OpenCV - VideoCapture()

Hello
I hope this question to be addressed to the right forum. My question is about the use of the function VideoCapture of opencv-python==4.4.0 (python3.6.9). I have installed this package using pip3 and I am working with L4T version 32.5.1. Everything seems to be OK during the installation and also during the load of all the python’s libraries I need for my project, even cv2.

However when I run an example:
cap1 = cv2.VideoCapture(“rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mov”)

I got this message:

Opening in BLOCKING MODE
Opening in BLOCKING MODE
NvMMLiteOpen : Block : BlockType = 261
NVMEDIA: Reading vendor.tegra.display-size : status: 6
NvMMLiteBlockCreate : Block : BlockType = 261

But nothing happend.
Am I missing something? Do I need to include any additional library for this videocapture to work?
Thank you
Juan Pablo

Hello Again
I have detected that in my opencv-python installation FFMPEG is not active (see below for all the configuration information):

General configuration for OpenCV 4.4.0 =====================================
Version control: unknown

Platform:
Timestamp: 2021-10-06T05:47:27Z
Host: Linux 4.9.201-tegra aarch64
CMake: 3.21.3
CMake generator: Ninja
CMake build tool: /usr/bin/ninja
Configuration: Release

CPU/HW features:
Baseline: NEON FP16
required: NEON
disabled: VFPV3

C/C++:
Built as dynamic libs?: NO
C++ standard: 11
C++ Compiler: /usr/bin/c++ (ver 7.5.0)
C++ flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wuninitialized -Winit-self -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG -DNDEBUG
C++ flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wuninitialized -Winit-self -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -fvisibility=hidden -fvisibility-inlines-hidden -g -O0 -DDEBUG -D_DEBUG
C Compiler: /usr/bin/cc
C flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wuninitialized -Winit-self -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -fvisibility=hidden -O3 -DNDEBUG -DNDEBUG
C flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wuninitialized -Winit-self -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -fvisibility=hidden -g -O0 -DDEBUG -D_DEBUG
Linker flags (Release): -Wl,–gc-sections -Wl,–as-needed
Linker flags (Debug): -Wl,–gc-sections -Wl,–as-needed
ccache: NO
Precompiled headers: NO
Extra dependencies: ade /usr/lib/aarch64-linux-gnu/libgthread-2.0.so /usr/lib/aarch64-linux-gnu/libglib-2.0.so /usr/lib/aarch64-linux-gnu/libz.so /usr/lib/aarch64-linux-gnu/libjpeg.so dl m pthread rt
3rdparty dependencies: ittnotify libprotobuf libwebp libpng libtiff libjasper IlmImf quirc tegra_hal

OpenCV modules:
To be built: calib3d core dnn features2d flann gapi highgui imgcodecs imgproc ml objdetect photo python3 stitching video videoio
Disabled: world
Disabled by dependency: -
Unavailable: java js python2 ts
Applications: -
Documentation: NO
Non-free algorithms: NO

GUI:
GTK+: NO
VTK support: NO

Media I/O:
ZLib: /usr/lib/aarch64-linux-gnu/libz.so (ver 1.2.11)
JPEG: /usr/lib/aarch64-linux-gnu/libjpeg.so (ver 80)
WEBP: build (ver encoder: 0x020f)
PNG: build (ver 1.6.37)
TIFF: build (ver 42 - 4.0.10)
JPEG 2000: build Jasper (ver 1.900.1)
OpenEXR: build (ver 2.3.0)
HDR: YES
SUNRASTER: YES
PXM: YES
PFM: YES

Video I/O:
DC1394: NO
FFMPEG: NO
avcodec: NO
avformat: NO
avutil: NO
swscale: NO
avresample: NO
GStreamer: YES (1.14.5)
v4l/v4l2: YES (linux/videodev2.h)

Parallel framework: pthreads

Trace: YES (with Intel ITT)

Other third-party libraries:
Lapack: NO
Eigen: YES (ver 3.3.4)
Custom HAL: YES (carotene (ver 0.0.1))
Protobuf: build (3.5.1)

OpenCL: YES (no extra features)
Include path: /tmp/pip-install-wd1usoad/opencv-python_d08293b8ca4c4367ba712c2542466572/opencv/3rdparty/include/opencl/1.2
Link libraries: Dynamic load

Python 3:
Interpreter: /usr/bin/python3 (ver 3.6.9)
Libraries: /usr/lib/aarch64-linux-gnu/libpython3.6m.so (ver 3.6.9)
numpy: /usr/local/lib/python3.6/dist-packages/numpy/core/include (ver 1.18.5)
install path: python

Python (for build): /usr/bin/python2.7

Java:
ant: NO
JNI: NO
Java wrappers: NO
Java tests: NO

Install to: /tmp/pip-install-wd1usoad/opencv-python_d08293b8ca4c4367ba712c2542466572/_skbuild/linux-aarch64-3.6/cmake-install

Does anybody know the way to install opencv-python (or just opencv) to have this function activated?
So far I have used pip3.

Thank you again
Juan Pablo

Hi,

It’s more recommended to use the GStreamer backend rather than FFmpeg.
FFmpeg is a CPU-based decoder and GStreamer is already enabled in the default package.

To open an RSTP source via GStreamer, you can try the pipeline shared in the below comment:

Thanks.

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