System information (version)
- OpenCV => 4.3.0
- Operating System / Platform => Windows 64 Bit
- Compiler => Visual Studio 2019
Detailed description
if I use mp4 which has no audio stream (audio stream was removed with ffmpeg), no problem.
I used opencv of release windows module(4.3.0).
result of code is as follows.
sample files are attached.
[ INFO:0] global C:\build\master_winpack-build-win64-vc15\opencv\modules\videoio\src\videoio_registry.cpp (187) cv::`anonymous-namespace'::VideoBackendRegistry::VideoBackendRegistry VIDEOIO: Enabled backends(7, sorted by priority): FFMPEG(1000); GSTREAMER(990); INTEL_MFX(980); MSMF(970); DSHOW(960); CV_IMAGES(950); CV_MJPEG(940)
[ WARN:0] global C:\build\master_winpack-build-win64-vc15\opencv\modules\videoio\src\cap_msmf.cpp (681) CvCapture_MSMF::initStream Failed to set mediaType (stream 0, (0x0 @ 1) MFVideoFormat_RGB32(unsupported media type)
ng
ok
Steps to reproduce
#include <stdio.h>
#include <iostream>
#include <opencv2/opencv.hpp>
int main()
{
cv::VideoCapture cap("sample-has-sound.mp4", cv::CAP_MSMF);
cv::Mat image;
if (cap.isOpened())
{
bool ret = cap.read(image);
if (ret)
{
std::cout << "ok" << std::endl;
}
else
{
std::cout << "ng" << std::endl;
}
}
cv::VideoCapture cap2("sample-no-sound.mp4", cv::CAP_MSMF);
if (cap2.isOpened())
{
bool ret = cap2.read(image);
if (ret)
{
std::cout << "ok" << std::endl;
}
else
{
std::cout << "ng" << std::endl;
}
}
} and I modified the code "cap_msmf.cpp" to pass only video types , it fixed;
// class FormatStorage
void read(IMFSourceReader* source)
{
HRESULT hr = S_OK;
MediaID cur;
GUID majorType;
while (SUCCEEDED(hr))
{
_ComPtr<IMFMediaType> raw_type;
hr = source->GetNativeMediaType(cur.stream, cur.media, &raw_type);
if (hr == MF_E_NO_MORE_TYPES)
{
hr = S_OK;
cur.nextStream();
}
else if (SUCCEEDED(hr))
{
raw_type.Get()->GetMajorType(&majorType);
if (majorType == MFMediaType_Video) // add this condition
{
formats[cur] = MediaType(raw_type.Get());
}
cur.nextMedia();
}
}
}samples.zip
System information (version)
Detailed description
if I use mp4 which has no audio stream (audio stream was removed with ffmpeg), no problem.
I used opencv of release windows module(4.3.0).
result of code is as follows.
sample files are attached.
Steps to reproduce
and I modified the code "cap_msmf.cpp" to pass only video types , it fixed;
samples.zip