Tuesday, December 30, 2014

Create animated GIF from MP4

This exercise show how to retrieve image frames from mp4 using MediaMetadataRetriever (refer last post), and create animated GIF using android-gif-encoder, an animated GIF encoder for Android, without any native code required.


test.GIF generated
MainActivity.java
package com.example.androidmediametadataretriever;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.media.MediaMetadataRetriever;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore.Images;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.Toast;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

 ImageView capturedImageView; 
 Button btnOpen, btnSave;
 TextView textInfo, textMaxDur, textCurDur;
 SeekBar timeFrameBar;
 
 long maxDur;
 
 MediaMetadataRetriever mediaMetadataRetriever = null;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  btnOpen = (Button)findViewById(R.id.open);
  btnSave = (Button)findViewById(R.id.save);
  textInfo = (TextView)findViewById(R.id.info);
  textMaxDur = (TextView)findViewById(R.id.maxdur);
  textCurDur = (TextView)findViewById(R.id.curdur);
  timeFrameBar = (SeekBar)findViewById(R.id.timeframe);

  capturedImageView = (ImageView) findViewById(R.id.capturedimage);

  mediaMetadataRetriever = new MediaMetadataRetriever();

  btnOpen.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View v) {

    Intent intent = new Intent(Intent.ACTION_GET_CONTENT, 
      Images.Media.EXTERNAL_CONTENT_URI);
    intent.setType("video/mp4");
    startActivityForResult(intent, 0);
   }});
  
  btnSave.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View v) {
    if(mediaMetadataRetriever != null){
     TaskSaveGIF myTaskSaveGIF = new TaskSaveGIF(timeFrameBar);
     myTaskSaveGIF.execute();
    }
   }});

  timeFrameBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener(){

   @Override
   public void onProgressChanged(SeekBar seekBar, int progress,
     boolean fromUser) {}

   @Override
   public void onStartTrackingTouch(SeekBar seekBar) {}

   @Override
   public void onStopTrackingTouch(SeekBar seekBar) {
    updateFrame();
   }});
 }
 
 private void updateFrame(){
  int frameProgress = timeFrameBar.getProgress();
  
  long frameTime = maxDur * frameProgress/100;
  
  textCurDur.setText(String.valueOf(frameTime) + " us");
  Bitmap bmFrame = mediaMetadataRetriever.getFrameAtTime(frameTime);
  capturedImageView.setImageBitmap(bmFrame);
 }

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);
  
  if(resultCode == RESULT_OK){
   Uri uri = data.getData();
   textInfo.setText(uri.toString());
   
   MediaMetadataRetriever tRetriever = new MediaMetadataRetriever();

   try{
    tRetriever.setDataSource(getBaseContext(), uri);
    
    mediaMetadataRetriever = tRetriever;
    //extract duration in millisecond, as String
    String DURATION = mediaMetadataRetriever.extractMetadata(
        MediaMetadataRetriever.METADATA_KEY_DURATION);
    textMaxDur.setText(DURATION + " ms");
    //convert to us, as int
    maxDur = (long)(1000*Double.parseDouble(DURATION));

    timeFrameBar.setProgress(0);
    updateFrame();
   }catch(RuntimeException e){
    e.printStackTrace();
    Toast.makeText(MainActivity.this, 
      "Something Wrong!", 
      Toast.LENGTH_LONG).show();
   }
   
  }
 }
 
 public class TaskSaveGIF extends AsyncTask<Void, Integer, String> {
  
  SeekBar bar;
  
  public TaskSaveGIF(SeekBar sb){
   bar = sb;
   Toast.makeText(MainActivity.this, 
     "Generate GIF animation", 
     Toast.LENGTH_LONG).show();
  }

  @Override
  protected String doInBackground(Void... params) {
   String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
   File outFile = new File(extStorageDirectory, "test.GIF");
   try {
    BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(outFile));
    bos.write(genGIF());
    bos.flush();
    bos.close();
    
    return(outFile.getAbsolutePath() + " Saved");
   } catch (FileNotFoundException e) {
    e.printStackTrace();
    return e.getMessage();
   } catch (IOException e) {
    e.printStackTrace();
    return e.getMessage();
   }
  }

  @Override
  protected void onPostExecute(String result) {
   Toast.makeText(MainActivity.this, 
     result, 
     Toast.LENGTH_LONG).show();
  }

  @Override
  protected void onProgressUpdate(Integer... values) {
   bar.setProgress(values[0]);
   updateFrame();
  }

  private byte[] genGIF(){
   ByteArrayOutputStream bos = new ByteArrayOutputStream();
    
   AnimatedGifEncoder animatedGifEncoder = new AnimatedGifEncoder();
   animatedGifEncoder.setDelay(1000);
   
   Bitmap bmFrame;
   animatedGifEncoder.start(bos);
   for(int i=0; i<100; i+=10){
    long frameTime = maxDur * i/100;
    bmFrame = mediaMetadataRetriever.getFrameAtTime(frameTime);
    animatedGifEncoder.addFrame(bmFrame);
    publishProgress(i);
   }
   
