Waterfall rec tab - voxo22/hackrf-spectrum-analyzer GitHub Wiki

Waterfall parameters

Date

The Date checkbox shows or hides the timestamp overlay. In LIVE mode it shows the current date and time. In REPLAY mode it follows the recorded/replayed time.

Note: If you record VIDEO with the timestamp on, it becomes part of the picture.

InfoBox

The InfoBox checkbox shows or hides the information panel on the lower right corner of the waterfall.

WFall

The WFall checkbox starts or stops the flow of waterfall display.

Palette start

Narrow strip (palette) on the right side of the spectral chart represents the color distribution of the amplitude magnitude on the waterfall. The strip can be moved with this slider up or down along the Y-axis.

Value on the slider sets the blue lower limit to the smallest amplitude in dBm.

Palette length

Narrow strip (palette) on the right side of the spectral chart represents the color distribution of the amplitude magnitude on the waterfall. The strip can be resized along the Y-axis.

Value on the slider sets the dynamic range of the waterfall (length of the color scale) in dBm.

Speed

This slider sets the speed of the waterfall scrolling. However, decreasing the speed can result to skipping very short pulses. To not miss any short waterfall amplitude pulse, set the speed to 10.

Recording parameters

STATS Log Interval

Sets the STATS logging interval. STATS are collected from the PEAK trace, so the PEAK trace must be displayed. Logging options:

  • once per minute
  • once per second
  • once per fraction of a second (1/10s)

Note: The last option will create the largest file in the same amount of time.

Recommended to set simultaneously on the PARAMS tab:

  • "Peak Fallout Time = 1" for any "Data Log Interval" option

and

  • "Peak Hold Time = 0" for the interval once per fraction of a second
  • "Peak Hold Time = 1" for the interval once per second
  • "Peak Hold Time = 60" for the interval once per minute

DATA REC FPS

Defines frame rate for native HSR spectrum DATA recording. FULL records every available frame. Setting the smaller number can significantly reduce amount of recorded data (file size) on fast spectrum sweeps and hours long recordings.

VIDEO REC area

Defines the VIDEO recording area:

  • SPECTR - only the spectrum chart
  • SPEC+WF - spectrum chart and waterfall
  • FULLSCR - full screen (including the Control panel)

Note: The last option will create the largest file at the same time.

VIDEO REC resolution

Defines the VIDEO recording resolution

360p, 540p, 720p or 1080p

Note: Video resolution is limited by your screen resolution.

VIDEO REC format

Defines the VIDEO recording format

  • GIF animated - original chart colors and sharpness, bitmap compression, nonlinear timing, demanding on disk space and buffer size
  • MP4 - H.264 compression, can be slightly discolored and softy (you may want to use thicker lines), linear timing (the timestamp on the picture corresponds to the real playback time), unlimited recording, saves disk space, includes audio demodulation track, if enabled.

Note: GIF is suitable for small, a few-second recordings, publish e.g. on websites. The GIF format preserves the original color of the chart traces, usually plays endlessly, capable to publish as a regular image. However, it has large file size in few seconds. Frames are buffered before save, therefore do not use GIF for minute or longer recordings, the buffer may overflow and the application can crash.

Note: even after GIF VIDEO recording stops, it may take a while before the saved file is accessible (the buffer should flush completely).

FPS

Defines the VIDEO recording frame rate (frames per second). For a smooth GIF animated picture, 15 fps is OK (non-linear timing). For a smooth H.264 MP4 picture, you should choose at least 20 fps. To record only sequential screenshots select 1 fps.