Recherche avancée

Sur d’autres sites (4986)

• FFmpeg - feed raw frames via pipe - FFmpeg does not detect pipe closure

  8 septembre 2018, par Rumble

  Im trying to follow these examples from C++ in Windows. Phyton Example C# Example

  I have an application that produces raw frames that shall be encoded with FFmpeg.
  The raw frames are transfered via IPC pipe to FFmpegs STDIN. That is working as expected, FFmpeg even displays the number of frames currently available.

  The problem occours when we are done sending frames. When I close the write end of the pipe I would expect FFmpeg to detect that, finish up and output the video. But that does not happen. FFmpeg stays open and seems to wait for more data.

  I made a small test project in VisualStudio.

  #include "stdafx.h" 
  
  //// stdafx.h 
  
  //#include "targetver.h"
  
  //#include 
  
  //#include 
  
  //#include <iostream>
  
  
  
  #include "Windows.h"
  
  #include <cstdlib>
  
  
  
  using namespace std;
  
  
  
  bool WritePipe(void* WritePipe, const UINT8 *const Buffer, const UINT32 Length)
  
  {
  
      if (WritePipe == nullptr || Buffer == nullptr || Length == 0)
  
      {
  
          cout &lt;&lt; __FUNCTION__ &lt;&lt; ": Some input is useless";
  
          return false;
  
      }
  
  
  
      // Write to pipe
  
      UINT32 BytesWritten = 0;
  
      UINT8 newline = '\n';
  
      bool bIsWritten = WriteFile(WritePipe, Buffer, Length, (::DWORD*)&amp;BytesWritten, nullptr);
  
      cout &lt;&lt; __FUNCTION__ &lt;&lt; " Bytes written to pipe " &lt;&lt; BytesWritten &lt;&lt; endl;
  
      //bIsWritten = WriteFile(WritePipe, &amp;newline, 1, (::DWORD*)&amp;BytesWritten, nullptr); // Do we need this? Actually this should destroy the image.
  
  
  
      FlushFileBuffers(WritePipe); // Do we need this?
  
  
  
      return bIsWritten;
  
  }
  
  
  
  #define PIXEL 80 // must be multiple of 8. Otherwise we get warning: Bytes are not aligned
  
  
  
  int main()
  
  {
  
      HANDLE PipeWriteEnd = nullptr;
  
      HANDLE PipeReadEnd = nullptr;
  
      {
  
          // create us a pipe for inter process communication
  
          SECURITY_ATTRIBUTES Attr = { sizeof(SECURITY_ATTRIBUTES), NULL, true };
  
          if (!CreatePipe(&amp;PipeReadEnd, &amp;PipeWriteEnd, &amp;Attr, 0))
  
          {
  
              cout &lt;&lt; "Could not create pipes" &lt;&lt; ::GetLastError() &lt;&lt; endl;
  
              system("Pause");
  
              return 0;
  
          }
  
      }
  
  
  
      // Setup the variables needed for CreateProcess
  
      // initialize process attributes
  
      SECURITY_ATTRIBUTES Attr;
  
      Attr.nLength = sizeof(SECURITY_ATTRIBUTES);
  
      Attr.lpSecurityDescriptor = NULL;
  
      Attr.bInheritHandle = true;
  
  
  
      // initialize process creation flags
  
      UINT32 CreateFlags = NORMAL_PRIORITY_CLASS;
  
      CreateFlags |= CREATE_NEW_CONSOLE;
  
  
  
      // initialize window flags
  
      UINT32 dwFlags = 0;
  
      UINT16 ShowWindowFlags = SW_HIDE;
  
  
  
      if (PipeWriteEnd != nullptr || PipeReadEnd != nullptr)
  
      {
  
          dwFlags |= STARTF_USESTDHANDLES;
  
      }
  
  
  
      // initialize startup info
  
      STARTUPINFOA StartupInfo = {
  
          sizeof(STARTUPINFO),
  
          NULL, NULL, NULL,
  
          (::DWORD)CW_USEDEFAULT,
  
          (::DWORD)CW_USEDEFAULT,
  
          (::DWORD)CW_USEDEFAULT,
  
          (::DWORD)CW_USEDEFAULT,
  
          (::DWORD)0, (::DWORD)0, (::DWORD)0,
  
          (::DWORD)dwFlags,
  
          ShowWindowFlags,
  
          0, NULL,
  
          HANDLE(PipeReadEnd),
  
          HANDLE(nullptr),
  
          HANDLE(nullptr)
  
