Feature: add MediaMetadataController

AndroidMedia/src/main/java/com/frank/androidmedia/controller/MediaDecodeController.kt

@@ -23,7 +23,7 @@ open class MediaDecodeController(val mSurface: Surface, val mFilePath: String, v
      * MediaExtractor extractor = new MediaExtractor();
      * extractor.setDataSource(...);
      * int numTracks = extractor.getTrackCount();
-     * for (int i = 0; i < numTracks; ++i) {
+     * for (int i = 0; i <= numTracks; ++i) {
      *   MediaFormat format = extractor.getTrackFormat(i);
      *   String mime = format.getString(MediaFormat.KEY_MIME);
      *   if (weAreInterestedInThisTrack) {

AndroidMedia/src/main/java/com/frank/androidmedia/controller/MediaMetadataController.kt

@@ -0,0 +1,109 @@
+package com.frank.androidmedia.controller
+
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.media.MediaMetadataRetriever
+import android.util.Log
+import java.lang.Exception
+
+/**
+ * Retrieve media metadata from video or audio,
+ * and get thumbnail/frame from video or audio
+ * @author frank
+ * @date 2022/3/18
+ */
+
+open class MediaMetadataController {
+
+    private var title: String? = null
+    private var duration: Long = 0
+    private var bitrate: Int = 0
+
+    private var width: Int = 0
+    private var height: Int = 0
+    private var frameRate: Float = 0.0f
+
+    private var thumbnail: Bitmap? = null
+
+    private var mRetriever: MediaMetadataRetriever? = null
+
+
+    fun retrieveMetadata(path: String) {
+        val retriever = MediaMetadataRetriever()
+        try {
+            retriever.setDataSource(path)
+            title = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_TITLE)
+            if (title != null) {
+                Log.i(TAG, "title=$title")
+            }
+            val durationStr = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION)
+            if (durationStr != null) {
+                duration = durationStr.toLong()
+                Log.i(TAG, "duration=$duration")
+            }
+            val bitrateStr = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_BITRATE)
+            if (bitrateStr != null) {
+                bitrate = bitrateStr.toInt()
+            }
+            val widthStr = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH)
+            if (widthStr != null) {
+                width = widthStr.toInt()
+            }
+            val heightStr = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT)
+            if (heightStr != null) {
+                height = heightStr.toInt()
+                Log.i(TAG, "video width=$width,height=$height")
+            }
+            try {
+                if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {
+                    val frameRateStr = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_CAPTURE_FRAMERATE)
+                    frameRate = frameRateStr.toFloat()
+                    Log.i(TAG, "frameRate=$frameRate")
+                }
+            } catch (e: Exception) {
+                Log.e(TAG, "retrieve frameRate error=$e")
+            }
+            val hasVideoStr = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_HAS_VIDEO)
+            val hasAudioStr = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_HAS_AUDIO)
+            if (hasVideoStr != null && "yes" == hasVideoStr) {
+                thumbnail = retriever.getFrameAtTime(0)
+            } else if (hasAudioStr != null && "yes" == hasAudioStr) {
+                val byteArray = retriever.embeddedPicture
+                thumbnail = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.size, null)
+            }
+            if (thumbnail != null) {
+                Log.i(TAG, "thumbnail width=${thumbnail?.width}, height=${thumbnail?.height}")
+            }
+        } catch (e: Exception) {
+            Log.e(TAG, "retrieve error=$e")
+        } finally {
+            retriever.release()
+        }
+    }
+
+    fun initRetriever(path: String) {
+        mRetriever = MediaMetadataRetriever()
+        try {
+            mRetriever?.setDataSource(path)
+        } catch (e: Exception) {
+            Log.e(TAG, "initRetriever error=$e")
+        }
+    }
+
+    fun getFrameAtTime(timeUs: Long) : Bitmap? {
+        if (mRetriever == null)
+            return null
+        return mRetriever!!.getFrameAtTime(timeUs)
+    }
+
+    fun releaseRetriever() {
+        if (mRetriever != null) {
+            mRetriever?.release()
+        }
+    }
+
+    companion object {
+        val TAG: String = MediaMetadataController::class.java.simpleName
+    }
+
+}