Package com.avpkit.core

Class IPacket

  • public class IPacket
extends IMediaData
    Represents an encoded piece of data that can be placed in an {IContainer}
    for a given {IStream} of data.


    You read this object out of {IContainer} objects when decoding, and
    pass to an {IStreamCoder} object to decode.


    You pass this object to a {IStreamCoder} to encode data, and then
    pass to an {IContainer} object to write to a data source.


    Lastly, the units of timestamps in an {IPacket} are determined by the
    {IContainer} it came from (or is going to). For example, FLV {IPacket}s
    are always in milliseconds (1/1000 of a second). You cannot assume these
    timestamps are in any given timeunit without getting an {IStream} object
    and finding out what Time Base that stream operates in.


    For convenience, the AVPKit API always uses Microseconds for raw data
    ({IVideoPicture} and {IAudioSamples} objects), and will convert to
    the right time stamp unit when decoding or encoding data (with an {IStreamCoder})
    from or to an {IContainer}.

    • Constructor Detail

      • IPacket

        protected IPacket​(long cPtr,
                  boolean cMemoryOwn)
        Internal Only.

      • IPacket

        protected IPacket​(long cPtr,
                  boolean cMemoryOwn,
                  java.util.concurrent.atomic.AtomicLong ref)
        Internal Only.

    • Method Detail

      • getCPtr

        public static long getCPtr​(IPacket obj)
        Internal Only. Not part of public API. Get the raw value of the native object that obj is proxying for.
        Parameters:
        obj - The java proxy object for a native object.
        Returns:
        The raw pointer obj is proxying for.

      • getMyCPtr

        public long getMyCPtr()
        Internal Only. Not part of public API. Get the raw value of the native object that we're proxying for.
        Overrides:
        getMyCPtr in class IMediaData
        Returns:
        The raw pointer we're proxying for.

      • copyReference

        public IPacket copyReference()
        Create a new IPacket object that is actually referring to the exact same underlying native object.
        Overrides:
        copyReference in class IMediaData
        Returns:
        the new Java object.

      • equals

        public boolean equals​(java.lang.Object obj)
        Compares two values, returning true if the underlying objects in native code are the same object. That means you can have two different Java objects, but when you do a comparison, you'll find out they are the EXACT same object.
        Overrides:
        equals in class IMediaData
        Returns:
        True if the underlying native object is the same. False otherwise.

      • hashCode

        public int hashCode()
        Get a hashable value for this object.
        Overrides:
        hashCode in class IMediaData
        Returns:
        the hashable value.

      • toString

        public java.lang.String toString()
        info about this packet
        Overrides:
        toString in class java.lang.Object
        Returns:
        information about this packet

      • reset

        public void reset()
        Clear out any data in this packet, but leaves
        the buffer available for reuse.

      • isComplete

        public boolean isComplete()
        Is this packet complete.
        Returns:
        Is this packet full and therefore has valid information.

      • getPts

        public long getPts()
        Get the Presentation Time Stamp (PTS) for this packet.

        This is the time at which the payload for this packet should
        be presented to the user, in units of
        {#getTimeBase()}, relative to the start of stream.

        Returns:
        Get the Presentation Timestamp for this packet.

      • setPts

        public void setPts​(long aPts)
        Set a new Presentation Time Stamp (PTS) for this packet.

        Parameters:
        aPts - a new PTS for this packet.

        See Also:
        getPts()

      • getDts

        public long getDts()
        Get the Decompression Time Stamp (DTS) for this packet.


        This is the time at which the payload for this packet should
        be decompressed, in units of
        {#getTimeBase()}, relative to the start of stream.



        Some media codecs can require packets from the "future" to
        be decompressed before earliest packets as an additional way to compress
        data. In general you don't need to worry about this, but if you're
        curious start reading about the difference between I-Frames, P-Frames
        and B-Frames (or Bi-Directional Frames). B-Frames can use information
        from future frames when compressed.


        Returns:
        Get the Decompression Timestamp (i.e. when this was read relative
        to the start of reading packets).

