Capture a DVB-T Stream to a movie-file - c#

I have a form with a liveview of the tv-signal (from dvb-t stick). I've the sampleproject "DTViewer" from http://directshownet.sourceforge.net/about.html.
Now I try to capture the stream to a movie-file by clicking a button, but how?
I use C# and DirectShow.NET.
I tried to search in many sampleprojcets but these are made for videoinputs not a dvb-t stick with a BDA (Broadcast Driver Architecture) interface.
Help!

Don’t really know what exactly do you mean by a “movie-file”, but I can tell you how to capture the entire MUX (transport stream). Create a graph with a Microsoft DVBT Network Provider, You_Name_It BDA DVBT Tuner, You_Name_It BDA Digital Capture and MPEG-2 Demultiplexer filters. Once you connect them, enumerate all output pins on the MPEG-2 Demultiplexer and render them. Tune the frequency of your choice (put_TuneRequest). At this point everything is ready to run the graph, but don’t run it! Enumerate all filters in the graph. Disconnect all filters except Microsoft DVBT Network Provider, You_Name_It BDA DVBT Tuner and You_Name_It BDA Digital Capture. Remove all these disconnected filters from the graph except the MPEG-2 Demultiplexer (it has to be in the graph although it is not connected). Add Sample Grabber filter and NULL Renderer filter. Connect Digital Capture filter to Sample Grabber and Sample Grabber to NULL Renderer. You can run the graph now. Through the callback in Sample Grabber filter you will receive the entire MUX. Of course, there is still some work to demux the data, but once you do that, you can capture all TV programs in one MUX at once. The easiest way is to capture it in a TS format because the TS is being broadcasted (188 bytes long packets).

It seems to me VLC has BDA support (BDA.c file reference), maybe you can snoop up something from their code?

There is no simple answer to your question. I have started one such project and have found out that there is very little I know about it, so here is little something from my research.
First, you'll have to understand that dvb-t tuner card or stick doesn't give video frames in the classical sense, but the decoding is done in the pc, on the cpu. External card will provide you with compressed data only, as it fetches it from the air.
Next - data that is delivered to you will be in MPEG2 or MPEG4 Transport Stream format. Which is suitable for streaming or broadcasting, not for saving to file. VLC is able to play TS written to the file, but to record a proper video file, you'll have to either transcode the file or repack it to Program Stream. Google it a little, you'll find the differences.
More - one frequency on the air consists of many channels, and that channel packing is called 'mux'. So - from the BDA tuner/capturer you'll get ALL data, and you'll have to demux it manually or let BDA demuxer do it for you.
Hope that's enough info to get you started, I can post you some interesting links when I get to the real keyboard.

Related

Raw H264 to JPEG, in C#

I get a stream of frames, an initial SPS and PPS h264 data packet and then packets for the I and P frames.
Using c# .NET I want to convert into a series of JPEGs? Has anyone done this?
I have tried AForge.NET FFMpeg wrapper, but can only go from MP4 file to JPEGs?
Also looked at DirectShow.
I can't seem to find an examples that even come close to doing this?
Thanks
In Directshow, it sounds like you need to introduce a SampleGrabber filter into your filter graph. Insert this after the H264 decoder.
This is a pass through filter which can receive a callback containing each video frame. You can then obviously choose what you do with the frame, is save it to disk as a jpeg etc.
Rather than regurgitate MSDN, there is a great page explaining its usage here:
https://msdn.microsoft.com/en-us/library/windows/desktop/dd407288(v=vs.85).aspx
Update taking account of Roman's comments:
SampleGrabber is deprecated as its part of Directshow Editing Services. However, it is quite self contained. If it was removed from a later version of Windows it would be straight forward to replace with an alternative filter. I still use it in one of my consumer applications. Roman is correct though - it has a steep learning curve.

Grab Audio Sessions as they appear in the windows audio mixer (C# or C++)

I'm trying to figure out how to grab the individual audio streams as they appear in the audio mixer to reroute them to an aggregate audio device. I'm specifically looking to keep them as discreet streams for the purposes of the program I'm making (If they're muxed down to a 2-channel mix, that defeats the purposes of what I'm trying to achieve.)
E.X.: (As I've just made this account, I apparently am not able to post images, so here's a link to the image)
windows audio mixer
In this, I'm hoping to grab "System Sounds" and "Stream Client Bootstrapper" as discreet audio streams to route elsewhere, while maintaining their original destination as well (essentially copying the audio going to the original audio device to another simultaneously).
I'm looking to do this in either C# or C++. I've perused the audio APIs that microsoft has published, and while some things look to be close to what I'm trying to do, nothing has hit the nail on the head. I appreciate any help. Thanks.
The sessions can be enumerated using IAudioSessionManager2::GetSessionEnumerator and friends (sample C++ code is here and there). Standard Windows volume mixer application is using this API as well.
The API however has no access to data streams, you won't have either (you certainly don't have data whether they are downmixed or not). Neither you can reroute streams to another device. Applications are not allowed to interfere that deep. The best you can do is to create your own device, interactively select it as default output device and then accept data from applications playing audio through this device.

