diff --git a/libraries/scrcpy-decoder-tinyh264/src/decoder.ts b/libraries/scrcpy-decoder-tinyh264/src/decoder.ts
index de1d98c4..dd58b8b3 100644
--- a/libraries/scrcpy-decoder-tinyh264/src/decoder.ts
+++ b/libraries/scrcpy-decoder-tinyh264/src/decoder.ts
@@ -1,4 +1,5 @@
 import { PromiseResolver } from "@yume-chan/async";
+import { EventEmitter } from "@yume-chan/event";
 import type { ScrcpyMediaStreamPacket } from "@yume-chan/scrcpy";
 import {
     AndroidAvcLevel,
@@ -51,6 +52,11 @@ export class TinyH264Decoder implements ScrcpyVideoDecoder {
         return this.#renderer;
     }
 
+    #sizeChanged = new EventEmitter<{ width: number; height: number }>();
+    get sizeChanged() {
+        return this.#sizeChanged.event;
+    }
+
     #frameRendered = 0;
     get frameRendered() {
         return this.#frameRendered;
@@ -112,6 +118,10 @@ export class TinyH264Decoder implements ScrcpyVideoDecoder {
             cropLeft,
             cropTop,
         } = h264ParseConfiguration(data);
+        this.#sizeChanged.fire({
+            width: croppedWidth,
+            height: croppedHeight,
+        });
 
         // H.264 Baseline profile only supports YUV 420 pixel format
         const chromaWidth = encodedWidth / 2;
diff --git a/libraries/scrcpy-decoder-tinyh264/src/types.ts b/libraries/scrcpy-decoder-tinyh264/src/types.ts
index 0d2bc0ad..5cf4936c 100644
--- a/libraries/scrcpy-decoder-tinyh264/src/types.ts
+++ b/libraries/scrcpy-decoder-tinyh264/src/types.ts
@@ -1,4 +1,4 @@
-import type { Disposable } from "@yume-chan/event";
+import type { Disposable, Event } from "@yume-chan/event";
 import type {
     ScrcpyMediaStreamPacket,
     ScrcpyVideoCodecId,
@@ -12,6 +12,7 @@ export interface ScrcpyVideoDecoderCapability {
 
 export interface ScrcpyVideoDecoder extends Disposable {
     readonly renderer: HTMLElement;
+    readonly sizeChanged: Event<{ width: number; height: number }>;
     readonly frameRendered: number;
     readonly frameSkipped: number;
     readonly writable: WritableStream<ScrcpyMediaStreamPacket>;
diff --git a/libraries/scrcpy-decoder-webcodecs/package.json b/libraries/scrcpy-decoder-webcodecs/package.json
index 9014db0f..a5ca7a7b 100644
--- a/libraries/scrcpy-decoder-webcodecs/package.json
+++ b/libraries/scrcpy-decoder-webcodecs/package.json
@@ -34,6 +34,7 @@
         "prepublishOnly": "npm run build"
     },
     "dependencies": {
+        "@yume-chan/event": "workspace:^0.0.22",
         "@yume-chan/scrcpy": "workspace:^0.0.22",
         "@yume-chan/scrcpy-decoder-tinyh264": "workspace:^0.0.22",
         "@yume-chan/stream-extra": "workspace:^0.0.22",
diff --git a/libraries/scrcpy-decoder-webcodecs/src/index.ts b/libraries/scrcpy-decoder-webcodecs/src/index.ts
index 1fde80a7..67ba3137 100644
--- a/libraries/scrcpy-decoder-webcodecs/src/index.ts
+++ b/libraries/scrcpy-decoder-webcodecs/src/index.ts
@@ -1,3 +1,4 @@
+import { EventEmitter } from "@yume-chan/event";
 import type {
     ScrcpyMediaStreamDataPacket,
     ScrcpyMediaStreamPacket,
@@ -62,6 +63,11 @@ export class WebCodecsDecoder implements ScrcpyVideoDecoder {
         return this.#frameSkipped;
     }
 
+    #sizeChanged = new EventEmitter<{ width: number; height: number }>();
+    get sizeChanged() {
+        return this.#sizeChanged.event;
+    }
+
     #context: CanvasRenderingContext2D;
     #decoder: VideoDecoder;
     #config: Uint8Array | undefined;
@@ -132,6 +138,10 @@ export class WebCodecsDecoder implements ScrcpyVideoDecoder {
 
                 this.#renderer.width = croppedWidth;
                 this.#renderer.height = croppedHeight;
+                this.#sizeChanged.fire({
+                    width: croppedWidth,
+                    height: croppedHeight,
+                });
 
                 // https://www.rfc-editor.org/rfc/rfc6381#section-3.3
                 // ISO Base Media File Format Name Space