correct for speed errors relative to the video stream. This is only active if the timing setting is "sync audio to video." A semitone is a step between minor notes on the musical scale, such as between the notes C and C#; a factor of +/-12.000 is a full octave (half or double speed). Positive values indicate the audio is being sped up (higher pitch), negative values indicate slowing (lower pitch), and zero means no change to the audio speed. This value is an instantaneous measurement, not an average, so a varying adjustment means varying speeds in the written audio track. An adjustment within about 0.030 semitones is not usually noticeable, and slow, gradual drifts or oscillations in this value are normal. However, factors above +/-0.100 semitones and rapid changes in this value indicate warbling in the resampler's output, which may indicate timing problems. Audio: Latency Estimated difference in arrival time, in milliseconds, between the audio and video streams. This is the difference between when VirtualDub sees a video frame and the audio that corresponds to that frame, not necessarily a sync error in the output. Positive values indicate the audio is arriving later, whereas negative values indicate it is arriving earlier. This value will typically be in to 10-100ms range for "TV tuner" style devices and possibly as high as +/-300ms for devices with integrated compression. An abnormally large value here, particularly in the range of seconds or more, likely indicates a timing problem.