1 /*
2 * Copyright (C) 2009 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 //#define LOG_NDEBUG 0
18 #define LOG_TAG "AMRExtractor"
19 #include <utils/Log.h>
20
21 #include <inttypes.h>
22
23 #include "AMRExtractor.h"
24
25 #include <media/stagefright/foundation/ADebug.h>
26 #include <media/stagefright/MediaBufferGroup.h>
27 #include <media/stagefright/MediaDefs.h>
28 #include <media/stagefright/MediaErrors.h>
29 #include <media/stagefright/MetaData.h>
30 #include <utils/String8.h>
31
32 namespace android {
33
34 class AMRSource : public MediaTrackHelper {
35 public:
36 AMRSource(
37 DataSourceHelper *source,
38 AMediaFormat *meta,
39 bool isWide,
40 const off64_t *offset_table,
41 size_t offset_table_length);
42
43 virtual media_status_t start();
44 virtual media_status_t stop();
45
46 virtual media_status_t getFormat(AMediaFormat *);
47
48 virtual media_status_t read(
49 MediaBufferHelper **buffer, const ReadOptions *options = NULL);
50
51 protected:
52 virtual ~AMRSource();
53
54 private:
55 DataSourceHelper *mDataSource;
56 AMediaFormat *mMeta;
57 bool mIsWide;
58
59 off64_t mOffset;
60 int64_t mCurrentTimeUs;
61 bool mStarted;
62 MediaBufferGroup *mGroup;
63
64 off64_t mOffsetTable[OFFSET_TABLE_LEN];
65 size_t mOffsetTableLength;
66
67 AMRSource(const AMRSource &);
68 AMRSource &operator=(const AMRSource &);
69 };
70
71 ////////////////////////////////////////////////////////////////////////////////
72
getFrameSize(bool isWide,unsigned FT)73 static size_t getFrameSize(bool isWide, unsigned FT) {
74 static const size_t kFrameSizeNB[16] = {
75 95, 103, 118, 134, 148, 159, 204, 244,
76 39, 43, 38, 37, // SID
77 0, 0, 0, // future use
78 0 // no data
79 };
80 static const size_t kFrameSizeWB[16] = {
81 132, 177, 253, 285, 317, 365, 397, 461, 477,
82 40, // SID
83 0, 0, 0, 0, // future use
84 0, // speech lost
85 0 // no data
86 };
87
88 if (FT > 15 || (isWide && FT > 9 && FT < 14) || (!isWide && FT > 11 && FT < 15)) {
89 ALOGE("illegal AMR frame type %d", FT);
90 return 0;
91 }
92
93 size_t frameSize = isWide ? kFrameSizeWB[FT] : kFrameSizeNB[FT];
94
95 // Round up bits to bytes and add 1 for the header byte.
96 frameSize = (frameSize + 7) / 8 + 1;
97
98 return frameSize;
99 }
100
getFrameSizeByOffset(DataSourceHelper * source,off64_t offset,bool isWide,size_t * frameSize)101 static media_status_t getFrameSizeByOffset(DataSourceHelper *source,
102 off64_t offset, bool isWide, size_t *frameSize) {
103 uint8_t header;
104 ssize_t count = source->readAt(offset, &header, 1);
105 if (count == 0) {
106 return AMEDIA_ERROR_END_OF_STREAM;
107 } else if (count < 0) {
108 return AMEDIA_ERROR_IO;
109 }
110
111 unsigned FT = (header >> 3) & 0x0f;
112
113 *frameSize = getFrameSize(isWide, FT);
114 if (*frameSize == 0) {
115 return AMEDIA_ERROR_MALFORMED;
116 }
117 return AMEDIA_OK;
118 }
119
SniffAMR(DataSourceHelper * source,bool * isWide,float * confidence)120 static bool SniffAMR(
121 DataSourceHelper *source, bool *isWide, float *confidence) {
122 char header[9];
123
124 if (source->readAt(0, header, sizeof(header)) != sizeof(header)) {
125 return false;
126 }
127
128 if (!memcmp(header, "#!AMR\n", 6)) {
129 if (isWide != nullptr) {
130 *isWide = false;
131 }
132 *confidence = 0.5;
133
134 return true;
135 } else if (!memcmp(header, "#!AMR-WB\n", 9)) {
136 if (isWide != nullptr) {
137 *isWide = true;
138 }
139 *confidence = 0.5;
140
141 return true;
142 }
143
144 return false;
145 }
146
AMRExtractor(DataSourceHelper * source)147 AMRExtractor::AMRExtractor(DataSourceHelper *source)
148 : mDataSource(source),
149 mMeta(NULL),
150 mInitCheck(NO_INIT),
151 mOffsetTableLength(0) {
152 float confidence;
153 if (!SniffAMR(mDataSource, &mIsWide, &confidence)) {
154 return;
155 }
156
157 mMeta = AMediaFormat_new();
158 AMediaFormat_setString(mMeta, AMEDIAFORMAT_KEY_MIME,
159 mIsWide ? MEDIA_MIMETYPE_AUDIO_AMR_WB : MEDIA_MIMETYPE_AUDIO_AMR_NB);
