--capture-preview always the same (first) output image (Nikon Z7)

[tokiAi]

Describe the bug

The output image of "gphoto2 --capture-preview" is the same.

Name the camera Nikon Z7

libgphoto2 and gphoto2 version 2.5.27

To Reproduce I use the command "gphoto2 --capture-preview", then change the object in front of the lens. If I delete the image capture_preview.jpg and execute the command again, I get the image with the first object again, not with the second object. Then I repeat that (delete + command) and I always get the same picture with the first object.

The alternatives also show the same behavior: "gphoto2 --show-preview" "gphoto2 --capture-movie=0 --stdout > capture_preview.jpg"

[tokiAi]

a question maybe a second bug: Why are the commands always executed twice in the debug? e.g.

0.333897 ptp_usb_getdata             (2): Reading PTP_OC 0x9203 (GetLiveViewImg) data...
0.333949 gp_port_read                (3): Reading 1024 = 0x400 bytes from port...
0.336250 gp_port_read                (3): Read    1024 = 0x400 bytes from port: (hexdump of 1024 bytes)

and

0.374783 ptp_usb_getdata             (2): Reading PTP_OC 0x9203 (GetLiveViewImg) data...
0.374807 gp_port_read                (3): Reading 1024 = 0x400 bytes from port...
0.376787 gp_port_read                (3): Read    1024 = 0x400 bytes from port: (hexdump of 1024 bytes)

[msmeissn]

if you capture a movie of like 10 seconds, is anything changing?

gphoto2 --capture-movie=10s

on enabling liveview we actually capture 2 frames, as we occasuionaly had the issue that the first frame was full white

[msmeissn]

i currently see the same, aalib is not refreshing the image with new data. reverse "r" key seems to change it, so its not a aalib refresh issue.

weird