Unhide the android.media.[Media]DataSource interface.

This allows apps to implement MediaDataSource, which is modeled on
stagefright's DataSource, to supply media data to the framework. This
was already implemented for MediaExtractor, but it was renamed from
DataSource.

MediaExtractor, MediaPlayer and MediaMetadataRetriever each have a new
overload: #setDataSource(android.media.MediaDataSource)

Only NuPlayer supports this new data source.

The change introduces:
 * IDataSource:        The binder interface for DataSource.
 * JMediaDataSource:   The native counterpart to the java interface. It
                       implements IDataSource.
 * CallbackDataSource: A stagefright DataSource that wraps an
                       IDataSource.

Change-Id: Ib3c944b49cc8a792c8eb9c85e5015c07f298ebc1

7 files changed, 183 insertions, 15 deletions

diff --git a/media/libstagefright/Android.mk b/media/libstagefright/Android.mk
index b0eeb7f..0ba6743 100644
--- a/media/libstagefright/Android.mk
+++ b/media/libstagefright/Android.mk
@@ -12,6 +12,7 @@ LOCAL_SRC_FILES:=                         \
         AudioPlayer.cpp                   \
         AudioSource.cpp                   \
         AwesomePlayer.cpp                 \
+        CallbackDataSource.cpp            \
         CameraSource.cpp                  \
         CameraSourceTimeLapse.cpp         \
         ClockEstimator.cpp                \
diff --git a/media/libstagefright/CallbackDataSource.cpp b/media/libstagefright/CallbackDataSource.cpp
new file mode 100644
index 0000000..e16cef7
--- /dev/null
+++ b/media/libstagefright/CallbackDataSource.cpp
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "CallbackDataSource"
+#include <utils/Log.h>
+
+#include "include/CallbackDataSource.h"
+
+#include <binder/IMemory.h>
+#include <media/IDataSource.h>
+#include <media/stagefright/foundation/ADebug.h>
+
+#include <algorithm>
+
+namespace android {
+
+CallbackDataSource::CallbackDataSource(
+    const sp<IDataSource>& binderDataSource)
+    : mIDataSource(binderDataSource) {
+    // Set up the buffer to read into.
+    mMemory = mIDataSource->getIMemory();
+}
+
+CallbackDataSource::~CallbackDataSource() {
+    ALOGV("~CallbackDataSource");
+    mIDataSource->close();
+}
+
+status_t CallbackDataSource::initCheck() const {
+    if (mMemory == NULL) {
+        return UNKNOWN_ERROR;
+    }
+    return OK;
+}
+
+ssize_t CallbackDataSource::readAt(off64_t offset, void* data, size_t size) {
+    if (mMemory == NULL) {
+        return -1;
+    }
+
+    // IDataSource can only read up to mMemory->size() bytes at a time, but this
+    // method should be able to read any number of bytes, so read in a loop.
+    size_t totalNumRead = 0;
+    size_t numLeft = size;
+    const size_t bufferSize = mMemory->size();
+
+    while (numLeft > 0) {
+        size_t numToRead = std::min(numLeft, bufferSize);
+        ssize_t numRead =
+            mIDataSource->readAt(offset + totalNumRead, numToRead);
+        // A negative return value represents an error. Pass it on.
+        if (numRead < 0) {
+            return numRead;
+        }
+        // A zero return value signals EOS. Return the bytes read so far.
+        if (numRead == 0) {
+            return totalNumRead;
+        }
+        // Sanity check.
+        CHECK((size_t)numRead <= numToRead && numRead >= 0 &&
+              numRead <= bufferSize);
+        memcpy(((uint8_t*)data) + totalNumRead, mMemory->pointer(), numRead);
+        numLeft -= numRead;
+        totalNumRead += numRead;
+    }
+
+    return totalNumRead;
+}
+
+status_t CallbackDataSource::getSize(off64_t *size) {
+    status_t err = mIDataSource->getSize(size);
+    if (err != OK) {
+        return err;
+    }
+    if (*size < 0) {
+        // IDataSource will set size to -1 to indicate unknown size, but
+        // DataSource returns ERROR_UNSUPPORTED for that.
+        return ERROR_UNSUPPORTED;
+    }
+    return OK;
+}
+
+} // namespace android
diff --git a/media/libstagefright/DataSource.cpp b/media/libstagefright/DataSource.cpp
index f7dcf35..6a89154 100644
--- a/media/libstagefright/DataSource.cpp
+++ b/media/libstagefright/DataSource.cpp
@@ -19,6 +19,7 @@
 #include "include/AMRExtractor.h"
 
 #include "include/AACExtractor.h"
+#include "include/CallbackDataSource.h"
 #include "include/DRMExtractor.h"
 #include "include/FLACExtractor.h"
 #include "include/HTTPBase.h"
@@ -281,6 +282,10 @@ sp<DataSource> DataSource::CreateMediaHTTP(const sp<IMediaHTTPService> &httpServ
     }
 }
 
+sp<DataSource> DataSource::CreateFromIDataSource(const sp<IDataSource> &source) {
+    return new CallbackDataSource(source);
+}
+
 String8 DataSource::getMIMEType() const {
     return String8("application/octet-stream");
 }
diff --git a/media/libstagefright/StagefrightMetadataRetriever.cpp b/media/libstagefright/StagefrightMetadataRetriever.cpp
index 101fc8a..5d2a32c 100644
--- a/media/libstagefright/StagefrightMetadataRetriever.cpp
+++ b/media/libstagefright/StagefrightMetadataRetriever.cpp
@@ -47,10 +47,7 @@ StagefrightMetadataRetriever::StagefrightMetadataRetriever()
 
