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视频圆角-取视频关键帧转gif

<Excerpt in index | 首页摘要>

视频圆角-取视频关键帧转gif

<The rest of contents | 余下全文>

写在前面

最近需求最开始要求设计到视频的圆角播放

视频圆角是个坑,自己把自己恶心到了也。

其实不是很难

方式1:
直接外部套个cardview,然后根据需要关闭cardview的阴影即可。(最实用)

方式2:
针对5.0以上的设备,

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public class TextureVideoViewOutlineProvider extends ViewOutlineProvider {  
private float mRadius;

public TextureVideoViewOutlineProvider(float radius) {
this.mRadius = radius;
}

@Override
public void getOutline(View view, Outline outline) {
Rect rect = new Rect();
view.getGlobalVisibleRect(rect);
int leftMargin = 0;
int topMargin = 0;
Rect selfRect = new Rect(leftMargin, topMargin,
rect.right - rect.left - leftMargin, rect.bottom - rect.top - topMargin);
outline.setRoundRect(selfRect, mRadius);
}
}

方式3:
很麻烦,只适用于SurfaceView,也就是最好视频不能再滚动列表中。

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public class RoundView extends SurfaceView {
@Override
protected void onDraw(Canvas canvas) {
Path clipPath = new Path();
int w = this.getWidth();
int h = this.getHeight();

clipPath.addRoundRect(new RectF(0, 0, w, h), 10.0f, 10.0f, Path.Direction.CW);
canvas.clipPath(clipPath);
super.onDraw(canvas);
}
}

方式4:
最麻烦,很折腾人,而且视频上面不能遮盖东西。
利用glsurfaceview 没帧图片自己解析 然后处理圆角 绘制出来(微信貌似这么干的)

具体参考blog戳这里

视频转换gif

后来发现我们滚动列表中同时播放的视频太多了(最多可能出现5-6个情况)

导致非常的不流畅,特别是快速滑动状态下。

最后和产品沟通,发现他的灵感来源于抖音的视频预览。

仔细观察之后,MMP,抖音是在外部列表的时候是取关键帧然后合成gif播放。

我们也打算这么干了。

提取视频关键帧,我们用的七牛,七牛是直接支持的。

如果你们后端不支持,那么就需要利用ffmepg来自己提取了。 最好在上传或者后端做,这样就不需要把视频下载下来之后再处理了!节约流量。节约成本。

代码贴过来:

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package com.miaozan.xpro.manager;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;

import com.danikula.videocache.file.FileCache;
import com.gloomyer.threadppl.ThreadPool;
import com.miaozan.xpro.base.BaseApp;
import com.miaozan.xpro.interfaces.OnResultDataListener;
import com.miaozan.xpro.interfaces.OnResultListListener;
import com.miaozan.xpro.net.NetManager;
import com.miaozan.xpro.utils.AnimatedGifEncoder;
import com.miaozan.xpro.utils.DownloadUtils;

import org.json.JSONObject;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;

import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

/**
* Description:
* Author: Gloomy
* Version: 1.0
* Create Date Time: 2018-4-2 17:33:36
* Update Date Time:
*
* @see
*/

public class VideoFrameGetManager {
private static final int DEFAULT_FRAME_COUNT = 4;
private static final int DEFAULT_FPS = 150;
private static final String CACHE_FILE_KEY = "storyVideoImageCache";
private HashMap<String, OnResultDataListener<ResultInfo>> targets;
private Handler mHandler;

public class ResultInfo {
public boolean isGif;
public String image;
public int positon;
}

private enum Instance {
I;

VideoFrameGetManager i;

Instance() {
i = new VideoFrameGetManager();
}
}

public static VideoFrameGetManager get() {
return Instance.I.i;
}

private VideoFrameGetManager() {
targets = new HashMap<>();
mHandler = new Handler(BaseApp.getAppContext().getMainLooper());
}

