diff --git a/include/media/stagefright/CachingDataSource.h b/include/media/stagefright/CachingDataSource.h
index e35e19e..b0fc4b2 100644
--- a/include/media/stagefright/CachingDataSource.h
+++ b/include/media/stagefright/CachingDataSource.h
@@ -29,9 +29,9 @@
     CachingDataSource(
             const sp<DataSource> &source, size_t pageSize, int numPages);
 
-    status_t InitCheck() const;
+    virtual status_t initCheck() const;
 
-    virtual ssize_t read_at(off_t offset, void *data, size_t size);
+    virtual ssize_t readAt(off_t offset, void *data, size_t size);
 
 protected:
     virtual ~CachingDataSource();
diff --git a/include/media/stagefright/DataSource.h b/include/media/stagefright/DataSource.h
index f46f0af..b843cd9 100644
--- a/include/media/stagefright/DataSource.h
+++ b/include/media/stagefright/DataSource.h
@@ -33,7 +33,9 @@
 public:
     DataSource() {}
 
-    virtual ssize_t read_at(off_t offset, void *data, size_t size) = 0;
+    virtual status_t initCheck() const = 0;
+
+    virtual ssize_t readAt(off_t offset, void *data, size_t size) = 0;
 
     // Convenience methods:
     bool getUInt16(off_t offset, uint16_t *x);
diff --git a/include/media/stagefright/FileSource.h b/include/media/stagefright/FileSource.h
index ccbe0ef..d7b42c3 100644
--- a/include/media/stagefright/FileSource.h
+++ b/include/media/stagefright/FileSource.h
@@ -29,12 +29,14 @@
 class FileSource : public DataSource {
 public:
     FileSource(const char *filename);
+
+    virtual status_t initCheck() const;
+
+    virtual ssize_t readAt(off_t offset, void *data, size_t size);
+
+protected:
     virtual ~FileSource();
 
-    status_t InitCheck() const;
-
-    virtual ssize_t read_at(off_t offset, void *data, size_t size);
-
 private:
     FILE *mFile;
     Mutex mLock;
diff --git a/include/media/stagefright/HTTPDataSource.h b/include/media/stagefright/HTTPDataSource.h
index 02d95fd..d5dc9e6 100644
--- a/include/media/stagefright/HTTPDataSource.h
+++ b/include/media/stagefright/HTTPDataSource.h
@@ -29,13 +29,13 @@
     HTTPDataSource(const char *host, int port, const char *path);
     HTTPDataSource(const char *uri);
 
+    virtual status_t initCheck() const;
+
+    virtual ssize_t readAt(off_t offset, void *data, size_t size);
+
+protected:
     virtual ~HTTPDataSource();
 
-    // XXXandih
-    status_t InitCheck() const { return OK; }
-
-    virtual ssize_t read_at(off_t offset, void *data, size_t size);
-
 private:
     enum {
         kBufferSize = 64 * 1024
@@ -50,6 +50,8 @@
     size_t mBufferLength;
     off_t mBufferOffset;
 
+    status_t mInitCheck;
+
     HTTPDataSource(const HTTPDataSource &);
     HTTPDataSource &operator=(const HTTPDataSource &);
 };
diff --git a/include/media/stagefright/MediaExtractor.h b/include/media/stagefright/MediaExtractor.h
index 4d6b989..d56d4b3 100644
--- a/include/media/stagefright/MediaExtractor.h
+++ b/include/media/stagefright/MediaExtractor.h
@@ -31,6 +31,9 @@
     static sp<MediaExtractor> Create(
             const sp<DataSource> &source, const char *mime = NULL);
 
+    static sp<MediaExtractor> CreateFromURI(
+            const char *uri, const char *mime = NULL);
+
     virtual size_t countTracks() = 0;
     virtual sp<MediaSource> getTrack(size_t index) = 0;
 
diff --git a/include/media/stagefright/MmapSource.h b/include/media/stagefright/MmapSource.h
index a8bd57f..1b39d53 100644
--- a/include/media/stagefright/MmapSource.h
+++ b/include/media/stagefright/MmapSource.h
@@ -30,13 +30,14 @@
     // Assumes ownership of "fd".
     MmapSource(int fd, int64_t offset, int64_t length);
 