   //last from at end
   bmFrame = mediaMetadataRetriever.getFrameAtTime(maxDur);
   animatedGifEncoder.addFrame(bmFrame);
   publishProgress(100);
   
   animatedGifEncoder.finish();
   return bos.toByteArray();
  }
 }

}

AnimatedGifEncoder.java, copy from https://github.com/nbadal/android-gif-encoder/blob/master/GifEncoder.java
//source: https://github.com/nbadal/android-gif-encoder/blob/master/GifEncoder.java
package com.example.androidmediametadataretriever;

import java.io.IOException;
import java.io.OutputStream;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Paint;

public class AnimatedGifEncoder {

 protected int width; // image size

 protected int height;

 protected int x = 0;

 protected int y = 0;

 protected int transparent = -1; // transparent color if given

 protected int transIndex; // transparent index in color table

 protected int repeat = -1; // no repeat

 protected int delay = 0; // frame delay (hundredths)

 protected boolean started = false; // ready to output frames

 protected OutputStream out;

 protected Bitmap image; // current frame

 protected byte[] pixels; // BGR byte array from frame

 protected byte[] indexedPixels; // converted frame indexed to palette

 protected int colorDepth; // number of bit planes

 protected byte[] colorTab; // RGB palette

 protected boolean[] usedEntry = new boolean[256]; // active palette entries

 protected int palSize = 7; // color table size (bits-1)

 protected int dispose = -1; // disposal code (-1 = use default)

 protected boolean closeStream = false; // close stream when finished

 protected boolean firstFrame = true;

 protected boolean sizeSet = false; // if false, get size from first frame

 protected int sample = 10; // default sample interval for quantizer

 /**
  * Sets the delay time between each frame, or changes it for subsequent
  * frames (applies to last frame added).
  * 
  * @param ms
  *            int delay time in milliseconds
  */
 public void setDelay(int ms) {
  delay = ms / 10;
 }

 /**
  * Sets the GIF frame disposal code for the last added frame and any
  * subsequent frames. Default is 0 if no transparent color has been set,
  * otherwise 2.
  * 
  * @param code
  *            int disposal code.
  */
 public void setDispose(int code) {
  if (code >= 0) {
   dispose = code;
  }
 }

 /**
  * Sets the number of times the set of GIF frames should be played. Default
  * is 1; 0 means play indefinitely. Must be invoked before the first image
  * is added.
  * 
  * @param iter
  *            int number of iterations.
  * @return
  */
 public void setRepeat(int iter) {
  if (iter >= 0) {
   repeat = iter;
  }
 }

 /**
  * Sets the transparent color for the last added frame and any subsequent
  * frames. Since all colors are subject to modification in the quantization
  * process, the color in the final palette for each frame closest to the
  * given color becomes the transparent color for that frame. May be set to
  * null to indicate no transparent color.
  * 
  * @param c
  *            Color to be treated as transparent on display.
  */
 public void setTransparent(int c) {
  transparent = c;
 }

 /**
  * Adds next GIF frame. The frame is not written immediately, but is
  * actually deferred until the next frame is received so that timing data
  * can be inserted. Invoking <code>finish()</code> flushes all frames. If
  * <code>setSize</code> was not invoked, the size of the first image is used
  * for all subsequent frames.
  * 
  * @param im
  *            BufferedImage containing frame to write.
  * @return true if successful.
  */
 public boolean addFrame(Bitmap im) {
  if ((im == null) || !started) {
   return false;
  }
  boolean ok = true;
  try {
   if (!sizeSet) {
    // use first frame's size
    setSize(im.getWidth(), im.getHeight());
   }
   image = im;
   getImagePixels(); // convert to correct format if necessary
   analyzePixels(); // build color table & map pixels
   if (firstFrame) {
    writeLSD(); // logical screen descriptior
    writePalette(); // global color table
    if (repeat >= 0) {
     // use NS app extension to indicate reps
     writeNetscapeExt();
    }
   }
   writeGraphicCtrlExt(); // write graphic control extension
   writeImageDesc(); // image descriptor
   if (!firstFrame) {
    writePalette(); // local color table
   }
   writePixels(); // encode and write pixel data
   firstFrame = false;
  } catch (IOException e) {
   ok = false;
  }

  return ok;
 }

 /**
  * Flushes any pending data and closes output file. If writing to an
  * OutputStream, the stream is not closed.
  */
 public boolean finish() {
  if (!started)
   return false;
  boolean ok = true;
  started = false;
  try {
   out.write(0x3b); // gif trailer
   out.flush();
   if (closeStream) {
    out.close();
   }
  } catch (IOException e) {
   ok = false;
  }

  // reset for subsequent use
  transIndex = 0;
  out = null;
  image = null;
  pixels = null;
  indexedPixels = null;
  colorTab = null;
  closeStream = false;
  firstFrame = true;

  return ok;
 }

 /**
  * Sets frame rate in frames per second. Equivalent to
  * <code>setDelay(1000/fps)</code>.
  * 
  * @param fps
  *            float frame rate (frames per second)
  */
 public void setFrameRate(float fps) {
  if (fps != 0f) {
   delay = (int) (100 / fps);
  }
 }

