Last modified on Thu Jan 26 23:27:35 PST 1995 by msm modified on Thu Aug 19 10:29:32 PDT 1993 by sfreeman
INTERFACEThe ports were once upon a time htons'ed. INET ports are in local endian (yes I know its wrong) unlike addreses which are never messed with. So to make sure the new code which doesn't mess with the ports interoperates with the old stuff we have to use some bizzare numbers here.jvprotocol ; IMPORT Utime; FROM Ctypes IMPORT int, unsigned_int, unsigned_short_int;
CONST PORT_AUDIO_SOURCE = 53001; PORT_AUDIO_HEAR = 53000; PORT_VIDEO = 53001;J-Video Protocol definitions
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Client -> server messages use a single character (0 - 255):
1 - 15: Number of credits - add to stream's current balance 16 - 31: Max credits - 1 (upper limit of balance) 48 - 63: '0' - '?' Quality 71: 'H' Heartbeat (source does nothing) : 'M' Client can handle multicast 81: 'Q' Qualities (reply with a set of strings) 83: 'S' Status (reply with a set of strings) : 'U' UDP request OK. : 'u' UDP request failed. : 'V' Suspend stream : 'v' Resume stream 128 - 254: Sync, where code is to be returned in sync reply. 255: Extended (more than one byte) command
TYPE ClientRequest = BITS 8 FOR [16_0 .. 16_ff]; ClientNumCredits = [16_01 .. 16_0f]; ClientMaxCredits = [16_10 .. 16_1f]; ClientQualityVal = [16_30 .. 16_3f]; ClientSyncVal = [16_80 .. 16_ff]; CONST ClientHeartbeat = 16_48; (* 'H' *) ClientMulticastAble = 16_4D; (* 'M' *) ClientQualities = 16_51; (* 'Q' *) ClientStatus = 16_53; (* 'S' *) ClientUDPRequestOK = 16_55; (* 'U' *) ClientUDPRequestFailed = 16_75; (* 'u' *) ClientSuspendStream = 16_56; (* 'V' *) ClientResumeStream = 16_76; (* 'v' *) ExtendedCommand = 16_FF;Extended commands
FrameRateHint = 1; TYPE FrameRateHintRec = RECORD type: int; period: int; END;server -> client messages
CONST
JVP_FirstEvent = JVP_VIDEO;
JVP_VIDEO = 1; (* used *)
JVP_RESOLUTION = 2; (* not used *)
JVP_TYPE = 3; (* used *)
JVP_AUDIO = 4; (* used *)
JVP_SYNC = 5; (* used *)
JVP_STATUS = 6; (* used *)
JVP_QUALITIES = 7; (* used *)
JVP_ENDMARK = 8; (* not used *)
JVP_ERROR = 9; (* not used *)
JVP_INFO = 10; (* not used *)
JVP_AUDIO_SILENCE = 11; (* not used *)
JVP_AUDIO_MULTICAST = 12;
JVP_VIDEO_UDP_REQUEST = 13;
JVP_VIDEO_UDP_RESPONSE = 14;
JVP_VIDEO_UDP_DATA = 15;
JVP_LastEvent = JVP_VIDEO_UDP_DATA;
TYPE TypeCode = BITS BITSIZE(int) FOR [JVP_FirstEvent .. JVP_LastEvent];
CONST MaxControlMsgBytes = 128; (* storage for non-video data *)
MaxControlMsgSize = 128 DIV BYTESIZE(CHAR);
TYPE ControlBuffer = ARRAY [0 .. MaxControlMsgSize - 1] OF CHAR;
TYPE
VideoFrame = RECORD
type : int := JVP_VIDEO;
length : int;
timestamp: Utime.struct_timeval;
(* data goes here for 'length' bytes *)
END;
VideoFramePtr = UNTRACED REF VideoFrame;
TYPE
Resolution =
RECORD
type : int := JVP_RESOLUTION;
swidth, sheight: int; (* Source width, height *)
cwidth, cheight: int; (* Width & height when compressed *)
END;
ResolutionPtr = UNTRACED REF Resolution;
CONST JVP_KIND_JPEG = 0;
TYPE
VideoType = RECORD
type : int := JVP_TYPE;
kind : int := JVP_KIND_JPEG;
qfactor: int; (* kludge; should send table *)
width : int;
height : int;
END;
VideoTypePtr = UNTRACED REF VideoType;
TYPE
AudioFrame = RECORD
type: int := JVP_AUDIO;
seqNum: unsigned_int; (* not consecutive; cumulative
