MediaParser

public final class MediaParser
extends Object

Parses media container formats and extracts contained media samples and metadata.

This class provides access to a battery of low-level media container parsers. Each instance of this class is associated to a specific media parser implementation which is suitable for extraction from a specific media container format. The media parser implementation assignment depends on the factory method (see create(MediaParser.OutputConsumer, String...) and createByName(String, MediaParser.OutputConsumer)) used to create the instance.

Users must implement the following to use this class.

• InputReader: Provides the media container's bytes to parse.
• OutputConsumer: Provides a sink for all extracted data and metadata.

The following code snippet includes a usage example:

 MyOutputConsumer myOutputConsumer = new MyOutputConsumer();
 MyInputReader myInputReader = new MyInputReader("www.example.com");
 MediaParser mediaParser = MediaParser.create(myOutputConsumer);

 while (mediaParser.advance(myInputReader)) {}

 mediaParser.release();
 mediaParser = null;
 

The following code snippet provides a rudimentary OutputConsumer sample implementation which extracts and publishes all video samples:

 class VideoOutputConsumer implements MediaParser.OutputConsumer {

     private static final int MAXIMUM_SAMPLE_SIZE = ...;
     private byte[] sampleDataBuffer = new byte[MAXIMUM_SAMPLE_SIZE];
     private int videoTrackIndex = -1;
     private int bytesWrittenCount = 0;

     \@Override
     public void onSeekMap(int i, @NonNull MediaFormat mediaFormat) { \/* Do nothing. *\/ }

     \@Override
     public void onTrackData(int i, @NonNull TrackData trackData) {
       MediaFormat mediaFormat = trackData.mediaFormat;
       if (videoTrackIndex == -1 && mediaFormat
           .getString(MediaFormat.KEY_MIME, \/* defaultValue= *\/ "").startsWith("video/")) {
         videoTrackIndex = i;
       }
     }

     \@Override
     public void onSampleData(int trackIndex, @NonNull InputReader inputReader)
         throws IOException, InterruptedException {
       int numberOfBytesToRead = (int) inputReader.getLength();
       if (videoTrackIndex != trackIndex) {
         // Discard contents.
         inputReader.read(\/* bytes= *\/ null, \/* offset= *\/ 0, numberOfBytesToRead);
       }
       int bytesRead = inputReader.read(sampleDataBuffer, bytesWrittenCount, numberOfBytesToRead);
       bytesWrittenCount += bytesRead;
     }

     \@Override
     public void onSampleCompleted(
         int trackIndex,
         long timeUs,
         int flags,
         int size,
         int offset,
         \@Nullable CryptoInfo cryptoData) {
       if (videoTrackIndex != trackIndex) {
         return; // It's not the video track. Ignore.
       }
       byte[] sampleData = new byte[size];
       System.arraycopy(sampleDataBuffer, bytesWrittenCount - size - offset, sampleData, \/*
       destPos= *\/ 0, size);
       // Place trailing bytes at the start of the buffer.
       System.arraycopy(
           sampleDataBuffer,
           bytesWrittenCount - offset,
           sampleDataBuffer,
           \/* destPos= *\/ 0,
           \/* size= *\/ offset);
       publishSample(sampleData, timeUs, flags);
     }
   }

 

Summary

Public methods

public boolean advance (MediaParser.SeekableInputReader seekableInputReader)

public static MediaParser create (MediaParser.OutputConsumer outputConsumer, 
                String... extractorNames)

public static MediaParser createByName (String name, 
                MediaParser.OutputConsumer outputConsumer)

public String getExtractorName ()

public static List<String> getExtractorNames (MediaFormat mediaFormat)

public void release ()

public void seek (MediaParser.SeekPoint seekPoint)