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• FFmpeg.AutoGen C# library Can't open Codec G726

  8 septembre 2024, par Rushdi Eskandar

  I am stuck with FFmpeg.AutoGen G726 Audio codec, it always shows error invalid argument.
Note that I Tried other codecs such as G722, G711 and it is working fine except for G726 codec. I also confirm that my binaries does support G726 codec using this command ffmpeg -formats. Please tell me what could be the reason, and if you know any other library for decoding G726 that would be better

  


  public unsafe class AudioDecoder : IDisposable
 {
   private AVCodecContext* _codecContext;
   private AVCodec* _codec;
   private AVFrame* _frame;
   private AVPacket* _packet;

   public AudioDecoder()
   {
       // Find the G726 decoder
       _codec = ffmpeg.avcodec_find_decoder(AVCodecID.AV_CODEC_ID_ADPCM_G726);
       if (_codec == null)
       {
           throw new Exception("G726 codec not found.");
       }

       // Allocate codec context
       _codecContext = ffmpeg.avcodec_alloc_context3(_codec);
       if (_codecContext == null)
       {
           throw new Exception("Failed to allocate codec context.");
       }

       // Print supported sample formats
       Console.WriteLine("Supported sample formats for G726 codec:");
       AVSampleFormat* sample_fmts = _codec->sample_fmts;
       if (sample_fmts != null)
       {
           while (*sample_fmts != AVSampleFormat.AV_SAMPLE_FMT_NONE)
           {
               Console.WriteLine($"Sample format: {*sample_fmts}");
               sample_fmts++;
           }
       }

       // Set codec parameters
       _codecContext->sample_rate = 8000;  // G726 typically uses 8000Hz
       if (_codec->sample_fmts != null)
       {
           _codecContext->sample_fmt = *_codec->sample_fmts;  // Use the first supported sample format
       }
       else
       {
           _codecContext->sample_fmt = AVSampleFormat.AV_SAMPLE_FMT_S16;  // Fallback to a common format
       }
       _codecContext->bit_rate = 32000;  // Example bitrate for G726

       // Attempt to open the codec with detailed error logging
       int ret = ffmpeg.avcodec_open2(_codecContext, _codec, null);
       if (ret < 0)
       {
           byte[] errBuf = new byte[1024];
           fixed (byte* errPtr = errBuf)
           {
               ffmpeg.av_strerror(ret, errPtr, (ulong)errBuf.Length);
           }
           string errMessage = System.Text.Encoding.UTF8.GetString(errBuf);
           throw new Exception($"Failed to open codec (Error code: {ret}): {errMessage}");
       }

       // Allocate packet and frame
       _packet = ffmpeg.av_packet_alloc();
       _frame = ffmpeg.av_frame_alloc();
       if (_packet == null || _frame == null)
       {
           throw new Exception("Failed to allocate packet or frame.");
       }
   }
}


  


• Convert video with FFMPEG Library in android

  27 septembre 2012, par Sanat Pandey

  I have a problem that I received a video foile from the server which can not be played throgh video view from the app I am making. I don't know what the actaul problem is because all videos are played through same video view but the video received from the server side is not played. So, I think that I have to integrate FFMPEG in our android app, so I can play every video at a runtime conversion. For this I have read much more about FFMPEG Library integration with android through many sites as :

  http://www.roman10.net/how-to-build-android-applications-based-on-ffmpeg-by-an-example/

  Downloaded some projects from GitHUb (https://github.com/appunite/AndroidFFmpeg) but unable to succeed for building the Library through NDK. Some thing I missed and I am working on Windows machine, probably this might be a problem. I want the exact solution regarding this, means step by step solution for building the android project with FFMPEG Library. If you have some useful suggestion then please share with me.

  Thanks in advance.

• Android - How can I pass camera stream to ffmpeg, using Camera2 library ?

  29 mars 2021, par Juan José Cetraro

  I am trying to create an app that shows the camera of the device on the screen, and also streams the camera by srt. To do this, I am using Camera2 library, and ffmpeg (in partucular I am using https://github.com/tanersener/mobile-ffmpeg, that is a ffmpeg wrapper for Android).

  


  My plan is to get the camera stream using Camera2 (using the method onImageAvailable on ImageReader.OnImageAvailableListener class), and send this stream to udp ://localhost:1234. Then, I can use ffmpeg to get that stream by udp, and send it by srt.

  


  I've already solved the part of sending the stream by srt using ffmpeg, and it works fine. In fact, if I set "android_camera" as the input of my ffmpeg command, my app works ok. The problem with this approach, is that if I do that, I block the access to the camera, so I can't show the camera on the screen with another library.

  


  I also found a code that uses Camera2 to stream the camera by udp, and it works, but the problem with this code is that converts each frame to bitmap before sending it by udp, and it makes that it is not performant.

  


  So, I need to know which is the best way to pass the data by udp to ffmpeg, so ffmpeg could process it and send it by srt ?

  


  Camera2 let me to configure which format I want to receive the frames on my listener :

  


  ImageReader.newInstance(1280, 720, ImageFormat.JPEG, /*maxImages*/2);


  


  In this example I am setting JPEG as ImageFormat, but here I let you all the available formats I could use :

  


  UNKNOWN, RGB_565, YV12, Y8, Y16, NV16, NV21, YUY2, JPEG, DEPTH_JPEG, YUV_420_888, YUV_422_888, YUV_444_888, FLEX_RGB_888, FLEX_RGBA_8888, RAW_SENSOR, RAW_PRIVATE, RAW10, RAW12, DEPTH16, DEPTH_POINT_CLOUD, RAW_DEPTH, PRIVATE, HEIC

  


  This is the method where I am going to receive each frame, and what I need to know is what kind of transformation I have to do before sending the frame by udp to ffmpeg ? :

  


  @Override
public void onImageAvailable(ImageReader reader) {

}


  


  Thanks in advance for reading the question :)