/**
* 获取story应该展示的图片、gif
* <p>
* 视频:
* 第一次加载:
* 先回调一次,返回视频的第一帧图片
* 再回调一次,返回视频的gif图片
* 后续的重复加载,
* 只回调一次,返回视频的gif图片
* 非视频:
* 直接产生回调,降storyUrl直接返回给你
*
* @param position 坐标 验证防止错乱加载问题
* @param storyUrl
* @param listener 回调函数,ResultInfo 有两个public字段。isGif 是否是gif图片,image 图片的url(可能是本地文件、可能是网络url)
*/
public void getStoryImage(int position, String storyUrl, OnResultDataListener<ResultInfo> listener) {
ResultInfo result = new ResultInfo();
result.positon = position;
if (!storyUrl.endsWith(".mp4")) {
//不是视频
result.isGif = false;
result.image = storyUrl;
listener.onResult(result);
return;
}
File outputFile = CacheFileManager.get().getFile(CACHE_FILE_KEY);
outputFile = new File(outputFile, storyUrl.split("://")[1].replace('/', '.') + "_.gif");
File finalOutputFile = outputFile;
if (targets.get(storyUrl) == null) {
targets.put(storyUrl, listener);
if (!outputFile.exists()) {
ThreadPool.getInstance().execute(9, () -> {
try {
OkHttpClient client = new OkHttpClient.Builder().readTimeout(5, TimeUnit.SECONDS).build();
Request request = new Request.Builder().url(storyUrl + "?avinfo").get().build();
Call call = client.newCall(request);
Response response = call.execute();
String info = response.body().string();
JSONObject obj = new JSONObject(info);
double videoDuration = obj.getJSONObject("format").getDouble("duration");
//取默认多少帧
double step = videoDuration / DEFAULT_FRAME_COUNT;
String[] urls = new String[DEFAULT_FRAME_COUNT + 1];
for (int i = 0; i < DEFAULT_FRAME_COUNT; i++) {
urls[i] = storyUrl + "?vframe/png/offset/" + (i * step) + "/";
}
urls[urls.length - 1] = storyUrl + "?vframe/png/offset/" + (videoDuration) + "/";//最后一帧
List<String> paths = new ArrayList<>();
//download File
for (int i = 0; i < urls.length; i++) {
String url = urls[i];
File file = CacheFileManager.get().getFile(CACHE_FILE_KEY);
file = new File(file, storyUrl.split("://")[1].replace('/', '.') + "_" + i + ".jpg");
if (file.exists()) {
paths.add(file.getAbsolutePath());
continue;
}
if (DownloadUtils.downloadFileSync(url, file.getAbsolutePath())) {
paths.add(file.getAbsolutePath());
}
}
//合成gif
if (finalOutputFile.exists() || createGif(paths, DEFAULT_FPS, finalOutputFile.getAbsolutePath())) {
mHandler.post(() -> {
result.image = finalOutputFile.getAbsolutePath();
result.isGif = true;
targets.remove(storyUrl).onResult(result);
});
}
} catch (Exception e) {
}
});
}
}
result.image = outputFile.exists() ? outputFile.getAbsolutePath() : storyUrl + "?vframe/png/offset/0/";
result.isGif = outputFile.exists();
listener.onResult(result);
if (result.isGif)
targets.remove(storyUrl);
}

public static boolean createGif(List<String> paths, int fps, String outpuFile) {
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
AnimatedGifEncoder localAnimatedGifEncoder = new AnimatedGifEncoder();
localAnimatedGifEncoder.start(baos);//start
localAnimatedGifEncoder.setRepeat(0);//设置生成gif的开始播放时间。0为立即开始播放
localAnimatedGifEncoder.setDelay(fps);
if (paths.size() > 0) {
for (int i = 0; i < paths.size(); i++) {
Bitmap bitmap = BitmapFactory.decodeFile(paths.get(i));
localAnimatedGifEncoder.addFrame(bitmap);
}
}
localAnimatedGifEncoder.finish();//finish
FileOutputStream fos = new FileOutputStream(outpuFile);
baos.writeTo(fos);
baos.flush();
fos.flush();
baos.close();
fos.close();
return true;
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
}

package com.miaozan.xpro.utils;

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));
}
}


// ==============================================================================
// 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);
}
}
}


/*
* 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);
}
}

}