I'm looking for build in library for converting videos/images. i heard something about DirectShow. Do you know any library you have used to convert videos/images?
For transcoding (converting one video format to another) using Directshow is bit tricky, you want to use Media Foundation for this job.
There is Transcode API available in Media Foundation to achieve this task. This link has more details on Transcode API, tutorials and samples to get you started.
You can use DirectShow for grabbing images from video stream. For it you must create your own filter node. It is complex task because of filter is COM object that will work within chain (DirectShow filter graph) of other filter nodes - codecs. So after creating you need register your filter in system. As for me i think you can try it because you can use all registered codecs in system and as result get decompressed/final image into your filter. As other solution i think that you can try to use modules from some open source media player. For example try VideoLAN but as i know it is big thing and not easy to use.
Good luck!
Related
I am newbie in media foundation programming and windows programing as well.
It might looks very silly question but i didn't get clear answer anywhere.
My application is to capture screen, scale, encode and send the data to network. I am looking to improve the performance of my pipeline. so i want to change some intermediate libraries like scaling or encoding libraries.
When i do a lot of search for better option of scaling and encoding, i end up with some MFT(media foundation transform) e.g.Video Processor MFT and H.264 Video Encoder MFT.
My application already implemented pipeline and i don't want to change complete architecture.
can we directly use MFT as a library and add in my project? or i have to build complete pipeline, source and sink.
As per architecture of Media foundation a MFT is intermediate block. It requires IMFTransform::GetInputStreamInfo and IMFTransform::GetOutputStreamInfo.
Is it any way to call direct API's of MFT to perform (scaling and encoding) with creating complete pipeline?
Please provide link if any similar question already asked.
Yes you can create this IMFTransform directly and use it in isolation from pipeline. It is very typical usage model for encoder MFT.
You will need to configure input / output media types, start streaming, feed input frames and grab output frames.
Depending on whether your transform is synchronous or asynchronous (which may differ depending on HW or SW implementation of your MFT) you may need use basic (https://msdn.microsoft.com/en-us/library/windows/desktop/aa965264(v=vs.85).aspx) or async (https://msdn.microsoft.com/en-us/library/windows/desktop/dd317909(v=vs.85).aspx) processing model.
I'm trying to make a multimedia database system using Qt. I'm using QMultimedia to play back videos in a QVideoWidget.
The following is the code I am using to play a video file in a QVideo Widget:
mMediaPlayer = new QMediaPlayer();
mMediaPlaylist = new QMediaPlaylist();
QMediaContent content(QMediaResource())
mMediaPlaylist->addMedia(QUrl::fromLocalFile(QDir(QString("data")).absoluteFilePath(QString("%1.dat").arg(mMedia.GetUID()))));
mMediaPlayer->setPlaylist(mMediaPlaylist);
mVideoWidget = new QVideoWidget();
mMediaPlayer->setVideoOutput(mVideoWidget);
this->setCentralWidget(mVideoWidget);
mVideoWidget->show();
mMediaPlayer->play();
Basically, it plays a file called 1.dat for example, which is just a renamed video file (video.mp4 for example). However, playing the video never works, and the following error is produced:
DirectShowPlayerService::doRender: Unresolved error code 80040266
With some google searching, I found that this error is because QMultimedia doesn't have the required codecs/filters to play the format of the video. I've tried converting my videos to many different formats using ffmpeg, while trying formats specified at Supported Formats in DirectShow and Supported Media Formats in Media Foundation. I've also tried installing Directshow Filters for Ogg Vorbis, Speex, Theora, FLAC, and WebM, and converting my video to theora/vorbis in an ogg container. Still no go.
I should note that I did manage to play one mpg file, so I do know QMultimedia is working. But I tried converting another video to mimic the properties of that mpg file, and it didn't seem to work, so it seems QMultimedia is extremely specific in what formats it supports.
What system is QMultimedia using for its backend decoding? How can I find out what types of encodings and containers it supports? Is it possible to write my own decoder in Qt?
Thanks
this document describe features supported by QMultimedia backends. Render to widget is not supported now.