 /**
  * Sets quality of color quantization (conversion of images to the maximum
  * 256 colors allowed by the GIF specification). Lower values (minimum = 1)
  * produce better colors, but slow processing significantly. 10 is the
  * default, and produces good color mapping at reasonable speeds. Values
  * greater than 20 do not yield significant improvements in speed.
  * 
  * @param quality
  *            int greater than 0.
  * @return
  */
 public void setQuality(int quality) {
  if (quality < 1)
   quality = 1;
  sample = quality;
 }

 /**
  * Sets the GIF frame size. The default size is the size of the first frame
  * added if this method is not invoked.
  * 
  * @param w
  *            int frame width.
  * @param h
  *            int frame width.
  */
 public void setSize(int w, int h) {
  width = w;
  height = h;
  if (width < 1)
   width = 320;
  if (height < 1)
   height = 240;
  sizeSet = true;
 }

 /**
  * Sets the GIF frame position. The position is 0,0 by default. Useful for
  * only updating a section of the image
  * 
  * @param w
  *            int frame width.
  * @param h
  *            int frame width.
  */
 public void setPosition(int x, int y) {
  this.x = x;
  this.y = y;
 }

 /**
  * Initiates GIF file creation on the given stream. The stream is not closed
  * automatically.
  * 
  * @param os
  *            OutputStream on which GIF images are written.
  * @return false if initial write failed.
  */
 public boolean start(OutputStream os) {
  if (os == null)
   return false;
  boolean ok = true;
  closeStream = false;
  out = os;
  try {
   writeString("GIF89a"); // header
  } catch (IOException e) {
   ok = false;
  }
  return started = ok;
 }

 /**
  * Analyzes image colors and creates color map.
  */
 protected void analyzePixels() {
  int len = pixels.length;
  int nPix = len / 3;
  indexedPixels = new byte[nPix];
  NeuQuant nq = new NeuQuant(pixels, len, sample);
  // initialize quantizer
  colorTab = nq.process(); // create reduced palette
  // convert map from BGR to RGB
  for (int i = 0; i < colorTab.length; i += 3) {
   byte temp = colorTab[i];
   colorTab[i] = colorTab[i + 2];
   colorTab[i + 2] = temp;
   usedEntry[i / 3] = false;
  }
  // map image pixels to new palette
  int k = 0;
  for (int i = 0; i < nPix; i++) {
   int index = nq.map(pixels[k++] & 0xff, pixels[k++] & 0xff,
     pixels[k++] & 0xff);
   usedEntry[index] = true;
   indexedPixels[i] = (byte) index;
  }
  pixels = null;
  colorDepth = 8;
  palSize = 7;
  // get closest match to transparent color if specified
  if (transparent != -1) {
   transIndex = findClosest(transparent);
  }
 }

 /**
  * Returns index of palette color closest to c
  * 
  */
 protected int findClosest(int c) {
  if (colorTab == null)
   return -1;
  int r = (c >> 16) & 0xff;
  int g = (c >> 8) & 0xff;
  int b = (c >> 0) & 0xff;
  int minpos = 0;
  int dmin = 256 * 256 * 256;
  int len = colorTab.length;
  for (int i = 0; i < len;) {
   int dr = r - (colorTab[i++] & 0xff);
   int dg = g - (colorTab[i++] & 0xff);
   int db = b - (colorTab[i] & 0xff);
   int d = dr * dr + dg * dg + db * db;
   int index = i / 3;
   if (usedEntry[index] && (d < dmin)) {
    dmin = d;
    minpos = index;
   }
   i++;
  }
  return minpos;
 }

 /**
  * Extracts image pixels into byte array "pixels"
  */
 protected void getImagePixels() {
  int w = image.getWidth();
  int h = image.getHeight();
  if ((w != width) || (h != height)) {
   // create new image with right size/format
   Bitmap temp = Bitmap.createBitmap(width, height, Config.RGB_565);
   Canvas g = new Canvas(temp);
   g.drawBitmap(image, 0, 0, new Paint());
   image = temp;
  }
  int[] data = getImageData(image);
  pixels = new byte[data.length * 3];
  for (int i = 0; i < data.length; i++) {
   int td = data[i];
   int tind = i * 3;
   pixels[tind++] = (byte) ((td >> 0) & 0xFF);
   pixels[tind++] = (byte) ((td >> 8) & 0xFF);
   pixels[tind] = (byte) ((td >> 16) & 0xFF);
  }
 }

 protected int[] getImageData(Bitmap img) {
  int w = img.getWidth();
  int h = img.getHeight();

  int[] data = new int[w * h];
  img.getPixels(data, 0, w, 0, 0, w, h);
  return data;
 }

 /**
  * Writes Graphic Control Extension
  */
 protected void writeGraphicCtrlExt() throws IOException {
  out.write(0x21); // extension introducer
  out.write(0xf9); // GCE label
  out.write(4); // data block size
  int transp, disp;
  if (transparent == -1) {
   transp = 0;
   disp = 0; // dispose = no action
  } else {
   transp = 1;
   disp = 2; // force clear if using transparent color
  }
  if (dispose >= 0) {
   disp = dispose & 7; // user override
  }
  disp <<= 2;

  // packed fields
  out.write(0 | // 1:3 reserved
    disp | // 4:6 disposal
    0 | // 7 user input - 0 = none
    transp); // 8 transparency flag

  writeShort(delay); // delay x 1/100 sec
  out.write(transIndex); // transparent color index
  out.write(0); // block terminator
 }

