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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 "WAVExtractor"
19 #include <utils/Log.h>
20 
21 #include "include/WAVExtractor.h"
22 
23 #include <audio_utils/primitives.h>
24 #include <media/stagefright/foundation/ADebug.h>
25 #include <media/stagefright/DataSource.h>
26 #include <media/stagefright/MediaBufferGroup.h>
27 #include <media/stagefright/MediaDefs.h>
28 #include <media/stagefright/MediaErrors.h>
29 #include <media/stagefright/MediaSource.h>
30 #include <media/stagefright/MetaData.h>
31 #include <utils/String8.h>
32 #include <cutils/bitops.h>
33 
34 #define CHANNEL_MASK_USE_CHANNEL_ORDER 0
35 
36 namespace android {
37 
38 enum {
39     WAVE_FORMAT_PCM        = 0x0001,
40     WAVE_FORMAT_IEEE_FLOAT = 0x0003,
41     WAVE_FORMAT_ALAW       = 0x0006,
42     WAVE_FORMAT_MULAW      = 0x0007,
43     WAVE_FORMAT_MSGSM      = 0x0031,
44     WAVE_FORMAT_EXTENSIBLE = 0xFFFE
45 };
46 
47 static const char* WAVEEXT_SUBFORMAT = "\x00\x00\x00\x00\x10\x00\x80\x00\x00\xAA\x00\x38\x9B\x71";
48 static const char* AMBISONIC_SUBFORMAT = "\x00\x00\x21\x07\xD3\x11\x86\x44\xC8\xC1\xCA\x00\x00\x00";
49 
U32_LE_AT(const uint8_t * ptr)50 static uint32_t U32_LE_AT(const uint8_t *ptr) {
51     return ptr[3] << 24 | ptr[2] << 16 | ptr[1] << 8 | ptr[0];
52 }
53 
U16_LE_AT(const uint8_t * ptr)54 static uint16_t U16_LE_AT(const uint8_t *ptr) {
55     return ptr[1] << 8 | ptr[0];
56 }
57 
58 struct WAVSource : public MediaSource {
59     WAVSource(
60             const sp<DataSource> &dataSource,
61             const sp<MetaData> &meta,
62             uint16_t waveFormat,
63             int32_t bitsPerSample,
64             off64_t offset, size_t size);
65 
66     virtual status_t start(MetaData *params = NULL);
67     virtual status_t stop();
68     virtual sp<MetaData> getFormat();
69 
70     virtual status_t read(
71             MediaBuffer **buffer, const ReadOptions *options = NULL);
72 
supportNonblockingReadandroid::WAVSource73     virtual bool supportNonblockingRead() { return true; }
74 
75 protected:
76     virtual ~WAVSource();
77 
78 private:
79     static const size_t kMaxFrameSize;
80 
81     sp<DataSource> mDataSource;
82     sp<MetaData> mMeta;
83     uint16_t mWaveFormat;
84     int32_t mSampleRate;
85     int32_t mNumChannels;
86     int32_t mBitsPerSample;
87     off64_t mOffset;
88     size_t mSize;
89     bool mStarted;
90     MediaBufferGroup *mGroup;
91     off64_t mCurrentPos;
92 
93     WAVSource(const WAVSource &);
94     WAVSource &operator=(const WAVSource &);
95 };
96 
WAVExtractor(const sp<DataSource> & source)97 WAVExtractor::WAVExtractor(const sp<DataSource> &source)
98     : mDataSource(source),
99       mValidFormat(false),
100       mChannelMask(CHANNEL_MASK_USE_CHANNEL_ORDER) {
101     mInitCheck = init();
102 }
103 
~WAVExtractor()104 WAVExtractor::~WAVExtractor() {
105 }
106 
getMetaData()107 sp<MetaData> WAVExtractor::getMetaData() {
108     sp<MetaData> meta = new MetaData;
109 
110     if (mInitCheck != OK) {
111         return meta;
112     }
113 
114     meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_WAV);
115 
116     return meta;
117 }
118 
countTracks()119 size_t WAVExtractor::countTracks() {
120     return mInitCheck == OK ? 1 : 0;
121 }
122 
getTrack(size_t index)123 sp<IMediaSource> WAVExtractor::getTrack(size_t index) {
124     if (mInitCheck != OK || index > 0) {
125         return NULL;
126     }
127 
128     return new WAVSource(
129             mDataSource, mTrackMeta,
130             mWaveFormat, mBitsPerSample, mDataOffset, mDataSize);
131 }
132 
getTrackMetaData(size_t index,uint32_t)133 sp<MetaData> WAVExtractor::getTrackMetaData(
