media

type AudioParameters interface {
	// Return the channel layout
	ChannelLayout() string

	// Return the sample format
	SampleFormat() string

	// Return the sample rate (Hz)
	Samplerate() int
}

type Codec interface {
	// Return the codec name
	Name() string

	// Return the codec description
	Description() string

	// Return the codec type (AUDIO, VIDEO, SUBTITLE, DATA, INPUT, OUTPUT)
	Type() Type
}

type Decoder interface {
	// Demultiplex media into packets. Pass a packet to a decoder function.
	// Stop when the context is cancelled or the end of the media stream is
	// reached.
	Demux(context.Context, DecoderFunc) error

	// Decode media into frames, and resample or resize the frame.
	// Stop when the context is cancelled or the end of the media stream is
	// reached.
	Decode(context.Context, FrameFunc) error
}

type DecoderFunc func(Packet) error

type DecoderMapFunc func(Stream) (Parameters, error)

type Device interface {
	// Device name, format depends on the device
	Name() string

	// Description of the device
	Description() string

	// Flags indicating the type INPUT or OUTPUT, AUDIO or VIDEO
	Type() Type

	// Whether this is the default device
	Default() bool
}

type Format interface {
	// Name(s) of the format
	Name() []string

	// Description of the format
	Description() string

	// Extensions associated with the format, if a stream. Each extension
	// should have a preceeding period (ie, ".mp4")
	Extensions() []string

	// MimeTypes associated with the format
	MimeTypes() []string

	// Flags indicating the type. INPUT for a demuxer or source, OUTPUT for a muxer or
	// sink, DEVICE for a device, FILE for a file. Plus AUDIO, VIDEO, DATA, SUBTITLE.
	Type() Type
}

type Frame interface {
	Parameters

	// Number of samples in the frame, for an audio frame.
	NumSamples() int

	// Return stride for each plane, for a video frame.
	Stride(int) int

	// Return a frame plane as a byte slice.
	Bytes(int) []byte

	// Return a frame plane as int16 slice
	Int16(int) []int16

	// Return the presentation timestamp for the frame or
	// a negative number if not set
	Time() time.Duration

	// Return a frame as an image, which supports the following
	// pixel formats: AV_PIX_FMT_GRAY8, AV_PIX_FMT_RGBA,
	// AV_PIX_FMT_RGB24, AV_PIX_FMT_YUV420P
	Image() (image.Image, error)
}

type FrameFunc func(Frame) error

type LogFunc func(string)

type Manager interface {
	// Open a media file or device for reading, from a path or url.
	// If a format is specified, then the format will be used to open
	// the file. Close the media object when done.
	Open(string, Format, ...string) (Media, error)

	// Open a media stream for reading.  If a format is
	// specified, then the format will be used to open the file. Close the
	// media object when done. It is the responsibility of the caller to
	// also close the reader when done.
	Read(io.Reader, Format, ...string) (Media, error)

	// Create a media file or device for writing, from a path. If a format is
	// specified, then the format will be used to create the file or else
	// the format is guessed from the path. If no parameters are provided,
	// then the default parameters for the format are used.
	Create(string, Format, []Metadata, ...Parameters) (Media, error)

	// Create a media stream for writing. The format will be used to
	// determine the format and one or more CodecParameters used to
	// create the streams. If no parameters are provided, then the
	// default parameters for the format are used. It is the responsibility
	// of the caller to also close the writer when done.
	Write(io.Writer, Format, []Metadata, ...Parameters) (Media, error)

	// Return supported input formats which match any filter, which can be
	// a name, extension (with preceeding period) or mimetype. The MediaType
	// can be NONE (for any) or combinations of DEVICE and STREAM.
	InputFormats(Type, ...string) []Format

	// Return supported output formats which match any filter, which can be
	// a name, extension (with preceeding period) or mimetype. The MediaType
	// can be NONE (for any) or combinations of DEVICE and STREAM.
	OutputFormats(Type, ...string) []Format

	// Return supported devices for a given format.
	// Not all devices may be supported on all platforms or listed
	// if the device does not support enumeration.
	Devices(Format) []Device

	// Return all supported channel layouts
	ChannelLayouts() []Metadata

	// Return all supported sample formats
	SampleFormats() []Metadata

	// Return all supported  pixel formats
	PixelFormats() []Metadata

	// Return all supported codecs
	Codecs() []Metadata

	// Return audio parameters for encoding
	// ChannelLayout, SampleFormat, Samplerate
	AudioParameters(string, string, int) (Parameters, error)

	// Return video parameters for encoding
	// Width, Height, PixelFormat
	VideoParameters(int, int, string) (Parameters, error)

	// Return version information for the media manager as a set of
	// metadata
	Version() []Metadata

	// Log error messages with arguments
	Errorf(string, ...any)

	// Log warning messages with arguments
	Warningf(string, ...any)

	// Log info messages  with arguments
	Infof(string, ...any)
}

type Media interface {
	io.Closer

	// Return a decoding context for the media stream, and
	// map the streams to decoders. If no function is provided
	// (ie, the argument is nil) then all streams are demultiplexed.
	// Will return an error if called on a writer.
	Decoder(DecoderMapFunc) (Decoder, error)

	// Multiplex media into packets. Pass a packet to a muxer function.
	// Stop when the context is cancelled or the end of the media stream is
	// signalled. Will return an error if called on a reader.
	Mux(context.Context, MuxFunc) error

	// Return INPUT for a demuxer or source, OUTPUT for a muxer or
	// sink, DEVICE for a device, FILE for a file or stream.
	Type() Type

	// Return the metadata for the media, filtering by keys if any
	// are included. Use the "artwork" key to return only artwork.
	Metadata(...string) []Metadata
}

type MediaType uint32

type Metadata interface {
	// Return the metadata key for the entry
	Key() string

	// Return the metadata value for the entry
	Value() any
}

type MuxFunc func(int) (Packet, error)

type Opt func(*opts) error

type Packet interface {
	// The packet can be audio, video, subtitle or data.
	Type() Type

	// The stream identifier for the packet
	Id() int
}

type Parameters interface {
	AudioParameters
	VideoParameters

	// Return the media type (AUDIO, VIDEO, SUBTITLE, DATA)
	Type() Type

	// Return the stream id for encoding, or zero if not set
	Id() int

	// Return number of planes for a specific PixelFormat
	// or SampleFormat and ChannelLayout combination
	NumPlanes() int
}

type Stream interface {
	// Return AUDIO, VIDEO, SUBTITLE or DATA
	Type() Type

	// Return the stream parameters
	Parameters() Parameters
}

type VideoParameters interface {
	// Return the width of the video frame
	Width() int

	// Return the height of the video frame
	Height() int

	// Return the pixel format
	PixelFormat() string
}