From ff1ed667294455aaae039dc1c9565958ea99110a Mon Sep 17 00:00:00 2001
From: David Wendt <dcrkid@yahoo.com>
Date: Sun, 25 Jun 2023 22:35:24 -0400
Subject: [PATCH] flv: VP6 video packets have a horizontal and vertical
 adjustment before the actual video data.

---
 core/src/streams.rs | 11 ++++++++++-
 flv/src/video.rs    | 48 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/core/src/streams.rs b/core/src/streams.rs
index 4d74d3bc6..b327322e2 100644
--- a/core/src/streams.rs
+++ b/core/src/streams.rs
@@ -359,7 +359,16 @@ impl<'gc> NetStream<'gc> {
                         let codec = VideoCodec::from_u8(codec_id as u8);
 
                         match (video_handle, codec, data) {
-                            (Some(video_handle), Some(codec), FlvVideoPacket::Data(data)) => {
+                            (Some(video_handle), Some(codec), FlvVideoPacket::Data(data))
+                            | (
+                                Some(video_handle),
+                                Some(codec),
+                                FlvVideoPacket::Vp6Data {
+                                    hadjust: _,
+                                    vadjust: _,
+                                    data,
+                                },
+                            ) => {
                                 // NOTE: Currently, no implementation of the decoder backend actually requires
                                 if tag_needs_preloading {
                                     let encoded_frame = EncodedFrame {
diff --git a/flv/src/video.rs b/flv/src/video.rs
index 216873ade..b3d2490f2 100644
--- a/flv/src/video.rs
+++ b/flv/src/video.rs
@@ -78,6 +78,11 @@ impl TryFrom<u8> for CommandFrame {
 #[derive(PartialEq, Eq, Debug, Clone)]
 pub enum VideoPacket<'a> {
     Data(&'a [u8]),
+    Vp6Data {
+        hadjust: u8,
+        vadjust: u8,
+        data: &'a [u8],
+    },
     AvcSequenceHeader(&'a [u8]),
     AvcNalu {
         composition_time_offset: i32,
@@ -122,6 +127,11 @@ impl<'a> VideoData<'a> {
             (FrameType::CommandFrame, _) => VideoPacket::CommandFrame(CommandFrame::try_from(
                 *data.first().ok_or(Error::ShortVideoBlock)?,
             )?),
+            (_, CodecId::On2Vp6) | (_, CodecId::On2Vp6Alpha) => VideoPacket::Vp6Data {
+                hadjust: data[0] & 0x0F,
+                vadjust: (data[0] & 0xF0) >> 4,
+                data: &data[1..],
+            },
             (_, CodecId::Avc) => {
                 let bytes = data.get(1..4).ok_or(Error::ShortVideoBlock)?;
                 let is_negative = bytes[0] & 0x80 != 0;
@@ -200,6 +210,44 @@ mod tests {
         );
     }
 
+    #[test]
+    fn read_videodata_vp6() {
+        let data = [0x14, 0x37, 0x12, 0x34, 0x56, 0x78];
+        let mut reader = FlvReader::from_source(&data);
+
+        assert_eq!(
+            VideoData::parse(&mut reader, data.len() as u32),
+            Ok(VideoData {
+                frame_type: FrameType::Keyframe,
+                codec_id: CodecId::On2Vp6,
+                data: VideoPacket::Vp6Data {
+                    hadjust: 0x07,
+                    vadjust: 0x03,
+                    data: &[0x12, 0x34, 0x56, 0x78]
+                }
+            })
+        );
+    }
+
+    #[test]
+    fn read_videodata_vp6alpha() {
+        let data = [0x15, 0x37, 0x12, 0x34, 0x56, 0x78];
+        let mut reader = FlvReader::from_source(&data);
+
+        assert_eq!(
+            VideoData::parse(&mut reader, data.len() as u32),
+            Ok(VideoData {
+                frame_type: FrameType::Keyframe,
+                codec_id: CodecId::On2Vp6Alpha,
+                data: VideoPacket::Vp6Data {
+                    hadjust: 0x07,
+                    vadjust: 0x03,
+                    data: &[0x12, 0x34, 0x56, 0x78]
+                }
+            })
+        );
+    }
+
     #[test]
     fn read_videodata_avcsequence() {
         let data = [0x17, 0x00, 0x00, 0x50, 0x00, 0x12, 0x34, 0x56, 0x78];