 /**
  * Writes Image Descriptor
  */
 protected void writeImageDesc() throws IOException {
  out.write(0x2c); // image separator
  writeShort(x); // image position x,y = 0,0
  writeShort(y);
  writeShort(width); // image size
  writeShort(height);
  // packed fields
  if (firstFrame) {
   // no LCT - GCT is used for first (or only) frame
   out.write(0);
  } else {
   // specify normal LCT
   out.write(0x80 | // 1 local color table 1=yes
     0 | // 2 interlace - 0=no
     0 | // 3 sorted - 0=no
     0 | // 4-5 reserved
     palSize); // 6-8 size of color table
  }
 }

 /**
  * Writes Logical Screen Descriptor
  */
 protected void writeLSD() throws IOException {
  // logical screen size
  writeShort(width);
  writeShort(height);
  // packed fields
  out.write((0x80 | // 1 : global color table flag = 1 (gct used)
  0x70 | // 2-4 : color resolution = 7
  0x00 | // 5 : gct sort flag = 0
  palSize)); // 6-8 : gct size

  out.write(0); // background color index
  out.write(0); // pixel aspect ratio - assume 1:1
 }

 /**
  * Writes Netscape application extension to define repeat count.
  */
 protected void writeNetscapeExt() throws IOException {
  out.write(0x21); // extension introducer
  out.write(0xff); // app extension label
  out.write(11); // block size
  writeString("NETSCAPE" + "2.0"); // app id + auth code
  out.write(3); // sub-block size
  out.write(1); // loop sub-block id
  writeShort(repeat); // loop count (extra iterations, 0=repeat forever)
  out.write(0); // block terminator
 }

 /**
  * Writes color table
  */
 protected void writePalette() throws IOException {
  out.write(colorTab, 0, colorTab.length);
  int n = (3 * 256) - colorTab.length;
  for (int i = 0; i < n; i++) {
   out.write(0);
  }
 }

 /**
  * Encodes and writes pixel data
  */
 protected void writePixels() throws IOException {
  LZWEncoder encoder = new LZWEncoder(width, height, indexedPixels,
    colorDepth);
  encoder.encode(out);
 }

 /**
  * Write 16-bit value to output stream, LSB first
  */
 protected void writeShort(int value) throws IOException {
  out.write(value & 0xff);
  out.write((value >> 8) & 0xff);
 }

 /**
  * Writes string to output stream
  */
 protected void writeString(String s) throws IOException {
  for (int i = 0; i < s.length(); i++) {
   out.write((byte) s.charAt(i));
  }
 }
}

/*
 * NeuQuant Neural-Net Quantization Algorithm
 * ------------------------------------------
 * 
 * Copyright (c) 1994 Anthony Dekker
 * 
 * NEUQUANT Neural-Net quantization algorithm by Anthony Dekker, 1994. See
 * "Kohonen neural networks for optimal colour quantization" in "Network:
 * Computation in Neural Systems" Vol. 5 (1994) pp 351-367. for a discussion of
 * the algorithm.
 * 
 * Any party obtaining a copy of these files from the author, directly or
 * indirectly, is granted, free of charge, a full and unrestricted irrevocable,
 * world-wide, paid up, royalty-free, nonexclusive right and license to deal in
 * this software and documentation files (the "Software"), including without
 * limitation the rights to use, copy, modify, merge, publish, distribute,
 * sublicense, and/or sell copies of the Software, and to permit persons who
 * receive copies from any such party to do so, with the only requirement being
 * that this copyright notice remain intact.
 */

// Ported to Java 12/00 K Weiner
class NeuQuant {

 protected static final int netsize = 256; /* number of colours used */

 /* four primes near 500 - assume no image has a length so large */
 /* that it is divisible by all four primes */
 protected static final int prime1 = 499;

 protected static final int prime2 = 491;

 protected static final int prime3 = 487;

 protected static final int prime4 = 503;

 protected static final int minpicturebytes = (3 * prime4);

 /* minimum size for input image */

 /*
  * Program Skeleton ---------------- [select samplefac in range 1..30] [read
  * image from input file] pic = (unsigned char*) malloc(3*width*height);
  * initnet(pic,3*width*height,samplefac); learn(); unbiasnet(); [write
  * output image header, using writecolourmap(f)] inxbuild(); write output
  * image using inxsearch(b,g,r)
  */

 /*
  * Network Definitions -------------------
  */

 protected static final int maxnetpos = (netsize - 1);

 protected static final int netbiasshift = 4; /* bias for colour values */

 protected static final int ncycles = 100; /* no. of learning cycles */

 /* defs for freq and bias */
 protected static final int intbiasshift = 16; /* bias for fractions */

 protected static final int intbias = (((int) 1) << intbiasshift);

 protected static final int gammashift = 10; /* gamma = 1024 */

 protected static final int gamma = (((int) 1) << gammashift);

 protected static final int betashift = 10;

 protected static final int beta = (intbias >> betashift); /* beta = 1/1024 */

 protected static final int betagamma = (intbias << (gammashift - betashift));

