I asked a slightly similar question previously but never got a good handle on this specific piece. Here's the setup:
Webserver: I have coded my own webserver. Works great. I have no issues here. It can handle any known mime-type (that I define) and send files accordingly. It can do so dynamically as well to send information within the responses like date/time, database results etc. So I need no help here.
Webcam code: I have coded a windows control that allows me to select whatever webcam I have hooked up and to view a preview inside the control. So I need no help here.
Here's where the issue arises. I want to connect these two components together so I can grab frames and stream them out the web server to viewers who request video.
Reading, I find that I probably want to write some sort of routine that takes regular "snapshots" at 5/10/20/30 frames per second and then, on-the-fly push them to some sort of MPEG routine to convert to MP4 and push the resulting bytes out to the viewer.
Can someone help enlighten me on how to do this? I don't know what the request should be from the client's end (presumably HTML5) and how to elegantly handle the stream. Thanks in advance!!!
Related
I want my android application record live audio from microphone and add my own binary data as image frames. I will be recording board game and whole image can be saved to around 50 bytes. The content should be possible to stream online so I want to put the data to some standard media container.
I checked various classes but can't build it together.
In MediaRecorder and AudioRecord classes I miss functions to add any sort of special data / tracks.
In MediaMuxer I can't find on the other hand a way how to record live, seems to me it only combines existing tracks.
Am I missing something in classes mentioned above? Or can this thing be done with MediaCodec and MediaExtractor? I don't much understand how these should be used.
Link to existing code would be welcome, I can check on my own, I just don't know where to search for the answer.
I should develop an application that records and plays recorded video while recording continues (without stopping graph). I know how to use and develop using DirectShow but I need architecture of my graph. What filters should I use?
I did it with raw video using DirectShow and SampleGrabber but I should compress video and I have no idea how to do it in compressed video file (which is not closed, because recording continues).
I think MPEG-2 recording is the best for my application but please guide me about filters I should use.
Thanks
Have you tried the StreamBufferEngine?
Recording a file and watching it at the same time is a little bit problematic, because the Demuxer needs to reparse the written file, to know about the new parts. I have never seen an demuxer doing this.
The other big problem is the file-locking! The DirectShow filewriter and most other similar filters lock the file for the writing. So no other process can open the file for reading.
You are searching for a TimeShift system. There are some thirt-party SDK for this. But it can also be implemented with own DirectShow Filters, but you will need a lot of time and knowledge for this. I know it's possible because I have done it in the videoplayer from my company (utilius fairplay 5).
I worked on that issue for weeks, SBE does not work well in H264 mux in transport
I came up with a solution , let me share
First , the encoder need to have small GOP , like 15 , not 150, otherwise the sync will take time and it will seen as a big hang.
The idea is to create directshow filter , start from Live source filter
(https://www.codeproject.com/Articles/158053/DirectShow-Filters-Development-Part-2-Live-Source)
Modified the filter , not to enter the frame from external program.
add winsock2 , for UDP binding , or multicast group.
Start receive the data from live source and sample it out to the output pin.
Suggest always to use Elecard SDk for setup.
On the sender you can use nw renderer but there you cannot change the encoder GOP
so open graph edit and build the sender graph
desktop capture->encoder->mux->nwrenderer.
Your new filter should know to receive the data and display it on screen
once you have that working you can than continue add the timeshift capabilities into your filter.
Allocate a very big buffer , 200 mega to 1 giga , up to you( on ram ofcourse)
the same data that you send to the output pin , copy it into that buffer, make it circular with rd and wr indexes.
You need to add interface to your filter, functions like
1. GoLive
2.SetSeekPoint
The way i did it is the following
I created a callback from the filter into the host ( c# ) that send the time and the wr pointer every 1 second or more( depends on the accurate i need)
In the host i created a list of those two information.
Now in c# i have the list of the wr pointer and its time.
easy to search and set the RD pointer back to the filter.
The filter have two modes than:
1. in live it send the current received data
2. in seek it send the data from the big buffer , following the rd pointer.
Hope it understood.
I am trying to create a radio app, which contains a collection of MP3-stream urls. However, I have run into some trouble streaming (or playing back) the audio.
I am trying to connect to a raw data stream like the ones you plug into VLC. An example url is http://mp3.ht-stream.net/;80 (just plugged this one and a few others into VLC and it worked perfectly). Basically your standard internet radio feed.
I have created the AudioPlaybackAgent, filled in what I think is needed to get this up and running, and everything works fine when I stream regular .mp3 files over the internet. But when I try to connect to these streams, it doesn't do (or play) anything.
I reckon it could be because I'm not using an AudioStreamingAgent (with a MediaStreamSource implementation), but that stuff is a bit too advanced for me, and as I understood after some hours searching the interwebs, mp3 streams could use the AudioPlaybackAgent instead.
Any advice on how I can make this work? Will I have to use an AudioStreamingAgent instead? Is there any open source examples as to how I implement this mysterious MediaStreamSource class? Should I scrap my great idea? Any answers will be greatly appreciated.