-    virtual ~MmapSource();
+    virtual status_t initCheck() const;
 
-    status_t InitCheck() const;
-
-    virtual ssize_t read_at(off_t offset, void *data, size_t size);
+    virtual ssize_t readAt(off_t offset, void *data, size_t size);
     virtual status_t getSize(off_t *size);
 
+protected:
+    virtual ~MmapSource();
+
 private:
     int mFd;
     void *mBase;
diff --git a/include/media/stagefright/ShoutcastSource.h b/include/media/stagefright/ShoutcastSource.h
index 352857a..bc67156 100644
--- a/include/media/stagefright/ShoutcastSource.h
+++ b/include/media/stagefright/ShoutcastSource.h
@@ -31,7 +31,6 @@
 public:
     // Assumes ownership of "http".
     ShoutcastSource(HTTPStream *http);
-    virtual ~ShoutcastSource();
 
     virtual status_t start(MetaData *params = NULL);
     virtual status_t stop();
@@ -41,6 +40,9 @@
     virtual status_t read(
             MediaBuffer **buffer, const ReadOptions *options = NULL);
 
+protected:
+    virtual ~ShoutcastSource();
+
 private:
     HTTPStream *mHttp;
     size_t mMetaDataOffset;
diff --git a/media/libmediaplayerservice/StagefrightMetadataRetriever.cpp b/media/libmediaplayerservice/StagefrightMetadataRetriever.cpp
index fc4f2c5..7a3aee86 100644
--- a/media/libmediaplayerservice/StagefrightMetadataRetriever.cpp
+++ b/media/libmediaplayerservice/StagefrightMetadataRetriever.cpp
@@ -48,26 +48,7 @@
 status_t StagefrightMetadataRetriever::setDataSource(const char *uri) {
     LOGV("setDataSource(%s)", uri);
 
-    sp<DataSource> source;
-    if (!strncasecmp("file://", uri, 7)) {
-        sp<MmapSource> mmapSource = new MmapSource(uri + 7);
-        if (mmapSource->InitCheck() != OK) {
-            return ERROR_IO;
-        }
-        source = mmapSource;
-    } else if (!strncasecmp("http://", uri, 7)) {
-        source = new HTTPDataSource(uri);
-        source = new CachingDataSource(source, 64 * 1024, 10);
-    } else {
-        // Assume it's a filename.
-        sp<MmapSource> mmapSource = new MmapSource(uri);
-        if (mmapSource->InitCheck() != OK) {
-            return ERROR_IO;
-        }
-        source = mmapSource;
-    }
-
-    mExtractor = MediaExtractor::Create(source);
+    mExtractor = MediaExtractor::CreateFromURI(uri);
 
     return mExtractor.get() != NULL ? OK : UNKNOWN_ERROR;
 }
diff --git a/media/libstagefright/AMRExtractor.cpp b/media/libstagefright/AMRExtractor.cpp
index 0d1e6d7..1e3c5a4 100644
--- a/media/libstagefright/AMRExtractor.cpp
+++ b/media/libstagefright/AMRExtractor.cpp
@@ -156,7 +156,7 @@
     *out = NULL;
 
     uint8_t header;
-    ssize_t n = mDataSource->read_at(mOffset, &header, 1);
+    ssize_t n = mDataSource->readAt(mOffset, &header, 1);
 
     if (n < 1) {
         return ERROR_IO;
@@ -192,7 +192,7 @@
     // Round up bits to bytes and add 1 for the header byte.
     frameSize = (frameSize + 7) / 8 + 1;
 
-    n = mDataSource->read_at(mOffset, buffer->data(), frameSize);
+    n = mDataSource->readAt(mOffset, buffer->data(), frameSize);
 
     if (n != (ssize_t)frameSize) {
         buffer->release();
@@ -218,7 +218,7 @@
         const sp<DataSource> &source, String8 *mimeType, float *confidence) {
     char header[9];
 
