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Stream your Windows desktop using ffmpeg

datePosted on 10:26, November 3rd, 2011 by Many Ayromlou

I’ve already covered how to do this with vlc a while back in parts 1 followed by part 2. I just found out that something very similar in results can be done with ffmpeg. ffmpeg has recently added support for directshow filters which now allows one to capture the screen and stream and/or save it. Here is how you can do this:

1.) Grab a copy of the Screen Capture DirectShow source filter from Unreal Streaming Technologies. It’s about half way down that page. They have both the UScreenCapture X86 Edition and the X64 Edition (depending on your OS installation). I used the 64 bit filter on a Windows 7 64 bit installation.

2.) Install the filter and make sure you make the following changes to your windows registry using regedit. The default frame rate for UScreenCapture filter is 10 f/s and we need to boost this to 30 frames/sec. You need to find the key HKLM\SOFTWARE\UNREAL\Live\UScreenCapture and insert a DWORD value of 30 for FrameRate (You have to create FrameRate, it does not exist by default). Once you’ve done the registry tweak, reboot.

3.) Install the latest greatest version of ffmpeg for your windows version from Zeranoe. I grabbed the 64 bit Static build since I didn’t want to deal with libraries and such. Extract it and stick it somewhere on your hard drive. Remember the path to this folder since we will need it later.

4.) Open a command line window and cd to the directory where you extracted ffmpeg into, find the bin directory and cd into it. This is were the ffmpeg executable resides. In my case (I extracted the ffmpeg files into “Program Files” directory) it is C:\Program Files\ffmpeg-git-059707e-win64-static\bin.

5.) If you’ve made it this far, hand in there, we’re almost home. Now you need to issue the command that gets the screen streaming going. But first we need to find out the name of the Screen filter device. So issue the following command:

ffmpeg -list_devices true -f dshow -i dummy

In the output look for a device called “UScreenCapture“. Hopefully if everything is working with the directshow filter you have a entry in the list. That’s the name of our device that we need to pass onto ffmpeg. While you’re there also look for your audio device entry as well. Mine was the truncated word “Stereo Mix (Realtek High Defini” (Yes mine was missing the end of that line). Jot that down somewhere as well. I will show you how to get audio going as well.

6.) So first step is to get video going. Assuming you have a “UScreenCapture” device (You could use another directshow filter if you like, this will work with most of them. I just used the Unreal filter for the heck of it), here is the command to start encoding and sending video:

ffmpeg -f dshow  -i video="UScreenCapture"  -r 30 -vcodec mpeg4 -q 12 -f mpegts udp://aaa.bbb.ccc.ddd:6666?pkt_size=188?buffer_size=65535
  • -f dshow specifies that you’re going to be using a directshow device as your input.
  • -i video=”UScreenCapture” is the name of the input directshow device which we picked up in step 5.
  • -r 30 is the frame rate.
  • -vcodec mpeg4 is our video codec of choice.
  • -q 12 is a quality measure for the encoding process (1 is the best and 30 the worst). We’re doing VBR encoding so this measures the compression ratio vs. picture quality.
  • -f mpegts is our output filetype. In this case mpeg-2 transport stream. Yes, we’re encapsulating mpeg4 video inside a mpeg-2 transport stream…..why?….google it.
  • udp://aaa.bbb.ccc.ddd:6666?pkt_size=188?buffer_size=65535 this last bit specifies the address and port number of the recipient machine (aaa.bbb.ccc.ddd is the ip address of that machine and 6666 is my arbitrary port number). We’re also instructing ffmpeg to create smaller 188 byte size udp packets (which is the size of the transport stream packets) to decrease latency and our buffer size is 64kb.

7.) On the receiving machine you should be able to use vlc, ffmpeg or mplayer to catch the stream. In vlc simply open the Network stream rtp://@:6666 , in ffmpeg you can use the command ffplay -i udp://:6666 or using mplayer you can issue the command mplayer -framedrop -double udp://:6666 .

