private bool _OpenVideoStream()
{
int videoStreamIndex;
SACDecoder decoder;
try
{
_Videodecoder = CAcinerella.AcCreateVideoDecoder(_Instance);
decoder = (SACDecoder)Marshal.PtrToStructure(_Videodecoder, typeof(SACDecoder));
videoStreamIndex = decoder.StreamIndex;
}
catch (Exception)
{
CLog.LogError("Error opening video file (can't find decoder): " + _FileName);
return(false);
}
if (videoStreamIndex < 0)
{
return(false);
}
_Width = decoder.StreamInfo.VideoInfo.FrameWidth;
_Height = decoder.StreamInfo.VideoInfo.FrameHeight;
if (decoder.StreamInfo.VideoInfo.FramesPerSecond > 0)
{
_FrameDuration = 1f / (float)decoder.StreamInfo.VideoInfo.FramesPerSecond;
}
_Framebuffer.Init(_Width * _Height * 4);
_FrameAvailable = false;
return(true);
}
private void _Decode()
{
const int minFrameDropCount = 4;
// With => seekThreshold frames to drop use seek instead of skip
const int seekThreshold = 25; // 25 frames = 0.5 second with _FrameDuration = 0.02f
if (_NoMoreFrames)
{
return;
}
float videoTime = RequestTime;
float timeDifference = videoTime - _LastDecodedTime;
bool dropFrame = timeDifference >= (minFrameDropCount - 1) * _FrameDuration;
bool hasFrameDecoded = false;
if (dropFrame)
{
var frameDropCount = (int)Math.Ceiling(timeDifference / _FrameDuration);
if (!_DropSeekEnabled || frameDropCount < seekThreshold)
{
hasFrameDecoded = _DropWithSkip(frameDropCount);
}
else
{
hasFrameDecoded = _DropWithSeek(videoTime, frameDropCount);
}
}
if (!hasFrameDecoded)
{
try
{
hasFrameDecoded = CAcinerella.AcGetFrame(_Instance, _Videodecoder);
}
catch (Exception)
{
CLog.LogError("Error AcGetFrame " + _FileName);
}
}
if (hasFrameDecoded)
{
_FrameAvailable = true;
}
else
{
if (Loop)
{
RequestTime = _LoopedRequestTime;
_Skip();
}
else
{
_NoMoreFrames = true;
}
}
}
//Just call this if thread is not alive
private void _Free()
{
if (_Videodecoder != IntPtr.Zero)
{
CAcinerella.AcFreeDecoder(_Videodecoder);
}
if (_Instance != IntPtr.Zero)
{
CAcinerella.AcClose(_Instance);
CAcinerella.AcFree(_Instance);
}
}
private bool _DropWithSkip(int frameDropCount)
{
bool hasFrameDecoded = false;
// Add 1 dropped frame per 16 frames (Power of 2 -> Div is fast) as skipping takes time too and we don't want to skip again
frameDropCount += frameDropCount / 16;
try
{
hasFrameDecoded = CAcinerella.AcSkipFrames(_Instance, _Videodecoder, frameDropCount);
}
catch (Exception)
{
CLog.LogError("Error AcSkipFrame " + _FileName);
}
return(hasFrameDecoded);
}
// Skip to a given time (in s)
private void _Skip()
{
float skipTime = RequestTime; //Copy to variable to have consistent checks
if (skipTime < 0 || skipTime >= Length)
{
skipTime = 0;
}
try
{
CAcinerella.AcSeek(_Videodecoder, -1, (Int64)(skipTime * 1000f));
}
catch (Exception e)
{
CLog.LogError("Error seeking video file \"" + _FileName + "\": " + e.Message);
}
_LastDecodedTime = skipTime;
_FrameAvailable = false;
}
private bool _DropWithSeek(float videoTime, int frameDropCount)
{
bool hasFrameDecoded = false;
try
{
hasFrameDecoded = CAcinerella.AcSeek(_Videodecoder, 0, (long)videoTime * 1000L);
}
catch (Exception)
{
CLog.LogError("Error AcSeek " + _FileName);
}
if (!hasFrameDecoded)
{
// Fallback to frame skipping
_DropSeekEnabled = false;
hasFrameDecoded = _DropWithSkip(frameDropCount);
}
return(hasFrameDecoded);
}
//Open the file and get the length.
public bool LoadFile(String fileName)
{
_FileName = fileName;
try
{
_Instance = CAcinerella.AcInit();
CAcinerella.AcOpen2(_Instance, fileName);
var instance = (SACInstance)Marshal.PtrToStructure(_Instance, typeof(SACInstance));
Length = instance.Info.Duration / 1000f;
bool ok = instance.Opened && Length > 0.001f;
_DropSeekEnabled = true;
if (ok)
{
return(true);
}
_Free();
}
catch (Exception) {}
CLog.LogError("Error opening video file: " + _FileName);
_Instance = IntPtr.Zero;
return(false);
}