 /* defs for decreasing radius factor */
 protected static final int initrad = (netsize >> 3); /*
               * for 256 cols, radius
               * starts
               */

 protected static final int radiusbiasshift = 6; /* at 32.0 biased by 6 bits */

 protected static final int radiusbias = (((int) 1) << radiusbiasshift);

 protected static final int initradius = (initrad * radiusbias); /*
                  * and
                  * decreases
                  * by a
                  */

 protected static final int radiusdec = 30; /* factor of 1/30 each cycle */

 /* defs for decreasing alpha factor */
 protected static final int alphabiasshift = 10; /* alpha starts at 1.0 */

 protected static final int initalpha = (((int) 1) << alphabiasshift);

 protected int alphadec; /* biased by 10 bits */

 /* radbias and alpharadbias used for radpower calculation */
 protected static final int radbiasshift = 8;

 protected static final int radbias = (((int) 1) << radbiasshift);

 protected static final int alpharadbshift = (alphabiasshift + radbiasshift);

 protected static final int alpharadbias = (((int) 1) << alpharadbshift);

 /*
  * Types and Global Variables --------------------------
  */

 protected byte[] thepicture; /* the input image itself */

 protected int lengthcount; /* lengthcount = H*W*3 */

 protected int samplefac; /* sampling factor 1..30 */

 // typedef int pixel[4]; /* BGRc */
 protected int[][] network; /* the network itself - [netsize][4] */

 protected int[] netindex = new int[256];

 /* for network lookup - really 256 */

 protected int[] bias = new int[netsize];

 /* bias and freq arrays for learning */
 protected int[] freq = new int[netsize];

 protected int[] radpower = new int[initrad];

 /* radpower for precomputation */

 /*
  * Initialise network in range (0,0,0) to (255,255,255) and set parameters
  * -----------------------------------------------------------------------
  */
 public NeuQuant(byte[] thepic, int len, int sample) {

  int i;
  int[] p;

  thepicture = thepic;
  lengthcount = len;
  samplefac = sample;

  network = new int[netsize][];
  for (i = 0; i < netsize; i++) {
   network[i] = new int[4];
   p = network[i];
   p[0] = p[1] = p[2] = (i << (netbiasshift + 8)) / netsize;
   freq[i] = intbias / netsize; /* 1/netsize */
   bias[i] = 0;
  }
 }

 public byte[] colorMap() {
  byte[] map = new byte[3 * netsize];
  int[] index = new int[netsize];
  for (int i = 0; i < netsize; i++)
   index[network[i][3]] = i;
  int k = 0;
  for (int i = 0; i < netsize; i++) {
   int j = index[i];
   map[k++] = (byte) (network[j][0]);
   map[k++] = (byte) (network[j][1]);
   map[k++] = (byte) (network[j][2]);
  }
  return map;
 }

 /*
  * Insertion sort of network and building of netindex[0..255] (to do after
  * unbias)
  * ------------------------------------------------------------------
  * -------------
  */
 public void inxbuild() {

  int i, j, smallpos, smallval;
  int[] p;
  int[] q;
  int previouscol, startpos;

  previouscol = 0;
  startpos = 0;
  for (i = 0; i < netsize; i++) {
   p = network[i];
   smallpos = i;
   smallval = p[1]; /* index on g */
   /* find smallest in i..netsize-1 */
   for (j = i + 1; j < netsize; j++) {
    q = network[j];
    if (q[1] < smallval) { /* index on g */
     smallpos = j;
     smallval = q[1]; /* index on g */
    }
   }
   q = network[smallpos];
   /* swap p (i) and q (smallpos) entries */
   if (i != smallpos) {
    j = q[0];
    q[0] = p[0];
    p[0] = j;
    j = q[1];
    q[1] = p[1];
    p[1] = j;
    j = q[2];
    q[2] = p[2];
    p[2] = j;
    j = q[3];
    q[3] = p[3];
    p[3] = j;
   }
   /* smallval entry is now in position i */
   if (smallval != previouscol) {
    netindex[previouscol] = (startpos + i) >> 1;
    for (j = previouscol + 1; j < smallval; j++)
     netindex[j] = i;
    previouscol = smallval;
    startpos = i;
   }
  }
  netindex[previouscol] = (startpos + maxnetpos) >> 1;
  for (j = previouscol + 1; j < 256; j++)
   netindex[j] = maxnetpos; /* really 256 */
 }

 /*
  * Main Learning Loop ------------------
  */
 public void learn() {

  int i, j, b, g, r;
  int radius, rad, alpha, step, delta, samplepixels;
  byte[] p;
  int pix, lim;

  if (lengthcount < minpicturebytes)
   samplefac = 1;
  alphadec = 30 + ((samplefac - 1) / 3);
  p = thepicture;
  pix = 0;
  lim = lengthcount;
  samplepixels = lengthcount / (3 * samplefac);
  delta = samplepixels / ncycles;
  alpha = initalpha;
  radius = initradius;

  rad = radius >> radiusbiasshift;
  if (rad <= 1)
   rad = 0;
  for (i = 0; i < rad; i++)
   radpower[i] = alpha
     * (((rad * rad - i * i) * radbias) / (rad * rad));