      • setDts

        public void setDts​(long aDts)
        Set a new Decompression Time Stamp (DTS) for this packet.
        Parameters:
        aDts - a new DTS for this packet.
        See Also:
        getDts()

      • getSize

        public int getSize()
        Get the size in bytes of the payload currently in this packet.
        Overrides:
        getSize in class IMediaData
        Returns:
        Size (in bytes) of payload currently in packet.

      • getMaxSize

        public int getMaxSize()
        Get the maximum size (in bytes) of payload this packet can hold.
        Returns:
        Get maximum size (in bytes) of payload this packet can hold.

      • getStreamIndex

        public int getStreamIndex()
        Get the container-specific index for the stream this packet is
        part of.
        Returns:
        Stream in container that this packet has data for.

      • getFlags

        public int getFlags()
        Get any flags set on this packet, as a 4-byte binary-ORed bit-mask.
        This is access to raw FFMPEG
        flags, but it is easier to use the is* methods below.
        Returns:
        Any flags on the packet.

      • isKeyPacket

        public boolean isKeyPacket()
        Does this packet contain Key data? i.e. data that needs no other
        frames or samples to decode.
        Returns:
        true if key; false otherwise.

      • getDuration

        public long getDuration()
        Return the duration of this packet, in units of {#getTimeBase()}
        Returns:
        Duration of this packet, in same time-base as the PTS.

      • getPosition

        public long getPosition()
        Return the position (in bytes) of this packet in the stream.
        Returns:
        The position of this packet in the stream, or -1 if
        unknown.

      • allocateNewPayload

        public int allocateNewPayload​(int payloadSize)
        Discard the current payload and allocate a new payload.


        Note that if any people have access to the old payload using
        getData(), the memory will continue to be available to them
        until they release their hold of the IBuffer.



        When requesting a packet size, the system
        may allocate a larger payloadSize.


        Parameters:
        payloadSize - The (minimum) payloadSize of this packet in bytes.

        Returns:
        >= 0 if successful. < 0 if error.

      • make

        public static IPacket make()
        Allocate a new packet.


        Note that any buffers this packet needs will be
        lazily allocated (i.e. we won't actually grab all
        the memory until we need it).



        Returns:
        a new packet, or null on error.

      • make

        public static IPacket make​(IBuffer buffer)
        Allocate a new packet that wraps an existing IBuffer.

        Parameters:
        buffer - The IBuffer to wrap.
        Returns:
        a new packet or null on error.

      • setKeyPacket

        public void setKeyPacket​(boolean keyPacket)
        Set if this is a key packet.

        Parameters:
        keyPacket - true for yes, false for no.

      • setFlags

        public void setFlags​(int flags)
        Set any internal flags.

        Parameters:
        flags - Flags to set

      • setComplete

        public void setComplete​(boolean complete,
                        int size)
        Set if this packet is complete, and what the total size of the data should be assumed to be.

        Parameters:
        complete - True for complete, false for not.
        size - Size of data in packet.

      • setStreamIndex

        public void setStreamIndex​(int streamIndex)
        Set the stream index for this packet.

        Parameters:
        streamIndex - The stream index, as determined from the {IContainer} this packet will be written to.

      • setDuration

        public void setDuration​(long duration)
        Set the duration.
        Parameters:
        duration - new duration
        See Also:
        getDuration()

      • setPosition

        public void setPosition​(long position)
        Set the position.
        Parameters:
        position - new position
        See Also:
        getPosition()

      • make

        public static IPacket make​(IPacket packet,
                           boolean copyData)
        Allocate a new packet wrapping the existing contents of
        a passed in packet. Callers can then modify
        {#getPts()},
        {#getDts()} and other get/set methods without
        modifying the original packet.

        Parameters:
        packet - Packet to reuse buffer from and to
        copy settings from.
        copyData - if true copy data from packet
        into our own buffer. If false, share the same
        data buffer that packet uses

        Returns:
        a new packet or null on error.

      • make

        public static IPacket make​(int size)
        Allocate a new packet.


        Note that any buffers this packet needs will be
        lazily allocated (i.e. we won't actually grab all
        the memory until we need it).


        Parameters:
        size - The maximum size, in bytes, of data you
        want to put in this packet.

        Returns:
        a new packet, or null on error.