void SSRVideoStreamWriter::NextFrame() {
// make sure all changes are visible
std::atomic_thread_fence(std::memory_order_release);
// go to the next frame
GLInjectHeader *header = GetGLInjectHeader();
header->ring_buffer_write_pos = (header->ring_buffer_write_pos + 1) % (GLINJECT_RING_BUFFER_SIZE * 2);
std::atomic_thread_fence(std::memory_order_release);
}
void SSRVideoStreamReader::GetCurrentSize(unsigned int* width, unsigned int* height) {
GLInjectHeader *header = GetGLInjectHeader();
std::atomic_thread_fence(std::memory_order_acquire);
if(header->identifier != GLINJECT_IDENTIFIER) {
*width = 0;
*height = 0;
return;
}
std::atomic_thread_fence(std::memory_order_acquire);
*width = header->current_width;
*height = header->current_height;
}
void SSRVideoStreamWriter::UpdateSize(unsigned int width, unsigned int height, int stride) {
if(m_width != width || m_height != height) {
GLINJECT_PRINT("[" << m_filename_main << "] frame size = " << width << "x" << height << ".");
m_width = width;
m_height = height;
GLInjectHeader *header = GetGLInjectHeader();
header->current_width = m_width;
header->current_height = m_height;
std::atomic_thread_fence(std::memory_order_release);
}
m_stride = stride;
}
void SSRVideoStreamReader::NextFrame() {
// tell the compiler that it should read the entire frame before continuing
// This is essentially a 'load-store' fence, which should be provided by both acquire and release fences,
// but I'm not completely sure so let's use both just to be safe.
std::atomic_thread_fence(std::memory_order_acq_rel);
// go to the next frame
GLInjectHeader *header = GetGLInjectHeader();
header->ring_buffer_read_pos = (header->ring_buffer_read_pos + 1) % (GLINJECT_RING_BUFFER_SIZE * 2);
std::atomic_thread_fence(std::memory_order_release);
}
double SSRVideoStreamReader::GetFPS() {
GLInjectHeader *header = GetGLInjectHeader();
int64_t timestamp = hrt_time_micro();
std::atomic_thread_fence(std::memory_order_acquire);
uint32_t frame_counter = header->frame_counter;
unsigned int time = timestamp - m_fps_last_timestamp;
if(time > 500000) {
unsigned int frames = frame_counter - m_fps_last_counter;
m_fps_last_timestamp = timestamp;
m_fps_last_counter = frame_counter;
m_fps_current = (double) frames / ((double) time * 1.0e-6);
}
return m_fps_current;
}
void SSRVideoStreamReader::Init() {
Logger::LogInfo("[SSRVideoStreamReader::Init] " + Logger::tr("Created video stream reader."));
// open main file
m_fd_main = open(m_filename_main.c_str(), O_RDWR | O_CLOEXEC);
if(m_fd_main == -1) {
Logger::LogError("[SSRVideoStreamReader::Init] " + Logger::tr("Error: Can't open video stream file!"));
throw SSRStreamException();
}
// resize main file
m_mmap_size_main = (sizeof(GLInjectHeader) + GLINJECT_RING_BUFFER_SIZE * sizeof(GLInjectFrameInfo) + m_page_size - 1) / m_page_size * m_page_size;
if(ftruncate(m_fd_main, m_mmap_size_main) == -1) {
Logger::LogError("[SSRVideoStreamReader::Init] " + Logger::tr("Error: Can't resize video stream file!"));
throw SSRStreamException();
}
// map main file
m_mmap_ptr_main = mmap(NULL, m_mmap_size_main, PROT_READ | PROT_WRITE, MAP_SHARED, m_fd_main, 0);
if(m_mmap_ptr_main == MAP_FAILED) {
Logger::LogError("[SSRVideoStreamReader::Init] " + Logger::tr("Error: Can't memory-map video stream file!"));
throw SSRStreamException();
}
// open frame files
for(unsigned int i = 0; i < GLINJECT_RING_BUFFER_SIZE; ++i) {
FrameData &fd = m_frame_data[i];
fd.m_fd_frame = open(fd.m_filename_frame.c_str(), O_RDWR | O_CLOEXEC);
if(fd.m_fd_frame == -1) {
Logger::LogError("[SSRVideoStreamReader::Init] " + Logger::tr("Error: Can't open video frame file!"));
throw SSRStreamException();
}
}
// initialize header
GLInjectHeader *header = GetGLInjectHeader();
header->capture_flags = 0;
