Cannot handle exception when extract frame and encode video

[huyphamquang]

I use this package to do some video task like extract frame and remake video from frame image. My code sometime raise exception like below. I try to add try-catch block to handle it but no luck. Pls show me how to handle exception from ffmpeg lib.

Exception info:
System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
at FFMediaToolkit.Decoding.Internal.InputContainer.ReadPacket() in C:\projects\ffmediatoolkit\FFMediaToolkit\Decoding\Internal\InputContainer.cs:line 174
at FFMediaToolkit.Decoding.Internal.InputContainer.GetPacketFromStream(Int32 streamIndex) in C:\projects\ffmediatoolkit\FFMediaToolkit\Decoding\Internal\InputContainer.cs:line 90
at FFMediaToolkit.Decoding.Internal.Decoder.DecodePacket() in C:\projects\ffmediatoolkit\FFMediaToolkit\Decoding\Internal\Decoder.cs:line 146
at FFMediaToolkit.Decoding.Internal.Decoder.ReadNextFrame() in C:\projects\ffmediatoolkit\FFMediaToolkit\Decoding\Internal\Decoder.cs:line 136
at FFMediaToolkit.Decoding.VideoStream.GetNextFrame() in C:\projects\ffmediatoolkit\FFMediaToolkit\Decoding\VideoStream.cs:line 51
at FFMediaToolkit.Decoding.VideoStream.TryGetNextFrame(ImageData& bitmap) in C:\projects\ffmediatoolkit\FFMediaToolkit\Decoding\VideoStream.cs:line 68

[jrz371]

Can you provide a code snippet and the video file? It's a bit hard to tell what's going on from just this

[huyphamquang]

here is the source for extract frame:

`[HandleProcessCorruptedStateExceptions]
[SecurityCritical]
private void timerCallback(object state)
{
MediaFile file = null;
long startTick = DateTime.Now.Ticks;
try
{
//int duration = 1000 / Properties.Settings.Default.FrameProcess;
if (PlayListInfo == null || PlayListInfo.Count == 0) return;
int idx = 0;
bool newVideo = true;
TimeSpan endTime = new TimeSpan();
double time_4_frame_ms = 0;
while (idx < PlayListInfo.Count && !request_stop)
{
var startProcess = DateTime.Now;
var curVideo = PlayListInfo[idx];
bool firstFrame = false;
if (newVideo)
{
if (file != null) file.Dispose();
startTick = DateTime.Now.Ticks;
file = MediaFile.Open(curVideo.fileName);
newVideo = false;
endTime = curVideo.stopTime < 0 ? file.Info.Duration : TimeSpan.FromSeconds(curVideo.stopTime);
if (!file.HasVideo)
{
Console.WriteLine($"Cannot load video file: {curVideo.fileName}");
}
else
{
Console.WriteLine($"Process video: {curVideo.fileName}, frame rate: {file.Video.Info.AvgFrameRate}");
time_4_frame_ms = file.Video.Info.NumberOfFrames == null ? 0 : file.Video.Info.Duration.TotalMilliseconds / file.Video.Info.NumberOfFrames.Value;
firstFrame = true;
}
}
TimeSpan sp = new TimeSpan(DateTime.Now.Ticks - startTick);
sp.Add(TimeSpan.FromSeconds(curVideo.startTime <= file.Info.StartTime.TotalSeconds ? file.Info.StartTime.TotalSeconds : curVideo.startTime));
ImageData img;
if (sp > endTime)
{
idx++;
newVideo = true;
continue;
}
if (file != null && file.HasVideo)
{
var t1 = DateTime.Now;
bool ck = false;
if (firstFrame)
{
ck = file.Video.TryGetFrame(sp, out img);
firstFrame = false;
}
else
{
do
{
ck = file.Video.TryGetNextFrame(out img);
}
while (ck && file.Video.Position < sp);
}
if (!ck)
{
Console.WriteLine($"Cannot read frame at {sp} of {curVideo.fileName}");
idx++;
newVideo = true;
continue;
}
else
using (var bitmap = ToBitmap(img))
{
var frametime = DateTime.Now - t1;
//Console.WriteLine($"Take {frametime.TotalMilliseconds} to extract frame of {curVideo.fileName}");
// dataShare.WriteFrameData(img.ImageSize.Width, img.ImageSize.Height,
//DataUtils.PixelFormatToBitCount(bitmap.PixelFormat), img.Data.ToArray());
if (checkBlankFrame(bitmap))
{
Console.WriteLine($"Found black frame at {sp} of {curVideo.fileName}");
}
else ProcessFrame(bitmap);
}
}
var processTime = DateTime.Now - startProcess;
//Console.WriteLine($"Process time of {curVideo.fileName}: {processTime.TotalMilliseconds}/ms");
int sleeptime = (int)(time_4_frame_ms - processTime.TotalMilliseconds);
if (sleeptime > 0)
System.Threading.Thread.Sleep(sleeptime);
}
}
catch (AccessViolationException ex)
{
Console.WriteLine(ex.ToString());
}
catch
{

