private static IntPtr GetCompressor(VfwApi.BitmapInfoHeader inBitmapInfo, VfwApi.BitmapInfoHeader outBitmapInfo, out VfwApi.CompressorInfo compressorInfo)
{
// Using ICLocate is time-consuming. Besides, it does not clean up something, so the process does not terminate on exit.
// Instead open a specific codec and query it for needed features.
var compressorHandle = VfwApi.ICOpen((uint)KnownFourCCs.CodecTypes.Video, outBitmapInfo.Compression, VfwApi.ICMODE_COMPRESS);
if (compressorHandle != IntPtr.Zero)
{
var inHeader = inBitmapInfo;
var outHeader = outBitmapInfo;
var result = VfwApi.ICSendMessage(compressorHandle, VfwApi.ICM_COMPRESS_QUERY, ref inHeader, ref outHeader);
if (result == VfwApi.ICERR_OK)
{
var infoSize = VfwApi.ICGetInfo(compressorHandle, out compressorInfo, Marshal.SizeOf(typeof(VfwApi.CompressorInfo)));
if (infoSize > 0 && compressorInfo.SupportsFastTemporalCompression)
{
return(compressorHandle);
}
}
VfwApi.ICClose(compressorHandle);
}
compressorInfo = new VfwApi.CompressorInfo();
return(IntPtr.Zero);
}
private int GetMaxEncodedSize()
{
var inHeader = inBitmapInfo;
var outHeader = outBitmapInfo;
return(VfwApi.ICSendMessage(compressorHandle, VfwApi.ICM_COMPRESS_GET_SIZE, ref inHeader, ref outHeader));
}
private int EncodeFrame(IntPtr sourcePtr, IntPtr destinationPtr, uint destinationSize, out bool isKeyFrame)
{
var outInfo = outBitmapInfo;
outInfo.ImageSize = destinationSize;
var inInfo = inBitmapInfo;
var flags = framesFromLastKey >= keyFrameRate ? VfwApi.ICCOMPRESS_KEYFRAME : 0;
var result = VfwApi.ICCompress(compressorHandle, flags,
ref outInfo, destinationPtr, ref inInfo, sourcePtr,
out _, out var outFlags, frameIndex,
0, quality, IntPtr.Zero, IntPtr.Zero);
CheckICResult(result);
frameIndex++;
isKeyFrame = (outFlags & VfwApi.AVIIF_KEYFRAME) == VfwApi.AVIIF_KEYFRAME;
if (isKeyFrame)
{
framesFromLastKey = 1;
}
else
{
framesFromLastKey++;
}
return((int)outInfo.ImageSize);
}
private void StartCompression()
{
var inHeader = inBitmapInfo;
var outHeader = outBitmapInfo;
var result = VfwApi.ICSendMessage(compressorHandle, VfwApi.ICM_COMPRESS_BEGIN, ref inHeader, ref outHeader);
CheckICResult(result);
needEnd = true;
framesFromLastKey = keyFrameRate;
}
private void CheckICResult(int result)
{
if (result != VfwApi.ICERR_OK)
{
var errorDesc = VfwApi.GetErrorDescription(result);
var resultStr = errorDesc == null
? result.ToString()
: string.Format("{0} ({1})", result, errorDesc);
throw new InvalidOperationException(string.Format("Encoder operation returned an error: {0}.", resultStr));
}
}
private void InitCompressFramesInfo(double fps, int frameCount)
{
var info = new VfwApi.CompressFramesInfo
{
StartFrame = 0,
FrameCount = frameCount,
Quality = quality,
KeyRate = keyFrameRate,
};
AviUtils.SplitFrameRate((decimal)fps, out info.FrameRateNumerator, out info.FrameRateDenominator);
var result = VfwApi.ICSendMessage(compressorHandle, VfwApi.ICM_COMPRESS_FRAMES_INFO, ref info, Marshal.SizeOf(typeof(VfwApi.CompressFramesInfo)));
CheckICResult(result);
}
/// <summary>Encodes a frame.</summary>
/// <seealso cref="IVideoEncoder.EncodeFrame"/>
public int EncodeFrame(byte[] source, int srcOffset, byte[] destination, int destOffset, out bool isKeyFrame)
{
