Bug 1133

Hi,

First of all: thank you very much for developing and sharing this really great tool.

I just compiled from source on a raspberry pi 3. 
I am using a Chinese USBEE clone (fx2lafw driver) to debug i2c communication.
When pre-trigger-capture-ratio is unequal to zero the time scale in the output of pulseview is not correct (factor 2 to small, time readings are to small, frequencies to high) for digital inputs. When pre-trigger-capture-ratio is set to zero the data are correctly displayed.
The analog input is always displayed correctly.

I did the same tests on a x86 linux machine, with also a recently compiled version of sigrok/pulseview. The outcome was the same: faulty display of digital signals when pre-trigger-capture-ratio is set unequal to zero.



PulseView 0.5.0-git-7b7ab1f

Qt
5.9.2
glibmm
2.54.1
Boost
1_62
libsigrok
0.6.0-git-187c300b/4:0:0 (rt: 0.6.0-git-187c300b/4:0:0)
- glib
2.54.3 (rt: 2.54.3/5403:3)
- libzip
1.1.2
- libserialport
0.1.1/1:0:1 (rt: 0.1.1/1:0:1)
- libusb-1.0
1.0.21.11156
- libftdi
1.4
- Host
armv7l-unknown-linux-gnueabihf, little-endian
- SCPI backends
TCP, RPC, serial, USBTMC
libsigrokdecode
0.6.0-git-fb1870b/4:0:0 (rt: 0.6.0-git-fb1870b/4:0:0)
- glib
2.54.3 (rt: 2.54.3/5403:3)
- Python
3.6.4+ / 0x30604f0 (API 1013, ABI 3)
- Host
armv7l-unknown-linux-gnueabihf, little-endian