AgoraIO · saudsami · Jul 9, 2024 · Jun 25, 2024 · Jul 9, 2024 · Jul 9, 2024
diff --git a/assets/images/common/audio-module.svg b/assets/images/common/audio-module.svg
diff --git a/assets/images/common/video-module.svg b/assets/images/common/video-module.svg
diff --git a/broadcast-streaming/overview/core-concepts.mdx b/broadcast-streaming/overview/core-concepts.mdx
@@ -2,7 +2,6 @@
 title: 'Core concepts'
 sidebar_position: 2
 type: docs
-platform_selector: false
 description: >
   Ideas that are central to developing with Agora.
 ---

diff --git a/interactive-live-streaming/overview/core-concepts.mdx b/interactive-live-streaming/overview/core-concepts.mdx
@@ -2,7 +2,6 @@
 title: 'Core concepts'
 sidebar_position: 2
 type: docs
-platform_selector: false
 description: >
   Ideas that are central to developing with Agora.
 ---

diff --git a/shared/common/_glossary.mdx b/shared/common/_glossary.mdx
@@ -102,7 +102,7 @@ In real-time audio and video communication, delay refers to the time elapsed fro
 
 ###  Dual-stream mode
 
-In the dual-stream mode, the SDK transmits a high-quality and a low-quality video stream from the sender.
+In the dual-stream mode, the <Vg k="VSDK" /> simultaneously transmits a higher-resolution video stream along with an additional low-resolution, low bitrate video stream.
 
 ## F
 

diff --git a/shared/common/core-concepts/audio-video-concepts.mdx b/shared/common/core-concepts/audio-video-concepts.mdx
@@ -6,6 +6,7 @@ The following diagram shows the basic workflow of using the <Vg k="COMPANY" /> S
 
 <Vg k="COMPANY" /> uses the following basic concepts:
 
+<PlatformWrapper platform="web">
 ### Track
 
 A track contains specific audio or video information and consists of three parts: input source, filter, and output end. According to the different functions in the RTC process, tracks can be further classified into uplink tracks (the sending end) and downlink tracks (the receiving end).
@@ -26,13 +27,23 @@ Performs a series of processing operations on audio and video, including pre-pro
 #### Output
 
 Located at the end of the track, such as an encoder, or a renderer.
+</PlatformWrapper>
 
+<PlatformWrapper notAllowed="web">
 ### Audio module
 
 In audio interaction, the main functions of the audio module are as shown in the figure below:
 
 ![An audio module](/images/common/audio-module.svg)
 
+ After you call `registerAudioFrameObserver`, you can obtain the raw audio data at the following observation points in the audio transmission process:
+1. Obtain the raw audio data of ear monitoring through the `onEarMonitoringAudioFrame` callback.  
+2. Obtain the captured raw audio data through the `onRecordAudioFrame` callback.  
+3. Obtain the raw audio playback data of each individual stream through the `onPlaybackAudioFrameBeforeMixing` callback.
+4. Obtain the raw audio playback data of all mixed streams through the `onPlaybackAudioFrame` callback.
+5. Obtain the raw audio data after mixing the captured and playback audio through the `onMixedAudioFrame` callback.  
+    (5) `onMixedAudioFrame` = (2) `onRecordAudioFrame` + (4) `onPlaybackAudioFrame`
+
 #### Audio routing
 
 The audio output device used by the app when playing audio. Common audio routes include wired headphones, earpieces, speakers, Bluetooth headphones, and others.
@@ -49,8 +60,17 @@ The following diagram shows the main functions of the video module in video inte
 
 ![Video module functions](/images/common/video-module.svg)
 
+The figure shows the following observation points: 
+
+1. `POSITION_POST_CAPTURER_ORIGIN`.
+2. `POSITION_POST_CAPTURER`, corresponds to the `onCaptureVideoFrame` callback.
+3. `POSITION_PRE_ENCODER`, corresponds to the `onPreEncodeVideoFrame` callback.
+4. `POSITION_PRE_RENDERER`, corresponds to the `onRenderVideoFrame` callback.
+
 The APIs used by the video module are as follows:
 
 - Enable local video collection: `enableLocalVideo`
 - Local preview: `setupLocalVideo` → `startPreview`
 - Video rendering shows: `setupRemoteVideo`
+
+</PlatformWrapper>
diff --git a/shared/video-sdk/develop/stream-fallback/index.mdx b/shared/video-sdk/develop/stream-fallback/index.mdx
@@ -18,7 +18,7 @@ When the stream fallback option is enabled, the system intelligently switches be
 
 ## Implement media stream fallback
 
-This section explains the logic to implement the media stream callback feature:
+This section explains the logic to implement the media stream fallback feature:
 
 <ProjectImplement/>
 

diff --git a/shared/video-sdk/develop/stream-raw-audio/index.mdx b/shared/video-sdk/develop/stream-raw-audio/index.mdx
@@ -38,6 +38,8 @@ Ensure that you have implemented the [SDK quickstart](../get-started/get-started
 ## Reference
 This section contains content that completes the information on this page, or points you to documentation that explains other aspects to this product.
 
+* [Audio module](../overview/core-concepts?platform=android#audio-module)
+
 <Reference/>
 </PlatformWrapper>
 

diff --git a/video-calling/overview/core-concepts.mdx b/video-calling/overview/core-concepts.mdx
@@ -2,7 +2,6 @@
 title: 'Core concepts'
 sidebar_position: 2
 type: docs
-platform_selector: false
 description: >
   Ideas that are central to developing with Agora.
 ---

diff --git a/voice-calling/overview/core-concepts.mdx b/voice-calling/overview/core-concepts.mdx
@@ -2,7 +2,6 @@
 title: 'Core concepts'
 sidebar_position: 2
 type: docs
-platform_selector: false
 description: >
   Ideas that are central to developing with Agora.
 ---