count of samples *)
length : int;
timestamp: Utime.struct_timeval;
(* data goes here for 'length' bytes *)
END;
AudioFramePtr = UNTRACED REF AudioFrame;
TYPE
SyncFrame = RECORD
type: int := JVP_SYNC;
code: int;
time: int;
END;
SyncFramePtr = UNTRACED REF SyncFrame;
TYPE
StatusFrame = RECORD
type : int := JVP_STATUS;
length: int;
END;
StatusFramePtr = UNTRACED REF StatusFrame;
TYPE
QualitiesFrame = RECORD
type : int := JVP_QUALITIES;
length: int;
(* Strings of the form "%d %d %d %d" quality, width,
height, qfactor *)
(* Terminated by a zero-length string *)
END;
QualitiesFramePtr = UNTRACED REF QualitiesFrame;
TYPE
EndMark = RECORD
type : int := JVP_ENDMARK;
timestamp: Utime.struct_timeval;
END;
EndMarkPtr = UNTRACED REF EndMark;
TYPE
ErrorFrame = RECORD
type : int := JVP_ERROR;
length: int;
(* Null terminated error string *)
END;
ErrorFramePtr = UNTRACED REF ErrorFrame;
TYPE
InfoFrame = RECORD
type : int := JVP_INFO;
length: int; (* of data following *)
code : int; (* whatever *)
timestamp: Utime.struct_timeval;
(* Additional data here *)
END;
InfoFramePtr = UNTRACED REF InfoFrame;
TYPE
AudioSilenceFrame =
RECORD
type: int := JVP_AUDIO_SILENCE;
seqNum: unsigned_int; (* not consecutive; cumulative count of
samples *)
length: int; (* number of silent samples *)
timestamp: Utime.struct_timeval;
END;
AudioSilenceFramePtr = UNTRACED REF AudioSilenceFrame;
TYPE
AudioMulticastInfo = RECORD
type: int := JVP_AUDIO_MULTICAST;
addr: unsigned_int;
END;
AudioMulticastInfoPtr = UNTRACED REF AudioMulticastInfo;
TYPE
VideoUdpControl = RECORD (* both req/response *)
type : int;
jvpu_daddr: unsigned_int;
jvpu_saddr: unsigned_int;
jvpu_dport: unsigned_short_int;
jvpu_sport: unsigned_short_int;
END;
VideoUdpControlPtr = UNTRACED REF VideoUdpControl;
TYPE
VideoUdpData = RECORD
type : int := JVP_VIDEO_UDP_DATA;
jvpu_length: int; (* total data *)
jvpu_timestamp: ARRAY [0 .. 1] OF Utime.struct_timeval;
(* lance wanted two *)
jvpu_sequence: int; (* for reassembly *)
END;
VideoUdpDataPtr = UNTRACED REF VideoUdpData;
CONST
HdrSizes = ARRAY TypeCode OF
CARDINAL{
BYTESIZE(VideoFrame), BYTESIZE(Resolution),
BYTESIZE(VideoType), BYTESIZE(AudioFrame),
BYTESIZE(SyncFrame), BYTESIZE(StatusFrame),
BYTESIZE(QualitiesFrame), BYTESIZE(EndMark),
BYTESIZE(ErrorFrame), BYTESIZE(InfoFrame),
BYTESIZE(AudioSilenceFrame), BYTESIZE(AudioMulticastInfo),
BYTESIZE(VideoUdpControl), BYTESIZE(VideoUdpControl),
BYTESIZE(VideoUdpData)};
no message is shorter than an AnyHeader, so we can always read in the
number of bytes in an AnyHeader
TYPE
AnyHeader = RECORD
type : int;
dummy: int;
END;
AnyHeaderPtr = UNTRACED REF AnyHeader;
CONST
MaxHdrSize = MaxHdrBytes DIV BYTESIZE(CHAR);
MaxHdrBytes =
MAX( BYTESIZE(ARRAY [0 .. 63] OF CHAR),
MAX( BYTESIZE(AnyHeader),
MAX( HdrSizes[JVP_VIDEO],
MAX( HdrSizes[JVP_RESOLUTION],
MAX( HdrSizes[JVP_TYPE],
MAX( HdrSizes[JVP_AUDIO],
MAX( HdrSizes[JVP_SYNC],
MAX( HdrSizes[JVP_STATUS],
MAX( HdrSizes[JVP_QUALITIES],
MAX( HdrSizes[JVP_ENDMARK],
MAX( HdrSizes[JVP_ERROR],
MAX( HdrSizes[JVP_INFO],
MAX( HdrSizes[JVP_AUDIO_SILENCE],
MAX( HdrSizes[JVP_AUDIO_MULTICAST],
MAX( HdrSizes[JVP_VIDEO_UDP_REQUEST],
MAX( HdrSizes[JVP_VIDEO_UDP_RESPONSE],
HdrSizes[JVP_VIDEO_UDP_DATA]))))))))))))))));
TYPE
Header = ARRAY [0 .. MaxHdrSize - 1] OF CHAR;
HeaderPtr = UNTRACED REF Header;
END jvprotocol.