header->capture_target_fps = 0;
std::atomic_thread_fence(std::memory_order_release);
// initialize frame counter
std::atomic_thread_fence(std::memory_order_acquire);
m_fps_last_timestamp = hrt_time_micro();
m_fps_last_counter = header->frame_counter;
m_fps_current = 0.0;
}
void* SSRVideoStreamReader::GetFrame(int64_t* timestamp, unsigned int* width, unsigned int* height, int* stride) {
// make sure that the stream has been initialized
GLInjectHeader *header = GetGLInjectHeader();
std::atomic_thread_fence(std::memory_order_acquire);
if(header->identifier != GLINJECT_IDENTIFIER)
return NULL;
// make sure that at least one frame is available
std::atomic_thread_fence(std::memory_order_acquire);
unsigned int read_pos = header->ring_buffer_read_pos;
unsigned int write_pos = header->ring_buffer_write_pos;
if(read_pos == write_pos)
return NULL;
// read frame info
GLInjectFrameInfo *frameinfo = GetGLInjectFrameInfo(read_pos % GLINJECT_RING_BUFFER_SIZE);
std::atomic_thread_fence(std::memory_order_acquire);
*timestamp = frameinfo->timestamp;
*width = frameinfo->width;
*height = frameinfo->height;
*stride = frameinfo->stride;
// verify the size (should never happen unless someone is messing with the files)
if(*width < 2 || *height < 2)
return NULL;
if(*width > 10000 || *height > 10000)
return NULL;
if(abs(*stride) > 10000 * 4)
return NULL;
// read frame
FrameData &fd = m_frame_data[read_pos % GLINJECT_RING_BUFFER_SIZE];
size_t required_size = (size_t) abs(*stride) * (size_t) *height;
if(required_size > fd.m_mmap_size_frame) {
// calculate new size
required_size = (required_size + m_page_size - 1) / m_page_size * m_page_size;
// unmap frame file
if(fd.m_mmap_ptr_frame != MAP_FAILED) {
munmap(fd.m_mmap_ptr_frame, fd.m_mmap_size_frame);
fd.m_mmap_ptr_frame = MAP_FAILED;
fd.m_mmap_size_frame = 0;
}
// check frame file size
{
struct stat statinfo;
if(fstat(fd.m_fd_frame, &statinfo) == -1 || (size_t) statinfo.st_size < required_size) {
Logger::LogError("[SSRVideoStreamReader::GetFrame] " + Logger::tr("Error: Size of video frame file is incorrect!"));
throw SSRStreamException();
}
required_size = statinfo.st_size / m_page_size * m_page_size;
}
// map frame file
fd.m_mmap_ptr_frame = mmap(NULL, required_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd.m_fd_frame, 0);
if(fd.m_mmap_ptr_frame == MAP_FAILED) {
Logger::LogError("[SSRVideoStreamReader::GetFrame] " + Logger::tr("Error: Can't memory-map video frame file!"));
throw SSRStreamException();
}
fd.m_mmap_size_frame = required_size;
}
return fd.m_mmap_ptr_frame;
}
void SSRVideoStreamReader::Clear() {
GLInjectHeader *header = GetGLInjectHeader();
std::atomic_thread_fence(std::memory_order_acquire);
header->ring_buffer_read_pos = header->ring_buffer_write_pos;
std::atomic_thread_fence(std::memory_order_release);
}
void SSRVideoStreamReader::ChangeCaptureParameters(unsigned int flags, unsigned int target_fps) {
GLInjectHeader *header = GetGLInjectHeader();
header->capture_flags = flags;
header->capture_target_fps = target_fps;
std::atomic_thread_fence(std::memory_order_release);
}
void SSRVideoStreamWriter::Init() {
GLINJECT_PRINT("[" << m_filename_main << "] Created video stream.");
bool relax_permissions = false;
{
char *ssr_stream_relax_permissions = getenv("SSR_STREAM_RELAX_PERMISSIONS");
if(ssr_stream_relax_permissions != NULL && atoi(ssr_stream_relax_permissions) > 0) {
GLINJECT_PRINT("Warning: Using relaxed file permissions, any user on this machine will be able to read or manipulate the stream!");
relax_permissions = true;
}
}
// create channel directory (permissions may be wrong because of umask, fix this later)
if(mkdir(m_channel_directory.c_str(), (relax_permissions)? 0777 : 0700) == -1) {
if(errno != EEXIST) { // does the directory already exist?
