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• Using ffplay or ffmpeg how can I get a pixel's rgb value in a frame

  21 mai 2014, par Pavan K

  I would like to extract a pixel’s rgb value in every frame that is decoded using ffmpeg. I looked into ffplay source code

  get_video_frame
  
  video_refresh
  
  queue_picture

  I tried the above three methods to hook on to the frame but I do not understand how to get a pixel’s rgb value. Could anyone kindly give some pointer into this

• How to make VideoCodec.Raw with Accord.Video.FFMPEG ?

  13 décembre 2020, par ryanm8227

  I have succeeded with VideoCodec.MPEG4 but unfortunately, the video quality is terrible :

  


  using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Accord.Video.FFMPEG;

namespace Screen_Recorder
{
    public partial class Form1 : Form
    {
        Timer timer1 = new Timer();
        VideoFileWriter vf = new VideoFileWriter();

        System.Random r = new System.Random();

        long rnd(double a, double b)
        {
            return Convert.ToInt64(a + r.NextDouble() * (b - a));
        }

        public Form1()
        {
            InitializeComponent();
            timer1.Interval = 10;
            timer1.Tick += Timer1_Tick;

            vf.Open(Convert.ToString(rnd(9999999999999999, 1000000000000000)) + ".mp4", 1920, 1080, 25, VideoCodec.MPEG4, 1000000);
            
        }

        private void Timer1_Tick(object sender, EventArgs e)
        {
            Bitmap bp = new Bitmap(1920, 1080);
            Graphics gr = Graphics.FromImage(bp);
            gr.CopyFromScreen(0, 0, 0, 0, new Size(bp.Width, bp.Height));

            pictureBox1.Image = bp;
            pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;

            vf.WriteVideoFrame(bp);
        }

        private void buttonStartRecording_Click(object sender, EventArgs e)
        {
            timer1.Start();
        }

        private void buttonStopRecording_Click(object sender, EventArgs e)
        {
            timer1.Stop();
            vf.Close();
        }
    }
}


  


  That being said, I would like to try making the video without the MPEG4, but with RAW, which is simply a non-compressed video. I expect the size to be pretty big, but that is not an issue.

  


• FFmpeg java.lang.UnsatisfiedLinkError dlopen failed : library "libavutil.so" not found in Vivo model device

  9 février 2024, par sejn

  Facing a lot of crashes in the Android Vivo devices with the above error. Can I restrict this to the Vivo models in Android.

  


  I'm using the implementation 'com.arthenica:mobile-ffmpeg-full:4.4'

  


  Fatal Exception: java.lang.UnsatisfiedLinkError dlopen failed: library "libavutil.so" not found

init {
    try{
        System.loadLibrary("avutil")
        System.loadLibrary("avcodec")
        System.loadLibrary("avformat")
        System.loadLibrary("swscale")
        System.loadLibrary("avfilter")
    }
    catch (e:Exception){
        Log.i("error","${e.message}")
    }
}


  


  In app/build.gradle

  


  


  ndk 
abiFilters 'armeabi-v7a','arm64-v8a','x86','x86_64'

  


  


  Note : If I migrate to the latest version ffmpeg-kit-full:6.0-2

  


  Clarifications :

  


  

  1. Shall I need to add this below in the code as well if I use the FFmpeg-kit

  


  2. If I did not need to use means, does it make any issues in the app ?.(i.e) if I removed

  


  3. Shall I need to add any additional loadlibrary in the init ?

  


  4. Is there any simple fix for the above error for Oppo alone without migrating ?

  


  5. Shall I need to add these architectures in ndk of my app ?

  


  


  


  arm-v7a, arm-v7a-neon, arm64-v8a, x86 and x86_64 architectures

  


  


   init {
        try{
            System.loadLibrary("avutil")
            System.loadLibrary("avcodec")
            System.loadLibrary("avformat")
            System.loadLibrary("swscale")
            System.loadLibrary("avfilter")
        }
        catch (e:Exception){
            Log.i("error","${e.message}")
        }
    }