internal VideoEncoder(AVStream *stream, VideoFormat format, VideoEncoderParameters encoderParams = null) : base(stream)
{
encoderParams = encoderParams ?? VideoEncoderParameters.Default;
InFormat = format;
Init(encoderParams);
}
private void Init(VideoEncoderParameters encoderParams)
{
var pixelFormats = GetSupportedPixelFormats(codec);
if (pixelFormats != null && !pixelFormats.Contains(InFormat.PixelFormat))
{
outFormat = new VideoFormat(InFormat.Width, InFormat.Height, pixelFormats[0]);
resampler = new VideoResampler(InFormat, OutFormat, encoderParams.ResampleFlags);
tempFrame = new VideoFrame();
}
else
{
outFormat = InFormat;
}
framePerSecond = encoderParams.FrameRate;
try {
codecContext->PixFmt = OutFormat.PixelFormat;
codecContext->Width = OutFormat.Width;
codecContext->Height = OutFormat.Height;
codecContext->BitRate = encoderParams.BitRate.Value;
codecContext->TimeBase = encoderParams.FrameRate.Reciprocal;
codecContext->Framerate = encoderParams.FrameRate;
if (encoderParams.GopSize != 0)
{
codecContext->GopSize = encoderParams.GopSize;
}
if (encoderParams.MaxBFrames != 0)
{
codecContext->MaxBFrames = encoderParams.MaxBFrames;
}
if (encoderParams.MbDecision != 0)
{
codecContext->MbDecision = encoderParams.MbDecision;
}
if (encoderParams.Qmin != 0)
{
codecContext->Qmin = encoderParams.Qmin;
}
if (encoderParams.Qmax != 0)
{
codecContext->Qmax = encoderParams.Qmax;
}
var result = FF.avcodec_open2(codecContext, codec, null);
if (result < 0)
{
throw new CSharp.FFmpegException(result);
}
} catch {
Dispose();
throw;
}
}
public VideoEncoder(AVCodecID codecID, VideoFormat format, VideoEncoderParameters encoderParams = null) : base(codecID)
{
encoderParams = encoderParams ?? VideoEncoderParameters.Default;
if (codec->Type != AVMediaType.Video)
{
throw new ArgumentException($"{codecID}不是视频格式", nameof(codecID));
}
codecContext = FF.avcodec_alloc_context3(codec);
if (codecContext == null)
{
throw new Exception("无法分配编码器上下文");
}
InFormat = format;
Init(encoderParams);
}
public MediaWriter AddVideo(VideoFormat format, VideoEncoderParameters encoderParams = null)
{
if (readyEncoders != null)
{
throw new InvalidOperationException($"该{nameof(MediaWriter)}对象已经初始化");
}
if (outputFormat == null)
{
throw new InvalidOperationException("无法确定媒体的输出格式");
}
if (outputFormat->VideoCodec == AVCodecID.None)
{
throw new InvalidOperationException($"该{nameof(MediaWriter)}对象并不支持视频");
}
var stream = FF.avformat_new_stream(formatContext, Codec.GetEncoder(outputFormat->VideoCodec));
if (stream == null)
{
throw new InvalidOperationException("无法创建流");
}
var codecContext = stream->Codec;
var videoEncoder = new VideoEncoder(stream, format, encoderParams);
stream->TimeBase = codecContext->TimeBase;
stream->AvgFrameRate = codecContext->Framerate;
int result = FF.avcodec_parameters_from_context(stream->Codecpar, codecContext);
if (result < 0)
{
throw new FFmpegException(result);
}
encoders.Add(videoEncoder);
return(this);
}
