snapshot of https://github.com/pion/webrtc.git (main, 2026-09-15; blobs > 131072B omitted)

pkg/media/ivfreader/ivfreader.go

@@ -0,0 +1,163 @@
+// SPDX-FileCopyrightText: 2026 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+// Package ivfreader implements IVF media container reader
+package ivfreader
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+)
+
+const (
+	ivfFileHeaderSignature = "DKIF"
+	ivfFileHeaderSize      = 32
+	ivfFrameHeaderSize     = 12
+)
+
+var (
+	errNilStream             = errors.New("stream is nil")
+	errIncompleteFrameHeader = errors.New("incomplete frame header")
+	errIncompleteFrameData   = errors.New("incomplete frame data")
+	errIncompleteFileHeader  = errors.New("incomplete file header")
+	errSignatureMismatch     = errors.New("IVF signature mismatch")
+	errUnknownIVFVersion     = errors.New("IVF version unknown, parser may not parse correctly")
+	errInvalidMediaTimebase  = errors.New("invalid media timebase")
+)
+
+// IVFFileHeader 32-byte header for IVF files
+// https://wiki.multimedia.cx/index.php/IVF
+type IVFFileHeader struct {
+	signature           string // 0-3
+	version             uint16 // 4-5
+	headerSize          uint16 // 6-7
+	FourCC              string // 8-11
+	Width               uint16 // 12-13
+	Height              uint16 // 14-15
+	TimebaseDenominator uint32 // 16-19
+	TimebaseNumerator   uint32 // 20-23
+	NumFrames           uint32 // 24-27
+	unused              uint32 // 28-31
+}
+
+// IVFFrameHeader 12-byte header for IVF frames
+// https://wiki.multimedia.cx/index.php/IVF
+type IVFFrameHeader struct {
+	FrameSize uint32 // 0-3
+	Timestamp uint64 // 4-11
+}
+
+// IVFReader is used to read IVF files and return frame payloads.
+type IVFReader struct {
+	stream               io.Reader
+	bytesReadSuccesfully int64
+	timebaseDenominator  uint32
+	timebaseNumerator    uint32
+}
+
+// NewWith returns a new IVF reader and IVF file header
+// with an io.Reader input.
+func NewWith(stream io.Reader) (*IVFReader, *IVFFileHeader, error) {
+	if stream == nil {
+		return nil, nil, errNilStream
+	}
+
+	reader := &IVFReader{
+		stream: stream,
+	}
+
+	header, err := reader.parseFileHeader()
+	if err != nil {
+		return nil, nil, err
+	}
+	if header.TimebaseDenominator == 0 || header.TimebaseNumerator == 0 {
+		return nil, nil, errInvalidMediaTimebase
+	}
+	reader.timebaseDenominator = header.TimebaseDenominator
+	reader.timebaseNumerator = header.TimebaseNumerator
+
+	return reader, header, nil
+}
+
+// ResetReader resets the internal stream of IVFReader. This is useful
+// for live streams, where the end of the file might be read without the
+// data being finished.
+func (i *IVFReader) ResetReader(reset func(bytesRead int64) io.Reader) {
+	i.stream = reset(i.bytesReadSuccesfully)
+}
+
+func (i *IVFReader) ptsToTimestamp(pts uint64) uint64 {
+	return pts * uint64(i.timebaseDenominator) / uint64(i.timebaseNumerator)
+}
+
+// ParseNextFrame reads from stream and returns IVF frame payload, header,
+// and an error if there is incomplete frame data.
+// Returns all nil values when no more frames are available.
+func (i *IVFReader) ParseNextFrame() ([]byte, *IVFFrameHeader, error) {
+	buffer := make([]byte, ivfFrameHeaderSize)
+	var header *IVFFrameHeader
+
+	bytesRead, err := io.ReadFull(i.stream, buffer)
+	headerBytesRead := bytesRead
+	if errors.Is(err, io.ErrUnexpectedEOF) {
+		return nil, nil, errIncompleteFrameHeader
+	} else if err != nil {
+		return nil, nil, err
+	}
+
+	pts := binary.LittleEndian.Uint64(buffer[4:12])
+	header = &IVFFrameHeader{
+		FrameSize: binary.LittleEndian.Uint32(buffer[:4]),
+		Timestamp: i.ptsToTimestamp(pts),
+	}
+
+	payload := make([]byte, header.FrameSize)
+	bytesRead, err = io.ReadFull(i.stream, payload)
+	if errors.Is(err, io.ErrUnexpectedEOF) {
+		return nil, nil, errIncompleteFrameData
+	} else if err != nil {
+		return nil, nil, err
+	}
+
+	i.bytesReadSuccesfully += int64(headerBytesRead) + int64(bytesRead)
+
+	return payload, header, nil
+}
+
+// parseFileHeader reads 32 bytes from stream and returns
+// IVF file header. This is always called before ParseNextFrame().
+func (i *IVFReader) parseFileHeader() (*IVFFileHeader, error) {
+	buffer := make([]byte, ivfFileHeaderSize)
+
+	bytesRead, err := io.ReadFull(i.stream, buffer)
+	if errors.Is(err, io.ErrUnexpectedEOF) {
+		return nil, errIncompleteFileHeader
+	} else if err != nil {
+		return nil, err
+	}
+
+	header := &IVFFileHeader{
+		signature:           string(buffer[:4]),
+		version:             binary.LittleEndian.Uint16(buffer[4:6]),
+		headerSize:          binary.LittleEndian.Uint16(buffer[6:8]),
+		FourCC:              string(buffer[8:12]),
+		Width:               binary.LittleEndian.Uint16(buffer[12:14]),
+		Height:              binary.LittleEndian.Uint16(buffer[14:16]),
+		TimebaseDenominator: binary.LittleEndian.Uint32(buffer[16:20]),
+		TimebaseNumerator:   binary.LittleEndian.Uint32(buffer[20:24]),
+		NumFrames:           binary.LittleEndian.Uint32(buffer[24:28]),
+		unused:              binary.LittleEndian.Uint32(buffer[28:32]),
+	}
+
+	if header.signature != ivfFileHeaderSignature {
+		return nil, errSignatureMismatch
+	} else if header.version != uint16(0) {
+		return nil, fmt.Errorf("%w: expected(0) got(%d)", errUnknownIVFVersion, header.version)
+	}
+
+	i.bytesReadSuccesfully += int64(bytesRead)
+
+	return header, nil
+}