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
17package com.android.messaging.util;
18
19import android.content.Context;
20import android.text.format.Formatter;
21
22import com.google.common.base.Stopwatch;
23
24import java.io.File;
25import 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 */
33public 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