      };
  
  
  
      LPSTR ffmpegURL = "\"PATHTOFFMPEGEXE\" -y -loglevel verbose -f rawvideo -vcodec rawvideo -framerate 1 -video_size 80x80 -pixel_format rgb24 -i - -vcodec mjpeg -framerate 1/4 -an \"OUTPUTDIRECTORY\"";
  
  
  
      // Finally create the process
  
      PROCESS_INFORMATION ProcInfo;
  
      if (!CreateProcessA(NULL, ffmpegURL, &amp;Attr, &amp;Attr, true, (::DWORD)CreateFlags, NULL, NULL, &amp;StartupInfo, &amp;ProcInfo))
  
      {
  
          cout &lt;&lt; "CreateProcess failed " &lt;&lt; ::GetLastError() &lt;&lt; endl;
  
      }
  
      //CloseHandle(ProcInfo.hThread);
  
  
  
  
  
          // Create images and write to pipe
  
  #define MYARRAYSIZE (PIXEL*PIXEL*3) // each pixel has 3 bytes
  
  
  
      UINT8* Bitmap = new UINT8[MYARRAYSIZE];
  
  
  
      for (INT32 outerLoopIndex = 9; outerLoopIndex >= 0; --outerLoopIndex)   // frame loop
  
      {
  
          for (INT32 innerLoopIndex = MYARRAYSIZE - 1; innerLoopIndex >= 0; --innerLoopIndex) // create the pixels for each frame
  
          {
  
              Bitmap[innerLoopIndex] = (UINT8)(outerLoopIndex * 20); // some gray color
  
          }
  
          system("pause");
  
          if (!WritePipe(PipeWriteEnd, Bitmap, MYARRAYSIZE))
  
          {
  
              cout &lt;&lt; "Failed writing to pipe" &lt;&lt; endl;
  
          }
  
      }
  
  
  
      // Done sending images. Tell the other process. IS THIS NEEDED? HOW TO TELL FFmpeg WE ARE DONE?
  
      //UINT8 endOfFile = 0xFF; // EOF = -1 == 1111 1111 for uint8
  
      //if (!WritePipe(PipeWriteEnd, &amp;endOfFile, 1))
  
      //{
  
      //  cout &lt;&lt; "Failed writing to pipe" &lt;&lt; endl;
  
      //}
  
      //FlushFileBuffers(PipeReadEnd); // Do we need this?
  
  
  
      delete Bitmap;
  
  
  
  
  
      system("pause");
  
  
  
      // clean stuff up
  
      FlushFileBuffers(PipeWriteEnd); // Do we need this?
  
  
  
      if (PipeWriteEnd != NULL &amp;&amp; PipeWriteEnd != INVALID_HANDLE_VALUE)
  
      {
  
          CloseHandle(PipeWriteEnd);
  
      }
  
  
  
      // We do not want to destroy the read end of the pipe? Should not as that belongs to FFmpeg
  
      //if (PipeReadEnd != NULL &amp;&amp; PipeReadEnd != INVALID_HANDLE_VALUE)
  
      //{
  
      //  ::CloseHandle(PipeReadEnd);
  
      //}
  
  
  
  
  
      return 0;
  
  
  
  }
  
  </cstdlib></iostream>

  And here the output of FFmpeg

  ffmpeg version 3.4.1 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with gcc 7.2.0 (GCC)
  
    configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth --enable-libmfx
  
    libavutil      55. 78.100 / 55. 78.100
  
    libavcodec     57.107.100 / 57.107.100
  
    libavformat    57. 83.100 / 57. 83.100
  
    libavdevice    57. 10.100 / 57. 10.100
  
    libavfilter     6.107.100 /  6.107.100
  
    libswscale      4.  8.100 /  4.  8.100
  
    libswresample   2.  9.100 /  2.  9.100
  
    libpostproc    54.  7.100 / 54.  7.100
  
  [rawvideo @ 00000221ff992120] max_analyze_duration 5000000 reached at 5000000 microseconds st:0
  
  Input #0, rawvideo, from 'pipe:':
  
    Duration: N/A, start: 0.000000, bitrate: 153 kb/s
  
      Stream #0:0: Video: rawvideo, 1 reference frame (RGB[24] / 0x18424752), rgb24, 80x80, 153 kb/s, 1 fps, 1 tbr, 1 tbn, 1 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> mjpeg (native))
  
