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

pkg/media/rtpdump/reader.go

@@ -0,0 +1,107 @@
+// SPDX-FileCopyrightText: 2026 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+package rtpdump
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"regexp"
+	"sync"
+)
+
+// Reader reads the RTPDump file format.
+type Reader struct {
+	readerMu sync.Mutex
+	reader   io.Reader
+}
+
+// NewReader opens a new Reader and immediately reads the Header from the start
+// of the input stream.
+func NewReader(r io.Reader) (*Reader, Header, error) {
+	var hdr Header
+
+	bio := bufio.NewReader(r)
+
+	// Look ahead to see if there's a valid preamble
+	peek, err := bio.Peek(preambleLen)
+	if errors.Is(err, io.EOF) {
+		return nil, hdr, errMalformed
+	}
+	if err != nil {
+		return nil, hdr, err
+	}
+
+	// The file starts with #!rtpplay1.0 address/port\n
+	preambleRegexp := regexp.MustCompile(`#\!rtpplay1\.0 \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\/\d{1,5}\n`)
+	if !preambleRegexp.Match(peek) {
+		return nil, hdr, errMalformed
+	}
+
+	// consume the preamble
+	_, _, err = bio.ReadLine()
+	if errors.Is(err, io.EOF) {
+		return nil, hdr, errMalformed
+	}
+	if err != nil {
+		return nil, hdr, err
+	}
+
+	hBuf := make([]byte, headerLen)
+	_, err = io.ReadFull(bio, hBuf)
+	if errors.Is(err, io.ErrUnexpectedEOF) || errors.Is(err, io.EOF) {
+		return nil, hdr, errMalformed
+	}
+	if err != nil {
+		return nil, hdr, err
+	}
+
+	if err := hdr.Unmarshal(hBuf); err != nil {
+		return nil, hdr, err
+	}
+
+	return &Reader{
+		reader: bio,
+	}, hdr, nil
+}
+
+// Next returns the next Packet in the Reader input stream.
+func (r *Reader) Next() (Packet, error) {
+	r.readerMu.Lock()
+	defer r.readerMu.Unlock()
+
+	hBuf := make([]byte, pktHeaderLen)
+
+	_, err := io.ReadFull(r.reader, hBuf)
+	if errors.Is(err, io.ErrUnexpectedEOF) {
+		return Packet{}, errMalformed
+	}
+	if err != nil {
+		return Packet{}, err
+	}
+
+	var header packetHeader
+	if err = header.Unmarshal(hBuf); err != nil {
+		return Packet{}, err
+	}
+
+	if header.Length == 0 {
+		return Packet{}, errMalformed
+	}
+
+	payload := make([]byte, header.Length-pktHeaderLen)
+	_, err = io.ReadFull(r.reader, payload)
+	if errors.Is(err, io.ErrUnexpectedEOF) {
+		return Packet{}, errMalformed
+	}
+	if err != nil {
+		return Packet{}, err
+	}
+
+	return Packet{
+		Offset:  header.offset(),
+		IsRTCP:  header.PacketLength == 0,
+		Payload: payload,
+	}, nil
+}