My AudioPlayer.cs code is available here if you'd like a peek - but it's mostly the standard stuff.
You can't easily play audio from the provided link because of this is not a regular audio file. This is SHOUTcast stream.
You can check some open source implementations and to figure out how to work with this audio stream. For example: Shoutcast MediaStreamSource.
So I can say that you need to implement a lot of stuff in your app to play this stream. There is no quick and easy way.
Look at the Background Audio Streamer sample.
I am trying to make a video download application for desktop in C#.
Now the problem is that following code works fine:
WebClient webOne = new WebClient();
string temp1 = " http://www.c-sharpcorner.com/UploadFile/shivprasadk/visual-studio-and-net-tips-and-tricks-15/Media/Tip15.wmv";
webOne.DownloadFile(new Uri(temp1), "video.wmv");
But following code doesn't:
temp1="http://www.youtube.com/watch?v=Y_..."
(in this case a 200-400 kilobyte junk file gets downloaded )
Difference between the two URLs is obvious, first one contains exact name for file while other seems to be encrypted in some way...
I was unable to find any proper and satisfactory solution to the problem so I would highly appreciate a little help here, Thanks.
Note:
from one of the questions here I got a link http://youtubefisher.codeplex.com/ so I visited there, got the source code and read it. It's great work but what I don't seem to get is that how in the world that person came to know what structures and classes he had to make for downloading a YouTube video and why did he have to go through all that trouble why isn't my method working?
Someone please guide. Thanks again.
In order to download a video from youtube, you have to find the actual video location. Not the page that you use to watch the video. The http://www.youtube.com/watch?v=... url, is an html page (much like this one) that will load the video from it's source location and display it. Normally, you have to parse the html and extract the video location from the html.
In your case, you found code that does this already - and lucky you, because downloading videos from youtube is not simple at all. Looking at the link you provided in your question, the magic behind the madness is available in YoutubeService.cs / GetDownloadUrl():
http://youtubefisher.codeplex.com/SourceControl/changeset/view/68461#1113202
That method is parsing the html page returned by a youtube watch url, and finding the actual video content. The added complexity, is that youtube videos can also be a variety of different formats.
If you need to convert the video type after downloading, i recommend FFMPEG
EDIT: In response to your comment - You didnt look at the source code of YoutubeFisher at all, did you.. I'd recommend analysing the file I mentioned (YoutubeService.cs). Although after taking a quick look myself, you'll have to parse the yt.playerConfig variable within the html page.
Use that source to help you.
EDIT: In response to your second comment: "Actually I am trying to develop an application that can download video from any video site." You say that like its easy - fyi, its not. Since every video website is different, you cant just write something that will work for everything out of the box. If I had to do it though, heres how i would: I would write custom parsers for the major video sharing websites (Metacafe, Youtube, Whatever else) so that those ones are guarenteed to work. After that, I would write a "fallover" if you will. Basically, if you're requesting a video from an unknown website, it would scour the html looking for known video extentions (flv, wmv, mp4, etc) and then extract the url from that.
You could use a regex for extracting the url in the latter case, or a combination of something like indexof, substring, and lastindexof.
I found this page # CodeProject, it shows you how to make a very efficient Youtube downloader using no third party libraries. Remember it is sometimes necessary to slightly modify the code as Youtube sometimes makes changes to it's web structure, which may interfere with the way your app interacts with Youtube.
Here is the link: here you can also download the C# project files and see the files directly.
CodeProject - Youtube downloader using C# .NET
I would like to emulate video input from a webcam for testing purposes.
So I need to be able to emulate a software video capture device in Windows and be able to dynamically generate its output.
How can I achieve this?
I would prefer a solution in C# or C++.
You can use a Virtual Webcam (old link, but there are others) it will take a video/images file and will display it in a webcam device. Your system will think that its a normal device.
Then you will need to create something that will generate the video/images, if you need static image then its pretty easy to generate a bmp.
Old (no selected answer) question.... actually probably one of the oldest I've ever seen... but I came across this looking for an answer myself, I remembered the day when "Virtual Webcam" still existed (now just a chinese ad site).
Fear not! There are new sources to solve your decade long quest:
First of all, checkout OBS, open source does a LOT with video streams:
https://obsproject.com/
Second, checkout this virtual webcam plugin for it. Does exactly what you're talking about, and does use #qbeuek's suggestion of DirectDraw:
https://obsproject.com/forum/resources/obs-virtualcam.949/
It is written in C++, so grabbing the bits you need and rewriting to C# is left as an exercise to the reader, but the capability is there.
As far as I know, there is a set of COM interfaces that govern the recording and playback of audio and video in Windows. It used to be called DirectShow, but maybe in the meantime the name has been changed. Those interfaces are used to construct a graph of audio and video filters, to encode / decode the data stream.
The way to go:
- read about the Microsoft DirectShow API,
- implement a COM object that implements the video source interface,