        }

        finally
        {
            if (file != null)
            {
                try
                {
                    file.Dispose();
                }
                catch
                {

                }
                file = null;
            }
        }

    }`

here is the source code for making video from bitmap:
`private unsafe void PushFrame(Bitmap bitmap)
{
try
{
lock (this)
{
var data = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
try
{
int len = data.Stride * data.Height;
byte[] bitmapData = new byte[len];
Marshal.Copy(data.Scan0, bitmapData, 0, len);
if (frameList.Count == 0) startTime = DateTime.Now.Ticks;
frameList.Add(bitmapData);
}
finally
{
bitmap.UnlockBits(data);
}
//ImageData data = VideoProcessEx.ToImageData(bitmap);
//mediaFile.Video.AddFrame(data);
TimeSpan sp = new TimeSpan(DateTime.Now.Ticks - startTime);
if (sp.TotalSeconds >= Properties.Settings.Default.LiveVideoDuration)
{
if (frameList.Count == 0) return;
videoCount++;
videoIndex = videoCount % 10;

                    var settings = new VideoEncoderSettings(width: bitmap.Width, height: bitmap.Height,
                        framerate: (int)(frameList.Count / sp.TotalSeconds), codec: VideoCodec.H264);
                    settings.EncoderPreset = EncoderPreset.Fast;
                    settings.CRF = 17;
                    //settings.VideoFormat = ImagePixelFormat.Rgb24;
                    string path = $"{VideoFolder}\\{videoIndex}.{videoExt}";
                    using (var mediaFile = MediaBuilder.CreateContainer(path)/*.UseFormatOption("g", "10").UseFormatOption("movflags", "frag_keyframe+empty_moov")*/.WithVideo(settings).Create())
                    {
                        Console.WriteLine($"create video: {MappingFile}.{videoIndex}.{videoExt} -- duration: {sp.TotalSeconds}, total frame: {frameList.Count}");
                        foreach (var item in frameList)
                        {
                            Span<byte> imgData = new Span<byte>(item, 0, item.Length);
                            //return new ImageData(imgData, ImagePixelFormat.Rgb24, bitmap.Size);
                            mediaFile.Video.AddFrame(new ImageData(imgData, ImagePixelFormat.Bgr24, bitmap.Size));
                            
                            //mediaFile.Video.Configuration.Framerate = (int)(mediaFile.Video.FramesCount / sp.TotalSeconds);
                        }
                        AddFileToPlayList(videoCount, $"{videoIndex}.{videoExt}", (decimal)sp.TotalSeconds);
                        //Task.Delay((int)(2) * 1000)
                        //    .ContinueWith((t) =>
                        //    {

                        //        AddFileToPlayList(videoCount, $"{videoIndex}.{videoExt}", (decimal)sp.TotalSeconds);
                        //    });
                    }
                    frameList.Clear();
                }
            }
        }
        catch(Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
    }`

[huyphamquang]

my application process a list of video file and that exeption occur ramdom, i'm not sure about the reson but I only want to catch if it raise exception