How to get video frames from UVC device in MJPG format on ARM64 system? (with python)
As the title. I want to get the highest performance from Logic HD Pro Webcam C920, which should be 1920*1080, FPS=30.0. I've tried many ways from Internet, however, neither could solve my problem. Generally, There are two methods could achieve the goal.
- opencv-python -> VideoCapture:
Here is my code.
cap = cv2.VideoCapture('/dev/video0')
cap.set(cv2.CAP_PROP_FOURCC, cv2.VideoWriter_fourcc(*'MJPG'))
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)
The problem is although I set the correct resolution and format which is supported by camera and computer, I still get the wrong FPS from camera (Result is 1920*1080 FPS=5). The camera I used is Logic HD Pro Webcam C920. Below are the camera information.
Index : 0
Type : Video Capture
Pixel Format: 'YUYV'
Name : YUYV 4:2:2
Size: Discrete 640x480
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 160x90
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 160x120
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 176x144
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 320x180
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 320x240
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 352x288
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 432x240
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 800x448
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 800x600
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 864x480
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 960x720
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1024x576
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1600x896
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 2304x1296
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 2304x1536
Interval: Discrete 0.500s (2.000 fps)
Index : 2
Type : Video Capture
Pixel Format: 'MJPG' (compressed)
Name : Motion-JPEG
Size: Discrete 640x480
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 160x90
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 160x120
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 176x144
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 320x180
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 320x240
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 352x288
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 432x240
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 800x448
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 800x600
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 864x480
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 960x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1024x576
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1600x896
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.133s (7.500 fps)
Interval: Discrete 0.200s (5.000 fps)
Factory Details:
Rank primary (256)
Long-name Video (video4linux2) Source
Klass Source/Video
Description Reads frames from a Video4Linux2 device
Author Edgard Lima <edgard.lima@gmail.com>, Stefan Kost <ensonic@users.sf.net>
Plugin Details:
Name video4linux2
Description elements for Video 4 Linux
Filename /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstvideo4linux2.so
Version 1.14.5
License LGPL
Source module gst-plugins-good
Source release date 2019-05-29
Binary package GStreamer Good Plugins (Ubuntu)
Origin URL https://launchpad.net/distros/ubuntu/+source/gst-plugins-good1.0
GObject
+----GInitiallyUnowned
+----GstObject
+----GstElement
+----GstBaseSrc
+----GstPushSrc
+----GstV4l2Src
Implemented Interfaces:
GstURIHandler
GstTuner
GstColorBalance
GstVideoOrientation
Pad Templates:
SRC template: 'src'
Availability: Always
Capabilities:
image/jpeg
video/mpeg
mpegversion: 4
systemstream: false
video/mpeg
mpegversion: 2
video/mpegts
systemstream: true
video/x-bayer
format: { (string)bggr, (string)gbrg, (string)grbg, (string)rggb }
width: [ 1, 32768 ]
height: [ 1, 32768 ]
framerate: [ 0/1, 2147483647/1 ]
video/x-dv
systemstream: true
video/x-h263
variant: itu
video/x-h264
stream-format: { (string)byte-stream, (string)avc }
alignment: au
video/x-pwc1
width: [ 1, 32768 ]
height: [ 1, 32768 ]
framerate: [ 0/1, 2147483647/1 ]
video/x-pwc2
width: [ 1, 32768 ]
height: [ 1, 32768 ]
framerate: [ 0/1, 2147483647/1 ]
video/x-raw
format: { (string)RGB16, (string)BGR, (string)RGB, (string)GRAY8, (string)GRAY16_LE, (string)GRAY16_BE, (string)YVU9, (string)YV12, (string)YUY2, (string)YVYU, (string)UYVY, (string)Y42B, (string)Y41B, (string)YUV9, (string)NV12_64Z32, (string)NV24, (string)NV61, (string)NV16, (string)NV21, (string)NV12, (string)I420, (string)BGRA, (string)BGRx, (string)ARGB, (string)xRGB, (string)BGR15, (string)RGB15 }
width: [ 1, 32768 ]
height: [ 1, 32768 ]
framerate: [ 0/1, 2147483647/1 ]
video/x-sonix
width: [ 1, 32768 ]
height: [ 1, 32768 ]
framerate: [ 0/1, 2147483647/1 ]
video/x-vp8
video/x-vp9
video/x-wmv
wmvversion: 3
format: WVC1
Element has no clocking capabilities.
URI handling capabilities:
Element can act as source.