160
161 AMediaFormat_setInt32(mMeta, AMEDIAFORMAT_KEY_CHANNEL_COUNT, 1);
162 AMediaFormat_setInt32(mMeta, AMEDIAFORMAT_KEY_SAMPLE_RATE, mIsWide ? 16000 : 8000);
163
164 off64_t offset = mIsWide ? 9 : 6;
165 off64_t streamSize;
166 size_t frameSize, numFrames = 0;
167 int64_t duration = 0;
168
169 if (mDataSource->getSize(&streamSize) == OK) {
170 while (offset < streamSize) {
171 status_t status = getFrameSizeByOffset(source, offset, mIsWide, &frameSize);
172 if (status == ERROR_END_OF_STREAM) {
173 break;
174 } else if (status != OK) {
175 return;
176 }
177
178 if ((numFrames % 50 == 0) && (numFrames / 50 < OFFSET_TABLE_LEN)) {
179 CHECK_EQ(mOffsetTableLength, numFrames / 50);
180 mOffsetTable[mOffsetTableLength] = offset - (mIsWide ? 9: 6);
181 mOffsetTableLength ++;
182 }
183
184 offset += frameSize;
185 duration += 20000; // Each frame is 20ms
186 numFrames ++;
187 }
188
189 AMediaFormat_setInt64(mMeta, AMEDIAFORMAT_KEY_DURATION, duration);
190 }
191
192 mInitCheck = OK;
193 }
194
~AMRExtractor()195 AMRExtractor::~AMRExtractor() {
196 delete mDataSource;
197 if (mMeta) {
198 AMediaFormat_delete(mMeta);
199 }
200 }
201
getMetaData(AMediaFormat * meta)202 media_status_t AMRExtractor::getMetaData(AMediaFormat *meta) {
203 AMediaFormat_clear(meta);
204
205 if (mInitCheck == OK) {
206 AMediaFormat_setString(meta,
207 AMEDIAFORMAT_KEY_MIME, mIsWide ? MEDIA_MIMETYPE_AUDIO_AMR_WB : "audio/amr");
208 }
209
210 return AMEDIA_OK;
211 }
212
countTracks()213 size_t AMRExtractor::countTracks() {
214 return mInitCheck == OK ? 1 : 0;
215 }
216
getTrack(size_t index)217 MediaTrackHelper *AMRExtractor::getTrack(size_t index) {
218 if (mInitCheck != OK || index != 0) {
219 return NULL;
220 }
221
222 return new AMRSource(mDataSource, mMeta, mIsWide,
223 mOffsetTable, mOffsetTableLength);
224 }
225
getTrackMetaData(AMediaFormat * meta,size_t index,uint32_t)226 media_status_t AMRExtractor::getTrackMetaData(AMediaFormat *meta, size_t index, uint32_t /* flags */) {
227 if (mInitCheck != OK || index != 0) {
228 return AMEDIA_ERROR_UNKNOWN;
229 }
230
231 return AMediaFormat_copy(meta, mMeta);
232 }
233
234 ////////////////////////////////////////////////////////////////////////////////
235
AMRSource(DataSourceHelper * source,AMediaFormat * meta,bool isWide,const off64_t * offset_table,size_t offset_table_length)236 AMRSource::AMRSource(
237 DataSourceHelper *source, AMediaFormat *meta,
238 bool isWide, const off64_t *offset_table, size_t offset_table_length)
239 : mDataSource(source),
240 mMeta(meta),
241 mIsWide(isWide),
242 mOffset(mIsWide ? 9 : 6),
243 mCurrentTimeUs(0),
244 mStarted(false),
245 mGroup(NULL),
246 mOffsetTableLength(offset_table_length) {
247 if (mOffsetTableLength > 0 && mOffsetTableLength <= OFFSET_TABLE_LEN) {
248 memcpy ((char*)mOffsetTable, (char*)offset_table, sizeof(off64_t) * mOffsetTableLength);
249 }
250 }
251
~AMRSource()252 AMRSource::~AMRSource() {
253 if (mStarted) {
254 stop();
255 }
256 }
257
start()258 media_status_t AMRSource::start() {
259 CHECK(!mStarted);
260
261 mOffset = mIsWide ? 9 : 6;
262 mCurrentTimeUs = 0;
263 mBufferGroup->add_buffer(128);
264 mStarted = true;
265
266 return AMEDIA_OK;
267 }
268
stop()269 media_status_t AMRSource::stop() {
270 CHECK(mStarted);
271
272 mStarted = false;
273 return AMEDIA_OK;
274 }
275
getFormat(AMediaFormat * meta)276 media_status_t AMRSource::getFormat(AMediaFormat *meta) {
277 return AMediaFormat_copy(meta, mMeta);
278 }
279
read(MediaBufferHelper ** out,const ReadOptions * options)280 media_status_t AMRSource::read(
281 MediaBufferHelper **out, const ReadOptions *options) {
282 *out = NULL;
283
284 int64_t seekTimeUs;
285 ReadOptions::SeekMode mode;
286 if (mOffsetTableLength > 0 && options && options->getSeekTo(&seekTimeUs, &mode)) {
287 size_t size;
288 const int64_t frameDurationUs = 20000LL; // 20ms per frame.
