• Blackmagic Design

  DisplayVideoFrameSync memory leaks problem

  Posted by Mauro Gattari on January 9, 2012 at 2:59 pm

  Hi,
  I’m trying to write a small C program that outputs frames to the card, but I’m experiencing memory leaks problems.

  The program is very simple, after having enabled video output:
  
deckLinkOutput->EnableVideoOutput(bmdModeHD720p50, bmdVideoOutputFlagDefault);

  It starts outputting frames at 50fps within a loop in which:
  1. create an output video frame:
  
deckLinkOutput->CreateVideoFrame(
1280, 720, 1280*4,
bmdFormat8BitBGRA, bmdFrameFlagDefault,
&videoFrame);

  2. write raw data within the frame (just a pattern of RED or GREEN pixels)
  3. display the frame:
  
deckLinkOutput->DisplayVideoFrameSync(videoFrame);

  4. release the frame:
  
videoFrame->Release();
videoFrame = NULL;


  The program works, but memory consumption grows fast (1MB per second) and I can’t understand why since I think I’m correctly releasing a video frame before creating a new one.

  Can anybody give me any help?
  Thanks!

  Linux Ubuntu 11.10
  DeckLink Studio
  Drivers 9.0

  ——————————————————————–
  This is the whole source code:

  #include "simple.h"

  #include "DeckLinkAPI.h"
  #include
  #include
  #include

  IDeckLink* deckLink = NULL;
  IDeckLinkOutput* deckLinkOutput = NULL;
  IDeckLinkMutableVideoFrame* videoFrame = NULL;

  unsigned char* publicCreateOutputVideoFrame()
  {
  unsigned char* outBytes = NULL;

  HRESULT result = deckLinkOutput->CreateVideoFrame(
  1280, 720, 1280*4,
  bmdFormat8BitBGRA, bmdFrameFlagDefault,
  &videoFrame);

  if (result != S_OK)
  return NULL;

  result = videoFrame->GetBytes((void**)&outBytes);

  return outBytes;
  }

  void publicDisplayVideoFrameSync()
  {
  deckLinkOutput->DisplayVideoFrameSync(videoFrame);
  /* ULONG refCount = */ videoFrame->Release();
  videoFrame = NULL;
  }

  void cleanUp()
  {
  if (deckLinkOutput != NULL)
  {
  deckLinkOutput->DisableVideoOutput();
  deckLinkOutput = NULL;
  }
  if (deckLink != NULL)
  {
  deckLink->Release();
  deckLink = NULL;
  }
  }

  int setUp()
  {
  IDeckLinkIterator* deckLinkIterator;
  HRESULT result;

  deckLinkIterator = CreateDeckLinkIteratorInstance();
  if (deckLinkIterator == NULL)
  {
  fprintf(stderr, "A DeckLink iterator could not be created. The DeckLink drivers may not be installed.n");
  return 1;
  }

  // Get the first DeckLinkCard
  result = deckLinkIterator->Next(&deckLink);
  if (result != S_OK)
  {
  fprintf(stderr, "Could not obtain the IDeckLink interface - result = %08dn", result);
  goto bail;
  }

  result = deckLink->QueryInterface(IID_IDeckLinkOutput, (void**)&deckLinkOutput);
  if (result != S_OK)
  {
  fprintf(stderr, "Could not obtain the IDeckLinkOutput interface - result = %08dn", result);
  goto bail;
  }

  deckLinkOutput->EnableVideoOutput(bmdModeHD720p50, bmdVideoOutputFlagDefault);

  bail:
  deckLinkIterator->Release();
  deckLinkIterator = NULL;

  return 0;
  }

  int main()
  {
  const int fps = 50;
  const int nrOfFramse = fps*60*1; // fps * seconds * minutes

  int i,j;
  unsigned int pattern;

  setUp();

  for(j=0; j nrOfFramse; j++)
  {
  unsigned char* frame = publicCreateOutputVideoFrame();

  if (frame != NULL)
  {
  if ((j/fps)%2==0)
  pattern = 0x0000ff00;
  else
  pattern = 0x000000ff;

  for(i=0; i<1280*720; i++)
  ((unsigned int *)frame)[i] = pattern; // AARRGGBB

  publicDisplayVideoFrameSync();
  }

  usleep(1000000/fps);
  }

  getchar();

  cleanUp();

  return 0;
}


  Mauro Gattari replied 14 years, 6 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Joshua Helling

  January 16, 2012 at 7:28 pm

  Might be best to contact developer@blackmagic-design.com to get help with this issue.

  Sincerely,

  Joshua
  Director of Support
  Blackmagic Design Inc.
• 

  Mauro Gattari

  January 16, 2012 at 7:30 pm

  Yes,
  I already contacted the developers and they acknowledged the issue. They are working on it, I’m waiting for the fix release.
  Thanks

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