-    if (source->read_at(0, header, sizeof(header)) != sizeof(header)) {
+    if (source->readAt(0, header, sizeof(header)) != sizeof(header)) {
         return false;
     }
 
diff --git a/media/libstagefright/CachingDataSource.cpp b/media/libstagefright/CachingDataSource.cpp
index fd00576..23f4897 100644
--- a/media/libstagefright/CachingDataSource.cpp
+++ b/media/libstagefright/CachingDataSource.cpp
@@ -61,11 +61,11 @@
     mData = NULL;
 }
 
-status_t CachingDataSource::InitCheck() const {
-    return OK;
+status_t CachingDataSource::initCheck() const {
+    return mSource->initCheck();
 }
 
-ssize_t CachingDataSource::read_at(off_t offset, void *data, size_t size) {
+ssize_t CachingDataSource::readAt(off_t offset, void *data, size_t size) {
     Mutex::Autolock autoLock(mLock);
 
     size_t total = 0;
@@ -82,7 +82,7 @@
         if (page == NULL) {
             page = allocate_page();
             page->mOffset = offset - offset % mPageSize;
-            ssize_t n = mSource->read_at(page->mOffset, page->mData, mPageSize);
+            ssize_t n = mSource->readAt(page->mOffset, page->mData, mPageSize);
             if (n < 0) {
                 page->mLength = 0;
             } else {
diff --git a/media/libstagefright/DataSource.cpp b/media/libstagefright/DataSource.cpp
index 933c2f6..210b2f6 100644
--- a/media/libstagefright/DataSource.cpp
+++ b/media/libstagefright/DataSource.cpp
@@ -28,7 +28,7 @@
     *x = 0;
 
     uint8_t byte[2];
-    if (read_at(offset, byte, 2) != 2) {
+    if (readAt(offset, byte, 2) != 2) {
         return false;
     }
 
diff --git a/media/libstagefright/FileSource.cpp b/media/libstagefright/FileSource.cpp
index f6b90b2..f318ee3 100644
--- a/media/libstagefright/FileSource.cpp
+++ b/media/libstagefright/FileSource.cpp
@@ -30,11 +30,11 @@
     }
 }
 
-status_t FileSource::InitCheck() const {
+status_t FileSource::initCheck() const {
     return mFile != NULL ? OK : NO_INIT;
 }
 
-ssize_t FileSource::read_at(off_t offset, void *data, size_t size) {
+ssize_t FileSource::readAt(off_t offset, void *data, size_t size) {
     Mutex::Autolock autoLock(mLock);
 
     int err = fseeko(mFile, offset, SEEK_SET);
diff --git a/media/libstagefright/HTTPDataSource.cpp b/media/libstagefright/HTTPDataSource.cpp
index cc25886..5536801 100644
--- a/media/libstagefright/HTTPDataSource.cpp
+++ b/media/libstagefright/HTTPDataSource.cpp
@@ -67,8 +67,7 @@
     mPort = port;
     mPath = strdup(path.c_str());
 
-    status_t err = mHttp->connect(mHost, mPort);
-    CHECK_EQ(err, OK);
+    mInitCheck = mHttp->connect(mHost, mPort);
 }
 
 HTTPDataSource::HTTPDataSource(const char *host, int port, const char *path)
@@ -79,8 +78,11 @@
       mBuffer(malloc(kBufferSize)),
       mBufferLength(0),
       mBufferOffset(0) {
-    status_t err = mHttp->connect(mHost, mPort);
-    CHECK_EQ(err, OK);
+    mInitCheck = mHttp->connect(mHost, mPort);
+}
+
+status_t HTTPDataSource::initCheck() const {
+    return mInitCheck;
 }
 
