//
// CommandCam - A command line image grabber
// Copyright (C) 2012 Ted Burke
//
// 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 3 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 (see the file "COPYING").
// If not, see .
//
// Website: http://batchloaf.wordpress.com
//
// To compile using the MSVC++ compiler:
//
// cl CommandCam.cpp ole32.lib strmiids.lib oleaut32.lib
//
// Last modified 21-4-2012
//
// DirectShow header file
#include
// This is a workaround for the missing header
// file qedit.h which seems to be absent from the
// Windows SDK versions 7.0 and 7.1.
// To use the items defined in this dll, the
// DexterLib namespace must be specified.
// The items in question are:
//
// DexterLib::_AMMediaType
// DexterLib::ISampleGrabber
// DexterLib::IID_ISampleGrabber
//
#import "qedit.dll" raw_interfaces_only named_guids
// For some reason, these are not included in the
// DirectShow headers. However, they are exported
// by strmiids.lib, so I'm just declaring them
// here as extern.
EXTERN_C const CLSID CLSID_NullRenderer;
EXTERN_C const CLSID CLSID_SampleGrabber;
// DirectShow objects
HRESULT hr;
ICreateDevEnum *pDevEnum = NULL;
IEnumMoniker *pEnum = NULL;
IMoniker *pMoniker = NULL;
IPropertyBag *pPropBag = NULL;
IGraphBuilder *pGraph = NULL;
ICaptureGraphBuilder2 *pBuilder = NULL;
IBaseFilter *pCap = NULL;
IBaseFilter *pSampleGrabberFilter = NULL;
DexterLib::ISampleGrabber *pSampleGrabber = NULL;
IBaseFilter *pNullRenderer = NULL;
IMediaControl *pMediaControl = NULL;
char *pBuffer = NULL;
void exit_message(const char* error_message, int error)
{
// Print an error message
fprintf(stderr, error_message);
fprintf(stderr, "\n");
// Clean up DirectShow / COM stuff
if (pBuffer != NULL) delete[] pBuffer;
if (pMediaControl != NULL) pMediaControl->Release();
if (pNullRenderer != NULL) pNullRenderer->Release();
if (pSampleGrabber != NULL) pSampleGrabber->Release();
if (pSampleGrabberFilter != NULL)
pSampleGrabberFilter->Release();
if (pCap != NULL) pCap->Release();
if (pBuilder != NULL) pBuilder->Release();
if (pGraph != NULL) pGraph->Release();
if (pPropBag != NULL) pPropBag->Release();
if (pMoniker != NULL) pMoniker->Release();
if (pEnum != NULL) pEnum->Release();
if (pDevEnum != NULL) pDevEnum->Release();
CoUninitialize();
// Exit the program
exit(error);
}
int main(int argc, char **argv)
{
// Capture settings
int snapshot_delay = 2000;
int show_preview_window = 0;
int list_devices = 0;
int device_number = 1;
char device_name[100];
char filename[100];
// Other variables
char char_buffer[100];
// Default device name and output filename
strcpy(device_name, "");
strcpy(filename, "image.bmp");
// Information message
fprintf(stderr, "\n");
fprintf(stderr, "CommandCam Copyright (C) 2012 Ted Burke\n");
fprintf(stderr, "This program comes with ABSOLUTELY NO WARRANTY;\n");
fprintf(stderr, "This is free software, and you are welcome to\n");
fprintf(stderr, "redistribute it under certain conditions;\n");
fprintf(stderr, "See the GNU General Public License v3,\n");
fprintf(stderr, "\n");
fprintf(stderr, "\n");
fprintf(stderr, "http://batchloaf.wordpress.com\n");
fprintf(stderr, "This version 21-4-2012\n");
fprintf(stderr, "\n");
// Parse command line arguments. Available options:
//
// /delay DELAY_IN_MILLISECONDS
// /filename OUTPUT_FILENAME
// /devnum DEVICE_NUMBER
// /devname DEVICE_NAME
// /preview
// /devlist
//
int n = 1;
while (n < argc)
{
// Process next command line argument
if (strcmp(argv[n], "/preview") == 0)
{
// Enable preview window
show_preview_window = 1;
}
else if (strcmp(argv[n], "/devlist") == 0)
{
// Set flag to list devices rather than capture image
