IMediaMetadataRetriever.cpp revision f311c557729099d002f4aae37c402a8287912369 
1/*
2**
3** Copyright (C) 2008 The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9**     http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18#include <stdint.h>
19#include <sys/types.h>
20#include <binder/Parcel.h>
21#include <SkBitmap.h>
22#include <media/IMediaMetadataRetriever.h>
23
24// The binder is supposed to propagate the scheduler group across
25// the binder interface so that remote calls are executed with
26// the same priority as local calls. This is currently not working
27// so this change puts in a temporary hack to fix the issue with
28// metadata retrieval which can be a huge CPU hit if done on a
29// foreground thread.
30#ifndef DISABLE_GROUP_SCHEDULE_HACK
31
32/* desktop Linux needs a little help with gettid() */
33#if defined(HAVE_GETTID) && !defined(HAVE_ANDROID_OS)
34#define __KERNEL__
35# include <linux/unistd.h>
36#ifdef _syscall0
37_syscall0(pid_t,gettid)
38#else
39pid_t gettid() { return syscall(__NR_gettid);}
40#endif
41#undef __KERNEL__
42#endif
43
44static int myTid() {
45#ifdef HAVE_GETTID
46    return gettid();
47#else
48    return getpid();
49#endif
50}
51
52#undef LOG_TAG
53#define LOG_TAG "IMediaMetadataRetriever"
54#include <utils/Log.h>
55#include <cutils/sched_policy.h>
56
57namespace android {
58
59static void sendSchedPolicy(Parcel& data)
60{
61    SchedPolicy policy;
62    get_sched_policy(myTid(), &policy);
63    data.writeInt32(policy);
64}
65
66static void setSchedPolicy(const Parcel& data)
67{
68    SchedPolicy policy = (SchedPolicy) data.readInt32();
69    set_sched_policy(myTid(), policy);
70}
71static void restoreSchedPolicy()
72{
73    set_sched_policy(myTid(), SP_FOREGROUND);
74}
75}; // end namespace android
76#endif
77
78namespace android {
79
80enum {
81    DISCONNECT = IBinder::FIRST_CALL_TRANSACTION,
82    SET_DATA_SOURCE_URL,
83    SET_DATA_SOURCE_FD,
84    SET_MODE,
85    GET_MODE,
86    CAPTURE_FRAME,
87    EXTRACT_ALBUM_ART,
88    EXTRACT_METADATA,
89};
90
91class BpMediaMetadataRetriever: public BpInterface<IMediaMetadataRetriever>
92{
93public:
94    BpMediaMetadataRetriever(const sp<IBinder>& impl)
95        : BpInterface<IMediaMetadataRetriever>(impl)
96    {
97    }
98
99    // disconnect from media metadata retriever service
100    void disconnect()
101    {
102        Parcel data, reply;
103        data.writeInterfaceToken(IMediaMetadataRetriever::getInterfaceDescriptor());
104        remote()->transact(DISCONNECT, data, &reply);
105    }
106
107    status_t setDataSource(const char* srcUrl)
108    {
109        Parcel data, reply;
110        data.writeInterfaceToken(IMediaMetadataRetriever::getInterfaceDescriptor());
111        data.writeCString(srcUrl);
112        remote()->transact(SET_DATA_SOURCE_URL, data, &reply);
113        return reply.readInt32();
114    }
115
116    status_t setDataSource(int fd, int64_t offset, int64_t length)
117    {
118        Parcel data, reply;
119        data.writeInterfaceToken(IMediaMetadataRetriever::getInterfaceDescriptor());
120        data.writeFileDescriptor(fd);
121        data.writeInt64(offset);
122        data.writeInt64(length);
123        remote()->transact(SET_DATA_SOURCE_FD, data, &reply);
124        return reply.readInt32();
125    }
126
127    status_t setMode(int mode)
128    {
129        Parcel data, reply;
130        data.writeInterfaceToken(IMediaMetadataRetriever::getInterfaceDescriptor());
131        data.writeInt32(mode);
132        remote()->transact(SET_MODE, data, &reply);
133        return reply.readInt32();
134    }
135
136    status_t getMode(int* mode) const
137    {
138        Parcel data, reply;
139        data.writeInterfaceToken(IMediaMetadataRetriever::getInterfaceDescriptor());
140        remote()->transact(GET_MODE, data, &reply);
141        *mode = reply.readInt32();
142        return reply.readInt32();
143    }
144
145    sp<IMemory> captureFrame()
146    {
147        Parcel data, reply;
148        data.writeInterfaceToken(IMediaMetadataRetriever::getInterfaceDescriptor());
149#ifndef DISABLE_GROUP_SCHEDULE_HACK
150        sendSchedPolicy(data);
151#endif
152        remote()->transact(CAPTURE_FRAME, data, &reply);
153        status_t ret = reply.readInt32();
154        if (ret != NO_ERROR) {
155            return NULL;
156        }
157        return interface_cast<IMemory>(reply.readStrongBinder());
158    }
159
160    sp<IMemory> extractAlbumArt()
161    {
162        Parcel data, reply;
163        data.writeInterfaceToken(IMediaMetadataRetriever::getInterfaceDescriptor());
164#ifndef DISABLE_GROUP_SCHEDULE_HACK
165        sendSchedPolicy(data);
166#endif
167        remote()->transact(EXTRACT_ALBUM_ART, data, &reply);
