TrimDataSource (#50)

* Add support for trim, related to issue #37 - New component TrimDataSource, wrapping DataSource to be trimmed. - MediaExtractorDataSource is an abstract class to limit visibility of MediaExtractor to package - Updates to Engine to replace selectAudio/transcode/selectVideo/transcode sequence by selectAudio/selectVideo/transcode/transcode * Added support for TrimDataSource into demo app Using 2 editText fields, default value is zero. * TranscoderOptions Builder support for TrimDataSource Builder can add directly trim values for UriDataSource * TrimDataSource updates following PR code review - fixed case where video track is absent - throw exceptions for invalid trim values * Removed unnecessary changes to Engine In the original sequence selectAudio / transcodeAudio / selectVideo / transcodeVideo the first step (selectAudio) is intercepted by selectVideo + seekVideo and the 3rd step (selectVideo) is skipped. So it becomes selectVideo / seekVideo / selectAudio / transcodeAudio / transcodeVideo - Also added throws IllegalArgumentException to TrimDataSource * Moved seekTo() from selectTrack() to canReadTrack() Cleaner simplified code :) The extractor needs a second call to seekTo() after reaching a video keyframe, to obtain better values for audio track. Otherwise, too many audio frames can be lost, causing visible off-sync. * Removed MediaExtractorDataSource Replaced by adding seekTo() to DataSource interface * Removed timestamp adjustment The rest of the lib already assumes that timestamps start from arbitrary values. * Use TrackTypeMap for readyTracks flags replacing two booleans * Handle trimEnd in isDrained() Stop reading when readUs is past duration. This removes the need to manually define KEY_DURATION in the mediaFormat * Fix seek vs canRead order to avoid possible bug where seekTo lands on a different track. Ex: The upstream source might be on AUDIO position, but if you seek later, the next position might VIDEO instead. * Apply seekTo() once per selected track - Updates to Engine to replace selectAudio/transcode/selectVideo/transcode sequence by selectAudio/selectVideo/transcode/transcode - remove unnecessary hasTrack() - seekTo() is applied in canReadTrack(), once per selected track. This now works because all track selection operations are done before the first call to canReadTrack(). - When 2 tracks are selected, seekTo() is called twice and this helps the extractor with Audio sampleTime issues. * seekBy() replaces seekTo(), selecting all tracks - reverted unnecessary changes to Engine class. Previous changes cannot guarantee that all calls to selectTracks() are done before the first canRead(). Latest bug was with merging multiple trimmed files. - use seekBy() to better handle first extractor timestamp - DefaultDataSource makes sure all available tracks are selected by extractor (without adding to mSelectedTracks array). Then seekTo() is called mutlitple times, using the resulting sampletimeUs for the later calls.

Author: mudar

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

@@ -3,10 +3,12 @@
 import android.annotation.SuppressLint;
 import android.content.ClipData;
 import android.content.Intent;
-import android.media.MediaMuxer;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.SystemClock;
+import android.text.Editable;
+import android.text.TextWatcher;
+import android.widget.EditText;
 import android.widget.ProgressBar;
 import android.widget.RadioGroup;
 import android.widget.TextView;
@@ -61,6 +63,8 @@ public class TranscoderActivity extends AppCompatActivity implements
 
  private ProgressBar mProgressView;
  private TextView mButtonView;
+ private EditText mTrimStartView;
+ private EditText mTrimEndView;
  private TextView mAudioReplaceView;
 
  private boolean mIsTranscoding;
@@ -74,6 +78,52 @@ public class TranscoderActivity extends AppCompatActivity implements
  private long mTranscodeStartTime;
  private TrackStrategy mTranscodeVideoStrategy;
  private TrackStrategy mTranscodeAudioStrategy;
+ private long mTrimStartUs = 0;
+ private long mTrimEndUs = 0;
+
+ private TextWatcher mTrimStartTextWatcher = new TextWatcher() {
+ @Override
+ public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+ }
+
+ @Override
+ public void onTextChanged(CharSequence s, int start, int before, int count) {
+ }
+
+ @Override
+ public void afterTextChanged(Editable s) {
+ if (s.length() > 0) {
+ try {
+ mTrimStartUs = Long.valueOf(s.toString()) * 1000000;
+ } catch (NumberFormatException e) {
+ mTrimStartUs = 0;
+ LOG.w("Failed to read trimStart value.");
+ }
+ }
+ }
+ };
+ private TextWatcher mTrimEndTextWatcher = new TextWatcher() {
+ @Override
+ public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+ }
+
+ @Override
+ public void onTextChanged(CharSequence s, int start, int before, int count) {
+ }
+
+ @Override
+ public void afterTextChanged(Editable s) {
+ if (s.length() > 0) {
+ try {
+ mTrimEndUs = Long.valueOf(s.toString()) * 1000000;
+ } catch (NumberFormatException e) {
+ mTrimEndUs = 0;
+ LOG.w("Failed to read trimEnd value.");
+ }
+ }
+ }
+ };
+
 
