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Mis à jour : Avril 2013
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Sur d’autres sites (4940)
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Play UDP live video stream in UWP
19 avril 2018, par Nicolas SévenoI need to display a live video stream in a UWP application.
The video stream comes from a GoPro. It is transported by UDP messages. I think it is a MPEG-2 TS stream.
I can play it successfully using FFPlay with the following command line :
ffplay -fflags nobuffer -f:v mpegts udp://:8554I would like to play it with MediaPlayerElement without using a third party library.
According to the following page :
https://docs.microsoft.com/en-us/windows/uwp/audio-video-camera/supported-codecs
UWP should be able to play it. (I installed the "MPEG 2 video extension" in the Windows Store).I tried using DatagramSocket and the MessageReceived event to receive the UDP packets, it works without problem :
_datagramSocket = new DatagramSocket();
_datagramSocket.MessageReceived += (s, args) =>
{
Debug.WriteLine("message received");
};
await _datagramSocket.BindServiceNameAsync(8554);Then I create a MseStreamSource :
_mseStreamSource = new MseStreamSource();
_mseStreamSource.Opened += (_, __) =>
{
_mseSourceBuffer = _mseStreamSource.AddSourceBuffer("video/mp2t");
};
this.MediaSource = MediaSource.CreateFromMseStreamSource(_mseStreamSource);And in the DatagramSocket.MessageReceived event I send the messages to the MseStreamSource :
using (IInputStream stream = args.GetDataStream())
{
_mseSourceBuffer.AppendStream(stream);
}The AppendStream method fails with error HRESULT 0x8070000B for some packets.
If I catch the error, the MediaPlayerElement displays the message "video not supported or incorrect file name". (not sure of the message, my Windows is in French).Is the MseStreamSource the correct way to display the stream ? Is there a better solution ?
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How to parallelize this for loop for rapidly converting YUV422 to RGB888 ?
16 avril 2015, par vineetI am using v4l2 api to grab images from a Microsoft Lifecam and then transferring these images over TCP to a remote computer. I am also encoding the video frames into a MPEG2VIDEO using ffmpeg API. These recorded videos play too fast which is probably because not enough frames have been captured and due to incorrect FPS settings.
The following is the code which converts a YUV422 source to a RGB888 image. This code fragment is the bottleneck in my code as it takes nearly 100 - 150 ms to execute which means I can’t log more than 6 - 10 FPS at 1280 x 720 resolution. The CPU usage is 100% as well.
for (int line = 0; line < image_height; line++) {
for (int column = 0; column < image_width; column++) {
*dst++ = CLAMP((double)*py + 1.402*((double)*pv - 128.0)); // R - first byte
*dst++ = CLAMP((double)*py - 0.344*((double)*pu - 128.0) - 0.714*((double)*pv - 128.0)); // G - next byte
*dst++ = CLAMP((double)*py + 1.772*((double)*pu - 128.0)); // B - next byte
vid_frame->data[0][line * frame->linesize[0] + column] = *py;
// increment py, pu, pv here
}’dst’ is then compressed as jpeg and sent over TCP and ’vid_frame’ is saved to the disk.
How can I make this code fragment faster so that I can get atleast 30 FPS at 1280x720 resolution as compared to the present 5-6 FPS ?
I’ve tried parallelizing the for loop across three threads using p_thread, processing one third of the rows in each thread.
for (int line = 0; line < image_height/3; line++) // thread 1
for (int line = image_height/3; line < 2*image_height/3; line++) // thread 2
for (int line = 2*image_height/3; line < image_height; line++) // thread 3This gave me only a minor improvement of 20-30 milliseconds per frame.
What would be the best way to parallelize such loops ? Can I use GPU computing or something like OpenMP ? Say spwaning some 100 threads to do the calculations ?I also noticed higher frame rates with my laptop webcam as compared to the Microsoft USB Lifecam.
Here are other details :
- Ubuntu 12.04, ffmpeg 2.6
- AMG-A8 quad core processor with 6GB RAM
- Encoder settings :
- codec : AV_CODEC_ID_MPEG2VIDEO
- bitrate : 4000000
- time_base : (AVRational)1, 20
- pix_fmt : AV_PIX_FMT_YUV420P
- gop : 10
- max_b_frames : 1
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xabe.ffmpeg not working in azure app service
28 décembre 2020, par Sripathi RajaI have a .net core application which generates video thumbnails for uploaded videos. I am using xabe.ffmpeg for this . The code runs fine in the local system and Iam able to generate the thumbnails . I have containerized this application and pushed it to azure app service . But when the code is deployed on azure app service its throws an error . I have placed the ffmpeg.exe ,ffprobe.exe , ffplay.exe inside a folder ffmpeg in wwwroot folder .
the app service logs give this error