168        status_t ret = reply.readInt32();
169        if (ret != NO_ERROR) {
170            return NULL;
171        }
172        return interface_cast<IMemory>(reply.readStrongBinder());
173    }
174
175    const char* extractMetadata(int keyCode)
176    {
177        Parcel data, reply;
178        data.writeInterfaceToken(IMediaMetadataRetriever::getInterfaceDescriptor());
179#ifndef DISABLE_GROUP_SCHEDULE_HACK
180        sendSchedPolicy(data);
181#endif
182        data.writeInt32(keyCode);
183        remote()->transact(EXTRACT_METADATA, data, &reply);
184        status_t ret = reply.readInt32();
185        if (ret != NO_ERROR) {
186            return NULL;
187        }
188        return reply.readCString();
189    }
190};
191
192IMPLEMENT_META_INTERFACE(MediaMetadataRetriever, "android.media.IMediaMetadataRetriever");
193
194// ----------------------------------------------------------------------
195
196status_t BnMediaMetadataRetriever::onTransact(
197    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
198{
199    switch (code) {
200        case DISCONNECT: {
201            CHECK_INTERFACE(IMediaMetadataRetriever, data, reply);
202            disconnect();
203            return NO_ERROR;
204        } break;
205        case SET_DATA_SOURCE_URL: {
206            CHECK_INTERFACE(IMediaMetadataRetriever, data, reply);
207            const char* srcUrl = data.readCString();
208            reply->writeInt32(setDataSource(srcUrl));
209            return NO_ERROR;
210        } break;
211        case SET_DATA_SOURCE_FD: {
212            CHECK_INTERFACE(IMediaMetadataRetriever, data, reply);
213            int fd = dup(data.readFileDescriptor());
214            int64_t offset = data.readInt64();
215            int64_t length = data.readInt64();
216            reply->writeInt32(setDataSource(fd, offset, length));
217            return NO_ERROR;
218        } break;
219        case SET_MODE: {
220            CHECK_INTERFACE(IMediaMetadataRetriever, data, reply);
221            int mode = data.readInt32();
222            reply->writeInt32(setMode(mode));
223            return NO_ERROR;
224        } break;
225        case GET_MODE: {
226            CHECK_INTERFACE(IMediaMetadataRetriever, data, reply);
227            int mode;
228            status_t status = getMode(&mode);
229            reply->writeInt32(mode);
230            reply->writeInt32(status);
231            return NO_ERROR;
232        } break;
233        case CAPTURE_FRAME: {
234            CHECK_INTERFACE(IMediaMetadataRetriever, data, reply);
235#ifndef DISABLE_GROUP_SCHEDULE_HACK
236            setSchedPolicy(data);
237#endif
238            sp<IMemory> bitmap = captureFrame();
239            if (bitmap != 0) {  // Don't send NULL across the binder interface
240                reply->writeInt32(NO_ERROR);
241                reply->writeStrongBinder(bitmap->asBinder());
242            } else {
243                reply->writeInt32(UNKNOWN_ERROR);
244            }
245#ifndef DISABLE_GROUP_SCHEDULE_HACK
246            restoreSchedPolicy();
247#endif
248            return NO_ERROR;
249        } break;
250        case EXTRACT_ALBUM_ART: {
251            CHECK_INTERFACE(IMediaMetadataRetriever, data, reply);
252#ifndef DISABLE_GROUP_SCHEDULE_HACK
253            setSchedPolicy(data);
254#endif
255            sp<IMemory> albumArt = extractAlbumArt();
256            if (albumArt != 0) {  // Don't send NULL across the binder interface
257                reply->writeInt32(NO_ERROR);
258                reply->writeStrongBinder(albumArt->asBinder());
259            } else {
260                reply->writeInt32(UNKNOWN_ERROR);
261            }
262#ifndef DISABLE_GROUP_SCHEDULE_HACK
263            restoreSchedPolicy();
264#endif
265            return NO_ERROR;
266        } break;
267        case EXTRACT_METADATA: {
268            CHECK_INTERFACE(IMediaMetadataRetriever, data, reply);
269#ifndef DISABLE_GROUP_SCHEDULE_HACK
270            setSchedPolicy(data);
271#endif
272            int keyCode = data.readInt32();
273            const char* value = extractMetadata(keyCode);
274            if (value != NULL) {  // Don't send NULL across the binder interface
275                reply->writeInt32(NO_ERROR);
276                reply->writeCString(value);
277            } else {
278                reply->writeInt32(UNKNOWN_ERROR);
279            }
280#ifndef DISABLE_GROUP_SCHEDULE_HACK
281            restoreSchedPolicy();
282#endif
283            return NO_ERROR;
284        } break;
285        default:
286            return BBinder::onTransact(code, data, reply, flags);
287    }
288}
289
290// ----------------------------------------------------------------------------
291
292}; // namespace android
293