akvirtualcamera/share/examples/output_windows.c

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2021-05-28 21:04:24 +00:00
/* akvirtualcamera, virtual camera for Mac and Windows.
* Copyright (C) 2021 Gonzalo Exequiel Pedone
*
* akvirtualcamera 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.
*
* akvirtualcamera 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 akvirtualcamera. If not, see <http://www.gnu.org/licenses/>.
*
* Web-Site: http://github.com/webcamoid/akvirtualcamera
*/
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
/* For the sake of simplicity, the program won't print anything to the terminal,
* or do any validation check, you are adviced the check every single value
* returned by each function.
* This program shows the very minimum code required to write frames to the
* plugin.
*/
// We'll assume this is a valid akvcam output device.
#define VIDEO_OUTPUT "AkVCamVideoDevice0"
// Send frames for about 30 seconds in a 30 FPS stream.
#define FPS 30
#define DURATION_SECONDS 30
#define N_FRAMES (FPS * DURATION_SECONDS)
struct StreamProcess
{
HANDLE stdinReadPipe;
HANDLE stdinWritePipe;
SECURITY_ATTRIBUTES pipeAttributes;
STARTUPINFOA startupInfo;
PROCESS_INFORMATION procInfo;
};
int main()
{
// Set the parameters of the stream.
const char cmd[1024];
const char format[] = "RGB24";
int width = 640;
int height = 480;
snprintf(cmd,
1024,
"AkVCamManager stream %s %s %d %d",
VIDEO_OUTPUT,
format,
width,
height);
// Get the handles to the standard input and standard output.
struct StreamProcess streamProc;
memset(&streamProc, 0, sizeof(struct StreamProcess));
streamProc.stdinReadPipe = NULL;
streamProc.stdinWritePipe = NULL;
memset(&streamProc.pipeAttributes, 0, sizeof(struct SECURITY_ATTRIBUTES));
streamProc.pipeAttributes.nLength = sizeof(struct SECURITY_ATTRIBUTES);
streamProc.pipeAttributes.bInheritHandle = true;
streamProc.pipeAttributes.lpSecurityDescriptor = NULL;
CreatePipe(&streamProc.stdinReadPipe,
&streamProc.stdinWritePipe,
&streamProc.pipeAttributes,
0);
SetHandleInformation(streamProc.stdinWritePipe,
HANDLE_FLAG_INHERIT,
0);
struct STARTUPINFOA startupInfo;
memset(&startupInfo, 0, sizeof(struct STARTUPINFOA));
startupInfo.cb = sizeof(struct STARTUPINFOA);
startupInfo.hStdInput = streamProc.stdinReadPipe;
startupInfo.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
startupInfo.wShowWindow = SW_HIDE;
struct PROCESS_INFORMATION procInfo;
memset(&procInfo, 0, sizeof(struct PROCESS_INFORMATION));
// Start the stream.
CreateProcessA(NULL,
cmd,
NULL,
NULL,
true,
0,
NULL,
NULL,
&startupInfo,
&procInfo);
// Allocate the frame buffer.
size_t buffer_size = 3 * width;
char *buffer = malloc(buffer_size);
// Generate some random noise frames.
srand(time(0));
for (int i = 0; i < N_FRAMES; i++) {
// Write the frame line by line.
for (int y = 0; y < height; y++) {
for (size_t byte = 0; byte < buffer_size; byte++)
buffer[byte] = rand() & 0xff;
// Write the frame data to the buffer.
DWORD bytesWritten = 0;
WriteFile(streamProc.stdinWritePipe,
buffer,
DWORD(buffer_size),
&bytesWritten,
NULL);
}
Sleep(1000 / FPS);
}
// Release the frame buffer.
free(buffer);
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// Close the standard input and standard output handles.
CloseHandle(streamProc.stdinWritePipe);
CloseHandle(streamProc.stdinReadPipe);
// Stop the stream.
WaitForSingleObject(streamProc.procInfo.hProcess, INFINITE);
CloseHandle(streamProc.procInfo.hProcess);
CloseHandle(streamProc.procInfo.hThread);
return 0;
}