Video cropping to any dimension (#6)

* Rename MediaTranscoder to Transcoder, MediaTranscoderOptions to TranscoderOptions

* Start supporting different aspect ratios

* Rename QueuedMuxer to TranscoderMuxer

* Pass scaleX and scaleY to video track transcoder

* Apply scale to GL matrix

* Create AspectRatioResizer and document

* Update sample app

* Use TrackType everywhere and simplify logic

Author: natario1

README.md

@@ -13,12 +13,12 @@ implementation 'com.otaliastudios:transcoder:0.4.0'
 Using Transcoder in the most basic form is pretty simple:
 
 ```java
-MediaTranscoder.into(filePath)
+Transcoder.into(filePath)
         .setDataSource(context, uri) // or...
         .setDataSource(filePath) // or...
         .setDataSource(fileDescriptor) // or...
         .setDataSource(dataSource)
-        .setListener(new MediaTranscoder.Listener() {
+        .setListener(new TranscoderListener() {
              public void onTranscodeProgress(double progress) {}
              public void onTranscodeCompleted(int successCode) {}
              public void onTranscodeCanceled() {}
@@ -32,6 +32,7 @@ Take a look at the demo app for a real example or keep reading below for documen
 It features a lot of improvements over the original project, including:*
 
 - *Multithreading support*
+- *Crop to any aspect ratio*
 - *Various bugs fixed*
 - *[Input](#data-sources): Accept content Uris and other types*
 - *[Real error handling](#listening-for-events) instead of errors being thrown*
@@ -83,9 +84,9 @@ Transcoding will happen on a background thread, but we will send updates through
 interface, which can be applied when building the request:
 
 ```java
-MediaTranscoder.into(filePath)
+Transcoder.into(filePath)
         .setListenerHandler(handler)
-        .setListener(new MediaTranscoder.Listener() {
+        .setListener(new TranscoderListener() {
              public void onTranscodeProgress(double progress) {}
              public void onTranscodeCompleted(int successCode) {}
              public void onTranscodeCanceled() {}
@@ -137,7 +138,7 @@ Validators tell the engine whether the transcoding process should start or not b
 of the audio and video track.
 
 ```java
-MediaTranscoder.into(filePath)
+Transcoder.into(filePath)
         .setValidator(validator)
         // ...
 ```
@@ -184,7 +185,7 @@ Output strategies return options for each track (audio or video) for the engine
 and **if** this track should be transcoded, and whether the whole process should be aborted.
 
 ```java
-MediaTranscoder.into(filePath)
+Transcoder.into(filePath)
         .setVideoOutputStrategy(videoStrategy)
         .setAudioOutputStrategy(audioStrategy)
         // ...
@@ -217,7 +218,7 @@ The default internal strategy for audio is a `DefaultAudioStrategy`, which conve
 audio stream to AAC format with the specified number of channels.
 
 ```java
-MediaTranscoder.into(filePath)
+Transcoder.into(filePath)
         .setAudioOutputStrategy(DefaultAudioStrategy(1)) // or..
         .setAudioOutputStrategy(DefaultAudioStrategy(2)) // or..
         .setAudioOutputStrategy(DefaultAudioStrategy(DefaultAudioStrategy.AUDIO_CHANNELS_AS_IS))
@@ -229,8 +230,9 @@ Take a look at the source code to understand how to manage the `android.media.Me
 ## Video Strategies
 
 The default internal strategy for video is a `DefaultVideoStrategy`, which converts the
-video stream to AVC format and is very configurable. The class helps in defining an output size
-that matches the aspect ratio of the input stream size, which is a basic requirement for video strategies.
+video stream to AVC format and is very configurable. The class helps in defining an output size.
+If the output size does not match the aspect ratio of the input stream size, `Transcoder` will
+crop part of the input so it matches the final ratio.
 
