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      1 /*
      2  * Copyright (C) 2013 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 "MediaAdapter"
     19 #include <utils/Log.h>
     20 
     21 #include <media/stagefright/foundation/ADebug.h>
     22 #include <media/stagefright/MediaAdapter.h>
     23 #include <media/stagefright/MediaBuffer.h>
     24 
     25 namespace android {
     26 
     27 MediaAdapter::MediaAdapter(const sp<MetaData> &meta)
     28     : mCurrentMediaBuffer(NULL),
     29       mStarted(false),
     30       mOutputFormat(meta) {
     31 }
     32 
     33 MediaAdapter::~MediaAdapter() {
     34     Mutex::Autolock autoLock(mAdapterLock);
     35     mOutputFormat.clear();
     36     CHECK(mCurrentMediaBuffer == NULL);
     37 }
     38 
     39 status_t MediaAdapter::start(MetaData *params) {
     40     Mutex::Autolock autoLock(mAdapterLock);
     41     if (!mStarted) {
     42         mStarted = true;
     43     }
     44     return OK;
     45 }
     46 
     47 status_t MediaAdapter::stop() {
     48     Mutex::Autolock autoLock(mAdapterLock);
     49     if (mStarted) {
     50         mStarted = false;
     51         // If stop() happens immediately after a pushBuffer(), we should
     52         // clean up the mCurrentMediaBuffer
     53         if (mCurrentMediaBuffer != NULL) {
     54             mCurrentMediaBuffer->release();
     55             mCurrentMediaBuffer = NULL;
     56         }
     57         // While read() is still waiting, we should signal it to finish.
     58         mBufferReadCond.signal();
     59     }
     60     return OK;
     61 }
     62 
     63 sp<MetaData> MediaAdapter::getFormat() {
     64     Mutex::Autolock autoLock(mAdapterLock);
     65     return mOutputFormat;
     66 }
     67 
     68 void MediaAdapter::signalBufferReturned(MediaBuffer *buffer) {
     69     Mutex::Autolock autoLock(mAdapterLock);
     70     CHECK(buffer != NULL);
     71     buffer->setObserver(0);
     72     buffer->release();
     73     ALOGV("buffer returned %p", buffer);
     74     mBufferReturnedCond.signal();
     75 }
     76 
     77 status_t MediaAdapter::read(
     78             MediaBuffer **buffer, const ReadOptions *options) {
     79     Mutex::Autolock autoLock(mAdapterLock);
     80     if (!mStarted) {
     81         ALOGV("Read before even started!");
     82         return ERROR_END_OF_STREAM;
     83     }
     84 
     85     while (mCurrentMediaBuffer == NULL && mStarted) {
     86         ALOGV("waiting @ read()");
     87         mBufferReadCond.wait(mAdapterLock);
     88     }
     89 
     90     if (!mStarted) {
     91         ALOGV("read interrupted after stop");
     92         CHECK(mCurrentMediaBuffer == NULL);
     93         return ERROR_END_OF_STREAM;
     94     }
     95 
     96     CHECK(mCurrentMediaBuffer != NULL);
     97 
     98     *buffer = mCurrentMediaBuffer;
     99     mCurrentMediaBuffer = NULL;
    100     (*buffer)->setObserver(this);
    101 
    102     return OK;
    103 }
    104 
    105 status_t MediaAdapter::pushBuffer(MediaBuffer *buffer) {
    106     if (buffer == NULL) {
    107         ALOGE("pushBuffer get an NULL buffer");
    108         return -EINVAL;
    109     }
    110 
    111     Mutex::Autolock autoLock(mAdapterLock);
    112     if (!mStarted) {
    113         ALOGE("pushBuffer called before start");
    114         return INVALID_OPERATION;
    115     }
    116     mCurrentMediaBuffer = buffer;
    117     mBufferReadCond.signal();
    118 
    119     ALOGV("wait for the buffer returned @ pushBuffer! %p", buffer);
    120     mBufferReturnedCond.wait(mAdapterLock);
    121 
    122     return OK;
    123 }
    124 
    125 }  // namespace android
    126 
    127