public Surface(int width, int height)
{
RequestedWidth = width;
RequestedHeight = height;
Frame = FFmpegApi.av_frame_alloc();
}
static FFmpegContext()
{
_logFunc = Log;
// Redirect log output.
FFmpegApi.av_log_set_level(AVLog.MaxOffset);
FFmpegApi.av_log_set_callback(_logFunc);
}
public FFmpegContext(AVCodecID codecId)
{
_codec = FFmpegApi.avcodec_find_decoder(codecId);
if (_codec == null)
{
Logger.Error?.PrintMsg(LogClass.FFmpeg, $"Codec wasn't found. Make sure you have the {codecId} codec present in your FFmpeg installation.");
return;
}
_context = FFmpegApi.avcodec_alloc_context3(_codec);
if (_context == null)
{
Logger.Error?.PrintMsg(LogClass.FFmpeg, "Codec context couldn't be allocated.");
return;
}
if (FFmpegApi.avcodec_open2(_context, _codec, null) != 0)
{
Logger.Error?.PrintMsg(LogClass.FFmpeg, "Codec couldn't be opened.");
return;
}
_packet = FFmpegApi.av_packet_alloc();
if (_packet == null)
{
Logger.Error?.PrintMsg(LogClass.FFmpeg, "Packet couldn't be allocated.");
return;
}
int avCodecRawVersion = FFmpegApi.avcodec_version();
int avCodecMajorVersion = avCodecRawVersion >> 16;
int avCodecMinorVersion = (avCodecRawVersion >> 8) & 0xFF;
// libavcodec 59.24 changed AvCodec to move its private API and also move the codec function to an union.
if (avCodecMajorVersion > 59 || (avCodecMajorVersion == 59 && avCodecMinorVersion > 24))
{
_decodeFrame = Marshal.GetDelegateForFunctionPointer <FFCodec.AVCodec_decode>(((FFCodec *)_codec)->CodecCallback);
}
// libavcodec 59.x changed AvCodec private API layout.
else if (avCodecMajorVersion == 59)
{
_decodeFrame = Marshal.GetDelegateForFunctionPointer <FFCodec.AVCodec_decode>(((FFCodecLegacy <AVCodec> *)_codec)->Decode);
}
// libavcodec 58.x and lower
else
{
_decodeFrame = Marshal.GetDelegateForFunctionPointer <FFCodec.AVCodec_decode>(((FFCodecLegacy <AVCodecLegacy> *)_codec)->Decode);
}
}
public void Dispose()
{
fixed(AVPacket **ppPacket = &_packet)
{
FFmpegApi.av_packet_free(ppPacket);
}
FFmpegApi.avcodec_close(_context);
fixed(AVCodecContext **ppContext = &_context)
{
FFmpegApi.avcodec_free_context(ppContext);
}
}
private static void Log(void *ptr, AVLog level, string format, byte *vl)
{
if (level > FFmpegApi.av_log_get_level())
{
return;
}
int lineSize = 1024;
byte *lineBuffer = stackalloc byte[lineSize];
int printPrefix = 1;
FFmpegApi.av_log_format_line(ptr, level, format, vl, lineBuffer, lineSize, &printPrefix);
string line = Marshal.PtrToStringAnsi((IntPtr)lineBuffer).Trim();
switch (level)
{
case AVLog.Panic:
case AVLog.Fatal:
case AVLog.Error:
Logger.Error?.Print(LogClass.FFmpeg, line);
break;
case AVLog.Warning:
Logger.Warning?.Print(LogClass.FFmpeg, line);
break;
case AVLog.Info:
Logger.Info?.Print(LogClass.FFmpeg, line);
break;
case AVLog.Verbose:
case AVLog.Debug:
Logger.Debug?.Print(LogClass.FFmpeg, line);
break;
case AVLog.Trace:
Logger.Trace?.Print(LogClass.FFmpeg, line);
break;
}
}
public int DecodeFrame(Surface output, ReadOnlySpan <byte> bitstream)
{
FFmpegApi.av_frame_unref(output.Frame);
int result;
int gotFrame;
fixed(byte *ptr = bitstream)
{
_packet->Data = ptr;
_packet->Size = bitstream.Length;
result = _decodeFrame(_context, output.Frame, &gotFrame, _packet);
}
if (gotFrame == 0)
{
FFmpegApi.av_frame_unref(output.Frame);
// If the frame was not delivered, it was probably delayed.
// Get the next delayed frame by passing a 0 length packet.
_packet->Data = null;
_packet->Size = 0;
result = _decodeFrame(_context, output.Frame, &gotFrame, _packet);
// We need to set B frames to 0 as we already consumed all delayed frames.
// This prevents the decoder from trying to return a delayed frame next time.
_context->HasBFrames = 0;
}
FFmpegApi.av_packet_unref(_packet);
if (gotFrame == 0)
{
FFmpegApi.av_frame_unref(output.Frame);
return(-1);
}
return(result < 0 ? result : 0);
}
public void Dispose()
{
FFmpegApi.av_frame_unref(Frame);
FFmpegApi.av_free(Frame);
}
