我正在尝试记录计算机屏幕，因为我正在使用Accord。
我使用Accord 3.8.0.0的版本一切正常，但是当我升级到3.8.2.0-alpha版本时，我的录制视频变慢了，大约需要翻倍才能完成。
所以10秒的视频实际上需要20秒才能播放（在视频播放器中，视频的持续时间也是10秒）。
我在Google中搜索，但没有找到有用的东西。可能是由于该发行版的Alpha版本所致。
我设法从使用此3.8.2.0-alpha版本https://github.com/cesarsouza/screencast-capture
的Accord项目的维护者中找到了一个项目。我下载了zip文件，解压缩了项目，构建了项目，修复了编译错误（将Dispose()更改为Stop()），然后运行了该应用程序，但是问题仍然存在...生成的视频文件仍然很慢...
我的3.8.2.0-alpha版本的代码的主要方法是这些（它们取自我下载的上一个项目）：
public void StartRecording()
{
if (IsRecording || !IsPlaying)
return;
int height = area.Height;
int width = area.Width;
Rational framerate = new Rational(1000, screenStream.FrameInterval);
int videoBitRate = 1200 * 1000;
OutputPath = Path.Combine(main.CurrentDirectory, fileName);
RecordingStartTime = DateTime.MinValue;
videoWriter = new VideoFileWriter();
videoWriter.BitRate = videoBitRate;
videoWriter.FrameRate = framerate;
videoWriter.Width = width;
videoWriter.Height = height;
videoWriter.VideoCodec = VideoCodec.H264;
videoWriter.VideoOptions["crf"] = "18";
videoWriter.VideoOptions["preset"] = "veryfast";
videoWriter.VideoOptions["tune"] = "zerolatency";
videoWriter.VideoOptions["x264opts"] = "no-mbtree:sliced-threads:sync-lookahead=0";
videoWriter.Open(OutputPath);
HasRecorded = false;
IsRecording = true;
}
void VideoPlayer_NewFrameReceived(object sender, Accord.Video.NewFrameEventArgs eventArgs)
{
DateTime currentFrameTime = eventArgs.CaptureFinished;
// Encode the last frame at the same time we prepare the new one
Task.WaitAll(
Task.Run(() =>
{
lock (syncObj) // Save the frame to the video file.
{
if (IsRecording)
{
if (RecordingStartTime == DateTime.MinValue)
RecordingStartTime = DateTime.Now;
TimeSpan timestamp = currentFrameTime - RecordingStartTime;
if (timestamp > TimeSpan.Zero)
videoWriter.WriteVideoFrame(this.lastFrame, timestamp, this.lastFrameRegion);
}
}
}),
Task.Run(() =>
{
// Adjust the window according to the current capture
// mode. Also adjusts to keep even widths and heights.
CaptureRegion = AdjustWindow();
// Crop the image if the mode requires it
if (CaptureMode == CaptureRegionOption.Fixed ||
CaptureMode == CaptureRegionOption.Window)
{
crop.Rectangle = CaptureRegion;
eventArgs.Frame = croppedImage = crop.Apply(eventArgs.Frame, croppedImage);
eventArgs.FrameSize = crop.Rectangle.Size;
}
//// Draw extra information on the screen
bool captureMouse = Settings.Default.CaptureMouse;
bool captureClick = Settings.Default.CaptureClick;
bool captureKeys = Settings.Default.CaptureKeys;
if (captureMouse || captureClick || captureKeys)
{
cursorCapture.CaptureRegion = CaptureRegion;
clickCapture.CaptureRegion = CaptureRegion;
keyCapture.Font = Settings.Default.KeyboardFont;
using (Graphics g = Graphics.FromImage(eventArgs.Frame))
{
g.CompositingQuality = CompositingQuality.HighSpeed;
g.SmoothingMode = SmoothingMode.HighSpeed;
float invWidth = 1; // / widthScale;
float invHeight = 1; // / heightScale;
if (captureMouse)
cursorCapture.Draw(g, invWidth, invHeight);
if (captureClick)
clickCapture.Draw(g, invWidth, invHeight);
if (captureKeys)
keyCapture.Draw(g, invWidth, invHeight);
}
}
})
);
// Save the just processed frame and mark it to be encoded in the next iteration:
lastFrame = eventArgs.Frame.Copy(lastFrame);
lastFrameRegion = new Rectangle(0, 0, eventArgs.FrameSize.Width, eventArgs.Frame.Height);
}
任何人都知道导致这种速度下降的可能是什么问题吗？
编辑：
我想我找到了自己的问题：
pts:4.032000e+003 pts_time:0.252 dts:2.016000e+003 dts_time:0.126 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:6.720000e+003 pts_time:0.42 dts:3.360000e+003 dts_time:0.21 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:1.075200e+004 pts_time:0.672 dts:5.376000e+003 dts_time:0.336 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:1.344000e+004 pts_time:0.84 dts:6.720000e+003 dts_time:0.42 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:1.612800e+004 pts_time:1.008 dts:8.064000e+003 dts_time:0.504 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:1.881600e+004 pts_time:1.176 dts:9.408000e+003 dts_time:0.588 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:2.150400e+004 pts_time:1.344 dts:1.075200e+004 dts_time:0.672 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:2.553600e+004 pts_time:1.596 dts:1.276800e+004 dts_time:0.798 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:2.822400e+004 pts_time:1.764 dts:1.411200e+004 dts_time:0.882 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:3.091200e+004 pts_time:1.932 dts:1.545600e+004 dts_time:0.966 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:3.494400e+004 pts_time:2.184 dts:1.747200e+004 dts_time:1.092 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:3.897600e+004 pts_time:2.436 dts:1.948800e+004 dts_time:1.218 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:4.166400e+004 pts_time:2.604 dts:2.083200e+004 dts_time:1.302 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:4.704000e+004 pts_time:2.94 dts:2.352000e+004 dts_time:1.47 duration:6.720000e+002 duration_time:0.042 stream_index:0
pts:5.107200e+004 pts_time:3.192 dts:2.553600e+004 dts_time:1.596 duration:6.720000e+002 duration_time:0.042 stream_index:0
PTS始终是DTS的两倍，这就是为什么视频以慢速播放的原因。
不幸的是，我不知道为什么会这样...有人有任何线索吗？
答案 0 :(得分：0)
这实际上是alpha发行版中的错误。 See here for more information.
您始终可以编辑源代码，并使用添加的更正内容构建项目，但是，如果我正确理解许可证，则可能需要释放用作LGPL的任何代码。但是请不要相信我，因为我不是律师。
可以避免法律问题的解决方法是仅将其降级为最新的正式版本，因为该错误不存在。