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• Error using FFMPEG to convert each input image into H264 compiling in Visual Studio running in MevisLab

  21 février 2014, par user3012914

  I am creating a ML Module in MevisLab Framework, I am using FFMPEG to convert each image i get into a H264 Video and save it after I get all the frames. But unfortunately I have problem allocating the output buffer size. The application crashes when I include this in my code.If I am not including it, the output file size is just 4kb. Nothing is stored in it.

  I am also not very sure whether it is correct way of getting the HBitmap into the Encoder. Would be great to have your suggestions.

  My Code :

  BITMAPINFO bitmapInfo;
  
              HDC        hdc;
  
  
  
              ZeroMemory(&bitmapInfo, sizeof(bitmapInfo));
  
  
  
              BITMAPINFOHEADER &bitmapInfoHeader = bitmapInfo.bmiHeader;
  
              bitmapInfoHeader.biSize            = sizeof(bitmapInfoHeader);
  
              bitmapInfoHeader.biWidth           = _imgWidth;
  
              bitmapInfoHeader.biHeight          = _imgHeight;
  
              bitmapInfoHeader.biPlanes          =  1;
  
              bitmapInfoHeader.biBitCount        = 24;
  
              bitmapInfoHeader.biCompression     = BI_RGB;
  
              bitmapInfoHeader.biSizeImage       = ((bitmapInfoHeader.biWidth * bitmapInfoHeader.biBitCount / 8 + 3) & 0xFFFFFFFC) * bitmapInfoHeader.biHeight;
  
              bitmapInfoHeader.biXPelsPerMeter   = 10000;
  
              bitmapInfoHeader.biYPelsPerMeter   = 10000;
  
              bitmapInfoHeader.biClrUsed         = 0;
  
              bitmapInfoHeader.biClrImportant    = 0;
  
              //RGBQUAD* Ref = new RGBQUAD[_imgWidth,_imgHeight];
  
              HDC hdcscreen = GetDC(0);
  
  
  
              hdc = CreateCompatibleDC(hdcscreen);
  
              ReleaseDC(0, hdcscreen);
  
  
  
              _hbitmap = CreateDIBSection(hdc, (BITMAPINFO*) &bitmapInfoHeader, DIB_RGB_COLORS, &_bits, NULL, NULL);

  To get the BitMap I use the above code. Then I allocate the Codec Context as followed

  c->bit_rate = 400000;
  
                  // resolution must be a multiple of two 
  
                  c->width = 1920;
  
                  c->height = 1080;
  
                  // frames per second 
  
                  frame_rate = _framesPerSecondFld->getIntValue();
  
                  //AVRational rational = {1,10};
  
                  //c->time_base = (AVRational){1,25};
  
                   //c->time_base = (AVRational){1,25};
  
                   c->gop_size = 10; // emit one intra frame every ten frames 
  
                   c->max_b_frames = 1;
  
                   c->keyint_min = 1;   //minimum GOP size
  
                   c->time_base.num = 1;                                  // framerate numerator
  
                   c->time_base.den = _framesPerSecondFld->getIntValue(); 
  
                   c->i_quant_factor = (float)0.71;                        // qscale factor between P and I frames
  
                   c->pix_fmt = AV_PIX_FMT_RGB32;
  
                   std::string msg;
  
                   msg.append("Context is stored");
  
                   _messageFld->setStringValue(msg.c_str());

  I create the Bitmap Image as followed from the input

  PagedImage *inImg = getUpdatedInputImage(0);
  
          ML_CHECK(inImg);
  
          ImageVector imgExt = inImg->getImageExtent();
  
          if ((imgExt.x = _imgWidth) && (imgExt.y == _imgHeight))
  
          {
  
          if (((imgExt.x % 4)==0) && ((imgExt.y % 4) == 0))
  
          {
  
                   // read out input image and write output image into video
  
                  // get input image as an array
  
                  void* imgData = NULL;
  
                  SubImageBox imageBox(imgExt); // get the whole image
  
                  getTile(inImg, imageBox, MLuint8Type, &imgData);
  
                  iData = (MLuint8*)imgData;
  
                  int r = 0; int g = 0;int  b = 0;
  
                  // since we have only images with
  
                  // a z-ext of 1, we can compute the c stride as follows
  
                  int cStride = _imgWidth * _imgHeight;
  
                  uint8_t offset  = 0;
  
                  // pointer into the bitmap that is
  
                  // used to write images into the avi
  
                  UCHAR* dst = (UCHAR*)_bits;
  
                  for (int y = _imgHeight-1; y >= 0; y--)
  
                  { // reversely scan the image. if y-rows of DIB are set in normal order, no compression will be available.
  
                      offset = _imgWidth * y;
  
                      for (int x = 0; x < _imgWidth; x++)
  
                      {
  
                          if (_isGreyValueImage)
  
                          {
  
                              r = iData[offset + x];
  
                              *dst++ = (UCHAR)r;
  
                              *dst++ = (UCHAR)r;
  
