package gst // #include "gst.go.h" import "C" import "unsafe" // ClockTime is a go representation of a GstClockTime. Most of the time these are casted // to time.Duration objects. It represents a time value in nanoseconds. type ClockTime uint64 const ( // ClockFormat is the string used when formatting clock strings ClockFormat string = "u:%02u:%02u.%09u" // ClockTimeNone means infinite timeout (unsigned representation of -1) or an otherwise unknown value. ClockTimeNone ClockTime = C.GST_CLOCK_TIME_NONE // BufferOffsetNone is a constant for no-offset return results. BufferOffsetNone ClockTime = C.GST_BUFFER_OFFSET_NONE ) // BufferFlags casts GstBufferFlags to a go type. type BufferFlags int // Type castings of BufferFlags const ( BufferFlagLive BufferFlags = C.GST_BUFFER_FLAG_LIVE // (16) – the buffer is live data and should be discarded in the PAUSED state. BufferFlagDecodeOnly BufferFlags = C.GST_BUFFER_FLAG_DECODE_ONLY // (32) – the buffer contains data that should be dropped because it will be clipped against the segment boundaries or because it does not contain data that should be shown to the user. BufferFlagDiscont BufferFlags = C.GST_BUFFER_FLAG_DISCONT // (64) – the buffer marks a data discontinuity in the stream. This typically occurs after a seek or a dropped buffer from a live or network source. BufferFlagResync BufferFlags = C.GST_BUFFER_FLAG_RESYNC // (128) – the buffer timestamps might have a discontinuity and this buffer is a good point to resynchronize. BufferFlagCorrupted BufferFlags = C.GST_BUFFER_FLAG_CORRUPTED // (256) – the buffer data is corrupted. BufferFlagMarker BufferFlags = C.GST_BUFFER_FLAG_MARKER // (512) – the buffer contains a media specific marker. for video this is the end of a frame boundary, for audio this is the start of a talkspurt. BufferFlagHeader BufferFlags = C.GST_BUFFER_FLAG_HEADER // (1024) – the buffer contains header information that is needed to decode the following data. BufferFlagGap BufferFlags = C.GST_BUFFER_FLAG_GAP // (2048) – the buffer has been created to fill a gap in the stream and contains media neutral data (elements can switch to optimized code path that ignores the buffer content). BufferFlagDroppable BufferFlags = C.GST_BUFFER_FLAG_DROPPABLE // (4096) – the buffer can be dropped without breaking the stream, for example to reduce bandwidth. BufferFlagDeltaUnit BufferFlags = C.GST_BUFFER_FLAG_DELTA_UNIT // (8192) – this unit cannot be decoded independently. BufferFlagSyncAfter BufferFlags = C.GST_BUFFER_FLAG_SYNC_AFTER // (32768) – Elements which write to disk or permanent storage should ensure the data is synced after writing the contents of this buffer. (Since: 1.6) BufferFlagNonDroppable BufferFlags = C.GST_BUFFER_FLAG_NON_DROPPABLE // (65536) – This buffer is important and should not be dropped. This can be used to mark important buffers, e.g. to flag RTP packets carrying keyframes or codec setup data for RTP Forward Error Correction purposes, or to prevent still video frames from being dropped by elements due to QoS. (Since: 1.14) BufferFlagLast BufferFlags = C.GST_BUFFER_FLAG_LAST // (1048576) – additional media specific flags can be added starting from this flag. ) // BufferCopyFlags casts GstBufferCopyFlags to a go type. type BufferCopyFlags int // Type castings of BufferCopyFlags const ( BufferCopyNone BufferCopyFlags = C.GST_BUFFER_COPY_NONE // (0) – copy nothing BufferCopyBufferFlags BufferCopyFlags = C.GST_BUFFER_COPY_FLAGS // (1) – flag indicating that buffer flags should be copied BufferCopyTimestamps BufferCopyFlags = C.GST_BUFFER_COPY_TIMESTAMPS // (2) – flag indicating that buffer pts, dts, duration, offset and offset_end should be copied BufferCopyMeta BufferCopyFlags = C.GST_BUFFER_COPY_META // (4) – flag indicating that buffer meta should be copied BufferCopyMemory BufferCopyFlags = C.GST_BUFFER_COPY_MEMORY // (8) – flag indicating that buffer memory should be reffed and appended to already existing memory. Unless the memory is marked as NO_SHARE, no actual copy of the memory is made but it is simply reffed. Add GST_BUFFER_COPY_DEEP to force a real copy. BufferCopyMerge BufferCopyFlags = C.GST_BUFFER_COPY_MERGE // (16) – flag indicating that buffer memory should be merged BufferCopyDeep BufferCopyFlags = C.GST_BUFFER_COPY_DEEP // (32) – flag indicating that memory should always be copied instead of reffed (Since: 1.2) ) // BufferingMode is a representation of GstBufferingMode type BufferingMode int // Type casts of buffering modes const ( BufferingStream BufferingMode = C.GST_BUFFERING_STREAM // (0) – a small amount of data is buffered BufferingDownload BufferingMode = C.GST_BUFFERING_DOWNLOAD // (1) – the stream is being downloaded BufferingTimeshift BufferingMode = C.GST_BUFFERING_TIMESHIFT // (2) – the stream is being downloaded in a ringbuffer BufferingLive BufferingMode = C.GST_BUFFERING_LIVE // (3) – the stream is a live stream ) // String implements a stringer on a BufferingMode. func (b BufferingMode) String() string { switch b { case BufferingStream: return "A small amount of data is buffered" case BufferingDownload: return "The stream is being downloaded" case BufferingTimeshift: return "The stream is being downloaded in a ringbuffer" case BufferingLive: return "The stream is live" } return "" } // Format is a representation of GstFormat. type Format int // Type casts of formats const ( FormatUndefined Format = C.GST_FORMAT_UNDEFINED // (0) – undefined format FormatDefault Format = C.GST_FORMAT_DEFAULT // (1) – the default format of the pad/element. This can be samples for raw audio, or frames/fields for raw video. FormatBytes Format = C.GST_FORMAT_BYTES // (2) - bytes FormatTime Format = C.GST_FORMAT_TIME // (3) – time in nanoseconds ) // String implements a stringer on GstFormat types func (f Format) String() string { switch f { case FormatUndefined: return "undefined" case FormatDefault: return "default" case FormatBytes: return "bytes" case FormatTime: return "time" } return "" } // MessageType is an alias to the C equivalent of GstMessageType. // See the official documentation for definitions of the messages: // https://gstreamer.freedesktop.org/documentation/gstreamer/gstmessage.html?gi-language=c#GstMessageType type MessageType int // Type casting of GstMessageTypes // See the official documentation for definitions of the messages: // https://gstreamer.freedesktop.org/documentation/gstreamer/gstmessage.html?gi-language=c#GstMessageType const ( MessageUnknown MessageType = C.GST_MESSAGE_UNKNOWN MessageEOS MessageType = C.GST_MESSAGE_EOS MessageError MessageType = C.GST_MESSAGE_ERROR MessageWarning MessageType = C.GST_MESSAGE_WARNING MessageInfo MessageType = C.GST_MESSAGE_INFO MessageTag MessageType = C.GST_MESSAGE_TAG MessageBuffering MessageType = C.GST_MESSAGE_BUFFERING MessageStateChanged MessageType = C.GST_MESSAGE_STATE_CHANGED MessageStateDirty MessageType = C.GST_MESSAGE_STATE_DIRTY MessageStepDone MessageType = C.GST_MESSAGE_STEP_DONE MessageClockProvide MessageType = C.GST_MESSAGE_CLOCK_PROVIDE MessageClockLost MessageType = C.GST_MESSAGE_CLOCK_LOST MessageNewClock MessageType = C.GST_MESSAGE_NEW_CLOCK MessageStructureChange MessageType = C.GST_MESSAGE_STRUCTURE_CHANGE MessageStreamStatus MessageType = C.GST_MESSAGE_STREAM_STATUS MessageApplication MessageType = C.GST_MESSAGE_APPLICATION MessageElement MessageType = C.GST_MESSAGE_ELEMENT MessageSegmentStart MessageType = C.GST_MESSAGE_SEGMENT_START MessageSegmentDone MessageType = C.GST_MESSAGE_SEGMENT_DONE MessageDurationChanged MessageType = C.GST_MESSAGE_DURATION_CHANGED MessageLatency MessageType = C.GST_MESSAGE_LATENCY MessageAsyncStart MessageType = C.GST_MESSAGE_ASYNC_START MessageAsyncDone MessageType = C.GST_MESSAGE_ASYNC_DONE MessageRequestState MessageType = C.GST_MESSAGE_REQUEST_STATE MessageStepStart MessageType = C.GST_MESSAGE_STEP_START MessageQoS MessageType = C.GST_MESSAGE_QOS MessageProgress MessageType = C.GST_MESSAGE_PROGRESS MessageTOC MessageType = C.GST_MESSAGE_TOC MessageResetTime MessageType = C.GST_MESSAGE_RESET_TIME MessageStreamStart MessageType = C.GST_MESSAGE_STREAM_START MessageNeedContext MessageType = C.GST_MESSAGE_NEED_CONTEXT MessageHaveContext MessageType = C.GST_MESSAGE_HAVE_CONTEXT MessageExtended MessageType = C.GST_MESSAGE_EXTENDED MessageDeviceAdded MessageType = C.GST_MESSAGE_DEVICE_ADDED MessageDeviceRemoved MessageType = C.GST_MESSAGE_DEVICE_REMOVED MessagePropertyNotify MessageType = C.GST_MESSAGE_PROPERTY_NOTIFY MessageStreamCollection MessageType = C.GST_MESSAGE_STREAM_COLLECTION MessageStreamsSelected MessageType = C.GST_MESSAGE_STREAMS_SELECTED MessageRedirect MessageType = C.GST_MESSAGE_REDIRECT MessageDeviceChanged MessageType = C.GST_MESSAGE_DEVICE_CHANGED MessageAny MessageType = C.GST_MESSAGE_ANY ) // String implements a stringer on MessageTypes func (m MessageType) String() string { return C.GoString(C.gst_message_type_get_name((C.GstMessageType)(m))) } // PadDirection is a cast of GstPadDirection to a go type. type PadDirection int // Type casting of pad directions const ( PadUnknown PadDirection = C.GST_PAD_UNKNOWN // (0) - the direction is unknown PadSource PadDirection = C.GST_PAD_SRC // (1) - the pad is a source pad PadSink PadDirection = C.GST_PAD_SINK // (2) - the pad is a sink pad ) // String implements a Stringer on PadDirection. func (p PadDirection) String() string { switch p { case PadUnknown: return "Unknown" case PadSource: return "Src" case PadSink: return "Sink" } return "" } // PadLinkReturn os a representation of GstPadLinkReturn. type PadLinkReturn int // Type casts for PadLinkReturns. const ( PadLinkOK PadLinkReturn = C.GST_PAD_LINK_OK PadLinkWrongHierarchy PadLinkReturn = C.GST_PAD_LINK_WRONG_HIERARCHY PadLinkWasLinked PadLinkReturn = C.GST_PAD_LINK_WAS_LINKED PadLinkWrongDirection PadLinkReturn = C.GST_PAD_LINK_WRONG_DIRECTION PadLinkNoFormat PadLinkReturn = C.GST_PAD_LINK_NOFORMAT PadLinkNoSched PadLinkReturn = C.GST_PAD_LINK_NOSCHED PadLinkRefused PadLinkReturn = C.GST_PAD_LINK_REFUSED ) // PadPresence is a cast of GstPadPresence to a go type. type PadPresence int // Type casting of pad presences const ( PadAlways PadPresence = C.GST_PAD_ALWAYS // (0) - the pad is always available PadSometimes PadPresence = C.GST_PAD_SOMETIMES // (1) - the pad will become available depending on the media stream PadRequest PadPresence = C.GST_PAD_REQUEST // (2) - the pad is only available on request with gst_element_request_pad. ) // String implements a stringer on PadPresence. func (p PadPresence) String() string { switch p { case PadAlways: return "Always" case PadSometimes: return "Sometimes" case PadRequest: return "Request" } return "" } // State is a type cast of the C GstState type State int // Type casting for GstStates const ( VoidPending State = C.GST_STATE_VOID_PENDING // (0) – no pending state. StateNull State = C.GST_STATE_NULL // (1) – the NULL state or initial state of an element. StateReady State = C.GST_STATE_READY // (2) – the element is ready to go to PAUSED. StatePaused State = C.GST_STATE_PAUSED // (3) – the element is PAUSED, it is ready to accept and process data. Sink elements however only accept one buffer and then block. StatePlaying State = C.GST_STATE_PLAYING // (4) – the element is PLAYING, the GstClock is running and the data is flowing. ) // String returns the string representation of this state. func (s State) String() string { return C.GoString(C.gst_element_state_get_name((C.GstState)(s))) } // SeekFlags is a representation of GstSeekFlags. type SeekFlags int // Type casts of SeekFlags const ( SeekFlagNone SeekFlags = C.GST_SEEK_FLAG_NONE SeekFlagFlush SeekFlags = C.GST_SEEK_FLAG_FLUSH SeekFlagAccurate SeekFlags = C.GST_SEEK_FLAG_ACCURATE SeekFlagKeyUnit SeekFlags = C.GST_SEEK_FLAG_KEY_UNIT SeekFlagSegment SeekFlags = C.GST_SEEK_FLAG_SEGMENT SeekFlagSkip SeekFlags = C.GST_SEEK_FLAG_SKIP SeekFlagSnapBefore SeekFlags = C.GST_SEEK_FLAG_SNAP_BEFORE SeekFlagSnapAfter SeekFlags = C.GST_SEEK_FLAG_SNAP_AFTER SeekFlagSnapNearest SeekFlags = C.GST_SEEK_FLAG_SNAP_NEAREST ) // SeekType is a representation of GstSeekType. type SeekType int // Type casts of seek types const ( SeekTypeNone SeekType = C.GST_SEEK_TYPE_NONE SeekTypeSet SeekType = C.GST_SEEK_TYPE_SET SeekTypeEnd SeekType = C.GST_SEEK_TYPE_END ) // StateChangeReturn is a representation of GstStateChangeReturn. type StateChangeReturn int // Type casts of state change returns const ( StateChangeFailure StateChangeReturn = C.GST_STATE_CHANGE_FAILURE StateChangeSuccess StateChangeReturn = C.GST_STATE_CHANGE_SUCCESS StateChangeAsync StateChangeReturn = C.GST_STATE_CHANGE_ASYNC StateChangeNoPreroll StateChangeReturn = C.GST_STATE_CHANGE_NO_PREROLL ) // ElementFlags casts C GstElementFlags to a go type type ElementFlags int // Type casting of element flags const ( ElementFlagLockedState ElementFlags = C.GST_ELEMENT_FLAG_LOCKED_STATE // (16) – ignore state changes from parent ElementFlagSink ElementFlags = C.GST_ELEMENT_FLAG_SINK // (32) – the element is a sink ElementFlagSource ElementFlags = C.GST_ELEMENT_FLAG_SOURCE // (64) – the element is a source. ElementFlagProvideClock ElementFlags = C.GST_ELEMENT_FLAG_PROVIDE_CLOCK // (128) – the element can provide a clock ElementFlagRequireClock ElementFlags = C.GST_ELEMENT_FLAG_REQUIRE_CLOCK // (256) – the element requires a clock ElementFlagIndexable ElementFlags = C.GST_ELEMENT_FLAG_INDEXABLE // (512) – the element can use an index ElementFlagLast ElementFlags = C.GST_ELEMENT_FLAG_LAST // (16384) – offset to define more flags ) // MiniObjectFlags casts GstMiniObjectFlags to a go type. type MiniObjectFlags int // Type casting of mini-object flags const ( MiniObjectFlagLockable MiniObjectFlags = C.GST_MINI_OBJECT_FLAG_LOCKABLE // (1) – the object can be locked and unlocked with gst_mini_object_lock and gst_mini_object_unlock. MiniObjectFlagLockReadOnly MiniObjectFlags = C.GST_MINI_OBJECT_FLAG_LOCK_READONLY // (2) – the object is permanently locked in READONLY mode. Only read locks can be performed on the object. MiniObjectFlagMayBeLeaked MiniObjectFlags = C.GST_MINI_OBJECT_FLAG_MAY_BE_LEAKED // (4) – the object is expected to stay alive even after gst_deinit has been called and so should be ignored by leak detection tools. (Since: 1.10) MiniObjectFlagLast MiniObjectFlags = C.GST_MINI_OBJECT_FLAG_LAST // (16) – first flag that can be used by subclasses. ) // FlowReturn is go type casting for GstFlowReturn. type FlowReturn int // Type casting of the GstFlowReturn types. Custom ones are omitted for now. const ( FlowOK FlowReturn = C.GST_FLOW_OK // Data passing was ok FlowNotLinked FlowReturn = C.GST_FLOW_NOT_LINKED // Pad is not linked FlowFlushing FlowReturn = C.GST_FLOW_FLUSHING // Pad is flushing FlowEOS FlowReturn = C.GST_FLOW_EOS // Pad is EOS FlowNotNegotiated FlowReturn = C.GST_FLOW_NOT_NEGOTIATED // Pad is not negotiated FlowError FlowReturn = C.GST_FLOW_ERROR // Some (fatal) error occurred FlowNotSupported FlowReturn = C.GST_FLOW_NOT_SUPPORTED // The operation is not supported. ) // MapFlags is a go casting of GstMapFlags type MapFlags int // Type casting of the map flag types const ( MapRead MapFlags = C.GST_MAP_READ // (1) – map for read access MapWrite MapFlags = C.GST_MAP_WRITE // (2) - map for write access MapFlagLast MapFlags = C.GST_MAP_FLAG_LAST // (65536) – first flag that can be used for custom purposes ) // StreamStatusType represents a type of change in a stream's status type StreamStatusType int // Type castings of the stream status types const ( StreamStatusCreate StreamStatusType = C.GST_STREAM_STATUS_TYPE_CREATE // (0) – A new thread need to be created. StreamStatusEnter StreamStatusType = C.GST_STREAM_STATUS_TYPE_ENTER // (1) – a thread entered its loop function StreamStatusLeave StreamStatusType = C.GST_STREAM_STATUS_TYPE_LEAVE // (2) – a thread left its loop function StreamStatusDestroy StreamStatusType = C.GST_STREAM_STATUS_TYPE_DESTROY // (3) – a thread is destroyed StreamStatusStart StreamStatusType = C.GST_STREAM_STATUS_TYPE_START // (8) – a thread is started StreamStatusPause StreamStatusType = C.GST_STREAM_STATUS_TYPE_PAUSE // (9) – a thread is paused StreamStatusStop StreamStatusType = C.GST_STREAM_STATUS_TYPE_STOP // (10) – a thread is stopped ) func (s StreamStatusType) String() string { switch s { case StreamStatusCreate: return "A new thread needs to be created" case StreamStatusEnter: return "A thread has entered its loop function" case StreamStatusLeave: return "A thread has left its loop function" case StreamStatusDestroy: return "A thread has been destroyed" case StreamStatusStart: return "A thread has started" case StreamStatusPause: return "A thread has paused" case StreamStatusStop: return "A thread has stopped" } return "" } // StructureChangeType is a go representation of a GstStructureChangeType type StructureChangeType int // Type castings of StructureChangeTypes const ( StructureChangePadLink StructureChangeType = C.GST_STRUCTURE_CHANGE_TYPE_PAD_LINK // (0) – Pad linking is starting or done. StructureChangePadUnlink StructureChangeType = C.GST_STRUCTURE_CHANGE_TYPE_PAD_UNLINK // (1) – Pad unlinking is starting or done. ) // String implements a stringer on StructureChangeTypes. func (s StructureChangeType) String() string { switch s { case StructureChangePadLink: return "pad link" case StructureChangePadUnlink: return "pad unlink" } return "" } // ProgressType is a go representation of a GstProgressType type ProgressType int // Type castings of ProgressTypes const ( ProgressTypeStart ProgressType = C.GST_PROGRESS_TYPE_START // (0) – A new task started. ProgressTypeContinue ProgressType = C.GST_PROGRESS_TYPE_CONTINUE // (1) – A task completed and a new one continues. ProgressTypeComplete ProgressType = C.GST_PROGRESS_TYPE_COMPLETE // (2) – A task completed. ProgressTypeCancelled ProgressType = C.GST_PROGRESS_TYPE_CANCELED // (3) – A task was canceled. ProgressTypeError ProgressType = C.GST_PROGRESS_TYPE_ERROR // (4) – A task caused an error. An error message is also posted on the bus. ) // String implements a stringer on ProgressTypes func (p ProgressType) String() string { switch p { case ProgressTypeStart: return "started" case ProgressTypeContinue: return "continuing" case ProgressTypeComplete: return "completed" case ProgressTypeCancelled: return "cancelled" case ProgressTypeError: return "error" } return "" } // StreamType is a go representation of a GstStreamType type StreamType int // Type castings of stream types const ( StreamTypeUnknown StreamType = C.GST_STREAM_TYPE_UNKNOWN // (1) – The stream is of unknown (unclassified) type. StreamTypeAudio StreamType = C.GST_STREAM_TYPE_AUDIO // (2) – The stream is of audio data StreamTypeVideo StreamType = C.GST_STREAM_TYPE_VIDEO // (4) – The stream carries video data StreamTypeContainer StreamType = C.GST_STREAM_TYPE_CONTAINER // (8) – The stream is a muxed container type StreamTypeText StreamType = C.GST_STREAM_TYPE_TEXT // (16) – The stream contains subtitle / subpicture data. ) // String implements a stringer on StreamTypes. func (s StreamType) String() string { name := C.gst_stream_type_get_name((C.GstStreamType)(s)) defer C.free(unsafe.Pointer(name)) return C.GoString(name) } // StreamFlags represent configuration options for a new stream. type StreamFlags int // Type castings of StreamFlags const ( StreamFlagNone StreamFlags = C.GST_STREAM_FLAG_NONE // (0) – This stream has no special attributes StreamFlagSparse StreamFlags = C.GST_STREAM_FLAG_SPARSE // (1) – This stream is a sparse stream (e.g. a subtitle stream), data may flow only in irregular intervals with large gaps in between. StreamFlagSelect StreamFlags = C.GST_STREAM_FLAG_SELECT // (2) – This stream should be selected by default. This flag may be used by demuxers to signal that a stream should be selected by default in a playback scenario. StreamFlagUnselect StreamFlags = C.GST_STREAM_FLAG_UNSELECT // (4) – This stream should not be selected by default. This flag may be used by demuxers to signal that a stream should not be selected by default in a playback scenario, but only if explicitly selected by the user (e.g. an audio track for the hard of hearing or a director's commentary track). ) // MemoryFlags represent flags for wrapped memory type MemoryFlags int // Type castins of MemoryFlags const ( MemoryFlagReadOnly MemoryFlags = C.GST_MEMORY_FLAG_READONLY // (2) – memory is readonly. It is not allowed to map the memory with GST_MAP_WRITE. MemoryFlagNoShare MemoryFlags = C.GST_MEMORY_FLAG_NO_SHARE // (16) – memory must not be shared. Copies will have to be made when this memory needs to be shared between buffers. (DEPRECATED: do not use in new code, instead you should create a custom GstAllocator for memory pooling instead of relying on the GstBuffer they were originally attached to.) MemoryFlagZeroPrefixed MemoryFlags = C.GST_MEMORY_FLAG_ZERO_PREFIXED // (32) – the memory prefix is filled with 0 bytes MemoryFlagZeroPadded MemoryFlags = C.GST_MEMORY_FLAG_ZERO_PADDED // (64) – the memory padding is filled with 0 bytes MemoryFlagPhysicallyContiguous MemoryFlags = C.GST_MEMORY_FLAG_PHYSICALLY_CONTIGUOUS // (128) – the memory is physically contiguous. (Since: 1.2) MemoryFlagNotMappable MemoryFlags = C.GST_MEMORY_FLAG_NOT_MAPPABLE // (256) – the memory can't be mapped via gst_memory_map without any preconditions. (Since: 1.2) MemoryFlagLast MemoryFlags = 1048576 // first flag that can be used for custom purposes ) // URIType casts C GstURIType to a go type type URIType int // Type cast URI types const ( URIUnknown URIType = C.GST_URI_UNKNOWN // (0) – The URI direction is unknown URISink URIType = C.GST_URI_SINK // (1) – The URI is a consumer. URISource URIType = C.GST_URI_SRC // (2) - The URI is a producer. ) func (u URIType) String() string { switch u { case URIUnknown: return "Unknown" case URISink: return "Sink" case URISource: return "Source" } return "" } // MetaFlags casts C GstMetaFlags to a go type. type MetaFlags int // Type casts of GstMetaFlags const ( MetaFlagNone MetaFlags = C.GST_META_FLAG_NONE // (0) – no flags MetaFlagReadOnly MetaFlags = C.GST_META_FLAG_READONLY // (1) – metadata should not be modified MetaFlagPooled MetaFlags = C.GST_META_FLAG_POOLED // (2) – metadata is managed by a bufferpool MetaFlagLocked MetaFlags = C.GST_META_FLAG_LOCKED // (4) – metadata should not be removed MetaFlagLast MetaFlags = C.GST_META_FLAG_LAST // (65536) – additional flags can be added starting from this flag. )