zoneminder/src/zm_libvlc_camera.cpp

/*
 * ZoneMinder Libvlc Camera Class Implementation, $Date$, $Revision$
 * Copyright (C) 2001-2008 Philip Coombes
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/  

#include "zm.h"
#include "zm_libvlc_camera.h"

#if HAVE_LIBVLC

// Do all the buffer checking work here to avoid unnecessary locking 
void* LibvlcLockBuffer(void* opaque, void** planes)
{
  LibvlcPrivateData* data = (LibvlcPrivateData*)opaque;
  data->mutex.lock();
  
  uint8_t* buffer = data->buffer;
  data->buffer = data->prevBuffer;
  data->prevBuffer = buffer;
  
  *planes = data->buffer;
  return NULL;
}

void LibvlcUnlockBuffer(void* opaque, void* picture, void *const *planes)
{
  LibvlcPrivateData* data = (LibvlcPrivateData*)opaque;
  
  bool newFrame = false;
  for(uint32_t i = 0; i < data->bufferSize; i++)
  {
    if(data->buffer[i] != data->prevBuffer[i])
    {
      newFrame = true;
      break;
    }
  }
  data->mutex.unlock();
  
  time_t now;
  time(&now);
  // Return frames slightly faster than 1fps (if time() supports greater than one second resolution)
  if(newFrame || difftime(now, data->prevTime) >= 0.8)
  {
    data->prevTime = now;
    data->newImage.updateValueSignal(true);
  }
}

LibvlcCamera::LibvlcCamera( int p_id, const std::string &p_path, const std::string &p_method, const std::string &p_options, int p_width, int p_height, int p_colours, int p_brightness, int p_contrast, int p_hue, int p_colour, bool p_capture ) :
  Camera( p_id, LIBVLC_SRC, p_width, p_height, p_colours, ZM_SUBPIX_ORDER_DEFAULT_FOR_COLOUR(p_colours), p_brightness, p_contrast, p_hue, p_colour, p_capture ),
  mPath( p_path ),
  mMethod( p_method ),
  mOptions( p_options )
{  
  mLibvlcInstance = NULL;
  mLibvlcMedia = NULL;
  mLibvlcMediaPlayer = NULL;
  mLibvlcData.buffer = NULL;
  mLibvlcData.prevBuffer = NULL;

  /* Has to be located inside the constructor so other components such as zma will receive correct colours and subpixel order */
  if(colours == ZM_COLOUR_RGB32) {
    subpixelorder = ZM_SUBPIX_ORDER_BGRA;
    mTargetChroma = "RV32";
    mBpp = 4;
  } else if(colours == ZM_COLOUR_RGB24) {
    subpixelorder = ZM_SUBPIX_ORDER_BGR;
    mTargetChroma = "RV24";
    mBpp = 3;
  } else if(colours == ZM_COLOUR_GRAY8) {
    subpixelorder = ZM_SUBPIX_ORDER_NONE;
    mTargetChroma = "GREY";
    mBpp = 1;
  } else {
    Panic("Unexpected colours: %d",colours);
  }
  
  if ( capture )
  {
    Initialise();
  }
}

LibvlcCamera::~LibvlcCamera()
{
  if ( capture )
  {
    Terminate();
  }
  if(mLibvlcMediaPlayer != NULL)
  {
    libvlc_media_player_release(mLibvlcMediaPlayer);
    mLibvlcMediaPlayer = NULL;
  }
  if(mLibvlcMedia != NULL)
  {
    libvlc_media_release(mLibvlcMedia);
    mLibvlcMedia = NULL;
  }
  if(mLibvlcInstance != NULL)
  {
    libvlc_release(mLibvlcInstance);
    mLibvlcInstance = NULL;
  }
  if (mOptArgV != NULL)
  {
    delete[] mOptArgV;
  }
}

void LibvlcCamera::Initialise()
{
}

void LibvlcCamera::Terminate()
{
  libvlc_media_player_stop(mLibvlcMediaPlayer);
  if(mLibvlcData.buffer != NULL)
  {
    zm_freealigned(mLibvlcData.buffer);
  }
  if(mLibvlcData.prevBuffer != NULL)
  {
    zm_freealigned(mLibvlcData.prevBuffer);
  }
}

int LibvlcCamera::PrimeCapture()
{
  Info("Priming capture from %s", mPath.c_str());
  
  StringVector opVect = split(Options(), ",");
  
  // Set transport method as specified by method field, rtpUni is default
  if ( Method() == "rtpMulti" )
    opVect.push_back("--rtsp-mcast");
  else if ( Method() == "rtpRtsp" )
    opVect.push_back("--rtsp-tcp");
  else if ( Method() == "rtpRtspHttp" )
    opVect.push_back("--rtsp-http");

  if (opVect.size() > 0) 
  {
    mOptArgV = new char*[opVect.size()];
    Debug(2, "Number of Options: %d",opVect.size());
    for (size_t i=0; i< opVect.size(); i++) {
      opVect[i] = trimSpaces(opVect[i]);
      mOptArgV[i] = (char *)opVect[i].c_str();
      Debug(2, "set option %d to '%s'", i,  opVect[i].c_str());
    }
  }

  mLibvlcInstance = libvlc_new (opVect.size(), (const char* const*)mOptArgV);
  if(mLibvlcInstance == NULL)
    Fatal("Unable to create libvlc instance due to: %s", libvlc_errmsg());
   
  mLibvlcMedia = libvlc_media_new_location(mLibvlcInstance, mPath.c_str());
  if(mLibvlcMedia == NULL)
    Fatal("Unable to open input %s due to: %s", mPath.c_str(), libvlc_errmsg());
  
  mLibvlcMediaPlayer = libvlc_media_player_new_from_media(mLibvlcMedia);
  if(mLibvlcMediaPlayer == NULL)
    Fatal("Unable to create player for %s due to: %s", mPath.c_str(), libvlc_errmsg());

  libvlc_video_set_format(mLibvlcMediaPlayer, mTargetChroma.c_str(), width, height, width * mBpp);
  libvlc_video_set_callbacks(mLibvlcMediaPlayer, &LibvlcLockBuffer, &LibvlcUnlockBuffer, NULL, &mLibvlcData);

  mLibvlcData.bufferSize = width * height * mBpp;
  // Libvlc wants 32 byte alignment for images (should in theory do this for all image lines)
  mLibvlcData.buffer = (uint8_t*)zm_mallocaligned(32, mLibvlcData.bufferSize);
  mLibvlcData.prevBuffer = (uint8_t*)zm_mallocaligned(32, mLibvlcData.bufferSize);
  
  mLibvlcData.newImage.setValueImmediate(false);

  libvlc_media_player_play(mLibvlcMediaPlayer);
  
  return(0);
}

int LibvlcCamera::PreCapture()
{  
  return(0);
}

// Should not return -1 as cancels capture. Always wait for image if available.
int LibvlcCamera::Capture( Image &image )
{   
  while(!mLibvlcData.newImage.getValueImmediate())
    mLibvlcData.newImage.getUpdatedValue(1);

  mLibvlcData.mutex.lock();
  image.Assign(width, height, colours, subpixelorder, mLibvlcData.buffer, width * height * mBpp);
  mLibvlcData.newImage.setValueImmediate(false);
  mLibvlcData.mutex.unlock();
  
  return (0);
}

int LibvlcCamera::PostCapture()
{
  return(0);
}

#endif // HAVE_LIBVLC