GLINJECT_PRINT("Error: Can't create channel directory!");
throw SSRStreamException();
}
}
// check ownership and permissions
struct stat statinfo;
if(lstat(m_channel_directory.c_str(), &statinfo) == -1) {
GLINJECT_PRINT("Error: Can't stat channel directory!");
throw SSRStreamException();
}
if(!S_ISDIR(statinfo.st_mode) || S_ISLNK(statinfo.st_mode)) {
GLINJECT_PRINT("Error: Channel directory is not a regular directory!");
throw SSRStreamException();
}
if(statinfo.st_uid == geteuid()) {
if(chmod(m_channel_directory.c_str(), (relax_permissions)? 0777 : 0700) == -1) {
GLINJECT_PRINT("Error: Can't set channel directory mode!");
throw SSRStreamException();
}
} else {
if(!relax_permissions) {
GLINJECT_PRINT("Error: Channel directory is owned by a different user! "
"Choose a different channel name, or enable relaxed file permissions to use it anyway.");
throw SSRStreamException();
}
}
// open frame files
for(unsigned int i = 0; i < GLINJECT_RING_BUFFER_SIZE; ++i) {
FrameData &fd = m_frame_data[i];
fd.m_fd_frame = open(fd.m_filename_frame.c_str(), O_RDWR | O_CREAT | O_EXCL | O_CLOEXEC, (relax_permissions)? 0666 : 0600);
if(fd.m_fd_frame == -1) {
GLINJECT_PRINT("Error: Can't open video frame file!");
throw SSRStreamException();
}
if(fchmod(fd.m_fd_frame, (relax_permissions)? 0666 : 0600) == -1) {
GLINJECT_PRINT("Error: Can't set video frame file mode!");
throw SSRStreamException();
}
}
// open main file
m_fd_main = open(m_filename_main.c_str(), O_RDWR | O_CREAT | O_EXCL | O_CLOEXEC, (relax_permissions)? 0666 : 0600);
if(m_fd_main == -1) {
GLINJECT_PRINT("Error: Can't open video stream file!");
throw SSRStreamException();
}
if(fchmod(m_fd_main, (relax_permissions)? 0666 : 0600) == -1) {
GLINJECT_PRINT("Error: Can't set video stream file mode!");
throw SSRStreamException();
}
// resize main file
m_mmap_size_main = (sizeof(GLInjectHeader) + GLINJECT_RING_BUFFER_SIZE * sizeof(GLInjectFrameInfo) + m_page_size - 1) / m_page_size * m_page_size;
if(ftruncate(m_fd_main, m_mmap_size_main) == -1) {
GLINJECT_PRINT("Error: Can't resize video stream file!");
throw SSRStreamException();
}
// map main file
m_mmap_ptr_main = mmap(NULL, m_mmap_size_main, PROT_READ | PROT_WRITE, MAP_SHARED, m_fd_main, 0);
if(m_mmap_ptr_main == MAP_FAILED) {
GLINJECT_PRINT("Error: Can't memory-map video stream file!");
throw SSRStreamException();
}
// initialize header
GLInjectHeader *header = GetGLInjectHeader();
header->identifier = 0; // will be set later
header->ring_buffer_read_pos = 0;
header->ring_buffer_write_pos = 0;
header->current_width = m_width;
header->current_height = m_height;
header->frame_counter = 0;
// initialize frame info
for(unsigned int i = 0; i < GLINJECT_RING_BUFFER_SIZE; ++i) {
GLInjectFrameInfo *frameinfo = GetGLInjectFrameInfo(i);