289 int64_t seekFrame = 0;
290 switch(mode & 0x7) {
291 case ReadOptions::SEEK_NEXT_SYNC:
292 seekFrame = (seekTimeUs + frameDurationUs - 1) / frameDurationUs;
293 break;
294 case ReadOptions::SEEK_CLOSEST_SYNC:
295 case ReadOptions::SEEK_CLOSEST:
296 seekFrame = (seekTimeUs + frameDurationUs/2) / frameDurationUs;
297 break;
298 case ReadOptions::SEEK_PREVIOUS_SYNC:
299 default:
300 seekFrame = seekTimeUs / frameDurationUs;
301 break;
302 }
303 mCurrentTimeUs = seekFrame * frameDurationUs;
304
305 size_t index = seekFrame < 0 ? 0 : seekFrame / 50;
306 if (index >= mOffsetTableLength) {
307 index = mOffsetTableLength - 1;
308 }
309
310 mOffset = mOffsetTable[index] + (mIsWide ? 9 : 6);
311
312 for (size_t i = 0; i< seekFrame - index * 50; i++) {
313 media_status_t err;
314 if ((err = getFrameSizeByOffset(mDataSource, mOffset,
315 mIsWide, &size)) != OK) {
316 return err;
317 }
318 mOffset += size;
319 }
320 }
321
322 uint8_t header;
323 ssize_t n = mDataSource->readAt(mOffset, &header, 1);
324
325 if (n < 1) {
326 return AMEDIA_ERROR_END_OF_STREAM;
327 }
328
329 if (header & 0x83) {
330 // Padding bits must be 0.
331
332 ALOGE("padding bits must be 0, header is 0x%02x", header);
333
334 return AMEDIA_ERROR_MALFORMED;
335 }
336
337 unsigned FT = (header >> 3) & 0x0f;
338
339 size_t frameSize = getFrameSize(mIsWide, FT);
340 if (frameSize == 0) {
341 return AMEDIA_ERROR_MALFORMED;
342 }
343
344 MediaBufferHelper *buffer;
345 status_t err = mBufferGroup->acquire_buffer(&buffer);
346 if (err != OK) {
347 return AMEDIA_ERROR_UNKNOWN;
348 }
349
350 n = mDataSource->readAt(mOffset, buffer->data(), frameSize);
351
352 if (n != (ssize_t)frameSize) {
353 buffer->release();
354 buffer = NULL;
355
356 if (n < 0) {
357 return AMEDIA_ERROR_IO;
358 } else {
359 // only partial frame is available, treat it as EOS.
360 mOffset += n;
361 return AMEDIA_ERROR_END_OF_STREAM;
362 }
363 }
364
365 buffer->set_range(0, frameSize);
366 AMediaFormat *meta = buffer->meta_data();
367 AMediaFormat_setInt64(meta, AMEDIAFORMAT_KEY_TIME_US, mCurrentTimeUs);
368 AMediaFormat_setInt32(meta, AMEDIAFORMAT_KEY_IS_SYNC_FRAME, 1);
369
370 mOffset += frameSize;
371 mCurrentTimeUs += 20000; // Each frame is 20ms
372
373 *out = buffer;
374
375 return AMEDIA_OK;
376 }
377
378 ////////////////////////////////////////////////////////////////////////////////
379
380 static const char *extensions[] = {
381 "amr",
382 "awb",
383 NULL
384 };
385
386 extern "C" {
387 // This is the only symbol that needs to be exported
388 __attribute__ ((visibility ("default")))
GETEXTRACTORDEF()389 ExtractorDef GETEXTRACTORDEF() {
390 return {
391 EXTRACTORDEF_VERSION,
392 UUID("c86639c9-2f31-40ac-a715-fa01b4493aaf"),
393 1,
394 "AMR Extractor",
395 {
396 .v3 = {
397 [](
398 CDataSource *source,
399 float *confidence,
400 void **,
401 FreeMetaFunc *) -> CreatorFunc {
402 DataSourceHelper helper(source);
403 if (SniffAMR(&helper, nullptr, confidence)) {
404 return [](
405 CDataSource *source,
406 void *) -> CMediaExtractor* {
407 return wrap(new AMRExtractor(new DataSourceHelper(source)));};
408 }
409 return NULL;
410 },
411 extensions
412 },
413 },
414 };
415 }
416
417 } // extern "C"
418
419 } // namespace android
420