  // fprintf(stderr,"beginning 1D learning: initial radius=%d\n", rad);

  if (lengthcount < minpicturebytes)
   step = 3;
  else if ((lengthcount % prime1) != 0)
   step = 3 * prime1;
  else {
   if ((lengthcount % prime2) != 0)
    step = 3 * prime2;
   else {
    if ((lengthcount % prime3) != 0)
     step = 3 * prime3;
    else
     step = 3 * prime4;
   }
  }

  i = 0;
  while (i < samplepixels) {
   b = (p[pix + 0] & 0xff) << netbiasshift;
   g = (p[pix + 1] & 0xff) << netbiasshift;
   r = (p[pix + 2] & 0xff) << netbiasshift;
   j = contest(b, g, r);

   altersingle(alpha, j, b, g, r);
   if (rad != 0)
    alterneigh(rad, j, b, g, r); /* alter neighbours */

   pix += step;
   if (pix >= lim)
    pix -= lengthcount;

   i++;
   if (delta == 0)
    delta = 1;
   if (i % delta == 0) {
    alpha -= alpha / alphadec;
    radius -= radius / radiusdec;
    rad = radius >> radiusbiasshift;
    if (rad <= 1)
     rad = 0;
    for (j = 0; j < rad; j++)
     radpower[j] = alpha
       * (((rad * rad - j * j) * radbias) / (rad * rad));
   }
  }
  // fprintf(stderr,"finished 1D learning: final alpha=%f
  // !\n",((float)alpha)/initalpha);
 }

 /*
  * Search for BGR values 0..255 (after net is unbiased) and return colour
  * index
  * --------------------------------------------------------------------
  * --------
  */
 public int map(int b, int g, int r) {

  int i, j, dist, a, bestd;
  int[] p;
  int best;

  bestd = 1000; /* biggest possible dist is 256*3 */
  best = -1;
  i = netindex[g]; /* index on g */
  j = i - 1; /* start at netindex[g] and work outwards */

  while ((i < netsize) || (j >= 0)) {
   if (i < netsize) {
    p = network[i];
    dist = p[1] - g; /* inx key */
    if (dist >= bestd)
     i = netsize; /* stop iter */
    else {
     i++;
     if (dist < 0)
      dist = -dist;
     a = p[0] - b;
     if (a < 0)
      a = -a;
     dist += a;
     if (dist < bestd) {
      a = p[2] - r;
      if (a < 0)
       a = -a;
      dist += a;
      if (dist < bestd) {
       bestd = dist;
       best = p[3];
      }
     }
    }
   }
   if (j >= 0) {
    p = network[j];
    dist = g - p[1]; /* inx key - reverse dif */
    if (dist >= bestd)
     j = -1; /* stop iter */
    else {
     j--;
     if (dist < 0)
      dist = -dist;
     a = p[0] - b;
     if (a < 0)
      a = -a;
     dist += a;
     if (dist < bestd) {
      a = p[2] - r;
      if (a < 0)
       a = -a;
      dist += a;
      if (dist < bestd) {
       bestd = dist;
       best = p[3];
      }
     }
    }
   }
  }
  return (best);
 }

 public byte[] process() {
  learn();
  unbiasnet();
  inxbuild();
  return colorMap();
 }

 /*
  * Unbias network to give byte values 0..255 and record position i to
  * prepare for sort
  * ----------------------------------------------------------
  * -------------------------
  */
 public void unbiasnet() {

  int i;

  for (i = 0; i < netsize; i++) {
   network[i][0] >>= netbiasshift;
   network[i][1] >>= netbiasshift;
   network[i][2] >>= netbiasshift;
   network[i][3] = i; /* record colour no */
  }
 }

 /*
  * Move adjacent neurons by precomputed alpha*(1-((i-j)^2/[r]^2)) in
  * radpower[|i-j|]
  * ----------------------------------------------------------
  * -----------------------
  */
 protected void alterneigh(int rad, int i, int b, int g, int r) {

  int j, k, lo, hi, a, m;
  int[] p;

  lo = i - rad;
  if (lo < -1)
   lo = -1;
  hi = i + rad;
  if (hi > netsize)
   hi = netsize;

  j = i + 1;
  k = i - 1;
  m = 1;
  while ((j < hi) || (k > lo)) {
   a = radpower[m++];
   if (j < hi) {
    p = network[j++];
    try {
     p[0] -= (a * (p[0] - b)) / alpharadbias;
     p[1] -= (a * (p[1] - g)) / alpharadbias;
     p[2] -= (a * (p[2] - r)) / alpharadbias;
    } catch (Exception e) {
    } // prevents 1.3 miscompilation
   }
   if (k > lo) {
    p = network[k--];
    try {
     p[0] -= (a * (p[0] - b)) / alpharadbias;
     p[1] -= (a * (p[1] - g)) / alpharadbias;
     p[2] -= (a * (p[2] - r)) / alpharadbias;
    } catch (Exception e) {
    }
   }
  }
 }

 /*
  * Move neuron i towards biased (b,g,r) by factor alpha
  * ----------------------------------------------------
  */
 protected void altersingle(int alpha, int i, int b, int g, int r) {

  /* alter hit neuron */
  int[] n = network[i];
  n[0] -= (alpha * (n[0] - b)) / initalpha;
  n[1] -= (alpha * (n[1] - g)) / initalpha;
  n[2] -= (alpha * (n[2] - r)) / initalpha;
 }

