While working on my SecurityCameraRTSPClientFFMpegCore project I noticed that every so often after opening the Realtime Streaming Protocol(RTSP) connection with my HiLook IPCT250H Security Camera there was a “Paremeter is not valid” or “A generic error occurred in GDI+.” exception and sometimes the image was corrupted.
My test harness code was “inspired” by the Continuous Snapshots on Live Stream #280 sample
sing (var ms = new MemoryStream())
{
await FFMpegArguments
.FromUrlInput(new Uri("udp://192.168.2.12:9000"))
.OutputToPipe(new StreamPipeSink(ms), options => options
.ForceFormat("rawvideo")
.WithVideoCodec(VideoCodec.Png)
.Resize(new Size(Config.JpgWidthLarge, Config.JpgHeightLarge))
.WithCustomArgument("-vf fps=1 -update 1")
)
.NotifyOnProgress(o =>
{
try
{
if (ms.Length > 0)
{
ms.Position = 0;
using (var bitmap = new Bitmap(ms))
{
// Modify bitmap here
// Save the bitmap
bitmap.Save("test.png");
}
ms.SetLength(0);
}
}
catch { }
})
.ProcessAsynchronously();
}
My implementation is slightly different because I caught then displayed any exceptions generated converting the image stream to a bitmap or saving it.
using (var ms = new MemoryStream())
{
await FFMpegArguments
.FromUrlInput(new Uri(_applicationSettings.CameraUrl))
.OutputToPipe(new StreamPipeSink(ms), options => options
.ForceFormat("mpeg1video")
//.ForceFormat("rawvideo")
.WithCustomArgument("-rtsp_transport tcp")
.WithFramerate(10)
.WithVideoCodec(VideoCodec.Png)
//.Resize(1024, 1024)
//.ForceFormat("image2pipe")
//.Resize(new Size(Config.JpgWidthLarge, Config.JpgHeightLarge))
//.Resize(new Size(Config.JpgWidthLarge, Config.JpgHeightLarge))
//.WithCustomArgument("-vf fps=1 -update 1")
//.WithCustomArgument("-vf fps=5 -update 1")
//.WithSpeedPreset( Speed.)
//.UsingMultithreading()
//.UsingThreads()
//.WithVideoFilters(filter => filter.Scale(640, 480))
//.UsingShortest()
//.WithFastStart()
)
.NotifyOnProgress(o =>
{
try
{
if (ms.Length > 0)
{
ms.Position = 0;
string outputPath = Path.Combine(_applicationSettings.SavePath, string.Format(_applicationSettings.FrameFileNameFormat, DateTime.UtcNow ));
using (var bitmap = new Bitmap(ms))
{
// Save the bitmap
bitmap.Save(outputPath);
}
ms.SetLength(0);
}
}
catch (Exception ex)
{
Console.WriteLine($"{DateTime.UtcNow:yy-MM-dd HH:mm:ss.fff} {ex.Message}");
}
})
.ProcessAsynchronously();
}
I have created a Continuous Snapshots on Live Stream Memory stream contains invalid bitmap image #562 to track the issue.
One odd thing that I noticed when scrolling “back and forth” through the images around when there was exception was that the date and time on the top left of the image was broken.
I wonder if the image was “broken” in some subtle way and FFMpegCore is handling this differently to the other libraries I’m trialing.
devMobile's blog 