MediaType CreateTargetAudioMediaType(MediaType nativeMediaType)
{
var numberOfChannels = nativeMediaType.AudioNumberOfChannels;
var sampleRate = nativeMediaType.AudioSamplesPerSecond;
var availableTypes = MFSystem.TranscodeGetAudioOutputAvailableTypes(TARGET_AUDIO_FORMAT, MFT_EnumFlag.All);
TraceDebug.WriteLine("Searching for audio transcoding for sampleRate of {0}khz and {1} channels".F(sampleRate / 1000, numberOfChannels));
var type = availableTypes
.OrderByDescending(t => t.AudioAverageBytesPerSecond)
.ThenByDescending(t => t.AudioNumberOfChannels)
.FirstOrDefault(t => t.AudioSamplesPerSecond == sampleRate && t.AudioNumberOfChannels == numberOfChannels);
if (type == null)
{
TraceDebug.WriteLine("No audio transcoder found. Searching for transcoding with 2 or fewer channels at any sample rate");
type = availableTypes
.OrderByDescending(t => t.AudioAverageBytesPerSecond)
.ThenByDescending(t => t.AudioNumberOfChannels)
.FirstOrDefault(t => t.AudioNumberOfChannels <= 2);
}
if (type == null)
{
TraceDebug.WriteLine("No audio transcoder found. Search for first compatible transcoder");
type = availableTypes
.OrderByDescending(t => t.AudioAverageBytesPerSecond)
.ThenByDescending(t => t.AudioNumberOfChannels)
.FirstOrDefault();
}
if (type != null)
{
TraceDebug.WriteLine("Found audio track. SampleRate: {0}, Channels: {1}, BitRate: {2}kbs".F(type.AudioSamplesPerSecond / 1000, type.AudioNumberOfChannels, type.AudioAverageBytesPerSecond * 8 / 1000));
return(new MediaType(type));
}
throw new Exception("Unable to find target audio format");
}
public static VideoDetails TestFor(string videoFileName)
{
List <int> supportedAudioBitRates = new List <int>();
using (MFSystem.Start())
{
var readWriteFactory = new ReadWriteClassFactory();
var sourceReader = readWriteFactory.CreateSourceReaderFromURL(videoFileName, null);
var videoStream = sourceReader.Streams.FirstOrDefault(s => s.IsSelected && s.NativeMediaType.IsVideo);
if (videoStream.IsNull)
{
throw new Exception("Unable to find video track within file.");
}
var audioStream = sourceReader.Streams.FirstOrDefault(s => s.IsSelected && s.NativeMediaType.IsAudio);
if (audioStream.IsNull)
{
throw new Exception("Unable to find audio track within file.");
}
var channels = audioStream.NativeMediaType.AudioNumberOfChannels;
var sampleRate = audioStream.NativeMediaType.AudioSamplesPerSecond;
var types = MFSystem.TranscodeGetAudioOutputAvailableTypes(MediaFoundation.MFMediaType.WMAudioV9, MediaFoundation.Transform.MFT_EnumFlag.All);
foreach (var bitRate in types
.Where(t => t.AudioSamplesPerSecond == sampleRate)
.Select(t => t.AudioAverageBytesPerSecond)
.Distinct()
.OrderBy(t => t))
{
supportedAudioBitRates.Add(bitRate);
}
int videoBitRate = 0;
videoStream.NativeMediaType.TryGetBitRate(out videoBitRate);
var audioSamplesPerSecond = audioStream.NativeMediaType.AudioSamplesPerSecond;
var audioAverageBytesPerSecond = audioStream.NativeMediaType.AudioAverageBytesPerSecond;
var audioSubTypeName = audioStream.CurrentMediaType.SubTypeName;
var videoSubTypeName = videoStream.CurrentMediaType.SubTypeName;
var transcoder = new Transcoder
{
VideoFiles = new[] { new SourceReaderExtra(videoFileName, null) },
DestinationFile = Path.ChangeExtension(videoFileName, "wmv"),
VideoBitRate = 5000000
};
var errorMessage = transcoder.TestVideoConversion();
return(new VideoDetails(
supportedAudioBitRates.ToArray(),
videoStream.NativeMediaType.FrameRate.ToInt(),
videoStream.NativeMediaType.FrameSize,
videoBitRate / 1000000,
audioSamplesPerSecond,
audioAverageBytesPerSecond,
videoSubTypeName,
audioSubTypeName,
transcoder,
errorMessage));
}
}