  [graph 0 input from stream 0:0 @ 00000221ff999c20] w:80 h:80 pixfmt:rgb24 tb:1/1 fr:1/1 sar:0/1 sws_param:flags=2
  
  [auto_scaler_0 @ 00000221ffa071a0] w:iw h:ih flags:'bicubic' interl:0
  
  [format @ 00000221ffa04e20] auto-inserting filter 'auto_scaler_0' between the filter 'Parsed_null_0' and the filter 'format'
  
  [swscaler @ 00000221ffa0a780] deprecated pixel format used, make sure you did set range correctly
  
  [auto_scaler_0 @ 00000221ffa071a0] w:80 h:80 fmt:rgb24 sar:0/1 -> w:80 h:80 fmt:yuvj444p sar:0/1 flags:0x4
  
  Output #0, mp4, to 'c:/users/vr3/Documents/Guenni/sometest.mp4':
  
    Metadata:
  
      encoder         : Lavf57.83.100
  
      Stream #0:0: Video: mjpeg, 1 reference frame (mp4v / 0x7634706D), yuvj444p(pc), 80x80, q=2-31, 200 kb/s, 1 fps, 16384 tbn, 1 tbc
  
      Metadata:
  
        encoder         : Lavc57.107.100 mjpeg
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
  
  frame=   10 fps=6.3 q=1.6 size=       0kB time=00:00:09.00 bitrate=   0.0kbits/s speed=5.63x

  As you can see in the last line of te FFmpeg output, the images got trough. 10 frames are available. But after closing the pipe, FFmpeg does not close, still expecting input.

  As the linked examples show, this should be a valid method.

  Trying for a week now...

• How to optimize FFMPEG with pipe and memory reuse in Tide SDK

  7 janvier 2014, par Vincent Duprez

  Im running into an speed optimization issue. Im building a video cut tool in web technologies on desktop with TideSDK. On of the tools has a timeline with a position slider

  basically, whenever the slider moves, (using jquery UI), I get the position, translate this into a timecode and asks FFMPEG to encode to a file, when a get the finished event, I simply update the background-image attribute of the 'viewer' to this file. The file is located in some temporary folder.

  The thing is, it is just a bit too slow. Usable, but slow (approx 2 fps on a High end Computer)
  I think there are 2 bottlenecks on this strategy :
   Writing ffmpeg output to a file & reading back in css
   repeatedly loading the same movie file in ffmpeg

  This is the code executed on each move (var timecode is the calculated timecode based on the pointer position)

  var cmd = [FFMPEG];
  
  cmd.push('-y'); //overwrite existing files
  
  cmd.push('-ss',timecode); //CUE position
  
  cmd.push('-i',input); //input file
  
  cmd.push('-f','image2'); //output format
  
  cmd.push('-vframes','1'); //number of images to render
  
  cmd.push(Ti.API.Application.getDataPath( )+"/encoderframe.jpg"); //output file
  
  
  
  var makeframe = Ti.Process.createProcess(cmd);
  
  makeframe.setOnReadLine(function(data){ /*console.log(data);*/ });
  
  var time = new Date().getTime();
  
  makeframe.setOnExit(function(){ ffmpegrunning = false;  $('#videoframe').css('background-image','url(file://'+Ti.API.Application.getDataPath( ).replace(" ","%20")+'/encoderframe.jpg?'+time+')');     });
  
  makeframe.launch();

  Basically, this repeatedly asks the same Command :

  ffmpeg -y -ss 00:00:01.04 -i /somepath/somevideo.mov -f image2 -vframes 1 /path/to/output/encoderframe204.jpg

  How can I optimize this code, Pipe to output straight to css background with Base64 data, or reuse loaded memory file in ffmpeg. ?

  Thanks !

• avconv/ffmpeg named pipe multiple sending

  22 janvier 2018, par alextheloafer

  I am using libav-tools for making snapshots from IP camera RTSP stream. I need to make 2 frames and send it to a named pipe. For saving snapshots to a files, I’m using

  avconv -i $url -vsync 1 -vframes 2 -qscale 3 -f image2 img%03d.jpg

  When I want to send snapshot to a pipe, I’m using

  avconv -i $url -vsync 1 -vframes 1 -qscale 3 -f image2 pipe:1>tmppipe

  But how I can send two snapshots ? (With -vframes 2)