list_devices = 1;
}
else if (strcmp(argv[n], "/filename") == 0)
{
// Set output filename to specified string
if (++n < argc) //strcpy(filename, argv[n]);
{
// Copy provided string into char buffer
strcpy(char_buffer, argv[n]);
// Trim inverted commas if present and copy
// provided string into filename char array
if (char_buffer[0] == '"')
{
strncat(filename, char_buffer, strlen(char_buffer)-2);
}
else
{
strcpy(filename, char_buffer);
}
}
else exit_message("Error: no filename specified", 1);
}
else if (strcmp(argv[n], "/delay") == 0)
{
// Set snapshot delay to specified value
if (++n < argc) snapshot_delay = atoi(argv[n]);
else exit_message("Error: invalid delay specified", 1);
if (snapshot_delay <= 0)
exit_message("Error: invalid delay specified", 1);
}
else if (strcmp(argv[n], "/devnum") == 0)
{
// Set device number to specified value
if (++n < argc) device_number = atoi(argv[n]);
else exit_message("Error: invalid device number", 1);
if (device_number <= 0)
exit_message("Error: invalid device number", 1);
}
else if (strcmp(argv[n], "/devname") == 0)
{
// Set device number to specified value
if (++n < argc)
{
// Copy device name into char buffer
strcpy(char_buffer, argv[n]);
// Trim inverted commas if present and copy
// provided string into device_name
if (char_buffer[0] == '"')
{
strncat(device_name, char_buffer, strlen(char_buffer)-2);
}
else
{
strcpy(device_name, char_buffer);
}
// Remember to choose by name rather than number
device_number = 0;
}
else exit_message("Error: invalid device name", 1);
}
else
{
// Unknown command line argument
fprintf(stderr, "Unrecognised option: %s\n", argv[n]);
exit_message("", 1);
}
// Increment command line argument counter
n++;
}
// Intialise COM
hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
if (hr != S_OK)
exit_message("Could not initialise COM", 1);
// Create filter graph
hr = CoCreateInstance(CLSID_FilterGraph, NULL,
CLSCTX_INPROC_SERVER, IID_IGraphBuilder,
(void**)&pGraph);
if (hr != S_OK)
exit_message("Could not create filter graph", 1);
// Create capture graph builder.
hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL,
CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2,
(void **)&pBuilder);
if (hr != S_OK)
exit_message("Could not create capture graph builder", 1);
// Attach capture graph builder to graph
hr = pBuilder->SetFiltergraph(pGraph);
if (hr != S_OK)
exit_message("Could not attach capture graph builder to graph", 1);
// Create system device enumerator
hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL,
CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pDevEnum));
if (hr != S_OK)
exit_message("Could not crerate system device enumerator", 1);
// Video input device enumerator
hr = pDevEnum->CreateClassEnumerator(
CLSID_VideoInputDeviceCategory, &pEnum, 0);
if (hr != S_OK)
exit_message("No video devices found", 1);
// If the user has included the "/list" command line
// argument, just list available devices, then exit.
if (list_devices != 0)
{
fprintf(stderr, "Available capture devices:\n");
n = 0;
while(1)
{
// Find next device
hr = pEnum->Next(1, &pMoniker, NULL);
if (hr == S_OK)
{
// Increment device counter
n++;
// Get device name
hr = pMoniker->BindToStorage(0, 0, IID_PPV_ARGS(&pPropBag));
VARIANT var;
VariantInit(&var);
hr = pPropBag->Read(L"FriendlyName", &var, 0);
fprintf(stderr, " %d. %ls\n", n, var.bstrVal);
VariantClear(&var);
}
else
{
// Finished listing device, so exit program
if (n == 0) exit_message("No devices found", 0);
else exit_message("", 0);
}
}
}
// Get moniker for specified video input device,
// or for the first device if no device number
// was specified.