134         size_t index, uint32_t /* flags */) {
135     if (mInitCheck != OK || index > 0) {
136         return NULL;
137     }
138 
139     return mTrackMeta;
140 }
141 
init()142 status_t WAVExtractor::init() {
143     uint8_t header[12];
144     if (mDataSource->readAt(
145                 0, header, sizeof(header)) < (ssize_t)sizeof(header)) {
146         return NO_INIT;
147     }
148 
149     if (memcmp(header, "RIFF", 4) || memcmp(&header[8], "WAVE", 4)) {
150         return NO_INIT;
151     }
152 
153     size_t totalSize = U32_LE_AT(&header[4]);
154 
155     off64_t offset = 12;
156     size_t remainingSize = totalSize;
157     while (remainingSize >= 8) {
158         uint8_t chunkHeader[8];
159         if (mDataSource->readAt(offset, chunkHeader, 8) < 8) {
160             return NO_INIT;
161         }
162 
163         remainingSize -= 8;
164         offset += 8;
165 
166         uint32_t chunkSize = U32_LE_AT(&chunkHeader[4]);
167 
168         if (chunkSize > remainingSize) {
169             return NO_INIT;
170         }
171 
172         if (!memcmp(chunkHeader, "fmt ", 4)) {
173             if (chunkSize < 16) {
174                 return NO_INIT;
175             }
176 
177             uint8_t formatSpec[40];
178             if (mDataSource->readAt(offset, formatSpec, 2) < 2) {
179                 return NO_INIT;
180             }
181 
182             mWaveFormat = U16_LE_AT(formatSpec);
183             if (mWaveFormat != WAVE_FORMAT_PCM
184                     && mWaveFormat != WAVE_FORMAT_IEEE_FLOAT
185                     && mWaveFormat != WAVE_FORMAT_ALAW
186                     && mWaveFormat != WAVE_FORMAT_MULAW
187                     && mWaveFormat != WAVE_FORMAT_MSGSM
188                     && mWaveFormat != WAVE_FORMAT_EXTENSIBLE) {
189                 return ERROR_UNSUPPORTED;
190             }
191 
192             uint8_t fmtSize = 16;
193             if (mWaveFormat == WAVE_FORMAT_EXTENSIBLE) {
194                 fmtSize = 40;
195             }
196             if (mDataSource->readAt(offset, formatSpec, fmtSize) < fmtSize) {
197                 return NO_INIT;
198             }
199 
200             mNumChannels = U16_LE_AT(&formatSpec[2]);
201 
202             if (mNumChannels < 1 || mNumChannels > 8) {
203                 ALOGE("Unsupported number of channels (%d)", mNumChannels);
204                 return ERROR_UNSUPPORTED;
205             }
206 
207             if (mWaveFormat != WAVE_FORMAT_EXTENSIBLE) {
208                 if (mNumChannels != 1 && mNumChannels != 2) {
209                     ALOGW("More than 2 channels (%d) in non-WAVE_EXT, unknown channel mask",
210                             mNumChannels);
211                 }
212             }
213 
214             mSampleRate = U32_LE_AT(&formatSpec[4]);
215 
216             if (mSampleRate == 0) {
217                 return ERROR_MALFORMED;
218             }
219 
220             mBitsPerSample = U16_LE_AT(&formatSpec[14]);
221 
222             if (mWaveFormat == WAVE_FORMAT_EXTENSIBLE) {
223                 uint16_t validBitsPerSample = U16_LE_AT(&formatSpec[18]);
224                 if (validBitsPerSample != mBitsPerSample) {
225                     if (validBitsPerSample != 0) {
226                         ALOGE("validBits(%d) != bitsPerSample(%d) are not supported",
227                                 validBitsPerSample, mBitsPerSample);
228                         return ERROR_UNSUPPORTED;
229                     } else {
230                         // we only support valitBitsPerSample == bitsPerSample but some WAV_EXT
231                         // writers don't correctly set the valid bits value, and leave it at 0.