  @SuppressLint("SetTextI18n")
  @Override
@@ -97,6 +147,8 @@ protected void onCreate(Bundle savedInstanceState) {
  mProgressView = findViewById(R.id.progress);
  mProgressView.setMax(PROGRESS_BAR_MAX);
 
+ mTrimStartView = findViewById(R.id.trim_start);
+ mTrimEndView = findViewById(R.id.trim_end);
  mAudioReplaceView = findViewById(R.id.replace_info);
 
  mAudioChannelsGroup = findViewById(R.id.channels);
@@ -113,6 +165,8 @@ protected void onCreate(Bundle savedInstanceState) {
  mVideoResolutionGroup.setOnCheckedChangeListener(this);
  mVideoAspectGroup.setOnCheckedChangeListener(this);
  mAudioSampleRateGroup.setOnCheckedChangeListener(this);
+ mTrimStartView.addTextChangedListener(mTrimStartTextWatcher);
+ mTrimEndView.addTextChangedListener(mTrimEndTextWatcher);
  syncParameters();
 
  mAudioReplaceGroup.setOnCheckedChangeListener((group, checkedId) -> {
@@ -257,13 +311,27 @@ private void transcode() {
  DataSink sink = new DefaultDataSink(mTranscodeOutputFile.getAbsolutePath());
  TranscoderOptions.Builder builder = Transcoder.into(sink);
  if (mAudioReplacementUri == null) {
- if (mTranscodeInputUri1 != null) builder.addDataSource(this, mTranscodeInputUri1);
- if (mTranscodeInputUri2 != null) builder.addDataSource(this, mTranscodeInputUri2);
- if (mTranscodeInputUri3 != null) builder.addDataSource(this, mTranscodeInputUri3);
+ if (mTrimStartUs > 0 || mTrimEndUs > 0) {
+ if (mTranscodeInputUri1 != null) builder.addDataSource(this, mTranscodeInputUri1, mTrimStartUs, mTrimEndUs);
+ if (mTranscodeInputUri2 != null) builder.addDataSource(this, mTranscodeInputUri2, mTrimStartUs, mTrimEndUs);
+ if (mTranscodeInputUri3 != null) builder.addDataSource(this, mTranscodeInputUri3, mTrimStartUs, mTrimEndUs);
+ }
+ else {
+ if (mTranscodeInputUri1 != null) builder.addDataSource(this, mTranscodeInputUri1);
+ if (mTranscodeInputUri2 != null) builder.addDataSource(this, mTranscodeInputUri2);
+ if (mTranscodeInputUri3 != null) builder.addDataSource(this, mTranscodeInputUri3);
+ }
  } else {
- if (mTranscodeInputUri1 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri1);
- if (mTranscodeInputUri2 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri2);
- if (mTranscodeInputUri3 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri3);
+ if (mTrimStartUs > 0 || mTrimEndUs > 0) {
+ if (mTranscodeInputUri1 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri1, mTrimStartUs, mTrimEndUs);
+ if (mTranscodeInputUri2 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri2, mTrimStartUs, mTrimEndUs);
+ if (mTranscodeInputUri3 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri3, mTrimStartUs, mTrimEndUs);
+ }
+ else {
+ if (mTranscodeInputUri1 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri1);
+ if (mTranscodeInputUri2 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri2);
+ if (mTranscodeInputUri3 != null) builder.addDataSource(TrackType.VIDEO, this, mTranscodeInputUri3);
+ }
  builder.addDataSource(TrackType.AUDIO, this, mAudioReplacementUri);
  }
  mTranscodeFuture = builder.setListener(this)