                              *dst++ = (UCHAR)r;
  
                          } 
  
                          else
  
                          {
  
                              b = iData[offset + x]; // windows bitmap need reverse order: bgr instead of rgb
  
                              g = iData[offset + x + cStride          ];
  
                              r = iData[offset + x + cStride + cStride];
  
  
  
                              *dst++ = (UCHAR)r;
  
                              *dst++ = (UCHAR)g;
  
                              *dst++ = (UCHAR)b;
  
                          }
  
                          // alpha channel in input image is ignored
  
                      }
  
                  }

  Then I add it to the Encoder as followed as write as H264

   in_width   = c->width;
  
                   in_height  = c->height;
  
                   out_width  = c->width;
  
                   out_height = c->height;
  
                   ibytes = avpicture_get_size(PIX_FMT_BGR32, in_width, in_height);
  
                   obytes = avpicture_get_size(PIX_FMT_YUV420P, out_width, out_height);
  
                   outbuf_size = 100000 + c->width*c->height*(32>>3);      // allocate output buffer
  
                   outbuf = static_cast(malloc(outbuf_size));
  
  
  
                   if(!obytes)
  
                   {
  
                       std::string msg;
  
                       msg.append("Bytes cannot be allocated");
  
                       _messageFld->setStringValue(msg.c_str());
  
                   }
  
                   else
  
                   {
  
                       std::string msg;
  
                       msg.append("Bytes allocation done");
  
                       _messageFld->setStringValue(msg.c_str());
  
                   }
  
                   //create buffer for the output image
  
                   inbuffer  =  (uint8_t*)av_malloc(ibytes);
  
                   outbuffer =  (uint8_t*)av_malloc(obytes);
  
                   inbuffer  =  (uint8_t*)dst;
  
  
  
                   //create ffmpeg frame structures.  These do not allocate space for image data, 
  
                   //just the pointers and other information about the image.
  
                   AVFrame* inpic = avcodec_alloc_frame();
  
                   AVFrame* outpic = avcodec_alloc_frame();
  
  
  
                   //this will set the pointers in the frame structures to the right points in 
  
                   //the input and output buffers.
  
                   avpicture_fill((AVPicture*)inpic, inbuffer, PIX_FMT_BGR32, in_width, in_height);
  
                   avpicture_fill((AVPicture*)outpic, outbuffer, PIX_FMT_YUV420P, out_width, out_height);
  
                   av_image_alloc(outpic->data, outpic->linesize, c->width, c->height, c->pix_fmt, 1); 
  
                   inpic->data[0] += inpic->linesize[0]*(_imgHeight-1);                                                      // flipping frame
  
                   inpic->linesize[0] = -inpic->linesize[0];    
  
  
  
                   if(!inpic)
  
                   {
  
                       std::string msg;
  
                       msg.append("Image is empty");
  
                       _messageFld->setStringValue(msg.c_str());
  
                   }
  
                   else
  
                   {
  
                       std::string msg;
  
                       msg.append("Picture has allocations");
  
                       _messageFld->setStringValue(msg.c_str());
  
                   }
  
  
  
                   //create the conversion context
  
                   fooContext = sws_getContext(in_width, in_height, PIX_FMT_BGR32, out_width, out_height, PIX_FMT_YUV420P, SWS_FAST_BILINEAR, NULL, NULL, NULL);
  
                   //perform the conversion
  
                   sws_scale(fooContext, inpic->data, inpic->linesize, 0, in_height, outpic->data, outpic->linesize);
  
                   //out_size = avcodec_encode_video(c, outbuf,outbuf_size, outpic);
  
                   if(!out_size)
  
                   {
  
                       std::string msg;
  
                       msg.append("Outsize is not valid");
  
                       _messageFld->setStringValue(msg.c_str());
  
                   } 
  
                   else
  
                   {
  
                       std::string msg;
  
                       msg.append("Outsize is valid");
  
                       _messageFld->setStringValue(msg.c_str());
  
                   }
  
                       fwrite(outbuf, 1, out_size, f);
  
                       if(!fwrite)
  
                   {
  
                       std::string msg;
  
                       msg.append("Frames couldnt be written");
  
                       _messageFld->setStringValue(msg.c_str());
  
                   } 
  
                   else
  
                   {
  
                       std::string msg;
  
                       msg.append("Frames written to the file");
  
                       _messageFld->setStringValue(msg.c_str());
  
                   }
  
                      // for (;out_size; i++)
  
                      // {
  
                            out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL); 
  
                            std::string msg;                       
  
                            msg.append("Writing Frames");
  
                            _messageFld->setStringValue(msg.c_str());// encode the delayed frames
  
                            _numFramesFld->setIntValue(_numFramesFld->getIntValue()+1);
  
                            fwrite(outbuf, 1, out_size, f);
  
                      // }
  
                       outbuf[0] = 0x00;
  
                       outbuf[1] = 0x00;                                                                                               // add sequence end code to have a real mpeg file
  
                       outbuf[2] = 0x01;
  
                       outbuf[3] = 0xb7;
  
                       fwrite(outbuf, 1, 4, f);
  
