/// <summary>
/// Initializes a new instance of the <see cref="AVFormatContext"/> class.
/// </summary>
/// <param name="client">
/// An implementation of the <see cref="FFmpegClient"/> which provides access to the native FFmpeg functions.
/// </param>
/// <param name="ioContext">
/// The I/O context which enables reading and writing data using custom callbacks.
/// </param>
/// <param name="formatContextHandle">
/// The formatContextHandle.
/// </param>
public AVFormatContext(FFmpegClient client, AVIOContext ioContext, AVFormatContextHandle formatContextHandle)
{
this.client = client;
this.handle = formatContextHandle;
this.ioContext = ioContext;
this.NativeObject->pb = ioContext.NativeObject;
}
/// <summary>
/// Initializes a new instance of the <see cref="AVFormatContext"/> class.
/// </summary>
/// <param name="client">
/// An implementation of the <see cref="FFmpegClient"/> which provides access to the native FFmpeg functions.
/// </param>
/// <param name="ioContext">
/// The I/O context which enables reading and writing data using custom callbacks.
/// </param>
public AVFormatContext(FFmpegClient client, AVIOContext ioContext)
: this(client, ioContext, new AVFormatContextHandle(client, client.AllocAVFormatContext()))
{
}
/// <summary>
/// Decodes the current stream and blocks until decoding is done.
/// </summary>
/// <param name="cancellationToken">
/// A <see cref="CancellationToken"/> which can be used to cancel the asynchronous operation.
/// </param>
public virtual unsafe void Decode(CancellationToken cancellationToken = default)
{
if (this.disposed)
{
throw new ObjectDisposedException(nameof(H264Decoder));
}
var readDelegate = new NativeReadPacket(this.Read);
var readFunc = new NativeReadPacketFunc()
{
Pointer = Marshal.GetFunctionPointerForDelegate(readDelegate),
};
using (var ioContext = new AVIOContext(this.client, ReadBufferSize, readFunc, null))
using (var formatContext = new AVFormatContext(this.client, ioContext))
{
formatContext.OpenInputStream("h264");
var stream = formatContext.GetVideoStream();
using (var codec = new AVCodec(this.client, stream))
using (var frame = new AVFrame(this.client))
using (var packet = new AVPacket(this.client))
{
int frameNumber = 0;
while (packet.ReadFrame(formatContext))
{
this.logger.LogDebug($"Got a frame for stream {packet.StreamIndex}");
if (packet.NativeObject->stream_index != stream.Index)
{
continue;
}
this.logger.LogDebug("Sending packet");
codec.SendPacket(packet);
int framesInPacket = 0;
while (codec.ReceiveFrame(frame))
{
this.logger.LogDebug("Receiving frame");
framesInPacket += 1;
if (frame.PictureType != NativeAVPictureType.AV_PICTURE_TYPE_NONE)
{
this.logger.LogDebug($"Got a picture of {frame.Width}x{frame.Height} in color space {frame.Format}");
// decode frame
this.FrameBuffer.DecompresFrame(
frame.Width,
frame.Height,
frame.Width,
frame.Height,
frame.Width * 4,
new Span <byte>(frame.NativeObject->data[0], frame.NativeObject->linesize[0]),
new Span <byte>(frame.NativeObject->data[1], frame.NativeObject->linesize[1]),
new Span <byte>(frame.NativeObject->data[2], frame.NativeObject->linesize[2]),
new int[] { frame.NativeObject->linesize[0], frame.NativeObject->linesize[1], frame.NativeObject->linesize[2] });
}
}
this.logger.LogInformation($"Add {framesInPacket} frames in packet.");
frameNumber++;
}
}
}
GC.KeepAlive(readDelegate);
}