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

@@ -285,6 +285,55 @@
  android:layout_height="wrap_content" />
  </RadioGroup>
 
+ <!-- TRIM -->
+ <TextView
+ android:layout_width="match_parent"
+ android:layout_height="wrap_content"
+ android:padding="16dp"
+ android:text="Trim (seconds)" />
+
+ <LinearLayout
+ android:layout_width="match_parent"
+ android:layout_height="?attr/listPreferredItemHeightSmall"
+ android:gravity="center"
+ android:orientation="horizontal">
+
+ <TextView
+ android:layout_width="wrap_content"
+ android:layout_height="wrap_content"
+ android:layout_marginEnd="8dp"
+ android:text="Start:" />
+
+ <com.google.android.material.textfield.TextInputEditText
+ android:id="@+id/trim_start"
+ android:layout_width="wrap_content"
+ android:layout_height="match_parent"
+ android:inputType="number"
+ android:maxLines="1"
+ android:gravity="center_horizontal"
+ android:minWidth="48dp"
+ android:singleLine="true"
+ android:text="0" />
+
+ <TextView
+ android:layout_width="wrap_content"
+ android:layout_height="wrap_content"
+ android:layout_marginStart="32dp"
+ android:layout_marginEnd="8dp"
+ android:text="End:" />
+
+ <com.google.android.material.textfield.TextInputEditText
+ android:id="@+id/trim_end"
+ android:layout_width="wrap_content"
+ android:layout_height="match_parent"
+ android:inputType="number"
+ android:maxLines="1"
+ android:gravity="center_horizontal"
+ android:minWidth="48dp"
+ android:singleLine="true"
+ android:text="0" />
+ </LinearLayout>
+
  <!-- REPLACE AUDIO -->
  <TextView
  android:padding="16dp"

lib/src/main/java/com/otaliastudios/transcoder/TranscoderOptions.java

@@ -13,6 +13,7 @@
 import com.otaliastudios.transcoder.source.DataSource;
 import com.otaliastudios.transcoder.source.FileDescriptorDataSource;
 import com.otaliastudios.transcoder.source.FilePathDataSource;
+import com.otaliastudios.transcoder.source.TrimDataSource;
 import com.otaliastudios.transcoder.source.UriDataSource;
 import com.otaliastudios.transcoder.strategy.DefaultAudioStrategy;
 import com.otaliastudios.transcoder.strategy.DefaultVideoStrategies;
@@ -174,12 +175,24 @@ public Builder addDataSource(@NonNull Context context, @NonNull Uri uri) {
  return addDataSource(new UriDataSource(context, uri));
  }
 
+ @NonNull
+ @SuppressWarnings({"unused", "UnusedReturnValue"})
+ public Builder addDataSource(@NonNull Context context, @NonNull Uri uri, long trimStartUs, long trimEndUs) {
+ return addDataSource(new TrimDataSource(new UriDataSource(context, uri), trimStartUs, trimEndUs));
+ }
+
  @NonNull
  @SuppressWarnings({"unused", "UnusedReturnValue"})
  public Builder addDataSource(@NonNull TrackType type, @NonNull Context context, @NonNull Uri uri) {
  return addDataSource(type, new UriDataSource(context, uri));
  }
 
+ @NonNull
+ @SuppressWarnings({"unused", "UnusedReturnValue"})
+ public Builder addDataSource(@NonNull TrackType type, @NonNull Context context, @NonNull Uri uri, long trimStartUs, long trimEndUs) {
+ return addDataSource(type, new TrimDataSource(new UriDataSource(context, uri), trimStartUs, trimEndUs));
+ }
+
  /**
  * Sets the audio output strategy. If absent, this defaults to
  * {@link com.otaliastudios.transcoder.strategy.DefaultAudioStrategy}.

lib/src/main/java/com/otaliastudios/transcoder/source/DataSource.java

@@ -54,6 +54,14 @@ public interface DataSource {
  */
  void selectTrack(@NonNull TrackType type);
 
+ /**
+ * Moves all selected tracks forward by the specified duration.
+ *
+ * @param durationUs requested duration
+ * @return the new presentation time in microseconds
+ */
+ long seekBy(long durationUs);
+
  /**
  * Returns true if we can read the given track at this point.
  * If true if returned, source should expect a {@link #readTrack(Chunk)} call.