 ### Video Size
 
@@ -239,7 +241,7 @@ We provide helpers for common tasks:
 ```java
 DefaultVideoStrategy strategy;
 
-// Sets an exact size. Of course this is risky if you don't read the input size first.
+// Sets an exact size. If aspect ratio does not match, cropping will take place.
 strategy = DefaultVideoStrategy.exact(1080, 720).build()
 
 // Keeps the aspect ratio, but scales down the input size with the given fraction.
@@ -257,7 +259,8 @@ resizer. We offer handy resizers:
 
 |Name|Description|
 |----|-----------|
-|`ExactResizer`|Returns the dimensions passed to the constructor. Throws if aspect ratio does not match.|
+|`ExactResizer`|Returns the exact dimensions passed to the constructor.|
+|`AspectRatioResizer`|Crops the input size to match the given aspect ratio.|
 |`FractionResizer`|Reduces the input size by the given fraction (0..1).|
 |`AtMostResizer`|If needed, reduces the input size so that the "at most" constraints are matched. Aspect ratio is kept.|
 |`PassThroughResizer`|Returns the input size unchanged.|
@@ -269,12 +272,18 @@ You can also group resizers through `MultiResizer`, which applies resizers in ch
 Resizer resizer = new MultiResizer()
 resizer.addResizer(new FractionResizer(0.5F))
 resizer.addResizer(new AtMostResizer(1000))
+
+// First makes it 16:9, then ensures size is at most 1000. Order matters!
+Resizer resizer = new MultiResizer()
+resizer.addResizer(new AspectRatioResizer(16F / 9F))
+resizer.addResizer(new AtMostResizer(1000))
 ```
 
 This option is already available through the DefaultVideoStrategy builder, so you can do:
 
 ```java
 DefaultVideoStrategy strategy = new DefaultVideoStrategy.Builder()
+        .addResizer(new AspectRatioResizer(16F / 9F))
         .addResizer(new FractionResizer(0.5F))
         .addResizer(new AtMostResizer(1000))
         .build()
@@ -305,7 +314,7 @@ Only a few codecs and sizes are strictly required to work.
 We collect common presets in the `DefaultVideoStrategies` class:
 
 ```java
-MediaTranscoder.into(filePath)
+Transcoder.into(filePath)
         .setVideoOutputStrategy(DefaultVideoStrategies.for720x1280()) // 16:9
         .setVideoOutputStrategy(DefaultVideoStrategies.for360x480()) // 4:3
         // ...

demo/src/main/java/com/otaliastudios/transcoder/demo/TranscoderActivity.java

@@ -9,13 +9,15 @@
 import android.widget.TextView;
 import android.widget.Toast;
 
-import com.otaliastudios.transcoder.MediaTranscoder;
+import com.otaliastudios.transcoder.Transcoder;
+import com.otaliastudios.transcoder.TranscoderListener;
 import com.otaliastudios.transcoder.internal.Logger;
 import com.otaliastudios.transcoder.strategy.DefaultAudioStrategy;
 import com.otaliastudios.transcoder.strategy.DefaultVideoStrategy;
 import com.otaliastudios.transcoder.strategy.OutputStrategy;
+import com.otaliastudios.transcoder.strategy.size.AspectRatioResizer;
 import com.otaliastudios.transcoder.strategy.size.FractionResizer;
-import com.otaliastudios.transcoder.strategy.size.Resizer;
+import com.otaliastudios.transcoder.strategy.size.PassThroughResizer;
 
 import java.io.File;
 import java.io.IOException;
@@ -27,7 +29,7 @@
 
 
 public class TranscoderActivity extends AppCompatActivity implements
-        MediaTranscoder.Listener,
+        TranscoderListener,
         RadioGroup.OnCheckedChangeListener {
 
     private static final String TAG = "DemoApp";
@@ -40,6 +42,7 @@ public class TranscoderActivity extends AppCompatActivity implements
     private RadioGroup mAudioChannelsGroup;
     private RadioGroup mVideoFramesGroup;
     private RadioGroup mVideoResolutionGroup;
+    private RadioGroup mVideoAspectGroup;
     private ProgressBar mProgressView;
     private TextView mButtonView;
 
@@ -73,9 +76,11 @@ protected void onCreate(Bundle savedInstanceState) {
         mAudioChannelsGroup = findViewById(R.id.channels);
         mVideoFramesGroup = findViewById(R.id.frames);
         mVideoResolutionGroup = findViewById(R.id.resolution);
+        mVideoAspectGroup = findViewById(R.id.aspect);
         mAudioChannelsGroup.setOnCheckedChangeListener(this);
         mVideoFramesGroup.setOnCheckedChangeListener(this);
         mVideoResolutionGroup.setOnCheckedChangeListener(this);
+        mVideoAspectGroup.setOnCheckedChangeListener(this);
         syncParameters();
     }
 