 /*
  * Search for biased BGR values ----------------------------
  */
 protected int contest(int b, int g, int r) {

  /* finds closest neuron (min dist) and updates freq */
  /* finds best neuron (min dist-bias) and returns position */
  /*
   * for frequently chosen neurons, freq[i] is high and bias[i] is
   * negative
   */
  /* bias[i] = gamma*((1/netsize)-freq[i]) */

  int i, dist, a, biasdist, betafreq;
  int bestpos, bestbiaspos, bestd, bestbiasd;
  int[] n;

  bestd = ~(((int) 1) << 31);
  bestbiasd = bestd;
  bestpos = -1;
  bestbiaspos = bestpos;

  for (i = 0; i < netsize; i++) {
   n = network[i];
   dist = n[0] - b;
   if (dist < 0)
    dist = -dist;
   a = n[1] - g;
   if (a < 0)
    a = -a;
   dist += a;
   a = n[2] - r;
   if (a < 0)
    a = -a;
   dist += a;
   if (dist < bestd) {
    bestd = dist;
    bestpos = i;
   }
   biasdist = dist - ((bias[i]) >> (intbiasshift - netbiasshift));
   if (biasdist < bestbiasd) {
    bestbiasd = biasdist;
    bestbiaspos = i;
   }
   betafreq = (freq[i] >> betashift);
   freq[i] -= betafreq;
   bias[i] += (betafreq << gammashift);
  }
  freq[bestpos] += beta;
  bias[bestpos] -= betagamma;
  return (bestbiaspos);
 }
}

// ==============================================================================
// Adapted from Jef Poskanzer's Java port by way of J. M. G. Elliott.
// K Weiner 12/00

class LZWEncoder {

 private static final int EOF = -1;

 private int imgW, imgH;

 private byte[] pixAry;

 private int initCodeSize;

 private int remaining;

 private int curPixel;

 // GIFCOMPR.C - GIF Image compression routines
 //
 // Lempel-Ziv compression based on 'compress'. GIF modifications by
 // David Rowley (mgardi@watdcsu.waterloo.edu)

 // General DEFINEs

 static final int BITS = 12;

 static final int HSIZE = 5003; // 80% occupancy

 // GIF Image compression - modified 'compress'
 //
 // Based on: compress.c - File compression ala IEEE Computer, June 1984.
 //
 // By Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
 // Jim McKie (decvax!mcvax!jim)
 // Steve Davies (decvax!vax135!petsd!peora!srd)
 // Ken Turkowski (decvax!decwrl!turtlevax!ken)
 // James A. Woods (decvax!ihnp4!ames!jaw)
 // Joe Orost (decvax!vax135!petsd!joe)

 int n_bits; // number of bits/code

 int maxbits = BITS; // user settable max # bits/code

 int maxcode; // maximum code, given n_bits

 int maxmaxcode = 1 << BITS; // should NEVER generate this code

 int[] htab = new int[HSIZE];

 int[] codetab = new int[HSIZE];

 int hsize = HSIZE; // for dynamic table sizing

 int free_ent = 0; // first unused entry

 // block compression parameters -- after all codes are used up,
 // and compression rate changes, start over.
 boolean clear_flg = false;

 // Algorithm: use open addressing double hashing (no chaining) on the
 // prefix code / next character combination. We do a variant of Knuth's
 // algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
 // secondary probe. Here, the modular division first probe is gives way
 // to a faster exclusive-or manipulation. Also do block compression with
 // an adaptive reset, whereby the code table is cleared when the compression
 // ratio decreases, but after the table fills. The variable-length output
 // codes are re-sized at this point, and a special CLEAR code is generated
 // for the decompressor. Late addition: construct the table according to
 // file size for noticeable speed improvement on small files. Please direct
 // questions about this implementation to ames!jaw.

 int g_init_bits;

 int ClearCode;

 int EOFCode;

 // output
 //
 // Output the given code.
 // Inputs:
 // code: A n_bits-bit integer. If == -1, then EOF. This assumes
 // that n_bits =< wordsize - 1.
 // Outputs:
 // Outputs code to the file.
 // Assumptions:
 // Chars are 8 bits long.
 // Algorithm:
 // Maintain a BITS character long buffer (so that 8 codes will
 // fit in it exactly). Use the VAX insv instruction to insert each
 // code in turn. When the buffer fills up empty it and start over.

 int cur_accum = 0;

 int cur_bits = 0;

 int masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F, 0x003F,
   0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF, 0x0FFF, 0x1FFF, 0x3FFF,
   0x7FFF, 0xFFFF };

 // Number of characters so far in this 'packet'
 int a_count;

 // Define the storage for the packet accumulator
 byte[] accum = new byte[256];

 // ----------------------------------------------------------------------------
 LZWEncoder(int width, int height, byte[] pixels, int color_depth) {
  imgW = width;
  imgH = height;
  pixAry = pixels;
  initCodeSize = Math.max(2, color_depth);
 }

 // Add a character to the end of the current packet, and if it is 254
 // characters, flush the packet to disk.
 void char_out(byte c, OutputStream outs) throws IOException {
  accum[a_count++] = c;
  if (a_count >= 254)
   flush_char(outs);
 }

