Opencv-python: H264 encoding failure

[bloodymeli]

Expected behaviour

I'm trying to open a VideoWriter using H264 encoding.

Actual behaviour

I'm getting an error when trying to write H264 encoded files/

OpenCV: FFMPEG: tag 0x34363248/'H264' is not supported with codec id 27 and format 'mp4 / MP4 (MPEG-4 Part 14)'
OpenCV: FFMPEG: fallback to use tag 0x31637661/'avc1'
Could not find encoder for codec id 27: Encoder not found

And I'm unable to write frames to file. I've tried using X264 but I get the same error.

Steps to reproduce

Code:

import cv2
fourcc = cv2.VideoWriter_fourcc(*'H264')
video_out = cv2.VideoWriter('test.mp4', int(fourcc), 25.0, (640, 480))

System setup:
Ubuntu 16.4,
FFMPEG 3.4.2 (upgraded from the default Ubuntu version due to this error, but it didn't solve it)
Opencv 3.4.1
Intel i7

[skvark]

If you installed this package via pip install opencv-python then there's no encoding support for x264 because it's under GPL license. Upgrading FFmpeg won't help because opencv-python ships with its own FFmpeg. See: https://github.com/skvark/opencv-python/issues/81

You'll have to compile OpenCV manually to get support for H264 encoding.

[Rahul-Venugopal]

I am using an mp4 video and is it possible to get support for it , when I install open-cv by pip ?

[skvark]

As explained above: no (if you mean encoding to h264).

[alexcanepa]

Sorry to bump this, but does anyone have any guidance on going about setting this up?
Whenever I try compiling the build with cmake, my locally installed ffmpeg implementation is not detected.

The opencv_thirdparty page says that the build should auto-detect ffmpeg if installed on UNIX systems...

[skvark]

Please ask at http://answers.opencv.org/questions/, you will get better answers there.

[kin-kins]

If you installed this package via pip install opencv-python then there's no encoding support for x264 because it's under GPL license. Upgrading FFmpeg won't help because opencv-python ships with its own FFmpeg. See: #81

You'll have to compile OpenCV manually to get support for H264 encoding.

How?

[skvark]

If you installed this package via pip install opencv-python then there's no encoding support for x264 because it's under GPL license. Upgrading FFmpeg won't help because opencv-python ships with its own FFmpeg. See: #81
You'll have to compile OpenCV manually to get support for H264 encoding.

How?

https://docs.opencv.org/master/df/d65/tutorial_table_of_content_introduction.html

[FantasyJXF]

If you installed this package via pip install opencv-python then there's no encoding support for x264 because it's under GPL license. Upgrading FFmpeg won't help because opencv-python ships with its own FFmpeg. See: #81

You'll have to compile OpenCV manually to get support for H264 encoding.

If install opencv python in anaconda, I could encode MP4 video with fourcc avc1, which let me get video format like this:

Video: h264 (High) (avc1 / 0x31637661), yuv420p

That's all right.

[FantasyJXF]

If you installed this package via pip install opencv-python then there's no encoding support for x264 because it's under GPL license. Upgrading FFmpeg won't help because opencv-python ships with its own FFmpeg. See: #81

You'll have to compile OpenCV manually to get support for H264 encoding.

I compile opencv with BUILD_opencv_python3=ON and the opencv_python I get could use fourcc AVC1.

HAHAHA

[kin-kins]

Could you guide me through the procedure?

On Sun, 17 Nov 2019 at 9:44 PM, FantasyJXF [e-mail] wrote:

If you installed this package via pip install opencv-python then there's
no encoding support for x264 because it's under GPL license. Upgrading
FFmpeg won't help because opencv-python ships with its own FFmpeg. See:

81 https://github.com/skvark/opencv-python/issues/81

You'll have to compile OpenCV manually to get support for H264 encoding.

I compile opencv with BUILD_opencv_python3=ON and the opencv_python I get
could use fourcc AVC1.

HAHAHA

—
You are receiving this because you commented.
Reply to this email directly, view it on GitHub
https://github.com/skvark/opencv-python/issues/100?email_source=notifications&email_token=AHJ6FQQKCJM4ZXKX6SY2533QUFUW3A5CNFSM4FDAIIIKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEEIPYTA#issuecomment-554761292,
or unsubscribe
https://github.com/notifications/unsubscribe-auth/AHJ6FQXMHILOUVXUP32S5YLQUFUW3ANCNFSM4FDAIIIA
.

[skvark]

Yeah, if you link OpenCV against local build of FFmpeg you will most likely get support for encoding to h264.

To compile OpenCV locally with this repo's toolchain:

1. Clone this repository
2. Optional: set up ENABLE_CONTRIB and ENABLE_HEADLESS environment variables to 1 if needed
3. Optional: add additional Cmake arguments to CMAKE_ARGS environment variable
4. Run python setup.py bdist_wheel

Note: Anaconda package is different than the package provided by this repository: https://github.com/conda-forge/opencv-feedstock

[FantasyJXF]

Env

• CentOS 7.3
• Python 3.6.8
• OpenCV 3.4.6
• OpenCV_Contrib_3.4.6
• ffmpeg 4.1.3

cmake config

cmake -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=/usr/local \
    -D OPENCV_EXTRA_MODULES_PATH=../../opencv_contrib-3.4.6/modules \
    -D PYTHON3_LIBRARY=/usr/local/python36/lib/libpython3.6m.a \
    -D PYTHON3_INCLUDE_DIR=/usr/local/python36/include/python3.6m \
    -D PYTHON3_EXECUTABLE=/usr/local/python36/bin/python3 \
    -D PYTHON3_PACKAGES_PATH=/usr/local/python36/lib/python3.6/site-packages \
    -D BUILD_opencv_python2=OFF \
    -D BUILD_opencv_python3=ON \
    -D INSTALL_PYTHON_EXAMPLES=ON \
    -D INSTALL_C_EXAMPLES=OFF \
    -D OPENCV_ENABLE_NONFREE=ON \
    -D WITH_FFMPEG=ON \
    -D CMAKE_CXX_FLAGS="-std=c++11" ..

Test Code

import cv2 as cv
import numpy as np

vid = cv.VideoWriter('pyout1.mp4', cv.VideoWriter_fourcc(*'avc1'), 25, (300,300))
#vid = cv.VideoWriter('pyout.mp4', 0x00000021, 25, (300,300))

for i in range(250):
    img = np.random.randint(0,255, (300,300,3), dtype=np.uint8)
    vid.write(img)
vid.release()

And you would get the H264(AVC1) coded video.