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• Révision 24109 : Fix #3564 : en statut propose c’est la date de publi de l’article qu’on regle

  29 septembre 2018, par cedric@yterium.com

• Cropping video stream in android-studio

  9 mai 2021, par Benjamin Basmaci

  I want stream a very large video (lets say 5000x5000) and I want to crop it to show 1000x1000 chunks. Currently I do so by streaming the video via TextureView.SurfaceTextureListener. Scaling the video up to the point where one chunk fits my view and can be played. Here is a little snippit :

  



  Matrix matrix = new Matrix();
matrix.setScale(scaleX, scaleY, 0, 0);
matrix.postTranslate(positionX, positionY);

textureView.setTransform(matrix);


  



  However, since its such a big video, some devices cant play it. Smaller videos work fine, even with the same codec. It seems like decoding it takes too long for it to be able to play. This even occured when I stored the video in resources. (maybe has something to do with the second answer in this question)

  



  I tried using ffmpeg, but when I did, according to this question, i got the error Message in ExecuteBinaryResponseHandler.onFailure(): "CANNOT LINK EXECUTABLE "/data/user/0/packageName/files/ffmpeg": /data/data/packageName/files/ffmpeg: has text relocations". So it seems that ffmpeg is not an option anymore, and wont ever be, according to these issues :

  



  

  • https://issuetracker.google.com/issues/37067983

  


  • https://trac.ffmpeg.org/ticket/4928

  


  



  So, a few questions about this.

  



  

  1. Is there an alternative to ffmpeg that lets me crop videos programmatically and with high performance, before they are decoded by the player ?

  


  2. Is there a way to restrict android to only load the parts 'visible' of a video after it has been scaled ? Boosting the performance of my first attempt, scaling the video up to a point where I only see a particular area ?

  


  3. Is there a way, other than lowering the quality of my video source, to ensure that a device can play the video or at least to detect programmatically that a video can not be played ?

  


  4. Is there another technique or a workaround that I can use to show a cropped part of a vide ?

  


  



  UPDATE

  



  As suggested in the comments, to boil it down to one question :
Is there a way for me to crop a video programmatically from url so that it plays on all modern devices ?

  


• C# server problem with FFmpeg Visual Studio 2022

  16 mai 2024, par seanofdead

  Hello everyone I've spent countless hours on my server I'm trying to create that will share video from one stream to another client computer. That is the goal anyway. I'm using Visual Studio 2022 most recent update. Currently this is my code

  


  using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading.Tasks;
using FFmpeg.AutoGen;
using NLog;

public class VideoStreamServer
{
    private const int Port = 5000;
    private TcpListener server;
    private FFmpegVideoEncoder encoder;
    private static readonly Logger logger = LogManager.GetCurrentClassLogger();

    public VideoStreamServer()
    {
        // Initialize FFmpeg network components
        Console.WriteLine("Initializing FFmpeg network components...");
        int result = ffmpeg.avformat_network_init();
        if (result != 0)
        {
            throw new ApplicationException($"Failed to initialize FFmpeg network components: {result}");
        }

        // Initialize encoder
        encoder = new FFmpegVideoEncoder(1920, 1080, AVCodecID.AV_CODEC_ID_H264); // Screen size & codec
    }

    public static void Main()
    {
        // Initialize NLog
        var logger = LogManager.GetCurrentClassLogger();
        logger.Info("Application started");

        var server = new VideoStreamServer();
        server.Start().Wait();
    }

    public async Task Start()
    {
        server = new TcpListener(IPAddress.Any, Port);
        server.Start();
        logger.Info($"Server started on port {Port}...");

        try
        {
            while (true)
            {
                TcpClient client = await server.AcceptTcpClientAsync();
                logger.Info("Client connected...");
                _ = HandleClientAsync(client);
            }
        }
        catch (Exception ex)
        {
            logger.Error(ex, "An error occurred");
        }
    }

    private async Task HandleClientAsync(TcpClient client)
    {
        using (client)
        using (NetworkStream netStream = client.GetStream())
        {
            try
            {
                await encoder.StreamEncodedVideoAsync(netStream);
            }
            catch (IOException ex)
            {
                logger.Error(ex, $"Network error: {ex.Message}");
                // Additional logging and recovery actions
            }
            catch (Exception ex)
            {
                logger.Error(ex, $"Unexpected error: {ex.Message}");
                // Log and handle other exceptions
            }
            finally
            {
                // Ensure all resources are cleaned up properly
                client.Close();
                logger.Info("Client connection closed properly.");
            }
        }
    }
}

public class FFmpegVideoEncoder
{
    private readonly int width;
    private readonly int height;
    private readonly AVCodecID codecId;
    private static readonly Logger logger = LogManager.GetCurrentClassLogger();

    public FFmpegVideoEncoder(int width, int height, AVCodecID codecId)
    {
        this.width = width;
        this.height = height;
        this.codecId = codecId;
        InitializeEncoder();
    }

    private void InitializeEncoder()
    {
        // Initialize FFmpeg encoder here
        logger.Debug("FFmpeg encoder initialized");
    }

    public async Task StreamEncodedVideoAsync(NetworkStream netStream)
    {
        // Initialize reusable buffers for efficiency
        byte[] buffer = new byte[4096];

        // Capture and encode video frames
        while (true)
        {
            try
            {
                // Simulate capture and encoding
                byte[] videoData = new byte[1024]; // This would come from the encoder

                // Simulate streaming
                for (int i = 0; i < videoData.Length; i += buffer.Length)
                {
                    int chunkSize = Math.Min(buffer.Length, videoData.Length - i);
                    Buffer.BlockCopy(videoData, i, buffer, 0, chunkSize);
                    await netStream.WriteAsync(buffer, 0, chunkSize);
                }
            }
            catch (Exception ex)
            {
                logger.Error(ex, "Error streaming video data");
                throw; // Rethrow to handle in the calling function
            }

            await Task.Delay(1000 / 30); // For 30 FPS
        }
    }
}


  


  When I build no issues but when i run it in debug mode I get this error

  


  System.DllNotFoundException
  HResult=0x80131524
  Message=Unable to load DLL 'avformat.59 under C:\Users\phlfo\Downloads\cfolder\server\ConsoleApp\bin\Debug\': The specified module could not be found.
  Source=FFmpeg.AutoGen
  StackTrace:
   at FFmpeg.AutoGen.ffmpeg.LoadLibrary(String libraryName, Boolean throwException)
   at FFmpeg.AutoGen.ffmpeg.<>c.<.cctor>b__7_0(String libraryName)
   at FFmpeg.AutoGen.ffmpeg.<>c.<.cctor>b__7_242()
   at FFmpeg.AutoGen.ffmpeg.avformat_network_init()
   at VideoStreamServer..ctor() in C:\Users\phlfo\Downloads\cfolder\server\ConsoleApp\Program.cs:line 20
   at VideoStreamServer.Main() in C:\Users\phlfo\Downloads\cfolder\server\ConsoleApp\Program.cs:line 36


  


  I have FFmpeg.AutoGen package installed through VS i originally started with 7.0 but then switched to 5.0 to see if an older version might work (it did not). I also have the files in the same directory as the .exe for testing purposes as seen in the screenshot. Can someone please help me figure out this error.