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• Force a vbscript to open command prompt in 64bit instead of 32bit

  26 juin 2015, par Arvo Bowen

  I have been trying to get this script to work all day !

  Here are some facts about my situation...

  • I have a program named "ffmpeg.exe" in my "C :\Windows\System32\" folder.
  • I DO NOT have that program in my "C :\Windows\SysWOW64\" folder.

  Currently this is the script I have...

  Option Explicit
  
  
  
  Dim oFSO, oShell, sCommand
  
  Dim sFilePath, sTempFilePath
  
  
  
  Set oFSO = CreateObject("Scripting.FileSystemObject")
  
  
  
  sFilePath = "C:\test\in_video.mkv"
  
  sTempFilePath = "C:\test\out_video.mp4"
  
  
  
  sCommand = "%comspec% /k ffmpeg -n -i """ + sFilePath + """ -c:v copy -c:a copy """ + sTempFilePath + """"
  
  WScript.Echo sCommand
  
  Set oShell = WScript.CreateObject("WScript.Shell")
  
  oShell.Run sCommand, 1, True
  
  Set oShell = Nothing
  
  
  
  Set oFSO = Nothing

  If I run this script manually at a command prompt then it seems to work just fine. But if I let another app run it (for example in this case uTorrent), it runs the script as expected but when it tries to process the oShell.Run command it runs that in a 32bit environment ! Then I get this...
  

  If I try to open up a new command prompt (nothing special) i seems to default to a 64bit environment and then I can type "ffmpeg" and it shows me the help content as expected.

  So for some reason I can’t get the script to run applications (specifically CMD) in the 64bit environment. Anyone know how I can achieve this ?

  ---

  Update

  Seems that my script is in fact being ran in 32bit mode ! Even though the script title bar says "C :\Windows\System32\cscript.exe", which is a 64bit environment !!

  I used the following script to determine that it was running in a 32bit environment...

  Dim WshShell
  
  Dim WshProcEnv
  
  Dim system_architecture
  
  Dim process_architecture
  
  
  
  Set WshShell =  CreateObject("WScript.Shell")
  
  Set WshProcEnv = WshShell.Environment("Process")
  
  
  
  process_architecture= WshProcEnv("PROCESSOR_ARCHITECTURE") 
  
  
  
  If process_architecture = "x86" Then    
  
      system_architecture= WshProcEnv("PROCESSOR_ARCHITEW6432")
  
  
  
      If system_architecture = ""  Then    
  
          system_architecture = "x86"
  
      End if    
  
  Else    
  
      system_architecture = process_architecture    
  
  End If
  
  
  
  WScript.Echo "Running as a " & process_architecture & " process on a " _ 
  
      & system_architecture & " system."

• Not able to decode mp4 file using latest ffmpeg library : av_decode_video2

  8 février 2017, par suvirai

  I am writing a wrapper code around latest ffmpeg library. I am supplying MP4 files from local system. My problem is that I am unable to get any decoded frames when I use av_decode_video2(). The return value comes out to be negative. I have used av_read_frame() which returns 0. I googled about the problem I am facing but no where could I find the correct explanation. Please give me insight here. Pasting the pseudo code here.

      av_init_packet(avpkt);
  
      picture=av_frame_alloc();
  
      pFrameRGB=av_frame_alloc();
  
      codec = avcodec_find_decoder(CODEC_ID_H264);
  
      c= avcodec_alloc_context3(codec)
  
      avcodec_open2(decoderLibraryData->c, decoderLibraryData->codec, NULL)
  
      FormatContext = avformat_alloc_context();
  
      char *pUrl ="./1.MP4";
  
  
  
      iRet = avformat_open_input(atContext, pUrl, pFmt, NULL);
  
  
  
      if(FormatContext == NULL)
  
      {
  
          printf("could not assign any memory !!!!!!!!! \n");
  
      }
  
  
  
      avformat_find_stream_info(FormatContext, NULL);
  
  
  
  
  
      while(av_read_frame(FormatContext,avpkt) >= 0)
  
      {
  
  
  
        len = avcodec_decode_video2(c, picture, &got_picture,avpkt);
  
  
  
        printf("CODEC MANAGER len %d Frame decompressed %d \n",len,got_picture);
  
  
  
        if (len <= 0) 
  
        {
  
          return ERROR;
  
        }
  
      }
  
  }
  
  
  
  
  
  
  
          if(lastHeight != 0 && lastWidth != 0)
  
          {
  
              if(lastWidth != c->width || lastHeight != c->height )
  
              {
  
                  av_free(buffer);
  
                  buffer = NULL;
  
                  lastWidth = c->width;
  
                  lastHeight = c->height;
  
  
  
              }
  
          }
  
          else
  
          {
  
              lastWidth = c->width;
  
              lastHeight = c->height;
  
          }
  
          decodeFlag = 1;
  
          if(!buffer)
  
          {
  
              int numBytes;
  
              v_mutex_lock(globalCodecLock);
  
              switch(inPixFormat)
  
              {
  
              case RGB:
  
  
  
  
  
                  // Determine required buffer size and allocate buffer
  
                  numBytes=avpicture_get_size(PIX_FMT_RGB24, c->width, c->height);
  
  
  
                  buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
                  avpicture_fill((AVPicture *)pFrameRGB,buffer,PIX_FMT_RGB24,c->width, c->height);
  
  
  
                  if(cntxt)
  
                      sws_freeContext(cntxt);
  
  
  
                  cntxt = sws_getContext(c->width, c->height, c->pix_fmt,
  
                          c->width, c->height, PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL);
  