How can I play H.264 RTSP video in Windows 8 Metro C# XAML app?

I have a device that provides an H.264 video stream from a URL like:
rtsp://192.168.0.10:554/videoservice
Since this is live video I don't need to be able to control it (pause, rewind, etc), just play. Is this supported by MediaElement or another standard class, do I need something like Smooth Streaming Client SDK or is this a lot more complicated than I thought?
Update:
I downloaded Microsoft's Player Framework but this doesn't play the stream either. I can't find anything in the examples about RTSP.
Update:
I used Wireshark to compare the packets that VLC Media Player (which works) sends with MediaElement and Player Framework and neither of them seemed to use RTSP protocol. Instead they're sending WPAD packets to a different address, even though I've provided the IP address of the source. Why is this necessary? Is there any way of turning this behaviour off?
See the post here. You need to wrap your data in MPEG-4 Part 14 containers and then pass them into MediaElement.SetSource. It appears you can't do this just using the documented API. Here is the important information from the link:
We don't support RTP but rather the MPEG-4 Part 14 container format.
You will need to write our own source to be able to parse the data a
pass it directly to the Microsoft decoder. At this time we do not have
any samples on how to write a custom source and have it loaded from
your Metro style app. Unfortunately it is not possible to simply use
the documentation to figure out how to do this. I have been talking
with Stan and we are trying to figure out how and when we can make
this information available. As soon as this information is available
I will announce it on my blog http://blogs.msdn.com/mediasdkstuff/.
Here is a list of supported video formats.
There is also an example here of how to extend the media class which might have an example of how to do something similar to what you are asking.
There is a similar example here.

Get Stream and save as jpeg (image) file from IP Camera using ffmpeg

How i can get stream from Ip Camera, Its using RTP, stream is MPEG4, i have multicast address and port,and i have ip camera's IP address and Port Number. And I cant reach via http forexample (http://ip/jpeg) And I cant reach stream with VLC Player too. forexample (rtp://ipadressofcam:port) and (rtp://multicastaddress:port)
So What is ffmpeg command of that?
I have windows OS, I only write code with C# right now.
But producer created their own ocx which used for viewing cam,that plugin can work on .net but i dont want to use it becouse it doesnt have much funcionality, I mean you cant get current picture or snapshot of cams, thats why i have to do it myself.
Are you sure the stream is not password-protected?
Try to see why your camera rejects VLC requests. And this is how to do it: Install Wireshark, start it, and put a filter for the camera address, like: ip.addr == camera_ip (xxxx.xxxx.xxxx.xxxx). Then, try to connect with VLC, and look there at the messages exchanged. If you see a DROP, UNAUTH, or something that tells you to use a passwd, introduce it. (VLC will first try to connect using an unauthenticated procedure, and if it fails, will ask for a passwd.)
Wireshark will give you clues if the failure reason is something different.
And keep in mind that if VLC can't access it, the chance to find some other way to do it is almost zero. Unless you're a video guru.
Hope it helps!
You can use VLC for such a thing ,and it's ActiveX control which is available for .NET also ,just need to install VLC Media Player and you can set it's control on VS toolbox
http://forum.videolan.org/viewtopic.php?f=32&t=54969
UPDATE
If you are ready to pay for this stuff you can use http://www.mainconcept.com/products/sdks/video.html this Company product's to advance with Decoding and Encoding ,where you can find a huge Library .
So you want to receive video stream from camera and convert individual frame into JPEG file. This sounds good and actually sounds natural: why not? there is a video feed being sent on network and we don't need much, just to pick individual frame.
The original stream is MPEG-4 (Part 2) and desired target encoding is JPEG. This breaks the task into parts of getting MPEG-4 video feed, decoding it into uncompressed images, and encoding into JPEG. Let us go through these from the last one backwards.
JPEG is a popular encoding and there are various codecs with different interface capable of compressing into JPEG. Options include GDI+ API, IJG JPEG library libjpeg, JPEG libraries and codecs for video with DirectShow and other interfaces.
MPEG-4 decoder is a complicated component, however is luckily well standardized and available in different interfaces and from several sources. In particular MPEG-4 Part 2 Video Decoder is shipped as DMO (and also through ) with Windows 7. Decoder is also available as DirectShow filter in ffdshow, Intel Media SDK.
Back to the first step, you need to reach MPEG-4 stream from network. First of all you indicated that the camera is available on multi-cast UDP address. This makes you open a socket and put into onto multi-cast group in order to start receiving RTP data. The data you would receive is not pure MPEG-4 yet, and is formatted according to RTP Payload Format for MPEG-4 Audio/Visual Streams and as you receive RTP stream of messages you will have to be prepared to receive out of order fragments, packet losses etc. You are supposed to receive what you can receive, check the RTP headers, and do your best in reconstructing MPEG-4 feed.
Eventually you need to cover these steps (not necessarily directly, you would rather use third party libraries including those mentioned in other answers) from your application and build a pipeline which stitches together receiving from network and transcoding.
So until now, I saw VLC cant open it but if we create .sdp file and play it with ffplay only a black screen appears.
vlc -vvv dshow:// --sout-keep --sout-all --sout=#rtp{dst=multicastaddress,port=portNo,sdp=file:///C:/test/my.sdp}
Of course this is not pure solution but there is little bit hope.
But obsolute solution can be like that;
There is no way to use just c# to achive what i intend. There are few c++ library components that i can use, but i can use it along with Managed c++ to write interop services and use those dlls in my c# code.Here is what i need:
1-I need an RTP Library, http://research.edm.uhasselt.be/~jori/page/index.php?n=CS.Jrtplib or live555 but live555 has certain limitations.
2-RTP Library is the transport for the MPEG4 stream i pull from my encoder. But i need ways to control the stream, those are provided producer's WSDLs.
3-After that i need a decoder; Libavcodec, I can use libavcodec to convert an Iframe to a jpeg image in .net.