232                         ALOGW("WAVE_EXT has 0 valid bits per sample, ignoring");
233                     }
234                 }
235 
236                 mChannelMask = U32_LE_AT(&formatSpec[20]);
237                 ALOGV("numChannels=%d channelMask=0x%x", mNumChannels, mChannelMask);
238                 if ((mChannelMask >> 18) != 0) {
239                     ALOGE("invalid channel mask 0x%x", mChannelMask);
240                     return ERROR_MALFORMED;
241                 }
242 
243                 if ((mChannelMask != CHANNEL_MASK_USE_CHANNEL_ORDER)
244                         && (popcount(mChannelMask) != mNumChannels)) {
245                     ALOGE("invalid number of channels (%d) in channel mask (0x%x)",
246                             popcount(mChannelMask), mChannelMask);
247                     return ERROR_MALFORMED;
248                 }
249 
250                 // In a WAVE_EXT header, the first two bytes of the GUID stored at byte 24 contain
251                 // the sample format, using the same definitions as a regular WAV header
252                 mWaveFormat = U16_LE_AT(&formatSpec[24]);
253                 if (memcmp(&formatSpec[26], WAVEEXT_SUBFORMAT, 14) &&
254                     memcmp(&formatSpec[26], AMBISONIC_SUBFORMAT, 14)) {
255                     ALOGE("unsupported GUID");
256                     return ERROR_UNSUPPORTED;
257                 }
258             }
259 
260             if (mWaveFormat == WAVE_FORMAT_PCM) {
261                 if (mBitsPerSample != 8 && mBitsPerSample != 16
262                     && mBitsPerSample != 24 && mBitsPerSample != 32) {
263                     return ERROR_UNSUPPORTED;
264                 }
265             } else if (mWaveFormat == WAVE_FORMAT_IEEE_FLOAT) {
266                 if (mBitsPerSample != 32) {  // TODO we don't support double
267                     return ERROR_UNSUPPORTED;
268                 }
269             }
270             else if (mWaveFormat == WAVE_FORMAT_MSGSM) {
271                 if (mBitsPerSample != 0) {
272                     return ERROR_UNSUPPORTED;
273                 }
274             } else if (mWaveFormat == WAVE_FORMAT_MULAW || mWaveFormat == WAVE_FORMAT_ALAW) {
275                 if (mBitsPerSample != 8) {
276                     return ERROR_UNSUPPORTED;
277                 }
278             } else {
279                 return ERROR_UNSUPPORTED;
280             }
281 
282             mValidFormat = true;
283         } else if (!memcmp(chunkHeader, "data", 4)) {
284             if (mValidFormat) {
285                 mDataOffset = offset;
286                 mDataSize = chunkSize;
287 
288                 mTrackMeta = new MetaData;
289 
290                 switch (mWaveFormat) {
291                     case WAVE_FORMAT_PCM:
292                     case WAVE_FORMAT_IEEE_FLOAT:
293                         mTrackMeta->setCString(
294                                 kKeyMIMEType, MEDIA_MIMETYPE_AUDIO_RAW);
295                         break;
296                     case WAVE_FORMAT_ALAW:
297                         mTrackMeta->setCString(
298                                 kKeyMIMEType, MEDIA_MIMETYPE_AUDIO_G711_ALAW);
299                         break;
300                     case WAVE_FORMAT_MSGSM:
301                         mTrackMeta->setCString(
302                                 kKeyMIMEType, MEDIA_MIMETYPE_AUDIO_MSGSM);
303                         break;
304                     default:
305                         CHECK_EQ(mWaveFormat, (uint16_t)WAVE_FORMAT_MULAW);
306                         mTrackMeta->setCString(
307                                 kKeyMIMEType, MEDIA_MIMETYPE_AUDIO_G711_MLAW);
308                         break;
309                 }
310 
311                 mTrackMeta->setInt32(kKeyChannelCount, mNumChannels);
312                 mTrackMeta->setInt32(kKeyChannelMask, mChannelMask);
313                 mTrackMeta->setInt32(kKeySampleRate, mSampleRate);
314                 mTrackMeta->setInt32(kKeyPcmEncoding, kAudioEncodingPcm16bit);
315 
316                 int64_t durationUs = 0;
317                 if (mWaveFormat == WAVE_FORMAT_MSGSM) {
318                     // 65 bytes decode to 320 8kHz samples
319                     durationUs =
320                         1000000LL * (mDataSize / 65 * 320) / 8000;
321                 } else {
322                     size_t bytesPerSample = mBitsPerSample >> 3;
323 
324                     if (!bytesPerSample || !mNumChannels)
325                         return ERROR_MALFORMED;
326 
327                     size_t num_samples = mDataSize / (mNumChannels * bytesPerSample);
