Make flags-only DecoderInputBuffer hold all flags

Currently a flags-only DecoderInputBuffer may hold only the end-of-stream
flag. This change makes flags-only buffer read any kind of flag set in
the next sample. If no sample is available RESULT_NOTHING_READ is
returned.

PiperOrigin-RevId: 237027581

library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java

@@ -723,8 +723,7 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
     if (result == C.RESULT_FORMAT_READ) {
     if (result == C.RESULT_FORMAT_READ) {
       onInputFormatChanged(formatHolder.format);
       onInputFormatChanged(formatHolder.format);
       return true;
       return true;
-    } else if (result == C.RESULT_BUFFER_READ) {
-      Assertions.checkState(flagsOnlyBuffer.isEndOfStream());
+    } else if (result == C.RESULT_BUFFER_READ && flagsOnlyBuffer.isEndOfStream()) {
       inputStreamEnded = true;
       inputStreamEnded = true;
       processEndOfStream();
       processEndOfStream();
     }
     }

library/core/src/main/java/com/google/android/exoplayer2/source/SampleMetadataQueue.java

@@ -219,25 +219,31 @@ import com.google.android.exoplayer2.util.Util;
    *
    *
    * @param formatHolder A {@link FormatHolder} to populate in the case of reading a format.
    * @param formatHolder A {@link FormatHolder} to populate in the case of reading a format.
    * @param buffer A {@link DecoderInputBuffer} to populate in the case of reading a sample or the
    * @param buffer A {@link DecoderInputBuffer} to populate in the case of reading a sample or the
-   *     end of the stream. If a sample is read then the buffer is populated with information
-   *     about the sample, but not its data. The size and absolute position of the data in the
-   *     rolling buffer is stored in {@code extrasHolder}, along with an encryption id if present
-   *     and the absolute position of the first byte that may still be required after the current
-   *     sample has been read. May be null if the caller requires that the format of the stream be
-   *     read even if it's not changing.
-   * @param formatRequired Whether the caller requires that the format of the stream be read even
-   *     if it's not changing. A sample will never be read if set to true, however it is still
-   *     possible for the end of stream or nothing to be read.
+   *     end of the stream. If a sample is read then the buffer is populated with information about
+   *     the sample, but not its data. The size and absolute position of the data in the rolling
+   *     buffer is stored in {@code extrasHolder}, along with an encryption id if present and the
+   *     absolute position of the first byte that may still be required after the current sample has
+   *     been read. If a {@link DecoderInputBuffer#isFlagsOnly() flags-only} buffer is passed, only
+   *     the buffer flags may be populated by this method and the read position of the queue will
+   *     not change. May be null if the caller requires that the format of the stream be read even
+   *     if it's not changing.
+   * @param formatRequired Whether the caller requires that the format of the stream be read even if
+   *     it's not changing. A sample will never be read if set to true, however it is still possible
+   *     for the end of stream or nothing to be read.
    * @param loadingFinished True if an empty queue should be considered the end of the stream.
    * @param loadingFinished True if an empty queue should be considered the end of the stream.
-   * @param downstreamFormat The current downstream {@link Format}. If the format of the next
-   *     sample is different to the current downstream format then a format will be read.
+   * @param downstreamFormat The current downstream {@link Format}. If the format of the next sample
+   *     is different to the current downstream format then a format will be read.
    * @param extrasHolder The holder into which extra sample information should be written.
    * @param extrasHolder The holder into which extra sample information should be written.
-   * @return The result, which can be {@link C#RESULT_NOTHING_READ}, {@link C#RESULT_FORMAT_READ}
-   *     or {@link C#RESULT_BUFFER_READ}.
+   * @return The result, which can be {@link C#RESULT_NOTHING_READ}, {@link C#RESULT_FORMAT_READ} or
+   *     {@link C#RESULT_BUFFER_READ}.
    */
    */
   @SuppressWarnings("ReferenceEquality")
   @SuppressWarnings("ReferenceEquality")
-  public synchronized int read(FormatHolder formatHolder, DecoderInputBuffer buffer,
-      boolean formatRequired, boolean loadingFinished, Format downstreamFormat,
+  public synchronized int read(
+      FormatHolder formatHolder,
+      DecoderInputBuffer buffer,
+      boolean formatRequired,
+      boolean loadingFinished,
+      Format downstreamFormat,
       SampleExtrasHolder extrasHolder) {
       SampleExtrasHolder extrasHolder) {
     if (!hasNextSample()) {
     if (!hasNextSample()) {
       if (loadingFinished || isLastSampleQueued) {
       if (loadingFinished || isLastSampleQueued) {
@@ -258,12 +264,12 @@ import com.google.android.exoplayer2.util.Util;
       return C.RESULT_FORMAT_READ;
       return C.RESULT_FORMAT_READ;
     }
     }
 