frameinfo->timestamp = 0;
frameinfo->width = 0;
frameinfo->height = 0;
frameinfo->stride = 0;
}
// set the identifier to indicate that initialization is complete
std::atomic_thread_fence(std::memory_order_release);
header->identifier = GLINJECT_IDENTIFIER;
std::atomic_thread_fence(std::memory_order_release);
}
void* SSRVideoStreamWriter::NewFrame(unsigned int* flags) {
// increment the frame counter
GLInjectHeader *header = GetGLInjectHeader();
++header->frame_counter;
std::atomic_thread_fence(std::memory_order_release);
// get capture parameters
std::atomic_thread_fence(std::memory_order_acquire);
*flags = header->capture_flags;
if(!(*flags & GLINJECT_FLAG_CAPTURE_ENABLED))
return NULL;
// check the timestamp and maybe limit the fps
unsigned int target_fps = header->capture_target_fps;
int64_t timestamp = hrt_time_micro();
if(target_fps > 0) {
int64_t interval = 1000000 / target_fps;
if(*flags & GLINJECT_FLAG_LIMIT_FPS) {
if(timestamp < m_next_frame_time) {
usleep(m_next_frame_time - timestamp);
timestamp = hrt_time_micro();
}
} else {
if(timestamp < m_next_frame_time - interval)
return NULL;
}
m_next_frame_time = std::max(m_next_frame_time + interval, timestamp);
}
// make sure that at least one frame is available
unsigned int read_pos = header->ring_buffer_read_pos;
unsigned int write_pos = header->ring_buffer_write_pos;
unsigned int frames_used = positive_mod((int) write_pos - (int) read_pos, GLINJECT_RING_BUFFER_SIZE * 2);
if(frames_used >= GLINJECT_RING_BUFFER_SIZE)
return NULL;
// write frame info
GLInjectFrameInfo *frameinfo = GetGLInjectFrameInfo(write_pos % GLINJECT_RING_BUFFER_SIZE);
frameinfo->timestamp = timestamp;
frameinfo->width = m_width;
frameinfo->height = m_height;
frameinfo->stride = m_stride;
// prepare the frame file
FrameData &fd = m_frame_data[write_pos % GLINJECT_RING_BUFFER_SIZE];
size_t required_size = (size_t) abs(m_stride) * (size_t) m_height;
if(required_size > fd.m_mmap_size_frame) {
// calculate new size
required_size = (required_size + required_size / 4 + m_page_size - 1) / m_page_size * m_page_size;
// unmap frame file
if(fd.m_mmap_ptr_frame != MAP_FAILED) {
munmap(fd.m_mmap_ptr_frame, fd.m_mmap_size_frame);
fd.m_mmap_ptr_frame = MAP_FAILED;
fd.m_mmap_size_frame = 0;
}
// resize frame file
if(ftruncate(fd.m_fd_frame, required_size) == -1) {
GLINJECT_PRINT("Error: Can't resize video frame file!");
throw SSRStreamException();
}
// map frame file
fd.m_mmap_ptr_frame = mmap(NULL, required_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd.m_fd_frame, 0);
if(fd.m_mmap_ptr_frame == MAP_FAILED) {
GLINJECT_PRINT("Error: Can't memory-map video frame file!");
throw SSRStreamException();
}
fd.m_mmap_size_frame = required_size;
}
return fd.m_mmap_ptr_frame;
}