328 
329                     if (!mSampleRate)
330                         return ERROR_MALFORMED;
331 
332                     durationUs =
333                         1000000LL * num_samples / mSampleRate;
334                 }
335 
336                 mTrackMeta->setInt64(kKeyDuration, durationUs);
337 
338                 return OK;
339             }
340         }
341 
342         offset += chunkSize;
343     }
344 
345     return NO_INIT;
346 }
347 
348 const size_t WAVSource::kMaxFrameSize = 32768;
349 
WAVSource(const sp<DataSource> & dataSource,const sp<MetaData> & meta,uint16_t waveFormat,int32_t bitsPerSample,off64_t offset,size_t size)350 WAVSource::WAVSource(
351         const sp<DataSource> &dataSource,
352         const sp<MetaData> &meta,
353         uint16_t waveFormat,
354         int32_t bitsPerSample,
355         off64_t offset, size_t size)
356     : mDataSource(dataSource),
357       mMeta(meta),
358       mWaveFormat(waveFormat),
359       mSampleRate(0),
360       mNumChannels(0),
361       mBitsPerSample(bitsPerSample),
362       mOffset(offset),
363       mSize(size),
364       mStarted(false),
365       mGroup(NULL) {
366     CHECK(mMeta->findInt32(kKeySampleRate, &mSampleRate));
367     CHECK(mMeta->findInt32(kKeyChannelCount, &mNumChannels));
368 
369     mMeta->setInt32(kKeyMaxInputSize, kMaxFrameSize);
370 }
371 
~WAVSource()372 WAVSource::~WAVSource() {
373     if (mStarted) {
374         stop();
375     }
376 }
377 
start(MetaData *)378 status_t WAVSource::start(MetaData * /* params */) {
379     ALOGV("WAVSource::start");
380 
381     CHECK(!mStarted);
382 
383     // some WAV files may have large audio buffers that use shared memory transfer.
384     mGroup = new MediaBufferGroup(4 /* buffers */, kMaxFrameSize);
385 
386     if (mBitsPerSample == 8) {
387         // As a temporary buffer for 8->16 bit conversion.
388         mGroup->add_buffer(new MediaBuffer(kMaxFrameSize));
389     }
390 
391     mCurrentPos = mOffset;
392 
393     mStarted = true;
394 
395     return OK;
396 }
397 
stop()398 status_t WAVSource::stop() {
399     ALOGV("WAVSource::stop");
400 
401     CHECK(mStarted);
402 
403     delete mGroup;
404     mGroup = NULL;
405 
406     mStarted = false;
407 
408     return OK;
409 }
410 
getFormat()411 sp<MetaData> WAVSource::getFormat() {
412     ALOGV("WAVSource::getFormat");
413 
414     return mMeta;
415 }
416 
read(MediaBuffer ** out,const ReadOptions * options)417 status_t WAVSource::read(
418         MediaBuffer **out, const ReadOptions *options) {
419     *out = NULL;
420 
421     if (options != nullptr && options->getNonBlocking() && !mGroup->has_buffers()) {
422         return WOULD_BLOCK;
423     }
424 
425     int64_t seekTimeUs;
426     ReadOptions::SeekMode mode;
427     if (options != NULL && options->getSeekTo(&seekTimeUs, &mode)) {
428         int64_t pos = 0;
429 
430         if (mWaveFormat == WAVE_FORMAT_MSGSM) {
431             // 65 bytes decode to 320 8kHz samples
432             int64_t samplenumber = (seekTimeUs * mSampleRate) / 1000000;
433             int64_t framenumber = samplenumber / 320;
434             pos = framenumber * 65;
435         } else {
436             pos = (seekTimeUs * mSampleRate) / 1000000 * mNumChannels * (mBitsPerSample >> 3);
437         }
438         if (pos > (off64_t)mSize) {
439             pos = mSize;
440         }
441         mCurrentPos = pos + mOffset;
442     }
443 
444     MediaBuffer *buffer;
445     status_t err = mGroup->acquire_buffer(&buffer);
446     if (err != OK) {
447         return err;
448     }
449 
450     // make sure that maxBytesToRead is multiple of 3, in 24-bit case
451     size_t maxBytesToRead =
452         mBitsPerSample == 8 ? kMaxFrameSize / 2 :
453         (mBitsPerSample == 24 ? 3*(kMaxFrameSize/3): kMaxFrameSize);
454 
455     size_t maxBytesAvailable =
456         (mCurrentPos - mOffset >= (off64_t)mSize)
457             ? 0 : mSize - (mCurrentPos - mOffset);
458 
459     if (maxBytesToRead > maxBytesAvailable) {
460         maxBytesToRead = maxBytesAvailable;
461     }
462 
463     if (mWaveFormat == WAVE_FORMAT_MSGSM) {
464         // Microsoft packs 2 frames into 65 bytes, rather than using separate 33-byte frames,
465         // so read multiples of 65, and use smaller buffers to account for ~10:1 expansion ratio
466         if (maxBytesToRead > 1024) {
467             maxBytesToRead = 1024;
468         }
469         maxBytesToRead = (maxBytesToRead / 65) * 65;
470     } else {
471         // read only integral amounts of audio unit frames.