// TODO: Introduce Width and Height in IVideoRecorder and add Requires to EncodeFrame contract
Contract.Assert(srcOffset + 4 * width * height <= source.Length);
BitmapUtils.FlipVertical(source, srcOffset, sourceBuffer, 0, height, width * 4);
var sourceHandle = GCHandle.Alloc(sourceBuffer, GCHandleType.Pinned);
var encodedHandle = GCHandle.Alloc(destination, GCHandleType.Pinned);
try
{
var outInfo = outBitmapInfo;
outInfo.ImageSize = (uint)destination.Length;
var inInfo = inBitmapInfo;
int outFlags;
int chunkID;
var flags = framesFromLastKey >= keyFrameRate ? VfwApi.ICCOMPRESS_KEYFRAME : 0;
var result = VfwApi.ICCompress(compressorHandle, flags,
ref outInfo, encodedHandle.AddrOfPinnedObject(), ref inInfo, sourceHandle.AddrOfPinnedObject(),
out chunkID, out outFlags, frameIndex,
0, quality, IntPtr.Zero, IntPtr.Zero);
CheckICResult(result);
frameIndex++;
isKeyFrame = (outFlags & VfwApi.AVIIF_KEYFRAME) == VfwApi.AVIIF_KEYFRAME;
if (isKeyFrame)
{
framesFromLastKey = 1;
}
else
{
framesFromLastKey++;
}
return((int)outInfo.ImageSize);
}
finally
{
sourceHandle.Free();
encodedHandle.Free();
}
}
/// <summary>
/// Releases all unmanaged resources used by the encoder.
/// </summary>
public void Dispose()
{
if (!isDisposed)
{
if (needEnd)
{
EndCompression();
}
if (compressorHandle != IntPtr.Zero)
{
VfwApi.ICClose(compressorHandle);
}
isDisposed = true;
GC.SuppressFinalize(this);
}
}
/// <summary>
/// Gets info about the supported codecs that are installed on the system.
/// </summary>
public static CodecInfo[] GetAvailableCodecs()
{
var result = new List <CodecInfo>();
var inBitmapInfo = CreateBitmapInfo(8, 8, 32, KnownFourCCs.Codecs.Uncompressed);
inBitmapInfo.ImageSize = (uint)4;
foreach (var codec in DefaultCodecPreference)
{
var outBitmapInfo = CreateBitmapInfo(8, 8, 24, codec);
VfwApi.CompressorInfo compressorInfo;
var compressorHandle = GetCompressor(inBitmapInfo, outBitmapInfo, out compressorInfo);
if (compressorHandle != IntPtr.Zero)
{
VfwApi.ICClose(compressorHandle);
result.Add(new CodecInfo(codec, compressorInfo.Description));
}
}
return(result.ToArray());
}
private static IntPtr GetCompressor(VfwApi.BitmapInfoHeader inBitmapInfo, VfwApi.BitmapInfoHeader outBitmapInfo, out VfwApi.CompressorInfo compressorInfo)
{
// Using ICLocate is time-consuming. Besides, it does not clean up something, so the process does not terminate on exit.
// Instead open a specific codec and query it for needed features.
var compressorHandle = VfwApi.ICOpen((uint)KnownFourCCs.CodecTypes.Video, outBitmapInfo.Compression, VfwApi.ICMODE_COMPRESS);
if (compressorHandle != IntPtr.Zero)
{
var inHeader = inBitmapInfo;
var outHeader = outBitmapInfo;
var result = VfwApi.ICSendMessage(compressorHandle, VfwApi.ICM_COMPRESS_QUERY, ref inHeader, ref outHeader);
if (result == VfwApi.ICERR_OK)
{
var infoSize = VfwApi.ICGetInfo(compressorHandle, out compressorInfo, Marshal.SizeOf(typeof(VfwApi.CompressorInfo)));
if (infoSize > 0 && compressorInfo.SupportsFastTemporalCompression)
return compressorHandle;
}
VfwApi.ICClose(compressorHandle);
}
compressorInfo = new VfwApi.CompressorInfo();
return IntPtr.Zero;
}
private void EndCompression()
{
var result = VfwApi.ICSendMessage(compressorHandle, VfwApi.ICM_COMPRESS_END, IntPtr.Zero, IntPtr.Zero);
CheckICResult(result);
}
