From 6e61ac6d2fc30443db676fdcde9db5a3f10b82d4 Mon Sep 17 00:00:00 2001
From: Alexey Khit <alexey.khit@gmail.com>
Date: Tue, 24 Jan 2023 17:48:31 +0300
Subject: [PATCH] Fix HTTP-FLV for Reolink cameras

---
 pkg/httpflv/flvio.go   | 97 ++++++++++++++++++++++++++++++++++++++++++
 pkg/httpflv/httpflv.go |  2 +-
 2 files changed, 98 insertions(+), 1 deletion(-)
 create mode 100644 pkg/httpflv/flvio.go

diff --git a/pkg/httpflv/flvio.go b/pkg/httpflv/flvio.go
new file mode 100644
index 00000000..d0a53f10
--- /dev/null
+++ b/pkg/httpflv/flvio.go
@@ -0,0 +1,97 @@
+package httpflv
+
+import (
+	"fmt"
+	"github.com/deepch/vdk/format/flv/flvio"
+	"github.com/deepch/vdk/utils/bits/pio"
+	"io"
+)
+
+// TODO: rewrite all of this someday
+
+func ReadTag(r io.Reader, b []byte) (tag flvio.Tag, ts int32, err error) {
+	if _, err = io.ReadFull(r, b[:flvio.TagHeaderLength]); err != nil {
+		return
+	}
+	var datalen int
+	if tag, ts, datalen, err = flvio.ParseTagHeader(b); err != nil {
+		return
+	}
+
+	data := make([]byte, datalen)
+	if _, err = io.ReadFull(r, data); err != nil {
+		return
+	}
+
+	n, err := ParseHeader(&tag, data)
+	if err != nil {
+		return
+	}
+	tag.Data = data[n:]
+
+	if _, err = io.ReadFull(r, b[:4]); err != nil {
+		return
+	}
+	return
+}
+
+func ParseHeader(self *flvio.Tag, b []byte) (n int, err error) {
+	switch self.Type {
+	case flvio.TAG_AUDIO:
+		return audioParseHeader(self, b)
+
+	case flvio.TAG_VIDEO:
+		return videoParseHeader(self, b)
+	}
+
+	return
+}
+
+func audioParseHeader(tag *flvio.Tag, b []byte) (n int, err error) {
+	if len(b) < n+1 {
+		err = fmt.Errorf("audiodata: parse invalid")
+		return
+	}
+
+	flags := b[n]
+	n++
+	tag.SoundFormat = flags >> 4
+	tag.SoundRate = (flags >> 2) & 0x3
+	tag.SoundSize = (flags >> 1) & 0x1
+	tag.SoundType = flags & 0x1
+
+	switch tag.SoundFormat {
+	case flvio.SOUND_AAC:
+		if len(b) < n+1 {
+			err = fmt.Errorf("audiodata: parse invalid")
+			return
+		}
+		tag.AACPacketType = b[n]
+		n++
+	}
+
+	return
+}
+
+func videoParseHeader(tag *flvio.Tag, b []byte) (n int, err error) {
+	if len(b) < n+1 {
+		err = fmt.Errorf("videodata: parse invalid")
+		return
+	}
+	flags := b[n]
+	tag.FrameType = flags >> 4
+	tag.CodecID = flags & 0xf
+	n++
+
+	if len(b) < n+4 {
+		err = fmt.Errorf("videodata: parse invalid")
+		return
+	}
+	tag.AVCPacketType = b[n]
+	n++
+
+	tag.CompositionTime = pio.I24BE(b[n:])
+	n += 3
+
+	return
+}
diff --git a/pkg/httpflv/httpflv.go b/pkg/httpflv/httpflv.go
index 7c566838..523401d8 100644
--- a/pkg/httpflv/httpflv.go
+++ b/pkg/httpflv/httpflv.go
@@ -141,7 +141,7 @@ func (c *Conn) Streams() ([]av.CodecData, error) {
 
 func (c *Conn) ReadPacket() (av.Packet, error) {
 	for {
-		tag, ts, err := flvio.ReadTag(c.reader, c.buf)
+		tag, ts, err := ReadTag(c.reader, c.buf)
 		if err != nil {
 			return av.Packet{}, err
 		}