Update RTCVideoEncoderH264.mm (webrtc-sdk#6)

Author: hiroshihorie

sdk/objc/components/video_codec/RTCVideoEncoderH264.mm

@@ -387,8 +387,8 @@ - (NSInteger)startEncodeWithSettings:(RTC_OBJC_TYPE(RTCVideoEncoderSettings) *)s
 - (NSInteger)encode:(RTC_OBJC_TYPE(RTCVideoFrame) *)frame
     codecSpecificInfo:(nullable id<RTC_OBJC_TYPE(RTCCodecSpecificInfo)>)codecSpecificInfo
            frameTypes:(NSArray<NSNumber *> *)frameTypes {
-  RTC_DCHECK_EQ(frame.width, _width);
-  RTC_DCHECK_EQ(frame.height, _height);
+  // RTC_DCHECK_EQ(frame.width, _width);
+  // RTC_DCHECK_EQ(frame.height, _height);
   if (!_callback || !_compressionSession) {
     return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
   }
@@ -571,6 +571,7 @@ - (BOOL)resetCompressionSessionIfNeededWithFrame:(RTC_OBJC_TYPE(RTCVideoFrame) *
   OSType framePixelFormat = [self pixelFormatOfFrame:frame];
 
   if (_compressionSession) {
+    _pixelBufferPool = VTCompressionSessionGetPixelBufferPool(_compressionSession);
     // The pool attribute `kCVPixelBufferPixelFormatTypeKey` can contain either an array of pixel
     // formats or a single pixel format.
     NSDictionary *poolAttributes =