 HTTPDataSource::~HTTPDataSource() {
@@ -96,7 +98,7 @@
     mHttp = NULL;
 }
 
-ssize_t HTTPDataSource::read_at(off_t offset, void *data, size_t size) {
+ssize_t HTTPDataSource::readAt(off_t offset, void *data, size_t size) {
     if (offset >= mBufferOffset
             && offset < (off_t)(mBufferOffset + mBufferLength)) {
         size_t num_bytes_available = mBufferLength - (offset - mBufferOffset);
diff --git a/media/libstagefright/JPEGSource.cpp b/media/libstagefright/JPEGSource.cpp
index d1dfd83..a4be2dd2 100644
--- a/media/libstagefright/JPEGSource.cpp
+++ b/media/libstagefright/JPEGSource.cpp
@@ -119,7 +119,7 @@
     MediaBuffer *buffer;
     mGroup->acquire_buffer(&buffer);
 
-    ssize_t n = mSource->read_at(mOffset, buffer->data(), mSize - mOffset);
+    ssize_t n = mSource->readAt(mOffset, buffer->data(), mSize - mOffset);
 
     if (n <= 0) {
         buffer->release();
@@ -156,13 +156,13 @@
 
     for (;;) {
         uint8_t marker;
-        if (mSource->read_at(i++, &marker, 1) != 1) {
+        if (mSource->readAt(i++, &marker, 1) != 1) {
             return ERROR_IO;
         }
 
         CHECK_EQ(marker, 0xff);
 
-        if (mSource->read_at(i++, &marker, 1) != 1) {
+        if (mSource->readAt(i++, &marker, 1) != 1) {
             return ERROR_IO;
         }
 
diff --git a/media/libstagefright/MP3Extractor.cpp b/media/libstagefright/MP3Extractor.cpp
index 82b3db7..736f1a9d6 100644
--- a/media/libstagefright/MP3Extractor.cpp
+++ b/media/libstagefright/MP3Extractor.cpp
@@ -177,7 +177,7 @@
         // of the datasource.
 
         uint8_t id3header[10];
-        if (source->read_at(0, id3header, sizeof(id3header))
+        if (source->readAt(0, id3header, sizeof(id3header))
                 < (ssize_t)sizeof(id3header)) {
             // If we can't even read these 10 bytes, we might as well bail out,
             // even if there _were_ 10 bytes of valid mp3 audio data...
@@ -228,7 +228,7 @@
             buffer_length = buffer_length - buffer_offset;
             buffer_offset = 0;
 
-            ssize_t n = source->read_at(
+            ssize_t n = source->readAt(
                     pos, &buffer[buffer_length], kMaxFrameSize - buffer_length);
 
             if (n <= 0) {
@@ -265,7 +265,7 @@
         valid = true;
         for (int j = 0; j < 3; ++j) {
             uint8_t tmp[4];
-            if (source->read_at(test_pos, tmp, 4) < 4) {
+            if (source->readAt(test_pos, tmp, 4) < 4) {
                 valid = false;
                 break;
             }
@@ -480,7 +480,7 @@
 
     size_t frame_size;
     for (;;) {
-        ssize_t n = mDataSource->read_at(mCurrentPos, buffer->data(), 4);
+        ssize_t n = mDataSource->readAt(mCurrentPos, buffer->data(), 4);
         if (n < 4) {
             buffer->release();
             buffer = NULL;
@@ -514,7 +514,7 @@
 
     CHECK(frame_size <= buffer->size());
 
-    ssize_t n = mDataSource->read_at(mCurrentPos, buffer->data(), frame_size);
+    ssize_t n = mDataSource->readAt(mCurrentPos, buffer->data(), frame_size);
     if (n < (ssize_t)frame_size) {
         buffer->release();
         buffer = NULL;
diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp
index f174516..5c3720e 100644
--- a/media/libstagefright/MPEG4Extractor.cpp
+++ b/media/libstagefright/MPEG4Extractor.cpp
@@ -249,7 +249,7 @@
 
 status_t MPEG4Extractor::parseChunk(off_t *offset, int depth) {
     uint32_t hdr[2];
-    if (mDataSource->read_at(*offset, hdr, 8) < 8) {
+    if (mDataSource->readAt(*offset, hdr, 8) < 8) {
         return ERROR_IO;
     }
     uint64_t chunk_size = ntohl(hdr[0]);
@@ -257,7 +257,7 @@
     off_t data_offset = *offset + 8;
 
     if (chunk_size == 1) {
-        if (mDataSource->read_at(*offset + 8, &chunk_size, 8) < 8) {
+        if (mDataSource->readAt(*offset + 8, &chunk_size, 8) < 8) {
             return ERROR_IO;
         }
         chunk_size = ntoh64(chunk_size);
@@ -274,7 +274,7 @@
 
     char buffer[256];
     if (chunk_size <= sizeof(buffer)) {
-        if (mDataSource->read_at(*offset, buffer, chunk_size) < chunk_size) {
+        if (mDataSource->readAt(*offset, buffer, chunk_size) < chunk_size) {
             return ERROR_IO;
         }
 
