File Input: Updated documentation

debian/changelog

@@ -2,6 +2,7 @@ sdrangel (4.2.2-1) unstable; urgency=medium
 
   * Spectrum: option to get max over a number of FFTs. Implements issue #207
   * File Input: fixed wrong times displays due to 32 bit integer ovevlow. Issue #206
+  * File Input: implemented play loop and playback acceleration
 
  -- Edouard Griffiths, F4EXB <f4exb06@gmail.com>  Sun, 14 Oct 2018 21:14:18 +0200
 

plugins/samplesource/filesource/readme.md

@@ -96,11 +96,19 @@ Use this button to read in a loop or read only once
 
 This is the play/pause button
 
-<h3>12: Relative timestamp and record length</h3>
+<h3>12: Playback acceleration</h3>
+
+Use this combo to select play back acceleration to values of 1 (no acceleration), 2, 5, 10, 20, 50, 100, 200, 500, 1k (1000) times. This is useful on long recordings used in conjunction with the spectrum "Max" averaging mode in order to see the waterfall over a long period. Thus the waterfall will be filled much faster.
+
+&#9758; Note that this control is enabled only in paused mode.
+
+&#9888; The result when using channel plugins with acceleration is unpredictable. Use this tool to locate your signal of interest then play at normal speed to get proper demodulation or decoding.
+
+<h3>13: Relative timestamp and record length</h3>
 
 Left is the relative timestamp of the current pointer from the start of the record. Right is the total record time.
 
-<h3>13: Current pointer gauge</h3>
+<h3>14: Current pointer gauge</h3>
 
 This represents the position of the current pointer position in the complete recording. It can be used it paused mode to position the current pointer by moving the slider.
  

sdrgui/readme.md

@@ -273,7 +273,7 @@ Use this combo to select which averaging mode is applied:
 
 <h4>4.6. Number of averaged samples</h4>
   
-Each FFT bin (squared magnitude) is averaged or max'ed over a number of samples. This combo allows selecting the number of samples between these values: 0 (no averaging), 2, 5, 10, 20, 50, 100, 200, 500, 1k (1000), 2k, 5k, 10k, 20k, 50k, 1e5 (100000), 2e5, 5e5, 1M (1000000). The tooltip mentions the resulting averaging period considering the baseband sample rate and FFT size.
+Each FFT bin (squared magnitude) is averaged or max'ed over a number of samples. This combo allows selecting the number of samples between these values: 1 (no averaging), 2, 5, 10, 20, 50, 100, 200, 500, 1k (1000), 2k, 5k, 10k, 20k, 50k, 1e5 (100000), 2e5, 5e5, 1M (1000000). The tooltip mentions the resulting averaging period considering the baseband sample rate and FFT size.
 Averaging reduces the noise variance and can be used to better detect weak continuous signals. The fixed averaging mode allows long time monitoring on the waterfall. The max mode helps showing short bursts that may appear during the "averaging" period.
 
 &#9758; Note: The spectrum display is refreshed every 50ms (20 FPS). Setting an averaging time above this value will make sure that a short burst is not missed particularly when using the max mode.