8.) Now to optionally add sound to the whole thing we can use this command on the encoding machine (instead of step 6). You need to know the device name for your sound card and you probably want to turn the volume down (at least initially) on the decoding machine.

ffmpeg -f dshow  -i video="UScreenCapture" -f dshow -i audio="Stereo Mix (Realtek High Defini" -r 30 -vcodec mpeg4 -q 20 -acodec libmp3lame -ab 128k -f mpegts udp://141.117.224.74:6666?pkt_size=188?buffer_size=65535
  • -f dshow specifies that you’re going to be using a directshow device as your input (VIDEO).
  • -i video=”UScreenCapture” is the name of the input directshow video device which we picked up in step 5.
  • -f dshow specifies that you’re going to be using a directshow device as your input (AUDIO).
  • -i audio=”Stereo Mix (Realtek High Defini” is the name of the input directshow audio device which we picked up in step 5.
  • -r 30 is the frame rate.
  • -vcodec mpeg4 is our video codec of choice.
  • -q 20 is a quality measure for the encoding process (1 is the best and 30 the worst). We’re doing VBR encoding so this measures the compression ratio vs. picture quality. I went with 20 instead of 12 from step 6 since the audio encoding slows the machine down a bit.
  • -acodec libmp3lame is our video codec of choice
  • -f mpegts is our output filetype. In this case mpeg-2 transport stream. Yes, we’re encapsulating mpeg4 video inside a mpeg-2 transport stream…..why?….google it.
  • udp://aaa.bbb.ccc.ddd:6666?pkt_size=188?buffer_size=65535 this last bit specifies the address and port number of the recipient machine (aaa.bbb.ccc.ddd is the ip address of that machine and 6666 is my arbitrary port number). We’re also instructing ffmpeg to create smaller 188 byte size udp packets (which is the size of the transport stream packets) to decrease latency and our buffer size is 64kb.

Quick Media Converter brings Windows GUI sanity to ffmpeg…..

datePosted on 14:28, August 25th, 2008 by Many Ayromlou

For those of you who’ve hated the opensource ffmpeg command line media conversion tool, here is Quick Media Converter. It’s a nice looking front-end for ffmpeg that hides the command line complexity of this swiss army like media converter. So What can you do with Quick Media Converter?

-Converting Video files from one format to another.
-Converting Audio files from one format to another.
-Extracting and converting Audio files from video or audio media.
-Extracting and converting Video without sound.
-Preview and/or listen to video and audio files with FFPLAY Multi format player (Fabrice Bellard).
- A myriad of formats is recognized by FFmpeg, those not recognized yet, are worked on by many people around the open source community and may most of the time, become available sooner or later.
-Many files to convert? No worry, batch files processing is also supported by QMC.
-You are lazy by nature and do not wish to start selecting files? That’s okay just drag and drop the files in the active worksheet.
-You have more specific needs and want to experiment with video and audio conversion, you can do so by using our Expert mode section.
-You want to capture a movie or picture directly from your webcam or DV Cam, just click on the webcam button and start capturing in raw flux or avi divx , after this is done the software will offer you to convert your file to other formats.
-You want to make a tutorial or capture your latest performance in your favorite video game? just click on Camstudio (open source) start recording and add comments on your avi divx movie output.

-Access our support forum directly from our application to get help, we usually respond to your questions within one day or two. We do not support expert mode in general as by essence if you use it you are considered an expert user.

It’s a Windows only utility and is free to download.

CineForm Direct-to-Disk Recorder

datePosted on 12:10, December 10th, 2007 by Many Ayromlou


I have to admit CineForm is one of my favourite companies out there. I’ve visited them once and they are the nicest bunch of engineers you’ll find on that side of the rockies :-). Aside from their famed CineForm Codec (which btw is awesome), they have just released the specs and conceptual drawings for what will probably be the coolest gadget at next years NAB ;-).

They anticipate developing multiple members in the recorder product family – each targeting different recording needs. This first device targets HDV camcorder users and offers the ability to bypass the highly-compressed MPEG format. The features specification is below. They also imagine a sister device that would support single-link and dual-link HD-SDI recording.