Android MedieCodec hard decoding mp3 and wma

Android MedieCodec hard decoding mp3 and wma

1 mediecodec supports more than 4.1 of systems and is a class of Google SDK.

2. decoding mp3 and wma audio files

3. Before decoding, The MediaExactor needs to extract the file information, including the file type, sampling rate,

 

 

Package com. dawin. mediacodec; import java. io. IOException; import java. nio. byteBuffer; import android. media. mediaCodec; import android. media. mediaExtractor; import android. media. mediaFormat; import android. media. mediaCodec. bufferInfo; public class MediaCodecTest {byte [] decodeData = new byte [1024*1024*20]; // 20 mMediaCodec; MediaExtractor mediaExtractor; MediaFormat mMediaFormat; final int TIMEO UT_US = 1000; BufferInfo info; boolean sawOutputEOS = false; boolean sawInputEOS = false; ByteBuffer [] codecInputBuffers; ByteBuffer [] codecOutputBuffers;/*** decodes audio files, return the final decoded data ** @ param url * @ return */public byte [] decode (String url) {url = ""; try {mediaExtractor. setDataSource (url);} catch (IOException e) {} mMediaFormat = mediaExtractor. getTrackFormat (0); String mime = mMediaFormat. getString (MediaFormat. KEY_MIME); try {mMediaCodec = MediaCodec. createDecoderByType (mime);} catch (IOException e) {// TODO Auto-generated catch blocke. printStackTrace ();} mMediaCodec. configure (mMediaFormat, null, null, 0); mMediaCodec. start (); codecInputBuffers = mMediaCodec. getInputBuffers (); codecOutputBuffers = mMediaCodec. getOutputBuffers (); info = new BufferInfo (); mediaExtractor. selectTrack (0); input (); output (); return deco DeData;} private void output () {final int res = mMediaCodec. dequeueOutputBuffer (info, TIMEOUT_US); if (res> = 0) {int outputBufIndex = res; ByteBuffer buf = codecOutputBuffers [outputBufIndex]; final byte [] chunk = new byte [info. size]; buf. get (chunk); // Read the buffer all at oncebuf. clear (); // ** must do !!! Otherwise the next time you get this // same buffer bad things will HAPPENif (chunk. length> 0) {System. arraycopy (chunk, 0, decodeData, 0, chunk. length); // mAudioTrack. write (chunk, 0, chunk. length);} mMediaCodec. releaseOutputBuffer (outputBufIndex, false/* render */); if (info. flags & MediaCodec. BUFFER_FLAG_END_OF_STREAM )! = 0) {sawOutputEOS = true;} else if (res = MediaCodec. INFO_OUTPUT_BUFFERS_CHANGED) {codecOutputBuffers = mMediaCodec. getOutputBuffers ();} else if (res = MediaCodec. INFO_OUTPUT_FORMAT_CHANGED) {final MediaFormat oformat = mMediaCodec. getOutputFormat (); // Log. d (LOG_TAG, "Output format has changed to" + oformat); // mAudioTrack. setPlaybackRate (oformat. getInteger (MediaFormat. KEY_SAMPLE_RATE) ;}} private Void input () {int inputBufIndex = mMediaCodec. dequeueInputBuffer (TIMEOUT_US); if (inputBufIndex> = 0) {ByteBuffer dstBuf = codecInputBuffers [inputBufIndex]; int sampleSize = mediaExtractor. readSampleData (dstBuf, 0); // Log. I (LOG_TAG, "sampleSize:" + sampleSize); long presentationTimeUs = 0; if (sampleSize <0 ){//. log. I (LOG_TAG, "Saw input end of stream! "); SawInputEOS = true; sampleSize = 0;} else {presentationTimeUs = mediaExtractor. getSampleTime (); // Log. I (LOG_TAG, "presentationTimeUs" + presentationTimeUs);} mMediaCodec. queueInputBuffer (inputBufIndex, 0, // offsetsampleSize, presentationTimeUs, sawInputEOS? MediaCodec. BUFFER_FLAG_END_OF_STREAM: 0); if (! SawInputEOS) {// Log. I (LOG_TAG, "extractor. advance ()"); mediaExtractor. advance ();}}}}