 
+    buffer.setFlags(flags[relativeReadIndex]);
+    buffer.timeUs = timesUs[relativeReadIndex];
     if (buffer.isFlagsOnly()) {
     if (buffer.isFlagsOnly()) {
-      return C.RESULT_NOTHING_READ;
+      return C.RESULT_BUFFER_READ;
     }
     }
 
 
-    buffer.timeUs = timesUs[relativeReadIndex];
-    buffer.setFlags(flags[relativeReadIndex]);
     extrasHolder.size = sizes[relativeReadIndex];
     extrasHolder.size = sizes[relativeReadIndex];
     extrasHolder.offset = offsets[relativeReadIndex];
     extrasHolder.offset = offsets[relativeReadIndex];
     extrasHolder.cryptoData = cryptoDatas[relativeReadIndex];
     extrasHolder.cryptoData = cryptoDatas[relativeReadIndex];

library/core/src/main/java/com/google/android/exoplayer2/source/SampleQueue.java

@@ -317,8 +317,10 @@ public class SampleQueue implements TrackOutput {
    *
    *
    * @param formatHolder A {@link FormatHolder} to populate in the case of reading a format.
    * @param formatHolder A {@link FormatHolder} to populate in the case of reading a format.
    * @param buffer A {@link DecoderInputBuffer} to populate in the case of reading a sample or the
    * @param buffer A {@link DecoderInputBuffer} to populate in the case of reading a sample or the
-   *     end of the stream. If the end of the stream has been reached, the
-   *     {@link C#BUFFER_FLAG_END_OF_STREAM} flag will be set on the buffer.
+   *     end of the stream. If the end of the stream has been reached, the {@link
+   *     C#BUFFER_FLAG_END_OF_STREAM} flag will be set on the buffer. If a {@link
+   *     DecoderInputBuffer#isFlagsOnly() flags-only} buffer is passed, only the buffer flags may be
+   *     populated by this method and the read position of the queue will not change.
    * @param formatRequired Whether the caller requires that the format of the stream be read even if
    * @param formatRequired Whether the caller requires that the format of the stream be read even if
    *     it's not changing. A sample will never be read if set to true, however it is still possible
    *     it's not changing. A sample will never be read if set to true, however it is still possible
    *     for the end of stream or nothing to be read.
    *     for the end of stream or nothing to be read.
@@ -328,8 +330,12 @@ public class SampleQueue implements TrackOutput {
    * @return The result, which can be {@link C#RESULT_NOTHING_READ}, {@link C#RESULT_FORMAT_READ} or
    * @return The result, which can be {@link C#RESULT_NOTHING_READ}, {@link C#RESULT_FORMAT_READ} or
    *     {@link C#RESULT_BUFFER_READ}.
    *     {@link C#RESULT_BUFFER_READ}.
    */
    */
-  public int read(FormatHolder formatHolder, DecoderInputBuffer buffer, boolean formatRequired,
-      boolean loadingFinished, long decodeOnlyUntilUs) {
+  public int read(
+      FormatHolder formatHolder,
+      DecoderInputBuffer buffer,
+      boolean formatRequired,
+      boolean loadingFinished,
+      long decodeOnlyUntilUs) {
     int result = metadataQueue.read(formatHolder, buffer, formatRequired, loadingFinished,
     int result = metadataQueue.read(formatHolder, buffer, formatRequired, loadingFinished,
         downstreamFormat, extrasHolder);
         downstreamFormat, extrasHolder);
     switch (result) {
     switch (result) {
@@ -341,13 +347,15 @@ public class SampleQueue implements TrackOutput {
           if (buffer.timeUs < decodeOnlyUntilUs) {
           if (buffer.timeUs < decodeOnlyUntilUs) {
             buffer.addFlag(C.BUFFER_FLAG_DECODE_ONLY);
             buffer.addFlag(C.BUFFER_FLAG_DECODE_ONLY);
           }
           }
-          // Read encryption data if the sample is encrypted.
-          if (buffer.isEncrypted()) {
-            readEncryptionData(buffer, extrasHolder);
+          if (!buffer.isFlagsOnly()) {
+            // Read encryption data if the sample is encrypted.
+            if (buffer.isEncrypted()) {
+              readEncryptionData(buffer, extrasHolder);
+            }
+            // Write the sample data into the holder.
+            buffer.ensureSpaceForWrite(extrasHolder.size);
+            readData(extrasHolder.offset, buffer.data, extrasHolder.size);
           }
           }
-          // Write the sample data into the holder.
-          buffer.ensureSpaceForWrite(extrasHolder.size);
-          readData(extrasHolder.offset, buffer.data, extrasHolder.size);
         }
         }
         return C.RESULT_BUFFER_READ;
         return C.RESULT_BUFFER_READ;
       case C.RESULT_NOTHING_READ:
       case C.RESULT_NOTHING_READ:

library/core/src/main/java/com/google/android/exoplayer2/source/SampleStream.java

@@ -45,18 +45,20 @@ public interface SampleStream {
 
 
   /**
   /**
    * Attempts to read from the stream.
    * Attempts to read from the stream.
-   * <p>
-   * If the stream has ended then {@link C#BUFFER_FLAG_END_OF_STREAM} flag is set on {@code buffer}
-   * and {@link C#RESULT_BUFFER_READ} is returned. Else if no data is available then
-   * {@link C#RESULT_NOTHING_READ} is returned. Else if the format of the media is changing or if
-   * {@code formatRequired} is set then {@code formatHolder} is populated and
-   * {@link C#RESULT_FORMAT_READ} is returned. Else {@code buffer} is populated and
-   * {@link C#RESULT_BUFFER_READ} is returned.
+   *
+   * <p>If the stream has ended then {@link C#BUFFER_FLAG_END_OF_STREAM} flag is set on {@code
+   * buffer} and {@link C#RESULT_BUFFER_READ} is returned. Else if no data is available then {@link
+   * C#RESULT_NOTHING_READ} is returned. Else if the format of the media is changing or if {@code
+   * formatRequired} is set then {@code formatHolder} is populated and {@link C#RESULT_FORMAT_READ}
+   * is returned. Else {@code buffer} is populated and {@link C#RESULT_BUFFER_READ} is returned.
    *
    *
    * @param formatHolder A {@link FormatHolder} to populate in the case of reading a format.
    * @param formatHolder A {@link FormatHolder} to populate in the case of reading a format.
    * @param buffer A {@link DecoderInputBuffer} to populate in the case of reading a sample or the
    * @param buffer A {@link DecoderInputBuffer} to populate in the case of reading a sample or the
-   *     end of the stream. If the end of the stream has been reached, the
-   *     {@link C#BUFFER_FLAG_END_OF_STREAM} flag will be set on the buffer.
+   *     end of the stream. If the end of the stream has been reached, the {@link
+   *     C#BUFFER_FLAG_END_OF_STREAM} flag will be set on the buffer. If a {@link
+   *     DecoderInputBuffer#isFlagsOnly() flags-only} buffer is passed, then no {@link
+   *     DecoderInputBuffer#data} will be read and the read position of the stream will not change,
+   *     but the flags of the buffer will be populated.
    * @param formatRequired Whether the caller requires that the format of the stream be read even if
    * @param formatRequired Whether the caller requires that the format of the stream be read even if
    *     it's not changing. A sample will never be read if set to true, however it is still possible
    *     it's not changing. A sample will never be read if set to true, however it is still possible
    *     for the end of stream or nothing to be read.
    *     for the end of stream or nothing to be read.

library/core/src/main/java/com/google/android/exoplayer2/source/SingleSampleMediaPeriod.java

@@ -326,8 +326,11 @@ import java.util.Arrays;
         return C.RESULT_FORMAT_READ;
         return C.RESULT_FORMAT_READ;
       } else if (loadingFinished) {
       } else if (loadingFinished) {
         if (loadingSucceeded) {
         if (loadingSucceeded) {
-          buffer.timeUs = 0;
           buffer.addFlag(C.BUFFER_FLAG_KEY_FRAME);
           buffer.addFlag(C.BUFFER_FLAG_KEY_FRAME);
+          buffer.timeUs = 0;
+          if (buffer.isFlagsOnly()) {
+            return C.RESULT_BUFFER_READ;
+          }
           buffer.ensureSpaceForWrite(sampleSize);
           buffer.ensureSpaceForWrite(sampleSize);
           buffer.data.put(sampleData, 0, sampleSize);
           buffer.data.put(sampleData, 0, sampleSize);
         } else {
         } else {