From 567448fec546145cc751fb988ebb2f74138b4c2e Mon Sep 17 00:00:00 2001 From: Brumi-2021 <86470699+Brumi-2021@users.noreply.github.com> Date: Wed, 30 Aug 2023 12:28:58 +0200 Subject: [PATCH] Updated Capture (markdown) --- Capture.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Capture.md b/Capture.md index 0783139..e628db6 100644 --- a/Capture.md +++ b/Capture.md @@ -13,7 +13,9 @@ The Key Items on the App that can be selected with the cursor and changed with t Note (*) : Currently , **for correct Replay application ,you should ONLY use Capture App selecting any Bandwith capture <= 1Mhz (but 500Khz is the recommended for majority micro SD cards compatibility because it requieres a quite common average write speed in our system >2MB/sec,C16)**. From 600khz till 1Mhz , you will need more fast and good quality micro sd card (with min average write speed in our system >3MB/sec (for BW=750khz,C16) , and >4MB/sec (for BW=1Mhz ,C16), and with as small as possible write random latency. (In the GUI , those correct bandwidth capture options appear with the Normal usual "REC" icon Background colour, as user recomended BW capture options). If you face too much % dropped samples when recording , you can retry it reducing C16 to C8 , that also reduces the needed average write speed :2 (example 1Mhz rec will need average sd interface speed of 4MB/sec in C16 or 2MB/sec in C8). -Above 1Mhz bandwith options (with YELLOW REC button background Icon), in current fw version , the recorded files have periodical sample drops , and therefore it has not recorded all full original samples content and therefore it is NOT useful for the Replay App , just useful to check the spectrum image, example using the linux tool "inspectrum" or "Audacity") . Anyway when replaying those captured files , the replay time will be shorter than real . but normally you should still get a correct modulation, but in case of voice contents, it would sound , unnatural , "like with accelerated playing speed" , because in fact,due to Hackrf One System (HW+SW) limitations, those recorded files (under those high speed BW with YELLOW icon) have decimated its content - when recorded there were skipped some real time samples. +Recently, thanks to x4 Oversampling and /4 Decimation introduction , we have added 1.25Mhz BW Rec , but it is in the limit of our hardware System limits and it starts to have some M4 sample drops. (It is still experimental). + +Above 1.25Mhz bandwith options (with YELLOW REC button background Icon), in current fw version , the recorded files have periodical sample drops , and therefore it has not recorded all full original samples content and therefore it is NOT useful for the Replay App , just useful to check the spectrum image, example using the linux tool "inspectrum" or "Audacity") . Anyway when replaying those captured files , the replay time will be shorter than real . but normally you should still get a correct modulation, but in case of voice contents, it would sound , unnatural , "like with accelerated playing speed" , because in fact,due to Hackrf One System (HW+SW) limitations, those recorded files (under those high speed BW with YELLOW icon) have decimated its content - when recorded there were skipped some real time samples. In future versions, it is pending to investigate and try to apply a correct .C16 recording files (without any samples drop) till a capture of 2Mhz. (We will keep updated that manual , when we achieve it) ![image](https://user-images.githubusercontent.com/86470699/162581344-446a1a0b-325e-4bb6-a451-f47ecc91d8e3.png)