VARIANT var;
n = 0;
while(1)
{
// Access next device
hr = pEnum->Next(1, &pMoniker, NULL);
if (hr == S_OK)
{
n++; // increment device count
}
else
{
if (device_number == 0)
{
fprintf(stderr,
"Video capture device %s not found\n",
device_name);
}
else
{
fprintf(stderr,
"Video capture device %d not found\n",
device_number);
}
exit_message("", 1);
}
// If device was specified by name rather than number...
if (device_number == 0)
{
// Get video input device name
hr = pMoniker->BindToStorage(0, 0, IID_PPV_ARGS(&pPropBag));
if (hr == S_OK)
{
// Get current device name
VariantInit(&var);
hr = pPropBag->Read(L"FriendlyName", &var, 0);
// Convert to a normal C string, i.e. char*
sprintf(char_buffer, "%ls", var.bstrVal);
VariantClear(&var);
pPropBag->Release();
pPropBag = NULL;
// Exit loop if current device name matched devname
if (strcmp(device_name, char_buffer) == 0) break;
}
else
{
exit_message("Error getting device names", 1);
}
}
else if (n >= device_number) break;
}
// Get video input device name
hr = pMoniker->BindToStorage(0, 0, IID_PPV_ARGS(&pPropBag));
VariantInit(&var);
hr = pPropBag->Read(L"FriendlyName", &var, 0);
fprintf(stderr, "Capture device: %ls\n", var.bstrVal);
VariantClear(&var);
// Create capture filter and add to graph
hr = pMoniker->BindToObject(0, 0,
IID_IBaseFilter, (void**)&pCap);
if (hr != S_OK) exit_message("Could not create capture filter", 1);
// Add capture filter to graph
hr = pGraph->AddFilter(pCap, L"Capture Filter");
if (hr != S_OK) exit_message("Could not add capture filter to graph", 1);
// Create sample grabber filter
hr = CoCreateInstance(CLSID_SampleGrabber, NULL,
CLSCTX_INPROC_SERVER, IID_IBaseFilter,
(void**)&pSampleGrabberFilter);
if (hr != S_OK)
exit_message("Could not create Sample Grabber filter", 1);
// Query the ISampleGrabber interface of the sample grabber filter
hr = pSampleGrabberFilter->QueryInterface(
DexterLib::IID_ISampleGrabber, (void**)&pSampleGrabber);
if (hr != S_OK)
exit_message("Could not get ISampleGrabber interface to sample grabber filter", 1);
// Enable sample buffering in the sample grabber filter
hr = pSampleGrabber->SetBufferSamples(TRUE);
if (hr != S_OK)
exit_message("Could not enable sample buffering in the sample grabber", 1);
// Set media type in sample grabber filter
AM_MEDIA_TYPE mt;
ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));
mt.majortype = MEDIATYPE_Video;
mt.subtype = MEDIASUBTYPE_RGB24;
hr = pSampleGrabber->SetMediaType((DexterLib::_AMMediaType *)&mt);
if (hr != S_OK)
exit_message("Could not set media type in sample grabber", 1);
// Add sample grabber filter to filter graph
hr = pGraph->AddFilter(pSampleGrabberFilter, L"SampleGrab");
if (hr != S_OK)
exit_message("Could not add Sample Grabber to filter graph", 1);
// Create Null Renderer filter
hr = CoCreateInstance(CLSID_NullRenderer, NULL,
CLSCTX_INPROC_SERVER, IID_IBaseFilter,
(void**)&pNullRenderer);
if (hr != S_OK)
exit_message("Could not create Null Renderer filter", 1);
// Add Null Renderer filter to filter graph
hr = pGraph->AddFilter(pNullRenderer, L"NullRender");
if (hr != S_OK)
exit_message("Could not add Null Renderer to filter graph", 1);
// Connect up the filter graph's capture stream
hr = pBuilder->RenderStream(
&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video,
pCap, pSampleGrabberFilter, pNullRenderer);
if (hr != S_OK)
exit_message("Could not render capture video stream", 1);
// Connect up the filter graph's preview stream
if (show_preview_window > 0)
{
hr = pBuilder->RenderStream(
&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video,
pCap, NULL, NULL);
if (hr != S_OK && hr != VFW_S_NOPREVIEWPIN)
exit_message("Could not render preview video stream", 1);
}
// Get media control interfaces to graph builder object
hr = pGraph->QueryInterface(IID_IMediaControl,
(void**)&pMediaControl);
if (hr != S_OK) exit_message("Could not get media control interface", 1);
// Run graph
while(1)
{
hr = pMediaControl->Run();
// Hopefully, the return value was S_OK or S_FALSE
if (hr == S_OK) break; // graph is now running
if (hr == S_FALSE) continue; // graph still preparing to run
// If the Run function returned something else,
// there must be a problem
fprintf(stderr, "Error: %u\n", hr);
exit_message("Could not run filter graph", 1);
}
// Wait for specified time delay (if any)
Sleep(snapshot_delay);
// Grab a sample
// First, find the required buffer size
long buffer_size = 0;
while(1)
{
// Passing in a NULL pointer signals that we're just checking
// the required buffer size; not looking for actual data yet.
