hi.
maybe the wrong forum for this question, but maybe zach or theo have some hints.
i wrote my own framegrabber now (based on DSVL) but i am stuck loading the grabbed sample into a opencv image or oftexture.
do you know what data layout IMediaSample::GetPointer() returns?
i can’t find anything on the web.
muchas gracias,
didi
question @ theo:
can you tell us more about the data layout for example for videoInput::getPixels()?
you wrote in the header that it "fills pixels as a BGR (for openCV) or RGB (for opengl) unsigned char array ".
but how does it fill?
R1 G1 B1, R2 G2 B1 … //line 1 - n
horizontal line by horizontal line?
or [RED CHANNEL] [GREEN CHANNEL] [BLUE CHANNEL]?
hey!
the format should be bgrbgrbgr etc
didito: Did you get your DSLV classes working? If so, can you post the source and how to use it with OF?
hey cerubcat.
yes, got it to work. where exactly are you stuck?
i have to check the code …
didito
Well I haven’t tried anything.
I just wanted to see what you did so I can compare it to the videoInput driver theo made and OF uses. Are you using DSLV instead? With our release of tbeta, we’re having some issues with cameras and not being able to access the property dialog sheet that DSLV has, so just wondering if yours would fix some of this.
yes, i am using DSVL and it works very well.
i had to apply some changes to it to compile on current visual studio, make it more safe and stable, easier to debug, etc.
and i implemented my own framegrabber class which is just my very own rewrite of the reactivision source.
i am sorry i can’t give you the whole code, but this is what the major parts look like.
i am still having a problem with my logitech webcam and DSVL. i get a nasty BSOD, i guess the directshow filter driver is somehow unstable.
header:
#ifndef __FRAMEGRABBER_HPP
#define __FRAMEGRABBER_HPP
#include <string>
//put COM header(s) here
#include "util/NoCopy.hpp"
#include "DSVL.h"
/*
* FrameGrabber class
* aka SampleGrabber, Sampler, ...
*
* can open camera stream (directshow)
* can grab current frame
* can be configured by xml strings -> i.e.: std::string config("<?xml version=\"1.0\" encoding=\"UTF-8\"?><dsvl_input><camera friendly_name=\"AVT 1394 camera\" show_format_dialog=\"true\"><pixel_format><RGB32/></pixel_format></camera></dsvl_input>");
*/
class FrameGrabber : public ext::NoCopy
{
public:
FrameGrabber(const std::string& configXmlString);
~FrameGrabber();
bool Start();
void Stop(bool forceToStop = false);
bool Initialize(const std::string& config);
inline bool IsInitialized() const { return isInitialized; }
void ShowSettings() const;
void GetCurrentFrameData(unsigned char* dst);
uint GetNumberOf8BitChannels() const;
uint GetWidth() const;
uint GetHeight() const;
int HasDroppedFrames() const;
private:
void getMediaFormatValues();
bool isInitialized;
DSVL_VideoSource* videoSource;
MemoryBufferHandle mbHandle;
LONGLONG timeStamp;
uint width;
uint height;
PIXELFORMAT format;
uint numBytes;
float fps;
unsigned char* buffer; //opaque handle to pixels, no need to clean up!
std::string config; //for saving and reloading
};
#endif
implementation:
#include <cassert>
#include <cstdio>
#include "FrameGrabber.hpp"
FrameGrabber::FrameGrabber(const std::string& configXmlString)
: isInitialized(false)
, videoSource (0)
, timeStamp (0)
, width (0)
, height (0)
, format (PIXELFORMAT_UNKNOWN)
, numBytes (0)
, fps (0.f)
, buffer (0)
, config (configXmlString)
{
//put your COM initialization routine here!
