1 /*
2  * Copyright 2018 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 
18 #define LOG_TAG "MediaHelper"
19 
20 #include "MediaTestHelpers.h"
21 
22 #include <android/asset_manager.h>
23 #include <android/asset_manager_jni.h>
24 #include <android/log.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #define ALOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)
29 
30 #define ASSERT(a)                                                              \
31   if (!(a)) {                                                                  \
32     ALOGE("Failure: " #a " at " __FILE__ ":%d", __LINE__);                     \
33     return false;                                                              \
34   }
35 
36 #define MEDIA_CALL(a) ASSERT(AMEDIA_OK == (a))
37 
~MediaHelper()38 MediaHelper::~MediaHelper() {
39   if (mCodec != nullptr) {
40     AMediaCodec_stop(mCodec);
41     AMediaCodec_delete(mCodec);
42     mCodec = nullptr;
43   }
44   if (mExtractor != nullptr) {
45     AMediaExtractor_delete(mExtractor);
46     mExtractor = nullptr;
47   }
48 }
49 
init(JNIEnv * env,jobject assetMgr,jstring jfilename,ANativeWindow * window)50 bool MediaHelper::init(JNIEnv *env, jobject assetMgr, jstring jfilename,
51                        ANativeWindow *window) {
52   // Create a media extractor which will provide codec data from jfilename.
53   ASSERT(createExtractor(env, assetMgr, jfilename));
54   // Create a media codec and image reader which receives frames from the
55   // codec.
56   ASSERT(createMediaCodec(window));
57 
58   return true;
59 }
60 
processOneFrame()61 bool MediaHelper::processOneFrame() {
62   ASSERT(mCodec);
63 
64   // Wait until the codec produces an output buffer, which we can read as
65   // an image.
66   bool gotOutputBuffer = false;
67   do {
68     ASSERT(processOneInputBuffer());
69     ASSERT(processOneOutputBuffer(&gotOutputBuffer));
70   } while (!gotOutputBuffer);
71 
72   return true;
73 }
74 
createExtractor(JNIEnv * env,jobject assetMgr,jstring jfilename)75 bool MediaHelper::createExtractor(JNIEnv *env, jobject assetMgr,
76                                   jstring jfilename) {
77   ASSERT(nullptr == mExtractor);
78   const char *filename = env->GetStringUTFChars(jfilename, NULL);
79   ASSERT(filename);
80 
81   struct ReleaseFd {
82     ~ReleaseFd() {
83       if (fd >= 0)
84         close(fd);
85     }
86 
87     int fd = -1;
88   } releaseFd;
89 
90   off_t outStart, outLen;
91   releaseFd.fd = AAsset_openFileDescriptor(
92       AAssetManager_open(AAssetManager_fromJava(env, assetMgr), filename, 0),
93       &outStart, &outLen);
94   env->ReleaseStringUTFChars(jfilename, filename);
95   ASSERT(releaseFd.fd >= 0);
96 
97   mExtractor = AMediaExtractor_new();
98   MEDIA_CALL(AMediaExtractor_setDataSourceFd(mExtractor, releaseFd.fd,
99                                              static_cast<off64_t>(outStart),
100                                              static_cast<off64_t>(outLen)));
101   return true;
102 }
103 
createMediaCodec(ANativeWindow * window)104 bool MediaHelper::createMediaCodec(ANativeWindow *window) {
105   ASSERT(mExtractor);
106   ASSERT(nullptr == mCodec);
107 
108   // Create a mCodec from the video track.
109   int numTracks = AMediaExtractor_getTrackCount(mExtractor);
110   AMediaFormat *format;
111   const char *mime;
112   for (int i = 0; i < numTracks; ++i) {
113     format = AMediaExtractor_getTrackFormat(mExtractor, i);
114     ASSERT(AMediaFormat_getString(format, AMEDIAFORMAT_KEY_MIME, &mime));
115 
116     if (!strncmp(mime, "video/", 6)) {
117       MEDIA_CALL(AMediaExtractor_selectTrack(mExtractor, i));
118       break;
119     }
120 
121     AMediaFormat_delete(format);
122   }
123 
124   mCodec = AMediaCodec_createDecoderByType(mime);
125   ASSERT(mCodec);
126   MEDIA_CALL(AMediaCodec_configure(mCodec, format, window, NULL, 0));
127   AMediaFormat_delete(format);
128   MEDIA_CALL(AMediaCodec_start(mCodec));
129 
130   return true;
131 }
132 
processOneInputBuffer()133 bool MediaHelper::processOneInputBuffer() {
134   ssize_t bufferIndex = AMediaCodec_dequeueInputBuffer(mCodec, 2000);
135   // No input buffer ready, just return, we'll try again.
136   if (bufferIndex < 0)
137     return true;
138 
139   size_t bufferSize = 0;
140   uint8_t *buffer =
141       AMediaCodec_getInputBuffer(mCodec, bufferIndex, &bufferSize);
142   ASSERT(buffer);
143 
144   ssize_t sampleSize =
145       AMediaExtractor_readSampleData(mExtractor, buffer, bufferSize);
146   ASSERT(sampleSize >= 0);
147 
148   auto presentationTimeUs = AMediaExtractor_getSampleTime(mExtractor);
149   MEDIA_CALL(AMediaCodec_queueInputBuffer(mCodec, bufferIndex, 0, sampleSize,
150                                           presentationTimeUs, 0));
151 
152   ASSERT(AMediaExtractor_advance(mExtractor));
153 
154   return true;
155 }
156 
157 // Returns true if we successfully got an output buffer.
processOneOutputBuffer(bool * didProcessBuffer)158 bool MediaHelper::processOneOutputBuffer(bool *didProcessBuffer) {
159   *didProcessBuffer = false;
160 
161   AMediaCodecBufferInfo info;
162   ssize_t index = AMediaCodec_dequeueOutputBuffer(mCodec, &info, 0);
163   if (index < 0) {
164     switch (index) {
165     case AMEDIACODEC_INFO_OUTPUT_BUFFERS_CHANGED:
166     case AMEDIACODEC_INFO_OUTPUT_FORMAT_CHANGED:
167     case AMEDIACODEC_INFO_TRY_AGAIN_LATER:
168       return true;
169     default:
170       return false;
171     }
172   }
173 
174   *didProcessBuffer = true;
175   MEDIA_CALL(AMediaCodec_releaseOutputBuffer(mCodec, index, info.size != 0));
176   return true;
177 }
178