hr = pSampleGrabber->GetCurrentBuffer(&buffer_size, NULL);
// Keep trying until buffer_size is set to non-zero value.
if (hr == S_OK && buffer_size != 0) break;
// If the return value isn't S_OK or VFW_E_WRONG_STATE
// then something has gone wrong. VFW_E_WRONG_STATE just
// means that the filter graph is still starting up and
// no data has arrived yet in the sample grabber filter.
if (hr != S_OK && hr != VFW_E_WRONG_STATE)
exit_message("Could not get buffer size", 1);
}
// Stop the graph
pMediaControl->Stop();
// Allocate buffer for image
pBuffer = new char[buffer_size];
if (!pBuffer)
exit_message("Could not allocate data buffer for image", 1);
// Retrieve image data from sample grabber buffer
hr = pSampleGrabber->GetCurrentBuffer(
&buffer_size, (long*)pBuffer);
if (hr != S_OK)
exit_message("Could not get buffer data from sample grabber", 1);
// Get the media type from the sample grabber filter
hr = pSampleGrabber->GetConnectedMediaType(
(DexterLib::_AMMediaType *)&mt);
if (hr != S_OK) exit_message("Could not get media type", 1);
// Retrieve format information
VIDEOINFOHEADER *pVih = NULL;
if ((mt.formattype == FORMAT_VideoInfo) &&
(mt.cbFormat >= sizeof(VIDEOINFOHEADER)) &&
(mt.pbFormat != NULL))
{
// Get video info header structure from media type
pVih = (VIDEOINFOHEADER*)mt.pbFormat;
// Print the resolution of the captured image
fprintf(stderr, "Capture resolution: %dx%d\n",
pVih->bmiHeader.biWidth,
pVih->bmiHeader.biHeight);
// Create bitmap structure
long cbBitmapInfoSize = mt.cbFormat - SIZE_PREHEADER;
BITMAPFILEHEADER bfh;
ZeroMemory(&bfh, sizeof(bfh));
bfh.bfType = 'MB'; // Little-endian for "BM".
bfh.bfSize = sizeof(bfh) + buffer_size + cbBitmapInfoSize;
bfh.bfOffBits = sizeof(BITMAPFILEHEADER) + cbBitmapInfoSize;
// Open output file
HANDLE hf = CreateFile(filename, GENERIC_WRITE,
FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, 0, NULL);
if (hf == INVALID_HANDLE_VALUE)
exit_message("Error opening output file", 1);
// Write the file header.
DWORD dwWritten = 0;
WriteFile(hf, &bfh, sizeof(bfh), &dwWritten, NULL);
WriteFile(hf, HEADER(pVih),
cbBitmapInfoSize, &dwWritten, NULL);
// Write pixel data to file
WriteFile(hf, pBuffer, buffer_size, &dwWritten, NULL);
CloseHandle(hf);
}
else
{
exit_message("Wrong media type", 1);
}
// Free the format block
if (mt.cbFormat != 0)
{
CoTaskMemFree((PVOID)mt.pbFormat);
mt.cbFormat = 0;
mt.pbFormat = NULL;
}
if (mt.pUnk != NULL)
{
// pUnk should not be used.
mt.pUnk->Release();
mt.pUnk = NULL;
}
// Clean up and exit
fprintf(stderr, "Captured image to %s", filename);
exit_message("", 0);
}