From ff10cbf7d931094f5afeab2c33ca63d61e5c62db Mon Sep 17 00:00:00 2001 From: f4exb Date: Fri, 16 Dec 2016 01:41:41 +0100 Subject: [PATCH] Updated sdrbase readme with details on how to use the recorded I/Q files --- sdrbase/readme.md | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/sdrbase/readme.md b/sdrbase/readme.md index 0eb6a78a1..42764746c 100644 --- a/sdrbase/readme.md +++ b/sdrbase/readme.md @@ -89,9 +89,18 @@ This is where the plugin GUI specific to the device is displayed. Control of one - When a square icon is displayed with a green background the device is currently running - When a play icon is displayed with a red background there is an error and a popup displays the error message. An Error typically occurs when you try to start the same device in more than one tab. -

2.2. Record I/Q

+

2.2. Record I/Q

-This is the I/Q from device record toggle. When a red background is displayed the recording is currently active. The name of the file created is `test_.sdriq` where `` is the slot number. +This is the I/Q from device record toggle. When a red background is displayed the recording is currently active. The name of the file created is `test_n.sdriq` where `n` is the slot number. + +The format is S16LE I/Q samples. Thus there are 4 bytes per sample. I and Q values are 16 bit signed integers. The file starts with a context header containing information about center frequency, sample rate and timestamp of the start of the recording. This header has a length which is a multiple of a sample size (normally 24 bytes thus 6 samples). Thus this file can be used as a raw I/Q file with S16LE samples tolerating a glitch at the start corresponding to the 6 "random" samples. + +You can also zap the 24 bytes header with this Linux command: `tail -c +25 myfile.sdriq > myfile.raw` + +To convert in another format you may use the sox utility. For example to convert to 32 bit (float) complex samples do: +`sox -r 48k −b 16 −e signed-integer -c 2 myfile.raw -e float -c 2 myfilec.raw` + +Note that you have to specify the sampling rate and use `.raw` for the file extensions.

2.3. Device sampling rate