 // Clear out the hash table

 // table clear for block compress
 void cl_block(OutputStream outs) throws IOException {
  cl_hash(hsize);
  free_ent = ClearCode + 2;
  clear_flg = true;

  output(ClearCode, outs);
 }

 // reset code table
 void cl_hash(int hsize) {
  for (int i = 0; i < hsize; ++i)
   htab[i] = -1;
 }

 void compress(int init_bits, OutputStream outs) throws IOException {
  int fcode;
  int i /* = 0 */;
  int c;
  int ent;
  int disp;
  int hsize_reg;
  int hshift;

  // Set up the globals: g_init_bits - initial number of bits
  g_init_bits = init_bits;

  // Set up the necessary values
  clear_flg = false;
  n_bits = g_init_bits;
  maxcode = MAXCODE(n_bits);

  ClearCode = 1 << (init_bits - 1);
  EOFCode = ClearCode + 1;
  free_ent = ClearCode + 2;

  a_count = 0; // clear packet

  ent = nextPixel();

  hshift = 0;
  for (fcode = hsize; fcode < 65536; fcode *= 2)
   ++hshift;
  hshift = 8 - hshift; // set hash code range bound

  hsize_reg = hsize;
  cl_hash(hsize_reg); // clear hash table

  output(ClearCode, outs);

  outer_loop: while ((c = nextPixel()) != EOF) {
   fcode = (c << maxbits) + ent;
   i = (c << hshift) ^ ent; // xor hashing

   if (htab[i] == fcode) {
    ent = codetab[i];
    continue;
   } else if (htab[i] >= 0) // non-empty slot
   {
    disp = hsize_reg - i; // secondary hash (after G. Knott)
    if (i == 0)
     disp = 1;
    do {
     if ((i -= disp) < 0)
      i += hsize_reg;

     if (htab[i] == fcode) {
      ent = codetab[i];
      continue outer_loop;
     }
    } while (htab[i] >= 0);
   }
   output(ent, outs);
   ent = c;
   if (free_ent < maxmaxcode) {
    codetab[i] = free_ent++; // code -> hashtable
    htab[i] = fcode;
   } else
    cl_block(outs);
  }
  // Put out the final code.
  output(ent, outs);
  output(EOFCode, outs);
 }

 // ----------------------------------------------------------------------------
 void encode(OutputStream os) throws IOException {
  os.write(initCodeSize); // write "initial code size" byte

  remaining = imgW * imgH; // reset navigation variables
  curPixel = 0;

  compress(initCodeSize + 1, os); // compress and write the pixel data

  os.write(0); // write block terminator
 }

 // Flush the packet to disk, and reset the accumulator
 void flush_char(OutputStream outs) throws IOException {
  if (a_count > 0) {
   outs.write(a_count);
   outs.write(accum, 0, a_count);
   a_count = 0;
  }
 }

 final int MAXCODE(int n_bits) {
  return (1 << n_bits) - 1;
 }

 // ----------------------------------------------------------------------------
 // Return the next pixel from the image
 // ----------------------------------------------------------------------------
 private int nextPixel() {
  if (remaining == 0)
   return EOF;

  --remaining;

  byte pix = pixAry[curPixel++];

  return pix & 0xff;
 }

 void output(int code, OutputStream outs) throws IOException {
  cur_accum &= masks[cur_bits];

  if (cur_bits > 0)
   cur_accum |= (code << cur_bits);
  else
   cur_accum = code;

  cur_bits += n_bits;

  while (cur_bits >= 8) {
   char_out((byte) (cur_accum & 0xff), outs);
   cur_accum >>= 8;
   cur_bits -= 8;
  }

  // If the next entry is going to be too big for the code size,
  // then increase it, if possible.
  if (free_ent > maxcode || clear_flg) {
   if (clear_flg) {
    maxcode = MAXCODE(n_bits = g_init_bits);
    clear_flg = false;
   } else {
    ++n_bits;
    if (n_bits == maxbits)
     maxcode = maxmaxcode;
    else
     maxcode = MAXCODE(n_bits);
   }
  }

  if (code == EOFCode) {
   // At EOF, write the rest of the buffer.
   while (cur_bits > 0) {
    char_out((byte) (cur_accum & 0xff), outs);
    cur_accum >>= 8;
    cur_bits -= 8;
   }

   flush_char(outs);
  }
 }
}

activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.androidmediametadataretriever.MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />
    
    <Button
        android:id="@+id/open"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Open"/>
    <TextView
        android:id="@+id/info"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
    <TextView
        android:id="@+id/maxdur"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
    <TextView
        android:id="@+id/curdur"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
    <SeekBar
        android:id="@+id/timeframe"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="100"
        android:progress="0"/>
    <Button
        android:id="@+id/save"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Save GIF"/>
    <ImageView
        android:id="@+id/capturedimage"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

Permission of "android.permission.READ_EXTERNAL_STORAGE" and "android.permission.WRITE_EXTERNAL_STORAGE" are needed in AndroidManifest.xml, minSdkVersion have to be 10 or higher.

download filesDownload the files.

1 comment:

Utkarsh Shrivastava said...

i want to pause the gif at last frame,and it should run only once
please help :(