@@ -106,8 +111,16 @@ private void syncParameters() {
             case R.id.resolution_third: fraction = 1F / 3F; break;
             default: fraction = 1F;
         }
-        mTranscodeVideoStrategy = DefaultVideoStrategy
-                .fraction(fraction)
+        float aspectRatio;
+        switch (mVideoAspectGroup.getCheckedRadioButtonId()) {
+            case R.id.aspect_169: aspectRatio = 16F / 9F; break;
+            case R.id.aspect_43: aspectRatio = 4F / 3F; break;
+            case R.id.aspect_square: aspectRatio = 1F; break;
+            default: aspectRatio = 0F;
+        }
+        mTranscodeVideoStrategy = new DefaultVideoStrategy.Builder()
+                .addResizer(aspectRatio > 0 ? new AspectRatioResizer(aspectRatio) : new PassThroughResizer())
+                .addResizer(new FractionResizer(fraction))
                 .frameRate(frames)
                 .build();
     }
@@ -146,7 +159,7 @@ private void transcode() {
         // Launch the transcoding operation.
         mTranscodeStartTime = SystemClock.uptimeMillis();
         setIsTranscoding(true);
-        mTranscodeFuture = MediaTranscoder.into(mTranscodeOutputFile.getAbsolutePath())
+        mTranscodeFuture = Transcoder.into(mTranscodeOutputFile.getAbsolutePath())
                 .setDataSource(this, mTranscodeInputUri)
                 .setListener(this)
                 .setAudioOutputStrategy(mTranscodeAudioStrategy)
@@ -166,7 +179,7 @@ public void onTranscodeProgress(double progress) {
 
     @Override
     public void onTranscodeCompleted(int successCode) {
-        if (successCode == MediaTranscoder.SUCCESS_TRANSCODED) {
+        if (successCode == Transcoder.SUCCESS_TRANSCODED) {
             LOG.w("Transcoding took " + (SystemClock.uptimeMillis() - mTranscodeStartTime) + "ms");
             onTranscodeFinished(true, "Transcoded file placed on " + mTranscodeOutputFile);
             Uri uri = FileProvider.getUriForFile(TranscoderActivity.this,
@@ -175,7 +188,7 @@ public void onTranscodeCompleted(int successCode) {
             startActivity(new Intent(Intent.ACTION_VIEW)
                     .setDataAndType(uri, "video/mp4")
                     .setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION));
-        } else if (successCode == MediaTranscoder.SUCCESS_NOT_NEEDED) {
+        } else if (successCode == Transcoder.SUCCESS_NOT_NEEDED) {
             // TODO: Not sure this works
             LOG.i("Transcoding was not needed.");
             onTranscodeFinished(true, "Transcoding not needed, source file not touched.");

demo/src/main/res/layout/activity_transcoder.xml

@@ -126,6 +126,49 @@
                     android:layout_height="wrap_content" />
             </RadioGroup>
 
+            <!-- VIDEO ASPECT RATIO -->
+            <TextView
+                android:padding="16dp"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="Video aspect ratio" />
+            <RadioGroup
+                android:id="@+id/aspect"
+                android:checkedButton="@id/aspect_input"
+                android:orientation="horizontal"
+                android:gravity="center"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+                <com.google.android.material.radiobutton.MaterialRadioButton
+                    android:id="@+id/aspect_input"
+                    android:text="As input"
+                    android:paddingLeft="8dp"
+                    android:paddingRight="8dp"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content" />
+                <com.google.android.material.radiobutton.MaterialRadioButton
+                    android:id="@+id/aspect_169"
+                    android:text="16:9"
+                    android:paddingLeft="8dp"
+                    android:paddingRight="8dp"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content" />
+                <com.google.android.material.radiobutton.MaterialRadioButton
+                    android:id="@+id/aspect_43"
+                    android:text="4:3"
+                    android:paddingLeft="8dp"
+                    android:paddingRight="8dp"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content" />
+                <com.google.android.material.radiobutton.MaterialRadioButton
+                    android:id="@+id/aspect_square"
+                    android:text="Square"
+                    android:paddingLeft="8dp"
+                    android:paddingRight="8dp"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content" />
+            </RadioGroup>
+
             <!-- INFO TEXT -->
             <TextView
                 android:padding="16dp"