private unsafe NewImageBufferReadyEventArgs GetFrameDataPooled(InteropVideodev2.V4l2FrameBuffer *buffers)
{
// Get one frame from the buffer
InteropVideodev2.v4l2_buffer frame = new InteropVideodev2.v4l2_buffer
{
type = InteropVideodev2.v4l2_buf_type.V4L2_BUF_TYPE_VIDEO_CAPTURE,
memory = InteropVideodev2.v4l2_memory.V4L2_MEMORY_MMAP,
};
V4l2Struct(InteropVideodev2.V4l2Request.VIDIOC_DQBUF, ref frame);
// Get data from pointer
IntPtr intptr = buffers[frame.index].Start;
var length = (int)buffers[frame.index].Length;
byte[] dataBuffer = Array.Empty <byte>();
if (ImageBufferPoolingEnabled)
{
dataBuffer = ArrayPool <byte> .Shared.Rent(length);
}
else
{
dataBuffer = new byte[length];
}
Marshal.Copy(source: intptr, destination: dataBuffer, startIndex: 0, length: (int)buffers[frame.index].Length);
// Requeue the buffer
V4l2Struct(InteropVideodev2.V4l2Request.VIDIOC_QBUF, ref frame);
return(new NewImageBufferReadyEventArgs(dataBuffer, length));
}
private unsafe InteropVideodev2.V4l2FrameBuffer[] ApplyFrameBuffers()
{
// Apply for buffers, use memory mapping
InteropVideodev2.v4l2_requestbuffers req = new InteropVideodev2.v4l2_requestbuffers
{
count = BufferCount,
type = InteropVideodev2.v4l2_buf_type.V4L2_BUF_TYPE_VIDEO_CAPTURE,
memory = InteropVideodev2.v4l2_memory.V4L2_MEMORY_MMAP
};
V4l2Struct(InteropVideodev2.V4l2Request.VIDIOC_REQBUFS, ref req);
// Mapping the applied buffer to user space
InteropVideodev2.V4l2FrameBuffer[] buffers = new InteropVideodev2.V4l2FrameBuffer[BufferCount];
for (uint i = 0; i < BufferCount; i++)
{
InteropVideodev2.v4l2_buffer buffer = new InteropVideodev2.v4l2_buffer
{
index = i,
type = InteropVideodev2.v4l2_buf_type.V4L2_BUF_TYPE_VIDEO_CAPTURE,
memory = InteropVideodev2.v4l2_memory.V4L2_MEMORY_MMAP
};
V4l2Struct(InteropVideodev2.V4l2Request.VIDIOC_QUERYBUF, ref buffer);
buffers[i].Length = buffer.length;
buffers[i].Start = Interop.mmap(IntPtr.Zero, (int)buffer.length, Interop.MemoryMappedProtections.PROT_READ | Interop.MemoryMappedProtections.PROT_WRITE, Interop.MemoryMappedFlags.MAP_SHARED, _deviceFileDescriptor, (int)buffer.m.offset);
}
// Put the buffer in the processing queue
for (uint i = 0; i < BufferCount; i++)
{
InteropVideodev2.v4l2_buffer buffer = new InteropVideodev2.v4l2_buffer
{
index = i,
type = InteropVideodev2.v4l2_buf_type.V4L2_BUF_TYPE_VIDEO_CAPTURE,
memory = InteropVideodev2.v4l2_memory.V4L2_MEMORY_MMAP
};
V4l2Struct(InteropVideodev2.V4l2Request.VIDIOC_QBUF, ref buffer);
}
return(buffers);
}
private unsafe byte[] GetFrameData(InteropVideodev2.V4l2FrameBuffer *buffers)
{
// Get one frame from the buffer
InteropVideodev2.v4l2_buffer frame = new InteropVideodev2.v4l2_buffer
{
type = InteropVideodev2.v4l2_buf_type.V4L2_BUF_TYPE_VIDEO_CAPTURE,
memory = InteropVideodev2.v4l2_memory.V4L2_MEMORY_MMAP,
};
V4l2Struct(InteropVideodev2.V4l2Request.VIDIOC_DQBUF, ref frame);
// Get data from pointer
IntPtr intptr = buffers[frame.index].Start;
byte[] dataBuffer = new byte[buffers[frame.index].Length];
Marshal.Copy(source: intptr, destination: dataBuffer, startIndex: 0, length: (int)buffers[frame.index].Length);
// Requeue the buffer
V4l2Struct(InteropVideodev2.V4l2Request.VIDIOC_QBUF, ref frame);
return(dataBuffer);
}