@@ -320,7 +320,7 @@
             CHECK(chunk_data_size >= 4);
 
             uint8_t version;
-            if (mDataSource->read_at(data_offset, &version, 1) < 1) {
+            if (mDataSource->readAt(data_offset, &version, 1) < 1) {
                 return ERROR_IO;
             }
 
@@ -334,7 +334,7 @@
                 }
 
                 uint8_t buffer[36 + 60];
-                if (mDataSource->read_at(
+                if (mDataSource->readAt(
                             data_offset, buffer, sizeof(buffer)) < (ssize_t)sizeof(buffer)) {
                     return ERROR_IO;
                 }
@@ -351,7 +351,7 @@
                 }
 
                 uint8_t buffer[24 + 60];
-                if (mDataSource->read_at(
+                if (mDataSource->readAt(
                             data_offset, buffer, sizeof(buffer)) < (ssize_t)sizeof(buffer)) {
                     return ERROR_IO;
                 }
@@ -389,7 +389,7 @@
             }
 
             uint8_t version;
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         data_offset, &version, sizeof(version))
                     < (ssize_t)sizeof(version)) {
                 return ERROR_IO;
@@ -406,7 +406,7 @@
             }
 
             uint32_t timescale;
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         timescale_offset, &timescale, sizeof(timescale))
                     < (ssize_t)sizeof(timescale)) {
                 return ERROR_IO;
@@ -416,7 +416,7 @@
 
             int64_t duration;
             if (version == 1) {
-                if (mDataSource->read_at(
+                if (mDataSource->readAt(
                             timescale_offset + 4, &duration, sizeof(duration))
                         < (ssize_t)sizeof(duration)) {
                     return ERROR_IO;
@@ -424,7 +424,7 @@
                 duration = ntoh64(duration);
             } else {
                 int32_t duration32;
-                if (mDataSource->read_at(
+                if (mDataSource->readAt(
                             timescale_offset + 4, &duration32, sizeof(duration32))
                         < (ssize_t)sizeof(duration32)) {
                     return ERROR_IO;
@@ -445,7 +445,7 @@
             }
 
             uint8_t buffer[24];
-            if (mDataSource->read_at(data_offset, buffer, 24) < 24) {
+            if (mDataSource->readAt(data_offset, buffer, 24) < 24) {
                 return ERROR_IO;
             }
 
@@ -472,7 +472,7 @@
 
             uint8_t buffer[8];
             CHECK(chunk_data_size >= (off_t)sizeof(buffer));
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         data_offset, buffer, 8) < 8) {
                 return ERROR_IO;
             }
@@ -515,7 +515,7 @@
                 return ERROR_MALFORMED;
             }
 
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         data_offset, buffer, sizeof(buffer)) < (ssize_t)sizeof(buffer)) {
                 return ERROR_IO;
             }
@@ -567,7 +567,7 @@
                 return ERROR_MALFORMED;
             }
 
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         data_offset, buffer, sizeof(buffer)) < (ssize_t)sizeof(buffer)) {
                 return ERROR_IO;
             }
@@ -678,7 +678,7 @@
                 return ERROR_BUFFER_TOO_SMALL;
             }
 
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         data_offset, buffer, chunk_data_size) < chunk_data_size) {
                 return ERROR_IO;
             }
@@ -702,7 +702,7 @@
                 return ERROR_BUFFER_TOO_SMALL;
             }
 
