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);
}
/// <summary>
/// Creates a new instance of <see cref="Mpeg4VcmVideoEncoder"/>.
/// </summary>
/// <param name="width">Frame width.</param>
/// <param name="height">Frame height.</param>
/// <param name="fps">Frame rate.</param>
/// <param name="frameCount">
/// Number of frames to be encoded.
/// If not known, specify 0.
/// </param>
/// <param name="quality">
/// Compression quality in the range [1..100].
/// Less values mean less size and lower image quality.
/// </param>
/// <param name="codecPreference">
/// List of codecs that can be used by this encoder, in preferred order.
/// </param>
/// <exception cref="InvalidOperationException">
/// No compatible codec was found in the system.
/// </exception>
/// <exception cref="PlatformNotSupportedException">
/// Running not on Windows.
/// </exception>
/// <remarks>
/// <para>
/// It is not guaranteed that the codec will respect the specified <paramref name="quality"/> value.
/// This depends on its implementation.
/// </para>
/// <para>
/// If no preferred codecs are specified, then <see cref="DefaultCodecPreference"/> is used.
/// MPEG-4 codecs that are not explicitly supported can be specified. However, in this case
/// the encoder is not guaranteed to work properly.
/// </para>
/// </remarks>
public Mpeg4VcmVideoEncoder(int width, int height, double fps, int frameCount, int quality, params FourCC[] codecPreference)
{
Argument.IsPositive(width, nameof(width));
Argument.IsPositive(height, nameof(height));
Argument.IsPositive(fps, nameof(fps));
Argument.IsNotNegative(frameCount, nameof(frameCount));
Argument.IsInRange(quality, 1, 100, nameof(quality));
CheckSupportedPlatform();
this.width = width;
this.height = height;
sourceBuffer = new byte[width * height * 4];
inBitmapInfo = CreateBitmapInfo(width, height, 32, CodecIds.Uncompressed);
inBitmapInfo.ImageSize = (uint)sourceBuffer.Length;
if (codecPreference == null || codecPreference.Length == 0)
{
codecPreference = DefaultCodecPreference.ToArray();
}
foreach (var codec in codecPreference)
{
outBitmapInfo = CreateBitmapInfo(width, height, 24, codec);
compressorHandle = GetCompressor(inBitmapInfo, outBitmapInfo, out compressorInfo);
if (compressorHandle != IntPtr.Zero)
{
break;
}
}
if (compressorHandle == IntPtr.Zero)
{
throw new InvalidOperationException("No compatible MPEG-4 encoder found.");
}
try
{
maxEncodedSize = GetMaxEncodedSize();
// quality for ICM ranges from 0 to 10000
this.quality = compressorInfo.SupportsQuality ? quality * 100 : 0;
// typical key frame rate ranges from FPS to 2*FPS
keyFrameRate = (int)Math.Round((2 - 0.01 * quality) * fps);
if (compressorInfo.RequestsCompressFrames)
{
InitCompressFramesInfo(fps, frameCount);
}
StartCompression();
}
catch
{
Dispose();
throw;
}
}
/// <summary>
/// Creates a new instance of <see cref="Mpeg4VideoEncoderVcm"/>.
/// </summary>
/// <param name="width">Frame width.</param>
/// <param name="height">Frame height.</param>
/// <param name="fps">Frame rate.</param>
/// <param name="frameCount">
/// Number of frames to be encoded.
/// If not known, specify 0.
/// </param>
/// <param name="quality">
/// Compression quality in the range [1..100].
/// Less values mean less size and lower image quality.
/// </param>
/// <param name="codecPreference">
/// List of codecs that can be used by this encoder, in preferred order.
/// </param>
/// <exception cref="InvalidOperationException">
/// No compatible codec was found in the system.
/// </exception>
/// <remarks>
/// <para>
/// It is not guaranteed that the codec will respect the specified <paramref name="quality"/> value.
/// This depends on its implementation.
/// </para>
/// <para>
/// If no preferred codecs are specified, then <see cref="DefaultCodecPreference"/> is used.
/// MPEG-4 codecs that are not explicitly supported can be specified. However, in this case
/// the encoder is not guaranteed to work properly.
