Sharp Media Foundation Interop

Simple Windows Media Foundation interop written in C#. No native dependencies, only managed code. Windows only, for H265 and AV1 support it requires you to install extensions from the Microsoft Store.

Codecs

Supported video codecs are:

• H264 (built-in Windows)
• H265 (requires paid HEVC Video Extensions from the Microsoft Store)
• AV1 (requires free AV1 Video Extensions from the Microsoft Store)

Supported audio codecs are:

• AAC (built-in Windows)
• Opus (built-in Windows, might require a newer version - works in Windows 11 25H2)

Video decoding

Create and initialize the decoder (all decoders have the same API):

using (var videoDecoder = new AV1Decoder(width, height, timescale, defaultSampleDuration))
{
   videoDecoder.Initialize();
   ...
}

Create a buffer to hold the decoded frame:

var nv12Buffer = new byte[videoDecoder.OutputSize];

Pass the frame to the decoder and get the output:

IEnumerable<byte[]> units = ...; // get a list of NALU/OBU from your video source
foreach (var unit in units)
{
   if (videoDecoder.ProcessInput(unit, 0))
   {
      while (videoDecoder.ProcessOutput(ref nv12Buffer, out _))
      {
         // nv12Buffer holds the decoded nv12 frame
         ...
      }
   }
}

Optionally, decode nv12 to RGB to display it:

using(var nv12Decoder = new ColorConverter(PInvoke.MFVideoFormat_NV12, PInvoke.MFVideoFormat_RGB24, width, height))
{
    nv12Decoder.Initialize();
    
    byte[] rgbBuffer = new byte[nv12Decoder.OutputSize];
    if(nv12Decoder.ProcessInput(nv12Buffer, 0))
    {
       if (nv12Decoder.ProcessOutput(ref rgbBuffer, out _))
       {
          // rgbBuffer holds the decoded RGB frame
          ...
       }
    }
}

Video encoding

Create and initialize the encoder (all encoders have the same API):

using (var videoEncoder = new H265Encoder(width, height, timescale, defaultSampleDuration))
{
   videoEncoder.Initialize();
   ...
}

Optionally, convert RGB to nv12:

using(var nv12Encoder = new ColorConverter(PInvoke.MFVideoFormat_RGB24, PInvoke.MFVideoFormat_NV12, width, height))
{
    nv12Encoder.Initialize();
    
    byte[] nv12Buffer = new byte[nv12Encoder.OutputSize];
    if(nv12Encoder.ProcessInput(rgbBuffer, 0))
    {
       if (nv12Encoder.ProcessOutput(ref nv12Buffer, out _))
       {
          // nv12Buffer holds the encoded nv12 frame
          ...
       }
    }
}

Create a buffer to hold the encoded NALU/OBU:

var au = new byte[videoEncoder.OutputSize];

Read encoded NALU/OBU:

if (videoEncoder.ProcessInput(nv12Buffer, timestamp))
{
   while (videoEncoder.ProcessOutput(ref au, out var length))
   {
      // au buffer holds the encoded access unit
      var parsedAU = AnnexBUtils.ParseNalu(au, length);
      foreach (var unit in parsedAU)
      {
         // here you can access the individual NALU/OBU
      }
   }
}

Audio decoding

Create and initialize the decoder:

using (var audioDecoder = new OpusDecoder(960, channelCount, samplingRate, bitsPerSample))
{
   audioDecoder.Initialize();
   ...
}

Create a buffer to hold the decoded frame:

var pcmBuffer = new byte[audioDecoder.OutputSize];

Pass the frame to the decoder and get the output:

IEnumerable<byte[]> audioFrames = ...; // get a list of frames from your audio source
foreach (var audioFrame in audioFrames)
{
   if (audioDecoder.ProcessInput(audioFrame, 0))
   {
      while (audioDecoder.ProcessOutput(ref pcmBuffer, out _))
      {
         // pcmBuffer holds the decoded audio
         ...
      }
   }
}

Audio encoding

Create and initialize the encoder:

using (var audioEncoder = new AACEncoder(channelCount, samplingRate, AACDecoder.CreateUserData(aacTrack.AudioSpecificConfig.ToBytes()), channelConfiguration))
{
   audioEncoder.Initialize();

   // audioDecoder.UserData holds the AAC user data
   ...
}

Create a buffer to hold the encoded frame:

var aacBuffer = new byte[audioEncoder.OutputSize];

Pass the frame to the decoder and get the output:

IEnumerable<byte[]> pcmFrames = ...; // get a list of frames from your audio source
foreach (var pcmFrame in pcmFrames)
{
   if (audioEncoder.ProcessInput(pcmFrame, 0))
   {
      while (audioEncoder.ProcessOutput(ref aacBuffer, out _))
      {
         // aacBuffer holds the encoded AAC audio
         ...
      }
   }
}

Screen capture

Captures your screen using the DuplicateOutput1 API. Start by enumerating the screens:

var screens = ScreenCapture.Enumerate();

Create the capture object:

using (var screenCapture = new ScreenCapture())
{
   ...
}

Initialize the selected screen capture:

screenCapture.Initialize(screens.First()); // select the screen (here we take the first one)

Create a buffer to hold the sample:

var buffer = new byte[screenCapture.OutputSize];

Read the sample:

if (screenCapture.ReadSample(buffer, out var timestamp))
{
   // captured screen is in the buffer
}

Device capture

Captures any Media Foundation device such as a webcam. Start by enumerating the devices:

var devices = DeviceCapture.Enumerate();

Create the capture object:

using(var device = new DeviceCapture())
{
   ...
}

Initialize the selected device:

device.Initialize(devices.First()); // select the device (here we take the first one) 

Create a buffer to hold the sample:

var buffer = new byte[device.OutputSize];

Read the sample:

if (device.ReadSample(buffer, out var timestamp))
{
   // captured image is in the buffer
}

Audio input

Audio input is implemented using the waveIn API. Start with creating the WaveIn:

using(var waveIn = new WaveIn())
{
    ...
}

Subscribe the FrameReceived callback:

waveIn.FrameReceived += (sender, e) => 
{
    byte[] pcmData = e.Data;
    ...
}

Recording starts right after you call Initialize.

waveIn.Initialize(sampleRate, channelCount, bitsPerSample);

To stop the recording, call Close or Dispose the object:

waveIn.Close();

Audio output

Audio output is implemented using the waveOut API. Start with creating the WaveOut:

using(var waveOut = new WaveOut())
{
    waveOut.Initialize(sampleRate, channelCount, bitsPerSample);
    ...
}

To playback audio, just enqueue it:

byte[] pcmSample = ...
waveOut.Enqueue(pcmSample, (uint)pcmSample.Length);

Samples

SharpMediaPlayer

Sample WPF video player that supports RTSP real-time video, MP4 files, AVIF/HEIC/HEIF images, screen capture and Media Foundation devices such as a webcam.

SharpMediaTranscoder

Demonstrates how to transcode H264 fragmented MP4 into H265 fragmented MP4.

SharpScreenCapture

Demonstrates how to capture the screen and encode it into H265 MP4.

SharpWavePlayer

Shows how to play AAC audio from a MP4 file.

SharpWebcamRecorder

Shows how to capture video from a webcam and record it into H265 MP4.