lib/src/main/java/com/otaliastudios/transcoder/source/DefaultDataSource.java

@@ -63,6 +63,22 @@ public void selectTrack(@NonNull TrackType type) {
  mExtractor.selectTrack(mIndex.require(type));
  }
 
+ @Override
+ public long seekBy(long durationUs) {
+ ensureExtractor();
+ final int trackCount = mExtractor.getTrackCount();
+ for (int i = 0; i < trackCount; i++) {
+ mExtractor.selectTrack(i);
+ }
+ long timestampUs = mExtractor.getSampleTime() + durationUs;
+ // Seeking once per track helps the extractor with Audio sampleTime issues
+ for (int i = 0; i < trackCount; i++) {
+ mExtractor.seekTo(timestampUs, MediaExtractor.SEEK_TO_CLOSEST_SYNC);
+ timestampUs = mExtractor.getSampleTime();
+ }
+ return timestampUs;
+ }
+
  @Override
  public boolean isDrained() {
  ensureExtractor();

lib/src/main/java/com/otaliastudios/transcoder/source/TrimDataSource.java

@@ -0,0 +1,115 @@
+package com.otaliastudios.transcoder.source;
+
+
+import android.media.MediaFormat;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.otaliastudios.transcoder.engine.TrackType;
+import com.otaliastudios.transcoder.internal.Logger;
+
+import org.jetbrains.annotations.Contract;
+
+/**
+ * A {@link DataSource} wrapper that trims source at both ends.
+ */
+public class TrimDataSource implements DataSource {
+ private static final String TAG = "TrimDataSource";
+ private static final Logger LOG = new Logger(TAG);
+ @NonNull
+ private DataSource source;
+ private long trimStartUs;
+ private long trimDurationUs;
+ private boolean didSeekTracks = false;
+
+ public TrimDataSource(@NonNull DataSource source, long trimStartUs, long trimEndUs) throws IllegalArgumentException {
+ if (trimStartUs < 0 || trimEndUs < 0) {
+ throw new IllegalArgumentException("Trim values cannot be negative.");
+ }
+ this.source = source;
+ this.trimStartUs = trimStartUs;
+ this.trimDurationUs = computeTrimDuration(source.getDurationUs(), trimStartUs, trimEndUs);
+ }
+
+ @Contract(pure = true)
+ private static long computeTrimDuration(long duration, long trimStart, long trimEnd) throws IllegalArgumentException {
+ if (trimStart + trimEnd > duration) {
+ throw new IllegalArgumentException("Trim values cannot be greater than media duration.");
+ }
+ return duration - trimStart - trimEnd;
+ }
+
+ @Override
+ public int getOrientation() {
+ return source.getOrientation();
+ }
+
+ @Nullable
+ @Override
+ public double[] getLocation() {
+ return source.getLocation();
+ }
+
+ @Override
+ public long getDurationUs() {
+ return trimDurationUs;
+ }
+
+ @Nullable
+ @Override
+ public MediaFormat getTrackFormat(@NonNull TrackType type) {
+ return source.getTrackFormat(type);
+ }
+
+ @Override
+ public void selectTrack(@NonNull TrackType type) {
+ source.selectTrack(type);
+ }
+
+ @Override
+ public long seekBy(long durationUs) {
+ return source.seekBy(durationUs);
+ }
+
+ @Override
+ public boolean canReadTrack(@NonNull TrackType type) {
+ if (!didSeekTracks) {
+ final long sampleTimeUs = seekBy(trimStartUs);
+ updateTrimValues(sampleTimeUs);
+ didSeekTracks = true;
+ }
+ return source.canReadTrack(type);
+ }
+
+ private void updateTrimValues(long timestampUs) {
+ trimDurationUs += trimStartUs - timestampUs;
+ trimStartUs = timestampUs;
+ }
+
+ @Override
+ public void readTrack(@NonNull Chunk chunk) {
+ source.readTrack(chunk);
+ }
+
+ @Override
+ public long getReadUs() {
+ return source.getReadUs();
+ }
+
+ @Override
+ public boolean isDrained() {
+ return source.isDrained() || getReadUs() >= getDurationUs();
+ }
+
+ @Override
+ public void releaseTrack(@NonNull TrackType type) {
+ source.releaseTrack(type);
+ }
+
+ @Override
+ public void rewind() {
+ didSeekTracks = false;
+ source.rewind();
+ }
+}