 StagefrightMetadataRetriever::~StagefrightMetadataRetriever() {
     ALOGV("~StagefrightMetadataRetriever()");
-
-    delete mAlbumArt;
-    mAlbumArt = NULL;
-
+    clearMetadata();
     mClient.disconnect();
 }
 
@@ -60,11 +57,7 @@ status_t StagefrightMetadataRetriever::setDataSource(
         const KeyedVector<String8, String8> *headers) {
     ALOGV("setDataSource(%s)", uri);
 
-    mParsedMetaData = false;
-    mMetaData.clear();
-    delete mAlbumArt;
-    mAlbumArt = NULL;
-
+    clearMetadata();
     mSource = DataSource::CreateFromURI(httpService, uri, headers);
 
     if (mSource == NULL) {
@@ -92,11 +85,7 @@ status_t StagefrightMetadataRetriever::setDataSource(
 
     ALOGV("setDataSource(%d, %" PRId64 ", %" PRId64 ")", fd, offset, length);
 
-    mParsedMetaData = false;
-    mMetaData.clear();
-    delete mAlbumArt;
-    mAlbumArt = NULL;
-
+    clearMetadata();
     mSource = new FileSource(fd, offset, length);
 
     status_t err;
@@ -117,6 +106,23 @@ status_t StagefrightMetadataRetriever::setDataSource(
     return OK;
 }
 
+status_t StagefrightMetadataRetriever::setDataSource(
+        const sp<DataSource>& source) {
+    ALOGV("setDataSource(DataSource)");
+
+    clearMetadata();
+    mSource = source;
+    mExtractor = MediaExtractor::Create(mSource);
+
+    if (mExtractor == NULL) {
+        ALOGE("Failed to instantiate a MediaExtractor.");
+        mSource.clear();
+        return UNKNOWN_ERROR;
+    }
+
+    return OK;
+}
+
 static bool isYUV420PlanarSupported(
             OMXClient *client,
             const sp<MetaData> &trackMeta) {
@@ -629,4 +635,11 @@ void StagefrightMetadataRetriever::parseMetaData() {
     }
 }
 
+void StagefrightMetadataRetriever::clearMetadata() {
+    mParsedMetaData = false;
+    mMetaData.clear();
+    delete mAlbumArt;
+    mAlbumArt = NULL;
+}
+
 }  // namespace android
diff --git a/media/libstagefright/include/AwesomePlayer.h b/media/libstagefright/include/AwesomePlayer.h
index 77d65e0..4704ad3 100644
--- a/media/libstagefright/include/AwesomePlayer.h
+++ b/media/libstagefright/include/AwesomePlayer.h
@@ -33,7 +33,7 @@ namespace android {
 
 struct AudioPlayer;
 struct ClockEstimator;
-struct DataSource;
+struct IDataSource;
 struct MediaBuffer;
 struct MediaExtractor;
 struct MediaSource;
diff --git a/media/libstagefright/include/CallbackDataSource.h b/media/libstagefright/include/CallbackDataSource.h
new file mode 100644
index 0000000..678eb2e
--- /dev/null
+++ b/media/libstagefright/include/CallbackDataSource.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_CALLBACKDATASOURCE_H
+#define ANDROID_CALLBACKDATASOURCE_H
+
+#include <media/stagefright/DataSource.h>
+#include <media/stagefright/foundation/ADebug.h>
+
+namespace android {
+
+class IDataSource;
+class IMemory;
+
+// A stagefright DataSource that wraps a binder IDataSource. It's a "Callback"
+// DataSource because it calls back to the IDataSource for data.
+class CallbackDataSource : public DataSource {
+public:
+    CallbackDataSource(const sp<IDataSource>& iDataSource);
+    virtual ~CallbackDataSource();
+
+    // DataSource implementation.
+    virtual status_t initCheck() const;
+    virtual ssize_t readAt(off64_t offset, void *data, size_t size);
+    virtual status_t getSize(off64_t *size);
+
+private:
+    sp<IDataSource> mIDataSource;
+    sp<IMemory> mMemory;
+
+    DISALLOW_EVIL_CONSTRUCTORS(CallbackDataSource);
+};
+
+}; // namespace android
+
+#endif // ANDROID_CALLBACKDATASOURCE_H
diff --git a/media/libstagefright/include/StagefrightMetadataRetriever.h b/media/libstagefright/include/StagefrightMetadataRetriever.h
index 6632c27..96a35f3 100644
--- a/media/libstagefright/include/StagefrightMetadataRetriever.h
+++ b/media/libstagefright/include/StagefrightMetadataRetriever.h
@@ -38,6 +38,7 @@ struct StagefrightMetadataRetriever : public MediaMetadataRetrieverInterface {
             const KeyedVector<String8, String8> *headers);
 
     virtual status_t setDataSource(int fd, int64_t offset, int64_t length);
+    virtual status_t setDataSource(const sp<DataSource>& source);
 
     virtual VideoFrame *getFrameAtTime(int64_t timeUs, int option);
     virtual MediaAlbumArt *extractAlbumArt();
@@ -53,6 +54,8 @@ private:
     MediaAlbumArt *mAlbumArt;
 
     void parseMetaData();
+    // Delete album art and clear metadata.
+    void clearMetadata();
 
     StagefrightMetadataRetriever(const StagefrightMetadataRetriever &);