//-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
// SendFrameArrivedMessage()
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
void ClientStream::SendFrameArrivedMessage(mach_port_t& recipient, Frame& frame)
{
// Setup the message
FrameArrivedMessage message =
{
{
MACH_MSGH_BITS_REMOTE(MACH_MSG_TYPE_COPY_SEND) | MACH_MSGH_BITS_COMPLEX, // mHeader.msgh_bits
sizeof(FrameArrivedMessage), // mHeader.msgh_size
recipient, // mHeader.msgh_remote_port
MACH_PORT_NULL, // mHeader.msgh_local_port
0, // mHeader.msgh_reserved
kFrameArrived // mHeader.msgh_id
},
{
1 // mBody.msgh_descriptor_count
},
{
// The mach_msg_ool_descriptor_t structure is layed out differently for 32 vs 64 bit architectures, so it is not intialiazed here
},
frame.GetFrameType(), // mFrameType
frame.GetHostTime(), // mHostTime
frame.GetTimingInfo(), // mTimingInfo
frame.GetDiscontinuityFlags() | GetDiscontinuityFlags(), // mDiscontinuityFlags
frame.GetDroppedFrameCount(), // mDroppedFrameCount
frame.GetFirstFrameTime() // mFirstFrameTime
};
// Initialize the mach_msg_ool_descriptor_t portion of the message
message.mDescriptor.address = frame.Get();
message.mDescriptor.size = frame.Size();
message.mDescriptor.deallocate = false;
message.mDescriptor.copy = MACH_MSG_VIRTUAL_COPY;
message.mDescriptor.type = MACH_MSG_OOL_DESCRIPTOR;
// If this frame or the ClientStream has any "hard" discontinuities in it, "extended duration" timing can't be used
if (~kCMIOSampleBufferDiscontinuityFlag_DurationWasExtended & (frame.GetDiscontinuityFlags() | GetDiscontinuityFlags()))
mExtendedFrameHostTime = 0;
// Use the "extended duration" timing if needed (indicated by a non-zero value for mExtendedFrameHostTime)
if (0 != mExtendedFrameHostTime)
{
// Use the extended frame host & cycle time
message.mHostTime = mExtendedFrameHostTime;
// Use the extended frame timing info & add the current frame's duration to the extended frame's duration
message.mTimingInfo = mExtendedFrameTimingInfo;
message.mTimingInfo.duration = CMTimeAdd(message.mTimingInfo.duration, frame.GetTimingInfo().duration);
// Indicate this frame has an extended duration
message.mDiscontinuityFlags |= kCMIOSampleBufferDiscontinuityFlag_DurationWasExtended;
}
// Send the message
mach_msg_return_t err = mach_msg(&message.mHeader, MACH_SEND_MSG | MACH_SEND_TIMEOUT, message.mHeader.msgh_size, 0, MACH_PORT_NULL, 15, MACH_PORT_NULL);
if (MACH_MSG_SUCCESS == err)
{
// The message was sent successfully, so clear the discontinuity flags
SetDiscontinuityFlags(kCMIOSampleBufferNoDiscontinuities);
// Reset the extended frame host time to 0 to signify that no extension is needed
mExtendedFrameHostTime = 0;
}
else
{
DebugMessage("SendFrameArrivedMessage() - Error sending frame to port %d 0x%08X", recipient, err);
// Something went wrong, so destroy the message so that all of its resources will be properly released
mach_msg_destroy(&message.mHeader);
// Update the recipient since it might have a new value since the send failed
recipient = message.mHeader.msgh_remote_port;
// Try and use "extended duration" timing if this frame and the ClientStream lacks any "hard" discontinuities
if (~kCMIOSampleBufferDiscontinuityFlag_DurationWasExtended & (frame.GetDiscontinuityFlags() | GetDiscontinuityFlags()))
{
// The were hard discontinuities, so update the ClientStream's discontinuity flags so they logical sum can be passed on with the next frame
SetDiscontinuityFlags(GetDiscontinuityFlags() | frame.GetDiscontinuityFlags() | kCMIOSampleBufferDiscontinuityFlag_StreamDiscontinuity);
}
else
{
// Rather than mark a "hard" discontinuity, remember the frame's duration and so the NEXT frame's can be extended accordingly
if (0 == mExtendedFrameHostTime)
{
// This is the first extension needed, so use this frame's host & cycle time for the next frame
mExtendedFrameHostTime = frame.GetHostTime();
mExtendedFrameTimingInfo = frame.GetTimingInfo();
}
else
{
// An extension is already taking place, so simply add this frame's duration to the extended frame's duration
mExtendedFrameTimingInfo.duration = CMTimeAdd(mExtendedFrameTimingInfo.duration, frame.GetTimingInfo().duration);
}
}
}
// Remove this client from the set of the native frame needs to message
frame.RemoveClient(mClient);
}