  }

  Then close and clean the Image Buffer and file

    ML_TRACE_IN("MovieCreator::_endRecording()")
  
  if (_numFramesFld->getIntValue() == 0)
  
  {
  
      _messageFld->setStringValue("Empty movie, nothing saved.");
  
  } 
  
  else 
  
  {
  
      _messageFld->setStringValue("Movie written to disk.");
  
      _numFramesFld->setIntValue(0);
  
  if (_hbitmap)
  
  { 
  
      DeleteObject(_hbitmap); 
  
  }
  
  if (c != NULL)
  
  {
  
         av_free(outbuffer);     
  
         av_free(inpic);
  
         av_free(outpic);
  
         fclose(f);
  
         avcodec_close(c);                                                                                               // freeing memory
  
         free(outbuf);
  
         av_free(c);
  
  }
  
  }

  }

  I think the Main Problem is over here !!

                       //out_size = avcodec_encode_video(c, outbuf,outbuf_size, outpic);

• OpenCV ffmpeg issues when running Windows 10 app on Windows 7

  1er novembre 2016, par David G.

  I need to maintain a desktop app written in C++, using Qt and OpenCV for some video processing. As far as I understood, the decoding part of OpenCV is delegated to ffmpeg in a separate DLL for licensing reasons.

  The development environment is on Windows 10, using QT Creator and MSVC12 64-bit as compiler. OpenCV version is 3.0, the official distribution. Here, everything runs fine, I am able to decode a video using VideoCapture::open().

  Issues arise when I try to run the application in a standalone fashion with all the required DLLs in the same folder as the .exe file. All cases below are 64-bit OSes.

  On a Windows 10 computer, not the same as the developement machine and no developer libraries present, the video decoding works fine. I have tested on a Windows 8 machine as well, no issues so far.

  On Windows 7, the things get tricky. The same video files that successfully load during the previous tests are not recognized by the app at all i.e. the isOpened call on VideoCapture returns false. For further testing, I stripped the opencv_ffmpeg300_64.dll file to narrow down the issue on Windows 10 and 8 ; as expected, without this DLL the app is no more able to open the same video files.

  It seems that the DLL is simply not recognized on Windows 7.

  • Did you encounter this type of issue and, maybe, have part of a solution ?
  • I would like to monitor which DLLs are loaded as the program runs and see possible "DLL not found" errors. Is it possible, especially on a machine that does not have the entire developement environment ?
  • Can building OpenCV on my own address the issue ?
  • Even further, would it be worth to port the development environment on Windows 7 and build from there ? This requires significant work due to the project itself.

• Why do I use the header file/library + ffplay.c download from the official website of ffmpeg to make the player worse than the official ffplay ?

  15 juillet 2020, par fredirty2017
  


  1. I am use win10 system with a "http_url_mp4" in hand, the MIME of this file is :
video/mp4 ; codecs="mp4a.40.2,avc1.640020" ; profiles="isom,mp41,mp42".

     


  


  2. I downloaded the header files, libraries, dlls, source code from https://ffmpeg.zeranoe.com/builds/ ,then :

     


  


  3. Run offical "ffplay http_url_mp4", audio and video viewing is normal ;

     


  


  4. I used VS2017 (the project has no special settings) to compile and link the fftools/ffplay.c，fftools/cmdutil.c and the included header files(libavcodec/libavutil and so on), libraries(such as avcodec.lib, avdevicelib, etc.), dlls(avcodec-58.dll / avformat-58.dll...), then run "myffplay http_url_mp4", The playback is stuttering, debugging found av_read_frame relative The processing cost more time, the calling frequency will be lower.

     


  


  5. i found config.h only line '#define FFMPEG_CONFIGURATION "—enable-gpl"', but offical ffplay cmdline shows :
'—disable-static —enable-shared —enable-gpl —enable-version3 —enable-cuda —enable-cuvid —enable-d3d11va —enable-dxva2 —enable-libmfx —enable-nvenc —enable-avisynth —enable-bzlib —enable-fontconfig —enable-frei0r —enable-gnutls —enable-iconv —enable-libass —enable-libbluray —enable-libbs2b —enable-libcaca —enable-libfreetype —enable-libgme —enable-libgsm —enable-libilbc —enable-libmodplug —enable-libmp3lame —enable-libopencore-amrnb —enable-libopencore-amrwb —enable-libopenh264 —enable-libopenjpeg —enable-libopus —enable-librtmp —enable-libsnappy —enable-libsoxr —enable-libspeex —enable-libtheora —enable-libtwolame —enable-libvidstab —enable-libvo-amrwbenc —enable-libvorbis —enable-libvpx —enable-libwavpack —enable-libwebp —enable-libx264 —enable-libx265 —enable-libxavs —enable-libxvid —enable-libzimg —enable-lzma —enable-zlib',

     


  


  6. Does the VS project need special settings or other codes ?