  
  
                  break;
  
  
  
              }
  
              v_mutex_unlock(globalCodecLock);
  
              if(cntxt == NULL)
  
              {
  
                  printf("sws_getContext error\n");
  
                  return ERROR;
  
              }
  
              }
  
  
  
          {
  
              sws_scale(cntxt, picture->data, picture->linesize, 0, c->height, pFrameRGB->data, pFrameRGB->linesize);
  
              if(rgbBuff)
  
              {
  
  
  
  
  
                  if(c->width <= *width && c->height <= *height)
  
                  {                   
  
                      saveFrame(pFrameRGB, c->width, c->height, rgbBuff,inPixFormat);
  
  
  
                      *width = c->width;
  
                      *height = c->height;
  
                      rs = SUCCESS;
  
                      break;
  
                  }
  
                  else
  
                  {
  
                      rs = VA_LOWBUFFERSIZE;
  
                  }
  
              }
  
              else
  
              {
  
                  rs = VA_LOWBUFFERSIZE;
  
              }
  
          }
  
          if(width)
  
          {
  
              *width = c->width;
  
          }
  
          if(height)
  
          {
  
              *height = c->height;
  
          }
  
          if(rs == VA_LOWBUFFERSIZE)
  
          {
  
              break;
  
          }

  I am getting the return value of av_read_frame as 0 but av_decode_video2 returns value in negative. I am not able to get any clue here.

• aaccoder : Implement Perceptual Noise Substitution for AAC

  15 avril 2015, par Rostislav Pehlivanov

  aaccoder : Implement Perceptual Noise Substitution for AAC
  This commit implements the perceptual noise substitution AAC extension. This is a proof of concept
  
  implementation, and as such, is not enabled by default. This is the fourth revision of this patch,
  
  made after some problems were noted out. Any changes made since the previous revisions have been indicated.
  In order to extend the encoder to use an additional codebook, the array holding each codebook has been
  
  modified with two additional entries - 13 for the NOISE_BT codebook and 12 which has a placeholder function.
  
  The cost system was modified to skip the 12th entry using an array to map the input and outputs it has. It
  
  also does not accept using the 13th codebook for any band which is not marked as containing noise, thereby
  
  restricting its ability to arbitrarily choose it for bands. The use of arrays allows the system to be easily
  
  extended to allow for intensity stereo encoding, which uses additional codebooks.
  The 12th entry in the codebook function array points to a function which stops the execution of the program
  
  by calling an assert with an always ’false’ argument. It was pointed out in an email discussion with
  
  Claudio Freire that having a ’NULL’ entry can result in unexpected behaviour and could be used as
  
  a security hole. There is no danger of this function being called during encoding due to the codebook maps introduced.
  Another change from version 1 of the patch is the addition of an argument to the encoder, ’-aac_pns’ to
  
  enable and disable the PNS. This currently defaults to disable the PNS, as it is experimental.
  
  The switch will be removed in the future, when the algorithm to select noise bands has been improved.
  
  The current algorithm simply compares the energy to the threshold (multiplied by a constant) to determine
  
  noise, however the FFPsyBand structure contains other useful figures to determine which bands carry noise more accurately.
  Some of the sample files provided triggered an assertion when the parameter to tune the threshold was set to
  
  a value of ’2.2’. Claudio Freire reported the problem’s source could be in the range of the scalefactor
  
  indices for noise and advised to measure the minimal index and clip anything above the maximum allowed
  
  value. This has been implemented and all the files which used to trigger the asserion now encode without error.
  The third revision of the problem also removes unneded variabes and comparisons. All of them were
  
  redundant and were of little use for when the PNS implementation would be extended.
  The fourth revision moved the clipping of the noise scalefactors outside the second loop of the two-loop
  
  algorithm in order to prevent their redundant calculations. Also, freq_mult has been changed to a float
  
  variable due to the fact that rounding errors can prove to be a problem at low frequencies.
  
  Considerations were taken whether the entire expression could be evaluated inside the expression
  
  , but in the end it was decided that it would be for the best if just the type of the variable were
  
  to change. Claudio Freire reported the two problems. There is no change of functionality
  
  (except for low sampling frequencies) so the spectral demonstrations at the end of this commit’s message were not updated.
  Finally, the way energy values are converted to scalefactor indices has changed since the first commit,
  
  as per the suggestion of Claudio Freire. This may still have some drawbacks, but unlike the first commit
  
  it works without having redundant offsets and outputs what the decoder expects to have, in terms of the
  
  ranges of the scalefactor indices.
  Some spectral comparisons : https://trac.ffmpeg.org/attachment/wiki/Encode/AAC/Original.png (original),
  
  https://trac.ffmpeg.org/attachment/wiki/Encode/AAC/PNS_NO.png (encoded without PNS),
  
  https://trac.ffmpeg.org/attachment/wiki/Encode/AAC/PNS1.2.png (encoded with PNS, const = 1.2),
  
  https://trac.ffmpeg.org/attachment/wiki/Encode/AAC/Difference1.png (spectral difference).
  
  The constant is the value which multiplies the threshold when it gets compared to the energy, larger
  
  values means more noise will be substituded by PNS values. Example when const = 2.2 :
  
  https://trac.ffmpeg.org/attachment/wiki/Encode/AAC/PNS_2.2.png
  Reviewed-by : Claudio Freire <klaussfreire@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/aaccoder.c
  • [DH] libavcodec/aacenc.c
  • [DH] libavcodec/aacenc.h