I recommend to use another library for encoding/decoding multimedia(f.e. ffmpeg) - QMultimedia now is not stable and I think that correct work only examples from documentation :(
The Kinect OpenNI library uses a custom video file format to store videos that contain rgb+d information. These videos have the extension *.oni. I am unable to find any information or documentation whatsoever on the ONI video format.
I'm looking for a way to convert a conventional rgb video to a *.oni video. The depth channel can be left blank (ie zeroed out). For example purposes, I have a MPEG-4 encoded .mov file with audio and video channels.
There are no restrictions on how this conversion must be made, I just need to convert it somehow! Ie, imagemagick, ffmpeg, mencoder are all ok, as is custom conversion code in C/C++ etc.
So far, all I can find is one C++ conversion utility in the OpenNI sources. From the looks of it, I this converts from one *.oni file to another though. I've also managed to find a C++ script by a phd student that converts images from a academic database into a *.oni file. Unfortunately the code is in spanish, not one of my native languages.
Any help or pointers much appreciated!
EDIT: As my usecase is a little odd, some explanation may be in order. The OpenNI Drivers (in my case I'm using the excellent Kinect for Matlab library) allow you to specify a *.oni file when creating the Kinect context. This allows you to emulate having a real Kinect attached that is receiving video data - useful when you're testing / developing code (you don't need to have the Kinect attached to do this). In my particular case, we will be using a Kinect in the production environment (process control in a factory environment), but during development all I have is a video file :) Hence wanting to convert to a *.oni file. We aren't using the Depth channel at the moment, hence not caring about it.
I don't have a complete answer for you, but take a look at the NiRecordRaw and NiRecordSynthetic examples in OpenNI/Samples. They demonstrate how to create an ONI with arbitrary or modified data. See how MockDepthGenerator is used in NiRecordSynthetic -- in your case you will need MockImageGenerator.
For more details you may want to ask in the openni-dev google group.
Did you look into this command and its associated documentation
NiConvertXToONI --
NiConvertXToONI opens any recording, takes every node within it, and records it to a new ONI recording. It receives both the input file and the output file from the command line.
I am just starting to learn DirectShow with C++. I need to use DirectShow to record the audio and write it to a WAV file on the disk. I heard from other people that Win 7 does not allow for rendering audio using DirectShow.
In addition, I would like to know how should I start with recoding audio using DirectShow with C++? If there is sample source, it would be great.
Thanks in advance.
I think you may have misunderstood these other people. Windows Media Foundation is aimed to be the successor of DirectShow, but DirectShow is still a very valid technology on Windows 7.
The easiest thing to accomplish what you want to do, is to get it right using the GraphEdit tool first ( I assume you want to do this programmatically).
Create a graph that contains your audio device, a WavDestFilter, and a file writer.
Source -> WavDest -> File Writer
Play the graph. Stop the graph and you should have created a .wav file with the recorded audio. If you can get this right, then you need to do the whole thing programmatically.
There are a couple of samples in the SDK that show you how to programmatically add filters to a graph and connect them, that should enable you to get started.
WRT the WavDestFilter, IIRC it might not be in all versions of the SDK, you'll have to find an appropriate one. You also need to build it, and regsvr32 it, so that it will show up in your list of available filters in GraphEdit.
If this all seems a bit much, I would read through the DirectShow documentation on MSDN to at least get an overview of DirectShow.
I am working on a C++ project with openCV. It is a simple web cam application with basic features like capturing pictures and videos. I have already been able to save video (w/o audio). Since openCV doesnot support audio processing, I was wondering if there is any way I can record audio separately in a different file and later combine those together to get one video file.
While searching on the internet, I did hear something about using ffmpeg with openCV. But I just cant figure out how to do it exactly.....
Can you guys help me? I would be very grateful... Thankyou!
P.S. I have used openCV and QT (for GUI)
As you said, opencv doesn't by itself deal with audio. However once you get a separate audio and video file, you can combine them using a technique called muxing. There are many many ways to do this. I use VirtualDub for most of my muxing needs, although it is windows only (not sure if that's a problem). I know ffmpeg is also capable of muxing (via the command line interface), I can't recall what the command is. There's also mplayer and a multitude of other programs out there to do this.
as far as i know openCV is good for video/image processing. To support audio processing, you can use other libraries e.g. PortAudio or C-sound.