diff --git a/document/gb28181.md b/document/gb28181.md
index 98a449a..ec354d1 100644
--- a/document/gb28181.md
+++ b/document/gb28181.md
@@ -254,7 +254,7 @@ Method: POST
     "channel_id": <string>,     // 通道ID
     "iris_in": <bool>,        // 光圈小
     "iris_out": <bool>       // 光圈大
-    "focus_near": <bool>       // 聚焦远
+    "focus_near": <bool>       // 聚焦近
     "focus_far": <bool>      // 聚焦远
     "speed": <int>             // 步长，1~8
 }
diff --git a/gb28181/ptz.go b/gb28181/ptz.go
index 4ce0f59..f36ecdf 100644
--- a/gb28181/ptz.go
+++ b/gb28181/ptz.go
@@ -93,10 +93,11 @@ func (p *Ptz) Pack() string {
 	buf[0] = PTZFirstByte
 	buf[1] = getAssembleCode()
 	buf[2] = 0
-	if p.ZoomIn {
+	if p.ZoomOut {
 		buf[3] |= 1 << 5
 	}
-	if p.ZoomOut {
+
+	if p.ZoomIn {
 		buf[3] |= 1 << 4
 	}
 	if p.Up {
@@ -113,7 +114,7 @@ func (p *Ptz) Pack() string {
 	}
 	buf[4] = p.Speed
 	buf[5] = p.Speed
-	buf[6] = p.Speed
+	buf[6] = p.Speed << 4
 	getVerificationCode(buf)
 	return hex.EncodeToString(buf)
 }