Recherche avancée

Sur d’autres sites (4086)

• How to directly embed an flv in actionscript so ffmpeg can convert from the compiled swf ?

  3 décembre 2012, par user1872755

  I have an flv that needs to be embedded into a swf. I am currently using the Embed tag and playing the flv with NetStream. The problem is that it does not seem to be directly embedding the flv file, as ffmpeg does not detect it. I am currently using mxmlc to compile. If published from Flash Professional the conversion works. I can't use Flash Professional because I need to use the command line. Is there a way to embed an FLV in actionscript and have ffmpeg convert it ?

• Increase/Decrease audio volume using FFmpeg

  9 juin 2016, par williamtroup

  I’m am currently using C# invokes to call the FFmpeg APIs to handle video and audio. I have the following code in place to extract the audio from a video and write it to a file.

  while (ffmpeg.av_read_frame(formatContext, &packet) >= 0)
  
  {
  
      if (packet.stream_index == streamIndex)
  
      {
  
          while (packet.size > 0)
  
          {
  
              int frameDecoded;
  
              int frameDecodedResult = ffmpeg.avcodec_decode_audio4(codecContext, frame, &frameDecoded, packet);
  
  
  
              if (frameDecoded > 0 && frameDecodedResult >= 0)
  
              {
  
                  //writeAudio.WriteFrame(frame);
  
  
  
                  packet.data += totalBytesDecoded;
  
                  packet.size -= totalBytesDecoded;
  
              }
  
          }
  
  
  
          frameIndex++;
  
      }
  
  
  
      Avcodec.av_free_packet(&packet);
  
  }

  This is all working correctly. I’m currently using the FFmpeg.AutoGen project for the API access.

  I want to be able to increase/decrease the volume of the audio before its written to the file, but I cannot seem to find a command or any help with this. Does it have to be done manually ?

  Update 1 :

  After receiving some help, this is the class layout I have :

  public unsafe class FilterVolume
  
  {
  
      #region Private Member Variables
  
  
  
      private AVFilterGraph* m_filterGraph = null;
  
      private AVFilterContext* m_aBufferSourceFilterContext = null;
  
      private AVFilterContext* m_aBufferSinkFilterContext = null;
  
  
  
      #endregion
  
  
  
      #region Private Constant Member Variables
  
  
  
      private const int EAGAIN = 11;
  
  
  
      #endregion
  
  
  
      public FilterVolume(AVCodecContext* codecContext, AVStream* stream, float volume)
  
      {
  
          CodecContext = codecContext;
  
          Stream = stream;
  
          Volume = volume;
  
  
  
          Initialise();
  
      }
  
  
  
      public AVFrame* Adjust(AVFrame* frame)
  
      {
  
          AVFrame* returnFilteredFrame = ffmpeg.av_frame_alloc();
  
  
  
          if (m_aBufferSourceFilterContext != null && m_aBufferSinkFilterContext != null)
  
          {
  
              int bufferSourceAddFrameResult = ffmpeg.av_buffersrc_add_frame(m_aBufferSourceFilterContext, frame);
  
              if (bufferSourceAddFrameResult < 0)
  
              {
  
              }
  
  
  
              int bufferSinkGetFrameResult = ffmpeg.av_buffersink_get_frame(m_aBufferSinkFilterContext, returnFilteredFrame);
  
              if (bufferSinkGetFrameResult < 0 && bufferSinkGetFrameResult != -EAGAIN)
  
              {
  
              }
  
          }
  
  
  
          return returnFilteredFrame;
  
      }
  
  
  
      public void Dispose()
  
      {
  
          Cleanup(m_filterGraph);
  
      }
  
  
  
      #region Private Properties
  
  
  
      private AVCodecContext* CodecContext { get; set; }
  
      private AVStream* Stream { get; set; }
  
      private float Volume { get; set; }
  
  
  
      #endregion
  
  
  
      #region Private Setup Helper Functions
  
  
  
      private void Initialise()
  
      {
  
          m_filterGraph = GetAllocatedFilterGraph();
  
  
  
          string aBufferFilterArguments = string.Format("sample_fmt={0}:channel_layout={1}:sample_rate={2}:time_base={3}/{4}",
  
              (int)CodecContext->sample_fmt,
  
              CodecContext->channel_layout,
  
              CodecContext->sample_rate,
  
              Stream->time_base.num,
  
              Stream->time_base.den);
  
  
  
          AVFilterContext* aBufferSourceFilterContext = CreateFilter("abuffer", m_filterGraph, aBufferFilterArguments);
  
          AVFilterContext* volumeFilterContext = CreateFilter("volume", m_filterGraph, string.Format("volume={0}", Volume));
  
          AVFilterContext* aBufferSinkFilterContext = CreateFilter("abuffersink", m_filterGraph);
  
  
  
          LinkFilter(aBufferSourceFilterContext, volumeFilterContext);
  
          LinkFilter(volumeFilterContext, aBufferSinkFilterContext);
  
  
  
          SetFilterGraphConfiguration(m_filterGraph, null);
  
  
  
          m_aBufferSourceFilterContext = aBufferSourceFilterContext;
  
          m_aBufferSinkFilterContext = aBufferSinkFilterContext;
  
      }
  
  
  
      #endregion
  
  
  
      #region Private Cleanup Helper Functions
  
  
  
      private static void Cleanup(AVFilterGraph* filterGraph)
  
      {
  
          if (filterGraph != null)
  
          {
  
              ffmpeg.avfilter_graph_free(&filterGraph);
  
          }
  
      }
  
  
  
      #endregion
  
  
  