Video Capturing + Uploading + Processing + Streaming back - .NET & C#

We are trying to find out any technologies/libraries available in .NET stack (even wrappers on top of 3rd party dlls) that'll help us to build an app that can
1 - Capture an image from a user's video device
2 - Upload it realtime to a server
3 - Process the video (in the server) - eg: Adding a watermark to the video
4 - Stream it back to the user/other users
Preferably, the time delay/latency between step2 and 4 should be minimal
The first requirement (capturing) seems pretty straight forward. The challenge is identifying a suitable way to do the upload, do the processing, and stream it back. Any valid suggestions or ideas?
Recently came acrsoss FFmpeg library, and it has a C# wrapper. Does FFmpeg can be used to do the processing side?
I would go about it this way:
Use silverlight or flash to capture the video camera input, e.g. as detailed here.
You can send the byte-stream over a socket that your server is listening to.
On the receiving end, just use the socket-accepting program as a router-program with a number of listening workers connected. Between workers and router-program, e.g. AMQP with RabbitMQ. Send asynchronous messages (e.g. with reactive extensions) with e.g. the stream encoding to the rabbit-node, which then can either further all messages to one single computer as a part of a conversation/user-session, or interleave between the available workers. Here's the manual. As the video is encoded, it is streamed asynchronously over the message bus back. According to intel tests the bus itself should work well at high throughputs, but they had to use the interleaved tcp channel mode (they tested on a gigabit lan). Other users here have suggested FFlib. You might also look into having the workers convert into webM, but if FFlib works, that might be a lot easier. Each worker publishes over AMQP the next encoded video piece. A server-running program, e.g. the router program I talked about before, starts sending to the client (see no. 4)
Have a client-program, e.g. silverlight/flash connect (for example over the same socket that you opened for client->server data, or over HTTP), and read the byte-stream with a decoder. Render the output.
VideoLab from Mitov can accomplish all of this and is free for personal use (not so free for commercial use, but pricing is not too heavy).
I have bought and use the Delphi version and know it works extremely well, so I'm pretty sure the .NET version will do what you need.
This kind of task is not trivial (as seen by the lack of responses here), so expect to struggle considerably with DirectX/Microsoft Media Encoder- but with this toolkit and some help from the author, you will eventually succeed.
http://www.mitov.com/html/videolab.html
It seems that Splicer can process static video and convert it - I'm not sure about processing a realtime uploaded video - http://splicer.codeplex.com/
Take a look at Video.Show by Vertigo. It's an open source website for user-generated video content. It uses the Expression Encoder to handle compression/video editing. It's not exactly what you need, but it's a good start!
You could use Silverlight for capture as is mentioned above, and then use Expression Encoder to push it to a stream server or stream from there directly.
It should have everything you need:
Smart encoding/smart recompression for
WMV if the source is also WMV and no
frame operations are performed [4],
cuts editing, serial batch encoding,
Live encoding from webcams and DV
camcorders
Decoding/import format support because
of DirectShow
Smooth streaming (720p+ video using
HTTP) with optimized client
(Silverlight) and server (IIS with
smooth streaming)
WebDAV publishing, publishing plugins
for Silverlight Streaming, Amazon S3
Importing XAML overlays created in
Expression Design and customizing
their timing, animation, opacity,
placement and looping
JavaScript trigger events
Windows Media 11 SDK and VC-1 SDK
integration, native MPEG-2 decoder
Adding captions to videos using SAMI
or W3C Timed Text format
Previewing and comparing encoding
settings in real time
Screen capture
Object model for the encoding engine,
SDK downloadable separately
The question is kind of short on details (is this a web server, what os is the server? etc) but I'll take a stab based on what I think you're trying to do.
One thing you might consider is doing the capture and process at one time. If the user is running your client app, have that do the capture and processing via DirectShow. Then all you need to do is upload the video and you can skip the entire server process. This is assuming that the 'user' is under your control - that this is not some random person out there uploading video, but an employee or someone otherwise trusted.
If this isnt the case, then ffmpeg can certainly be used to watermark video on your server. You dont really need 'wrappers' for it. You can just call it as a command line app from your server application and wait for it to finish.
The process really isnt that complex... its the details that are going to matter (for example - what does 'stream' mean to you? Do you really mean 'stream', or is this via http? Thats a huge topic right there)

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