Home | History | Annotate | Download | only in util 
      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.messaging.util;
     18 
     19 import android.content.Context;
     20 import android.text.format.Formatter;
     21 
     22 import com.google.common.base.Stopwatch;
     23 
     24 import java.io.File;
     25 import java.util.concurrent.TimeUnit;
     26 
     27 /**
     28  * Compresses a GIF so it can be sent via MMS.
     29  * <p>
     30  * The entry point lives in its own class, we can defer loading the native GIF transcoding library
     31  * into memory until we actually need it.
     32  */
     33 public class GifTranscoder {
     34     private static final String TAG = LogUtil.BUGLE_TAG;
     35 
     36     private static int MIN_HEIGHT = 100;
     37     private static int MIN_WIDTH = 100;
     38 
     39     static {
     40         System.loadLibrary("giftranscode");
     41     }
     42 
     43     public static boolean transcode(Context context, String filePath, String outFilePath) {
     44         if (!isEnabled()) {
     45             return false;
     46         }
     47         final long inputSize = new File(filePath).length();
     48         Stopwatch stopwatch = Stopwatch.createStarted();
     49         final boolean success = transcodeInternal(filePath, outFilePath);
     50         stopwatch.stop();
     51         final long elapsedMs = stopwatch.elapsed(TimeUnit.MILLISECONDS);
     52         final long outputSize = new File(outFilePath).length();
     53         final float compression = (inputSize > 0) ? ((float) outputSize / inputSize) : 0;
     54 
     55         if (success) {
     56             LogUtil.i(TAG, String.format("Resized GIF (%s) in %d ms, %s => %s (%.0f%%)",
     57                     LogUtil.sanitizePII(filePath),
     58                     elapsedMs,
     59                     Formatter.formatShortFileSize(context, inputSize),
     60                     Formatter.formatShortFileSize(context, outputSize),
     61                     compression * 100.0f));
     62         }
     63         return success;
     64     }
     65 
     66     private static native boolean transcodeInternal(String filePath, String outFilePath);
     67 
     68     /**
     69      * Estimates the size of a GIF transcoded from a GIF with the specified size.
     70      */
     71     public static long estimateFileSizeAfterTranscode(long fileSize) {
     72         // I tested transcoding on ~70 GIFs and found that the transcoded files are in general
     73         // about 25-35% the size of the original. This compression ratio is very consistent for the
     74         // class of GIFs we care about most: those converted from video clips and 1-3 MB in size.
     75         return (long) (fileSize * 0.35f);
     76     }
     77 
     78     public static boolean canBeTranscoded(int width, int height) {
     79         if (!isEnabled()) {
     80             return false;
     81         }
     82         return width >= MIN_WIDTH && height >= MIN_HEIGHT;
     83     }
     84 
     85     private static boolean isEnabled() {
     86         final boolean enabled = BugleGservices.get().getBoolean(
     87                 BugleGservicesKeys.ENABLE_GIF_TRANSCODING,
     88                 BugleGservicesKeys.ENABLE_GIF_TRANSCODING_DEFAULT);
     89         if (!enabled) {
     90             LogUtil.w(TAG, "GIF transcoding is disabled");
     91         }
     92         return enabled;
     93     }
     94 }
     95