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         data_offset, buffer, chunk_data_size) < chunk_data_size) {
                 return ERROR_IO;
             }
@@ -889,7 +889,7 @@
     if (!mIsAVC || mWantsNALFragments) {
         if (newBuffer) {
             ssize_t num_bytes_read =
-                mDataSource->read_at(offset, (uint8_t *)mBuffer->data(), size);
+                mDataSource->readAt(offset, (uint8_t *)mBuffer->data(), size);
 
             if (num_bytes_read < (ssize_t)size) {
                 mBuffer->release();
@@ -944,7 +944,7 @@
         // the start code (0x00 00 00 01).
 
         ssize_t num_bytes_read =
-            mDataSource->read_at(offset, mSrcBuffer, size);
+            mDataSource->readAt(offset, mSrcBuffer, size);
 
         if (num_bytes_read < (ssize_t)size) {
             mBuffer->release();
@@ -995,7 +995,7 @@
         const sp<DataSource> &source, String8 *mimeType, float *confidence) {
     uint8_t header[8];
 
-    ssize_t n = source->read_at(4, header, sizeof(header));
+    ssize_t n = source->readAt(4, header, sizeof(header));
     if (n < (ssize_t)sizeof(header)) {
         return false;
     }
diff --git a/media/libstagefright/MediaExtractor.cpp b/media/libstagefright/MediaExtractor.cpp
index 5e1270a..d51802c 100644
--- a/media/libstagefright/MediaExtractor.cpp
+++ b/media/libstagefright/MediaExtractor.cpp
@@ -22,9 +22,12 @@
 #include "include/MP3Extractor.h"
 #include "include/MPEG4Extractor.h"
 
+#include <media/stagefright/CachingDataSource.h>
 #include <media/stagefright/DataSource.h>
+#include <media/stagefright/HTTPDataSource.h>
 #include <media/stagefright/MediaDefs.h>
 #include <media/stagefright/MediaExtractor.h>
+#include <media/stagefright/MmapSource.h>
 #include <utils/String8.h>
 
 namespace android {
@@ -59,4 +62,25 @@
     return NULL;
 }
 
+// static
+sp<MediaExtractor> MediaExtractor::CreateFromURI(
+        const char *uri, const char *mime) {
+    sp<DataSource> source;
+    if (!strncasecmp("file://", uri, 7)) {
+        source = new MmapSource(uri + 7);
+    } else if (!strncasecmp("http://", uri, 7)) {
+        source = new HTTPDataSource(uri);
+        source = new CachingDataSource(source, 64 * 1024, 10);
+    } else {
+        // Assume it's a filename.
+        source = new MmapSource(uri);
+    }
+
+    if (source == NULL || source->initCheck() != OK) {
+        return NULL;
+    }
+
+    return Create(source, mime);
+}
+
 }  // namespace android
diff --git a/media/libstagefright/MediaPlayerImpl.cpp b/media/libstagefright/MediaPlayerImpl.cpp
index 4e0e996..76f4182 100644
--- a/media/libstagefright/MediaPlayerImpl.cpp
+++ b/media/libstagefright/MediaPlayerImpl.cpp
@@ -26,9 +26,7 @@
 #include <unistd.h>
 
 #include <media/stagefright/AudioPlayer.h>
-#include <media/stagefright/CachingDataSource.h>
 // #include <media/stagefright/CameraSource.h>
-#include <media/stagefright/HTTPDataSource.h>
 #include <media/stagefright/MediaDebug.h>
 #include <media/stagefright/MediaExtractor.h>
 #include <media/stagefright/MediaPlayerImpl.h>
@@ -71,18 +69,7 @@
         mVideoDecoder = CameraSource::Create();
 #endif
     } else {
-        sp<DataSource> source;
-        if (!strncasecmp("file://", uri, 7)) {
-            source = new MmapSource(uri + 7);
-        } else if (!strncasecmp("http://", uri, 7)) {
-            source = new HTTPDataSource(uri);
-            source = new CachingDataSource(source, 64 * 1024, 10);
-        } else {
-            // Assume it's a filename.
-            source = new MmapSource(uri);
-        }
-
-        mExtractor = MediaExtractor::Create(source);
+        mExtractor = MediaExtractor::CreateFromURI(uri);
 
         if (mExtractor == NULL) {
             return;
diff --git a/media/libstagefright/MmapSource.cpp b/media/libstagefright/MmapSource.cpp
index 8277c15..42749cf 100644
--- a/media/libstagefright/MmapSource.cpp
+++ b/media/libstagefright/MmapSource.cpp
@@ -81,12 +81,12 @@
     }
 }
 