472         const size_t inputUnitFrameSize = mNumChannels * mBitsPerSample / 8;
473         maxBytesToRead -= maxBytesToRead % inputUnitFrameSize;
474     }
475 
476     ssize_t n = mDataSource->readAt(
477             mCurrentPos, buffer->data(),
478             maxBytesToRead);
479 
480     if (n <= 0) {
481         buffer->release();
482         buffer = NULL;
483 
484         return ERROR_END_OF_STREAM;
485     }
486 
487     buffer->set_range(0, n);
488 
489     // TODO: add capability to return data as float PCM instead of 16 bit PCM.
490     if (mWaveFormat == WAVE_FORMAT_PCM) {
491         if (mBitsPerSample == 8) {
492             // Convert 8-bit unsigned samples to 16-bit signed.
493 
494             // Create new buffer with 2 byte wide samples
495             MediaBuffer *tmp;
496             CHECK_EQ(mGroup->acquire_buffer(&tmp), (status_t)OK);
497             tmp->set_range(0, 2 * n);
498 
499             memcpy_to_i16_from_u8((int16_t *)tmp->data(), (const uint8_t *)buffer->data(), n);
500             buffer->release();
501             buffer = tmp;
502         } else if (mBitsPerSample == 24) {
503             // Convert 24-bit signed samples to 16-bit signed in place
504             const size_t numSamples = n / 3;
505 
506             memcpy_to_i16_from_p24((int16_t *)buffer->data(), (const uint8_t *)buffer->data(), numSamples);
507             buffer->set_range(0, 2 * numSamples);
508         }  else if (mBitsPerSample == 32) {
509             // Convert 32-bit signed samples to 16-bit signed in place
510             const size_t numSamples = n / 4;
511 
512             memcpy_to_i16_from_i32((int16_t *)buffer->data(), (const int32_t *)buffer->data(), numSamples);
513             buffer->set_range(0, 2 * numSamples);
514         }
515     } else if (mWaveFormat == WAVE_FORMAT_IEEE_FLOAT) {
516         if (mBitsPerSample == 32) {
517             // Convert 32-bit float samples to 16-bit signed in place
518             const size_t numSamples = n / 4;
519 
520             memcpy_to_i16_from_float((int16_t *)buffer->data(), (const float *)buffer->data(), numSamples);
521             buffer->set_range(0, 2 * numSamples);
522         }
523     }
524 
525     int64_t timeStampUs = 0;
526 
527     if (mWaveFormat == WAVE_FORMAT_MSGSM) {
528         timeStampUs = 1000000LL * (mCurrentPos - mOffset) * 320 / 65 / mSampleRate;
529     } else {
530         size_t bytesPerSample = mBitsPerSample >> 3;
531         timeStampUs = 1000000LL * (mCurrentPos - mOffset)
532                 / (mNumChannels * bytesPerSample) / mSampleRate;
533     }
534 
535     buffer->meta_data()->setInt64(kKeyTime, timeStampUs);
536 
537     buffer->meta_data()->setInt32(kKeyIsSyncFrame, 1);
538     mCurrentPos += n;
539 
540     *out = buffer;
541 
542     return OK;
543 }
544 
545 ////////////////////////////////////////////////////////////////////////////////
546 
SniffWAV(const sp<DataSource> & source,String8 * mimeType,float * confidence,sp<AMessage> *)547 bool SniffWAV(
548         const sp<DataSource> &source, String8 *mimeType, float *confidence,
549         sp<AMessage> *) {
550     char header[12];
551     if (source->readAt(0, header, sizeof(header)) < (ssize_t)sizeof(header)) {
552         return false;
553     }
554 
555     if (memcmp(header, "RIFF", 4) || memcmp(&header[8], "WAVE", 4)) {
556         return false;
557     }
558 
559     sp<MediaExtractor> extractor = new WAVExtractor(source);
560     if (extractor->countTracks() == 0) {
561         return false;
562     }
563 
564     *mimeType = MEDIA_MIMETYPE_CONTAINER_WAV;
565     *confidence = 0.3f;
566 
567     return true;
568 }
569 
570 }  // namespace android
571