      #region Provate Helpers
  
  
  
      private AVFilterGraph* GetAllocatedFilterGraph()
  
      {
  
          AVFilterGraph* filterGraph = ffmpeg.avfilter_graph_alloc();
  
          if (filterGraph == null)
  
          {
  
          }
  
  
  
          return filterGraph;
  
      }
  
  
  
      private AVFilter* GetFilterByName(string name)
  
      {
  
          AVFilter* filter = ffmpeg.avfilter_get_by_name(name);
  
          if (filter == null)
  
          {
  
          }
  
  
  
          return filter;
  
      }
  
  
  
      private void SetFilterGraphConfiguration(AVFilterGraph* filterGraph, void* logContext)
  
      {
  
          int filterGraphConfigResult = ffmpeg.avfilter_graph_config(filterGraph, logContext);
  
          if (filterGraphConfigResult < 0)
  
          {
  
          }
  
      }
  
  
  
      private AVFilterContext* CreateFilter(string filterName, AVFilterGraph* filterGraph, string filterArguments = null)
  
      {
  
          AVFilter* filter = GetFilterByName(filterName);
  
          AVFilterContext* filterContext;
  
  
  
          int aBufferFilterCreateResult = ffmpeg.avfilter_graph_create_filter(&filterContext, filter, filterName, filterArguments, null, filterGraph);
  
          if (aBufferFilterCreateResult < 0)
  
          {
  
          }
  
  
  
          return filterContext;
  
      }
  
  
  
      private void LinkFilter(AVFilterContext* source, AVFilterContext* destination)
  
      {
  
          int filterLinkResult = ffmpeg.avfilter_link(source, 0, destination, 0);
  
          if (filterLinkResult < 0)
  
          {
  
          }
  
      }
  
  
  
      #endregion
  
  }

  The Adjust() function is called after a frame is decoded. I’m currently getting a -22 error when av_buffersrc_add_frame() is called. This indicates that a parameter is invalid, but after debugging, I cannot see anything that would be causing this.

  This is how the code is called :

  while (ffmpeg.av_read_frame(formatContext, &packet) >= 0)
  
  {
  
      if (packet.stream_index == streamIndex)
  
      {
  
          while (packet.size > 0)
  
          {
  
              int frameDecoded;
  
              int frameDecodedResult = ffmpeg.avcodec_decode_audio4(codecContext, frame, &frameDecoded, packet);
  
  
  
              if (frameDecoded > 0 && frameDecodedResult >= 0)
  
              {
  
                  AVFrame* filteredFrame = m_filterVolume.Adjust(frame);
  
  
  
                  //writeAudio.WriteFrame(filteredFrame);
  
  
  
                  packet.data += totalBytesDecoded;
  
                  packet.size -= totalBytesDecoded;
  
              }
  
          }
  
  
  
          frameIndex++;
  
      }
  
  
  
      Avcodec.av_free_packet(&packet);
  
  }

  Update 2 :

  Cracked it. The "channel_layout" option in the filter argument string is supposed to be a hexadecimal. This is what the string formatting should look like :

  string aBufferFilterArguments = string.Format("sample_fmt={0}:channel_layout=0x{1}:sample_rate={2}:time_base={3}/{4}",
  
      (int)CodecContext->sample_fmt,
  
      CodecContext->channel_layout,
  
      CodecContext->sample_rate,
  
      Stream->time_base.num,
  
      Stream->time_base.den);

• FFMPEG multi livestream - recorded stream send to different services like YT and Twitch at different time (on different button clicks )

  4 octobre 2022, par Ganesh

  Trying for the last 10 days and still no success, I am creating a python application that will accept the URL and visit that URL using chromium, capture that screen and send that real-time screen recording to different live stream acceptors as youtube live, twitch Twitter, Facebook live or some other sources and many of these could be multiple.

  


  There are two challenges (both challenges depend on a user action like different button clicks) -

  


  

  • The time of starting the Livestream we know only one Livestream acceptor and other acceptors could be sent via another API at any time or may not be sent on the whole live stream.

  


  • Any of the streams could be stopped at any moment including the first one which started the original live streaming service

  


  


  To Solve these challenges I am trying the following process (i took mp4 as a source for simplifying)

  


  

  • create a stream and store it into PIPE.stdout

  


  


  ffmpeg_Command_get_stream = 'ffmpeg -re -i test.mp4 -f flv pipe:1'
ffmpeg_Command_get_stream=ffmpeg_Command_get_stream.split()
pipe = sp.Popen(ffmpeg_Command_get_stream,
            stdout=sp.PIPE,
            stderr=sp.PIPE,
            bufsize=8000000,
            shell=True,
            universal_newlines=True
            )
out,err = pipe.communicate()


  


  


  • and send that stream with the help of FFMPEG to the Livestream acceptor with the click of the youtube Livestream button

    


    ffmpeg_Command_send_stream = ['ffmpeg','-i',pipe.stdout,'-f','flv',RTMPURL_YOUTUBE]

    


  


  


  Update Trying to Explain it a little more :

  


  step 1 - I need a real-time stream from the first command, so I used -re in FFMPEG

  


  step 2 - Use above stream as an input for other command and send that as an output as a Livestream to youtube (or twitch/Facebook), But the second step would happen only when the user click on the button "YT LiveStream", Here the tricky thing is there are multiple buttons (YT LiveStream, Twitch LiveStream, Facebook LiveStream) and user can click any time on any of button, also can click on all button one by one.

  


  

  


  sorry for bad explaination

  


  what I am doing wrong ? , Is this Possible ? or need to go with another process,

  


  any help would be greatly appreciated