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POHow to remove noise from .wav file after mixed?
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copied!<p>I have read the manual from <a href="https://stackoverflow.com/questions/15783032/how-to-remove-noise-from-wav-file">this link</a> but still can not solve your problems.</p> <p>After mix two wav files using code I get a wav file (music.wav on sdcard) but play it as <strong>noise</strong>. I really do not know how to remove it from the file music.wav. It is a difficult issue for me.</p> <p><strong>This is my source code:</strong></p> <pre><code> public class MainActivity extends Activity { public static final int FREQUENCY = 44100; private InputStream in1, in2; private byte[] output; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); try { mixSound(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } private void mixSound() throws IOException { // AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, 44100, AudioFormat.CHANNEL_OUT_STEREO, AudioFormat.ENCODING_PCM_16BIT, 44100, AudioTrack.MODE_STREAM); in1 = getResources().openRawResource(R.raw.media_b); in2 = getResources().openRawResource(R.raw.media_c); byte[] arrayMusic1 = null; arrayMusic1 = new byte[in1.available()]; arrayMusic1 = createMusicArray(in1); in1.close(); byte[] arrayMusic2 = null; arrayMusic2 = new byte[in2.available()]; arrayMusic2 = createMusicArray(in2); in2.close(); output = new byte[arrayMusic1.length]; /** old audioTrack.play(); */ for (int i = 0; i < output.length; i++) { float samplef1 = arrayMusic1[i] / 128.0f; float samplef2 = arrayMusic2[i] / 128.0f; float mixed = samplef1 + samplef2; // reduce the volume a bit: mixed *= 0.8; // hard clipping if (mixed > 1.0f) mixed = 1.0f; if (mixed < -1.0f) mixed = -1.0f; byte outputSample = (byte) (mixed * 128.0f); output[i] = outputSample; } /** old audioTrack.write(output, 0, output.length); convertByteToFile(output); save(); */ saveToFile(); } public static byte[] createMusicArray(InputStream is) throws IOException { ByteArrayOutputStream baos = new ByteArrayOutputStream(); //10*1024 = 10KB byte[] byteBuffer = new byte[10*1024]; int i = Integer.MAX_VALUE; while ((i = is.read(byteBuffer, 0, byteBuffer.length)) > 0) { baos.write(byteBuffer, 0, i); } return baos.toByteArray(); } /** * .WAV * more info --> https://ccrma.stanford.edu/courses/422/projects/WaveFormat/ The canonical WAVE format starts with the RIFF header: | FILE OFFSET | FIELD SIZE | FIELD NAME 0 4 ChunkID Contains the letters "RIFF" in ASCII form (0x52494646 big-endian form). 4 4 ChunkSize 36 + SubChunk2Size, or more precisely: 4 + (8 + SubChunk1Size) + (8 + SubChunk2Size) This is the size of the rest of the chunk following this number. This is the size of the entire file in bytes minus 8 bytes for the two fields not included in this count: ChunkID and ChunkSize. 8 4 Format Contains the letters "WAVE" (0x57415645 big-endian form). The "WAVE" format consists of two subchunks: "fmt " and "data": The "fmt " subchunk describes the sound data's format: 12 4 Subchunk1ID Contains the letters "fmt " (0x666d7420 big-endian form). 16 4 Subchunk1Size 16 for PCM. This is the size of the rest of the Subchunk which follows this number. 20 2 AudioFormat PCM = 1 (i.e. Linear quantization) Values other than 1 indicate some form of compression. 22 2 NumChannels Mono = 1, Stereo = 2, etc. 24 4 SampleRate 8000, 44100, etc. 28 4 ByteRate == SampleRate * NumChannels * BitsPerSample/8 32 2 BlockAlign == NumChannels * BitsPerSample/8 The number of bytes for one sample including all channels. I wonder what happens when this number isn't an integer? 34 2 BitsPerSample 8 bits = 8, 16 bits = 16, etc. 2 ExtraParamSize if PCM, then doesn't exist X ExtraParams space for extra parameters The "data" subchunk contains the size of the data and the actual sound: 36 4 Subchunk2ID Contains the letters "data" (0x64617461 big-endian form). 