/// </para>
/// </remarks>
public Mpeg4VideoEncoderVcm(int width, int height, double fps, int frameCount, int quality, params FourCC[] codecPreference)
{
Contract.Requires(width > 0);
Contract.Requires(height > 0);
Contract.Requires(fps > 0);
Contract.Requires(frameCount >= 0);
Contract.Requires(1 <= quality && quality <= 100);
this.width = width;
this.height = height;
sourceBuffer = new byte[width * height * 4];
inBitmapInfo = CreateBitmapInfo(width, height, 32, KnownFourCCs.Codecs.Uncompressed);
inBitmapInfo.ImageSize = (uint)sourceBuffer.Length;
if (codecPreference == null || codecPreference.Length == 0)
{
codecPreference = DefaultCodecPreference.ToArray();
}
foreach (var codec in codecPreference)
{
outBitmapInfo = CreateBitmapInfo(width, height, 24, codec);
compressorHandle = GetCompressor(inBitmapInfo, outBitmapInfo, out compressorInfo);
if (compressorHandle != IntPtr.Zero)
{
break;
}
}
if (compressorHandle == IntPtr.Zero)
{
throw new InvalidOperationException("No compatible MPEG-4 encoder found.");
}
try
{
maxEncodedSize = GetMaxEncodedSize();
// quality for ICM ranges from 0 to 10000
this.quality = compressorInfo.SupportsQuality ? quality * 100 : 0;
// typical key frame rate ranges from FPS to 2*FPS
keyFrameRate = (int)Math.Round((2 - 0.01 * quality) * fps);
if (compressorInfo.RequestsCompressFrames)
{
InitCompressFramesInfo(fps, frameCount);
}
StartCompression();
}
catch
{
Dispose();
throw;
}
}
/// <summary>
/// Creates a new instance of <see cref="Mpeg4VideoEncoderVcm"/>.
/// </summary>
/// <param name="width">Frame width.</param>
/// <param name="height">Frame height.</param>
/// <param name="fps">Frame rate.</param>
/// <param name="frameCount">
/// Number of frames to be encoded.
/// If not known, specify 0.
/// </param>
/// <param name="quality">
/// Compression quality in the range [1..100].
/// Less values mean less size and lower image quality.
/// </param>
/// <param name="codecPreference">
/// List of codecs that can be used by this encoder, in preferred order.
/// </param>
/// <exception cref="InvalidOperationException">
/// No compatible codec was found in the system.
/// </exception>
/// <remarks>
/// <para>
/// It is not guaranteed that the codec will respect the specified <paramref name="quality"/> value.
/// This depends on its implementation.
/// </para>
/// <para>
/// If no preferred codecs are specified, then <see cref="DefaultCodecPreference"/> is used.
/// MPEG-4 codecs that are not explicitly supported can be specified. However, in this case
/// the encoder is not guaranteed to work properly.
/// </para>
/// </remarks>
public Mpeg4VideoEncoderVcm(int width, int height, double fps, int frameCount, int quality, params FourCC[] codecPreference)
{
Contract.Requires(width > 0);
Contract.Requires(height > 0);
Contract.Requires(fps > 0);
Contract.Requires(frameCount >= 0);
Contract.Requires(1 <= quality && quality <= 100);
this.width = width;
this.height = height;
sourceBuffer = new byte[width * height * 4];
inBitmapInfo = CreateBitmapInfo(width, height, 32, KnownFourCCs.Codecs.Uncompressed);
inBitmapInfo.ImageSize = (uint)sourceBuffer.Length;
if (codecPreference == null || codecPreference.Length == 0)
{
codecPreference = DefaultCodecPreference.ToArray();
}
foreach (var codec in codecPreference)
{
outBitmapInfo = CreateBitmapInfo(width, height, 24, codec);
compressorHandle = GetCompressor(inBitmapInfo, outBitmapInfo, out compressorInfo);
if (compressorHandle != IntPtr.Zero)
break;
}
if (compressorHandle == IntPtr.Zero)
{
throw new InvalidOperationException("No compatible MPEG-4 encoder found.");
}
try
{
maxEncodedSize = GetMaxEncodedSize();
// quality for ICM ranges from 0 to 10000
this.quality = compressorInfo.SupportsQuality ? quality * 100 : 0;
// typical key frame rate ranges from FPS to 2*FPS
keyFrameRate = (int)Math.Round((2 - 0.01 * quality) * fps);
if (compressorInfo.RequestsCompressFrames)
{
InitCompressFramesInfo(fps, frameCount);
}
StartCompression();
}
catch
{
Dispose();
throw;
}
}