videoSource = new DSVL_VideoSource();
assert(videoSource);
if (videoSource)
{
if (Initialize(configXmlString))
{
isInitialized = true;
printf("[INFO] DSVL based framegrabber successfully initialized\n");
}
else
{
printf("[ERROR] could NOT initialize DSVL based framegrabber with configstring:\n\t%s\n\n", configXmlString.c_str());
}
}
else
{
printf("[ERROR] could NOT allocate DSVL video source\n");
}
}
FrameGrabber::~FrameGrabber()
{
Stop();
if (videoSource)
{
videoSource->DisableMemoryBuffer();
delete videoSource;
videoSource = 0;
}
//deinitialize COM here, but could be a problem when you construct more than one instance
}
bool FrameGrabber::Initialize(const std::string& config)
{
assert(videoSource);
if (FAILED(videoSource->BuildGraphFromXMLString(const_cast<char*>(config.c_str()))))
{
printf("[ERROR] could NOT build filtergraph\n");
return false;
}
getMediaFormatValues();
return true;
}
void FrameGrabber::getMediaFormatValues()
{
//get current values
LONG w = 0;
LONG h = 0;
double f = 0.0;
PIXELFORMAT pxf;
assert(videoSource);
if (FAILED(videoSource->GetCurrentMediaFormat(&w, &h, &f, &pxf)))
{
printf("[ERROR] could NOT retrieve media format\n");
return;
}
//assign values back to class members
width = w;
height = h;
fps = f;
format = pxf;
printf("[INFO] chosen mediaformat: w=%d h=%d fps=%.f format=%d\n", w, h, f, pxf);
numBytes = 1; //choose grayscale as default
//print info and set number of bytes (components, channels)
switch (pxf)
{
//--- only handle the two most important cases here!! ---
case PIXELFORMAT_RGB24:
numBytes = 3;
printf("[INFO] current pixel format is RGB24\n");
break;
case PIXELFORMAT_RGB32:
numBytes = 4;
printf("[INFO] current pixel format is RGB32\n");
break;
//--------------------------------------
default:
printf("[WARNING] something is wrong with current pixel format\n");
break;
}
}
bool FrameGrabber::Start()
{
if (!isInitialized)
{
printf("[ERROR] could NOT start streaming, NOT initialized yet\n");
return false;
}
//TODO: replace this naive checks
assert(format != PIXELFORMAT_UNKNOWN);
assert(format != PIXELFORMAT_INVALID);
assert(numBytes > 0);
assert(width > 0);
assert(height > 0);
assert(fps > 0);
assert(videoSource);
printf("[INFO] trying to enable sample memory buffer and start querying threads\n");
if (FAILED(videoSource->EnableMemoryBuffer(3))) //here 3 concurrent threads will concurrently query for samples
{
printf("[ERROR] could NOT start streaming\n");
return false;
}
printf("[INFO] trying to start streaming\n");
if (FAILED(videoSource->Run()))
{
printf("[ERROR] could NOT start streaming\n");
return false;
}
return true;
}
void FrameGrabber::Stop(bool forceToStop)
{
printf("[INFO] trying to stop streaming\n");
assert(videoSource);
if (videoSource)
videoSource->Stop(forceToStop);
}
void FrameGrabber::GetCurrentFrameData(unsigned char* dst)
{
assert(videoSource);
assert(videoSource->IsGraphInitialized());
assert(dst);
if (!videoSource || !videoSource->IsGraphInitialized() || !dst)
{
printf("[WARNING] can NOT grab current frame\n");
return;
}
//taken from reactivision source (dslibcamera.cpp), magic values?, better strategy?
DWORD wait_result = videoSource->WaitForNextSample(/*INFINITE*/ (long)(100.f / fps));
/*if (wait_result != WAIT_OBJECT_0)
{
//wait another 1.5 seconds
wait_result = videoSource->WaitForNextSample(1500);
if (wait_result != WAIT_OBJECT_0)
{
//printf("[WARNING] camera stopped\n");
//Stop();
}
}*/
//if (wait_result == WAIT_OBJECT_0)
{
if (SUCCEEDED(videoSource->CheckoutMemoryBuffer(&mbHandle, &buffer)))
{
timeStamp = videoSource->GetCurrentTimestamp();
//printf("LIVE VIDEO TIMESTAMP: %d\n", timeStamp);
//prepare array
::memcpy(dst, buffer, width*height*numBytes); //3 works with RGB24
videoSource->CheckinMemoryBuffer(mbHandle);
buffer = 0;
}
else
{
printf("[WARNING] could NOT checkout membuffer (get sample)\n");
}
}
/*else
{
printf("[WARNING] could NOT aquire camera input\n");
}*/
}
uint FrameGrabber::GetNumberOf8BitChannels() const
{
return numBytes;
}
uint FrameGrabber::GetWidth() const
{
return width;
}
uint FrameGrabber::GetHeight() const
{
return height;
}
void FrameGrabber::ShowSettings() const
{
assert(videoSource);
if (videoSource && videoSource->IsGraphInitialized())
videoSource->ShowFilterProperties();
else
printf("[ERROR] can NOT show settings, NOT initialized yet\n");
}
int FrameGrabber::HasDroppedFrames() const
{
assert(videoSource);
int numDroppedFrames = 0;
numDroppedFrames = videoSource->HasDroppedFrames();
return numDroppedFrames;
}
USAGE:
you need in your TestApp:
FrameGrabber* framegrabber;
colorImage* video; //for processing further, similar like openframeworks opencv addon image
unsigned char* videoData; //to read out of capture device
in
void TestApp::setup()
{
//...