the first line is the path : /app/wwwroot/ffmpeg


2020-12-25T14:34:01.347103909Z /app/wwwroot/ffmpeg
2020-12-25T14:34:01.443016709Z [41m[30mfail[39m[22m[49m : Microsoft.AspNetCore.Server.Kestrel[13]
2020-12-25T14:34:01.443066009Z Connection id "0HM58S8AE014U", Request id "0HM58S8AE014U:00000002" : An unhandled exception was thrown by the application.
2020-12-25T14:34:01.456821709Z System.ComponentModel.Win32Exception (2) : No such file or directory
2020-12-25T14:34:01.462537109Z at System.Diagnostics.Process.ForkAndExecProcess(String filename, String[] argv, String[] envp, String cwd, Boolean redirectStdin, Boolean redirectStdout, Boolean redirectStderr, Boolean setCredentials, UInt32 userId, UInt32 groupId, UInt32[] groups, Int32& stdinFd, Int32& stdoutFd, Int32& stderrFd, Boolean usesTerminal, Boolean throwOnNoExec)
2020-12-25T14:34:01.462555709Z at System.Diagnostics.Process.StartCore(ProcessStartInfo startInfo)
2020-12-25T14:34:01.462560609Z at System.Diagnostics.Process.Start()
2020-12-25T14:34:01.463739309Z at Xabe.FFmpeg.FFmpeg.RunProcess(String args, String processPath, Nullable
1 priority, Boolean standardInput, Boolean standardOutput, Boolean standardError) 2020-12-25T14:34:01.463755809Z at Xabe.FFmpeg.FFprobeWrapper.<>c__DisplayClass9_0.<runprocess>b__0() 2020-12-25T14:34:01.463761809Z at System.Threading.Tasks.Task</runprocess>1.InnerInvoke()
2020-12-25T14:34:01.463766309Z at System.Threading.Tasks.Task.<>c.<.cctor>b__274_0(Object obj)
2020-12-25T14:34:01.463781109Z at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
2020-12-25T14:34:01.463786509Z --- End of stack trace from previous location where exception was thrown ---
2020-12-25T14:34:01.463790909Z at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
2020-12-25T14:34:01.463795509Z at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
2020-12-25T14:34:01.463800009Z --- End of stack trace from previous location where exception was thrown ---
2020-12-25T14:34:01.463813709Z at Xabe.FFmpeg.FFprobeWrapper.RunProcess(String args, CancellationToken cancellationToken)
2020-12-25T14:34:01.463818109Z at Xabe.FFmpeg.FFprobeWrapper.GetStreams(String videoPath, CancellationToken cancellationToken)
2020-12-25T14:34:01.463821909Z at Xabe.FFmpeg.FFprobeWrapper.SetProperties(MediaInfo mediaInfo, CancellationToken cancellationToken)
2020-12-25T14:34:01.463825509Z at Xabe.FFmpeg.MediaInfo.Get(String filePath, CancellationToken cancellationToken)
2020-12-25T14:34:01.463829109Z at Xabe.FFmpeg.MediaInfo.Get(String filePath)
2020-12-25T14:34:01.463832609Z at Xabe.FFmpeg.FFmpeg.GetMediaInfo(String fileName)
2020-12-25T14:34:01.467009509Z at root2webAPI.Controllers.AzureStorageControllers.BlobExplorerController.GetVideoThumbnailAsync(IFormFile file, Int32 frameTarget) in /src/root2webAPI/Controllers/AzureStorageControllers/BlobExplorerController.cs:line 271
2020-12-25T14:34:01.467023809Z at root2webAPI.Controllers.AzureStorageControllers.BlobExplorerController.UploadMediaBlob(IFormFile file, String parentId) in /src/root2webAPI/Controllers/AzureStorageControllers/BlobExplorerController.cs:line 96
2020-12-25T14:34:01.467028709Z at lambda_method(Closure , Object )
2020-12-25T14:34:01.467032109Z at Microsoft.Extensions.Internal.ObjectMethodExecutorAwaitable.Awaiter.GetResult()
2020-12-25T14:34:01.467035909Z at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
2020-12-25T14:34:01.467039409Z at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
2020-12-25T14:34:01.467043209Z at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
2020-12-25T14:34:01.467055709Z at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
2020-12-25T14:34:01.467060609Z at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
2020-12-25T14:34:01.467067409Z at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
2020-12-25T14:34:01.467071609Z at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
2020-12-25T14:34:01.467075209Z at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
2020-12-25T14:34:01.467078709Z at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
2020-12-25T14:34:01.467089009Z at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
2020-12-25T14:34:01.467093409Z at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
2020-12-25T14:34:01.467096909Z at Microsoft.AspNetCore.Routing.EndpointMiddleware.g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
2020-12-25T14:34:01.467100509Z at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
2020-12-25T14:34:01.467103809Z at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext]

here is my relevant .net application code


private async Task<mediametadata> GetVideoThumbnailAsync(IFormFile file,int frameTarget)
 {
 var fileName = file.FileName;
 var filePath = Path.Combine(_rootPath, "videos", fileName);
 var fileExtension = Path.GetExtension(filePath);
 
 // the xabe wrapper works with only mp4 extension to create thumbnail , if the file is any other format first convert it to
 //the mp4 format and then goahead with creating the thumbnail. 
 var thumbnailImageName = fileName.Replace(fileExtension, ".jpg");
 var thumbnailImagePath = Path.Combine(_rootPath, "thumbnails", thumbnailImageName);
 
 using (Stream fileStream = new FileStream(filePath, FileMode.Create)) {
 
 await file.CopyToAsync(fileStream);
 }
 Console.WriteLine(Path.Combine(_rootPath,"ffmpeg"));
 FFmpeg.SetExecutablesPath(Path.Combine(_rootPath,"ffmpeg"));
 IMediaInfo mediaInfo = await FFmpeg.GetMediaInfo(filePath);
 var videoDuration = mediaInfo.VideoStreams.First().Duration;
 IConversion conversion = await FFmpeg.Conversions.FromSnippet.Snapshot(filePath, thumbnailImagePath , TimeSpan.FromSeconds(frameTarget));
 IConversionResult result = await conversion.Start();
 MediaMetadata media = new MediaMetadata();
 media.DurationSeconds=Convert.ToInt32(videoDuration.TotalMilliseconds);
 // media.DurationSeconds=10;
 media.ThumbnailImagePath= thumbnailImagePath;
 return media;
 
 }
</mediametadata>

could you help me out with this ..many thanks


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