Supported URI protocols:
v4l2
Pads:
SRC: 'src'
Pad Template: 'src'
Element Properties:
name : The name of the object
flags: readable, writable
String. Default: "v4l2src0"
parent : The parent of the object
flags: readable, writable
Object of type "GstObject"
blocksize : Size in bytes to read per buffer (-1 = default)
flags: readable, writable
Unsigned Integer. Range: 0 - 4294967295 Default: 4096
num-buffers : Number of buffers to output before sending EOS (-1 = unlimited)
flags: readable, writable
Integer. Range: -1 - 2147483647 Default: -1
typefind : Run typefind before negotiating (deprecated, non-functional)
flags: readable, writable, deprecated
Boolean. Default: false
do-timestamp : Apply current stream time to buffers
flags: readable, writable
Boolean. Default: false
device : Device location
flags: readable, writable
String. Default: "/dev/video0"
device-name : Name of the device
flags: readable
String. Default: null
device-fd : File descriptor of the device
flags: readable
Integer. Range: -1 - 2147483647 Default: -1
flags : Device type flags
flags: readable
Flags "GstV4l2DeviceTypeFlags" Default: 0x00000000, "(none)"
(0x00000001): capture - Device supports video capture
(0x00000002): output - Device supports video playback
(0x00000004): overlay - Device supports video overlay
(0x00000010): vbi-capture - Device supports the VBI capture
(0x00000020): vbi-output - Device supports the VBI output
(0x00010000): tuner - Device has a tuner or modulator
(0x00020000): audio - Device has audio inputs or outputs
brightness : Picture brightness, or more precisely, the black level
flags: readable, writable, controllable
Integer. Range: -2147483648 - 2147483647 Default: 0
contrast : Picture contrast or luma gain
flags: readable, writable, controllable
Integer. Range: -2147483648 - 2147483647 Default: 0
saturation : Picture color saturation or chroma gain
flags: readable, writable, controllable
Integer. Range: -2147483648 - 2147483647 Default: 0
hue : Hue or color balance
flags: readable, writable, controllable
Integer. Range: -2147483648 - 2147483647 Default: 0
norm : video standard
flags: readable, writable
Enum "V4L2_TV_norms" Default: 0, "none"
(0): none - none
(45056): NTSC - NTSC
(4096): NTSC-M - NTSC-M
(8192): NTSC-M-JP - NTSC-M-JP
(32768): NTSC-M-KR - NTSC-M-KR
(16384): NTSC-443 - NTSC-443
(255): PAL - PAL
(7): PAL-BG - PAL-BG
(1): PAL-B - PAL-B
(2): PAL-B1 - PAL-B1
(4): PAL-G - PAL-G
(8): PAL-H - PAL-H
(16): PAL-I - PAL-I
(224): PAL-DK - PAL-DK
(32): PAL-D - PAL-D
(64): PAL-D1 - PAL-D1
(128): PAL-K - PAL-K
(256): PAL-M - PAL-M
(512): PAL-N - PAL-N
(1024): PAL-Nc - PAL-Nc
(2048): PAL-60 - PAL-60
(16711680): SECAM - SECAM
(65536): SECAM-B - SECAM-B
(262144): SECAM-G - SECAM-G
(524288): SECAM-H - SECAM-H
(3276800): SECAM-DK - SECAM-DK
(131072): SECAM-D - SECAM-D
(1048576): SECAM-K - SECAM-K
(2097152): SECAM-K1 - SECAM-K1
(4194304): SECAM-L - SECAM-L
(8388608): SECAM-Lc - SECAM-Lc
io-mode : I/O mode
flags: readable, writable
Enum "GstV4l2IOMode" Default: 0, "auto"
(0): auto - GST_V4L2_IO_AUTO
(1): rw - GST_V4L2_IO_RW
(2): mmap - GST_V4L2_IO_MMAP
(3): userptr - GST_V4L2_IO_USERPTR
(4): dmabuf - GST_V4L2_IO_DMABUF
(5): dmabuf-import - GST_V4L2_IO_DMABUF_IMPORT
extra-controls : Extra v4l2 controls (CIDs) for the device
flags: readable, writable
Boxed pointer of type "GstStructure"
pixel-aspect-ratio : Overwrite the pixel aspect ratio of the device
flags: readable, writable
String. Default: null
force-aspect-ratio : When enabled, the pixel aspect ratio will be enforced
flags: readable, writable
Boolean. Default: true
Element Signals:
"prepare-format" : void user_function (GstElement* object,
gint arg0,
GstCaps* arg1,
gpointer user_data);
- Gstreamer
Here is my code and it doesn't work, either. Unless remove the pixelformat, and set width=2304,height=1536,framerate=2/1
gst_str = 'v4l2src device=/dev/video0 ! '
'video/x-raw, pixelformat=2, width=1920, height=1080, framerate=30/1 ! '
'videoconvert ! appsink'
cap = cv2.VideoCapture(gst_str, cv2.CAP_GSTREAMER)
This has already perplexed me for a long time. I really wonder how to get the correct resolution, fps and format from UVC device. I'll very very very appreciate it if someone could solve the problem and told me what's going on.
asked on Stack Overflow Nov 30, 2020 by 
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