//debug/test strings, could be external xml file
std::string config = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><dsvl_input><camera friendly_name=\"AVT 1394 camera\" show_format_dialog=\"false\"><pixel_format><RGB24 /></pixel_format></camera></dsvl_input>";
framegrabber = new FrameGrabber(config);
assert(framegrabber);
if (framegrabber && framegrabber->IsInitialized())
{
//framegrabber->ShowSettings(); //to force to show settings
framegrabber->Start();
int numChannels = framegrabber->GetNumberOf8BitChannels(); //NOTE: it is very important for the array (char) that it is 8 bit!
if (numChannels == 3) //RGB (RGB24)
{
video = new colorImage(camWidth, camHeight, false, false);
assert(video);
videoData = new unsigned char[camWidth*camHeight*numChannels];
assert(videoData);
ZERO_MEMORY(videoData, camWidth*camHeight*numChannels);
}
else
if (numChannels == 4) //RGBA
{
printf("[ERROR] RGBA format NOT implemented yet\n");
}
else
if (numChannels == 1) //GRAYSCALE, default return value
{
printf("[ERROR] grayscale format NOT implemented yet\n");
}
else //0, ctor default
{
printf("[ERROR] invalid return value for media format / number of channels (%d)\n", numChannels);
}
}
else
{
printf("[FATAL] could NOT allocate or initialize framegrabber\n");
}
}
in
void TestApp::update()
{
assert(framegrabber);
if (framegrabber)
{
assert(videoData);
framegrabber->GetCurrentFrameData(videoData);
assert(video);
if (video)
{
video->setFromNonIppImage(videoData, camWidth, camHeight, camWidth*framegrabber->GetNumberOf8BitChannels());
//video is not ready for drawing!
}
}
}
i hope this helps! tell me if you need the changed DSVL sourcecode (a pity that this software is not mainteined anymore).
cheers, didi
didito, I created a addon for DSVL that seems to work ok and is similar to yours, but a little less complicated/feature rich. One major problem though, occasionally it slows down randomly to low fps. I’m not sure what the hangup is. Did you experience anything similar and is this what you had to customize?
This is my class:
#include "ofxDSVL.h"
ofxDSVL::ofxDSVL()
{
//touchlib
dsvl_vs = NULL;
buffer = NULL;
pbuffer = NULL;
g_Timestamp = _INVALID_TIMESTAMP;
cap_width = 0;
cap_height = 0;
cap_fps = 0.0;
colour = false;
newFrame = false;
bytes = 0;
}
void ofxDSVL::setDeviceID(int id)
{
}
unsigned char * ofxDSVL::getPixels()
{
return pbuffer;
}
int ofxDSVL::getDeviceID()
{
return 0;
}
void ofxDSVL::initDSVL()
{
CoInitialize(NULL);
dsvl_vs = new DSVL_VideoSource();
if(FAILED(dsvl_vs->BuildGraphFromXMLFile("DSVL_config.xml"))){return;}
if(FAILED(dsvl_vs->GetCurrentMediaFormat(&cap_width,&cap_height,&cap_fps,NULL))){return;}
PIXELFORMAT pxf;
if(FAILED(dsvl_vs->GetCurrentMediaFormat(&cap_width,&cap_height,&cap_fps,&pxf))){return;}
//choose byte size. grayscale by default
bytes = 1;
switch (pxf)
{ //only handle the two most important cases here
case PIXELFORMAT_RGB24:
bytes = 3;
printf("[INFO] current pixel format is RGB24\n");
break;
case PIXELFORMAT_RGB32:
bytes = 4;
printf("[INFO] current pixel format is RGB32\n");
break;
}
if(FAILED(dsvl_vs->EnableMemoryBuffer(3))){return;}
// three concurrent threads will concurrently query for samples
if(FAILED(dsvl_vs->Run())){return;}
camWidth = cap_width;
camHeight = cap_height;
fps = (int)cap_fps;
pbuffer = new unsigned char[camWidth*camHeight*bytes];
}
bool ofxDSVL::isFrameNew()
{
//taken from reactivision source (dslibcamera.cpp), magic values?, better strategy?
DWORD wait_result = dsvl_vs->WaitForNextSample(/*INFINITE*/ (long)(1000.0f/fps));
{
if (SUCCEEDED(dsvl_vs->CheckoutMemoryBuffer(&g_mbHandle, &buffer)))
{
g_Timestamp = dsvl_vs->GetCurrentTimestamp();
//prepare array
memcpy(pbuffer, buffer, camWidth*camHeight*bytes);
dsvl_vs->CheckinMemoryBuffer(g_mbHandle);
buffer = 0;
return true;
}
else
{
printf("[WARNING] could NOT checkout membuffer (get sample)\n");
}
}
return false;
}
int ofxDSVL::getCamWidth()
{
return camWidth;
}
int ofxDSVL::getCamHeight()
{
return camHeight;
}
int ofxDSVL::getNumByes()
{
return bytes;
}
void ofxDSVL::showSettingsDialog() {
dsvl_vs->ShowFilterProperties();
}
//Clean up
ofxDSVL::~ofxDSVL()
{
dsvl_vs->Stop();
dsvl_vs->ReleaseGraph();
if (pbuffer!=NULL) delete []pbuffer;
delete dsvl_vs;
}