(This question is also available at
https://stackoverflow.com/questions/64415461.) Running GStreamer pipeline that feeds from v4l2src element may change camera format implicitly. Here is an example (also note that /dev/video0 is everywhere implied). One of my cameras supports these formats $ v4l2-ctl --list-formats-ext ioctl: VIDIOC_ENUM_FMT Type: Video Capture [0]: 'YUYV' (YUYV 4:2:2) Size: Discrete 640x480 Interval: Discrete 0.033s (30.000 fps) Interval: Discrete 0.067s (15.000 fps) Size: Discrete 320x240 Interval: Discrete 0.033s (30.000 fps) Interval: Discrete 0.067s (15.000 fps) Size: Discrete 1280x800 Interval: Discrete 0.133s (7.500 fps) Size: Discrete 1280x1024 Interval: Discrete 0.133s (7.500 fps) The current format is $ v4l2-ctl --get-fmt-video Format Video Capture: Width/Height : 640/480 Pixel Format : 'YUYV' (YUYV 4:2:2) Field : None Bytes per Line : 1280 Size Image : 614400 Colorspace : Default Transfer Function : Default (maps to Rec. 709) YCbCr/HSV Encoding: Default (maps to ITU-R 601) Quantization : Default (maps to Limited Range) Flags : If I just run this pipeline $ gst-launch-1.0 -e v4l2src ! videoconvert ! autovideosink This will change the current format (before the pipeline is run, but it will also be left in that state) to $ v4l2-ctl --get-fmt-video Format Video Capture: Width/Height : 1280/1024 Pixel Format : 'YUYV' (YUYV 4:2:2) Field : None Bytes per Line : 2560 Size Image : 2621440 Colorspace : Default Transfer Function : Default (maps to Rec. 709) YCbCr/HSV Encoding: Default (maps to ITU-R 601) Quantization : Default (maps to Limited Range) Flags : And this is not what I want. What I want is for GStreamer to use already set format and not change it. How I can accomplish that programmatically (gst-launch-1.0 was just an example, I'm primarily interested in doing this in code)? _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel |
Le dim. 18 oct. 2020 17 h 00, Nikola Pantelic <[hidden email]> a écrit : (This question is also available at When it reach ready state, you can get through properties the device fd, you can then configure a caps filter to preserve the last format used. _______________________________________________ _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel |
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