40 4 Subchunk2Size == NumSamples * NumChannels * BitsPerSample/8 This is the number of bytes in the data. You can also think of this as the size of the read of the subchunk following this number. 44 * Data The actual sound data. */ public void saveToFile() { try { long mySubChunk1Size = 16; int myBitsPerSample = 16; int myFormat = 1; long myChannels = 2; long mySampleRate = 44100; long myByteRate = mySampleRate * myChannels * (myBitsPerSample/8); int myBlockAlign = (int) (myChannels * myBitsPerSample/8); long myDataSize = output.length; long myChunk2Size = myDataSize * myChannels * myBitsPerSample/8; long myChunkSize = 36 + myChunk2Size; OutputStream os = new FileOutputStream(new File(Environment.getExternalStorageDirectory().getPath()+"/videokit/mixed.wav")); BufferedOutputStream bos = new BufferedOutputStream(os); DataOutputStream outFile = new DataOutputStream(bos); outFile.writeBytes("RIFF"); // 00 - RIFF outFile.write(intToByteArray((int)myChunkSize), 0, 4); // 04 - how big is the rest of this file? outFile.writeBytes("WAVE"); // 08 - WAVE outFile.writeBytes("fmt "); // 12 - fmt outFile.write(intToByteArray((int)mySubChunk1Size), 0, 4); // 16 - size of this chunk outFile.write(shortToByteArray((short)myFormat), 0, 2); // 20 - what is the audio format? 1 for PCM = Pulse Code Modulation outFile.write(shortToByteArray((short)myChannels), 0, 2); // 22 - mono or stereo? 1 or 2? (or 5 or ???) outFile.write(intToByteArray((int)mySampleRate), 0, 4); // 24 - samples per second (numbers per second) outFile.write(intToByteArray((int)myByteRate), 0, 4); // 28 - bytes per second outFile.write(shortToByteArray((short)myBlockAlign), 0, 2); // 32 - # of bytes in one sample, for all channels outFile.write(shortToByteArray((short)myBitsPerSample), 0, 2); // 34 - how many bits in a sample(number)? usually 16 or 24 outFile.writeBytes("data"); // 36 - data outFile.write(intToByteArray((int)myDataSize), 0, 4); // 40 - how big is this data chunk outFile.write(output); // 44 - the actual data itself - just a long string of numbers outFile.flush(); outFile.close(); } catch (IOException e) { e.printStackTrace(); } } public static byte[] getBytesFromFile(File file) throws IOException { InputStream is = new FileInputStream(file); long length = file.length(); if (length > Integer.MAX_VALUE) { } byte[] bytes = new byte[(int)length]; int offset = 0; int numRead = 0; while (offset < bytes.length && (numRead = is.read(bytes, offset, Math.min(bytes.length - offset, 512*1024))) >= 0) { offset += numRead; } if (offset < bytes.length) { Log.i("xxx", "Could not completely read file"); } is.close(); return bytes; } private static byte[] intToByteArray(int i) { byte[] b = new byte[4]; b[0] = (byte) (i & 0x00FF); b[1] = (byte) ((i >> 8) & 0x000000FF); b[2] = (byte) ((i >> 16) & 0x000000FF); b[3] = (byte) ((i >> 24) & 0x000000FF); return b; } public static byte[] shortToByteArray(short data) { return new byte[]{(byte)(data & 0xff),(byte)((data >>> 8) & 0xff)}; } public static long byteArrayToLong(byte[] b) { int start = 0; int i = 0; int len = 4; int cnt = 0; byte[] tmp = new byte[len]; for (i = start; i < (start + len); i++) { tmp[cnt] = b[i]; cnt++; } long accum = 0; i = 0; for (int shiftBy = 0; shiftBy < 32; shiftBy += 8) { accum |= ((long) (tmp[i] & 0xff)) << shiftBy; i++; } return accum; } </code></pre> <p>}</p> <p><strong>spectral analysis of file mixed.wav, noise range view</strong> <a href="http://i1287.photobucket.com/albums/a639/noe_love2/Screenshotfrom2013-05-2811_28_33_zps75564960.png" rel="nofollow noreferrer">enter link description here</a></p> <p>If you're experiencing this problem, please give me a solution. What do I do with my code. Can you help me, please. I'm looking forward to suggestions from you. Thank you very much.</p>

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