-status_t MmapSource::InitCheck() const {
+status_t MmapSource::initCheck() const {
     return mFd == -1 ? NO_INIT : OK;
 }
 
-ssize_t MmapSource::read_at(off_t offset, void *data, size_t size) {
-    LOGV("read_at offset:%ld data:%p size:%d", offset, data, size);
+ssize_t MmapSource::readAt(off_t offset, void *data, size_t size) {
+    LOGV("readAt offset:%ld data:%p size:%d", offset, data, size);
     CHECK(offset >= 0);
 
     size_t avail = 0;
diff --git a/media/libstagefright/SampleTable.cpp b/media/libstagefright/SampleTable.cpp
index 3eed52a..4aec0e9 100644
--- a/media/libstagefright/SampleTable.cpp
+++ b/media/libstagefright/SampleTable.cpp
@@ -70,7 +70,7 @@
     }
 
     uint8_t header[8];
-    if (mDataSource->read_at(
+    if (mDataSource->readAt(
                 data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
         return ERROR_IO;
     }
@@ -108,7 +108,7 @@
     }
 
     uint8_t header[8];
-    if (mDataSource->read_at(
+    if (mDataSource->readAt(
                 data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
         return ERROR_IO;
     }
@@ -142,7 +142,7 @@
     }
 
     uint8_t header[12];
-    if (mDataSource->read_at(
+    if (mDataSource->readAt(
                 data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
         return ERROR_IO;
     }
@@ -194,7 +194,7 @@
     }
 
     uint8_t header[8];
-    if (mDataSource->read_at(
+    if (mDataSource->readAt(
                 data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
         return ERROR_IO;
     }
@@ -208,7 +208,7 @@
     mTimeToSample = new uint32_t[mTimeToSampleCount * 2];
 
     size_t size = sizeof(uint32_t) * mTimeToSampleCount * 2;
-    if (mDataSource->read_at(
+    if (mDataSource->readAt(
                 data_offset + 8, mTimeToSample, size) < (ssize_t)size) {
         return ERROR_IO;
     }
@@ -228,7 +228,7 @@
     mSyncSampleOffset = data_offset;
 
     uint8_t header[8];
-    if (mDataSource->read_at(
+    if (mDataSource->readAt(
                 data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
         return ERROR_IO;
     }
@@ -264,7 +264,7 @@
     if (mChunkOffsetType == kChunkOffsetType32) {
         uint32_t offset32;
 
-        if (mDataSource->read_at(
+        if (mDataSource->readAt(
                     mChunkOffsetOffset + 8 + 4 * chunk_index,
                     &offset32,
                     sizeof(offset32)) < (ssize_t)sizeof(offset32)) {
@@ -276,7 +276,7 @@
         CHECK_EQ(mChunkOffsetType, kChunkOffsetType64);
 
         uint64_t offset64;
-        if (mDataSource->read_at(
+        if (mDataSource->readAt(
                     mChunkOffsetOffset + 8 + 8 * chunk_index,
                     &offset64,
                     sizeof(offset64)) < (ssize_t)sizeof(offset64)) {
@@ -313,7 +313,7 @@
     uint32_t index = 0;
     while (index < mNumSampleToChunkOffsets) {
         uint8_t buffer[12];
-        if (mDataSource->read_at(mSampleToChunkOffset + 8 + index * 12,
+        if (mDataSource->readAt(mSampleToChunkOffset + 8 + index * 12,
                                  buffer, sizeof(buffer)) < (ssize_t)sizeof(buffer)) {
             return ERROR_IO;
         }
@@ -362,7 +362,7 @@
     switch (mSampleSizeFieldSize) {
         case 32:
         {
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         mSampleSizeOffset + 12 + 4 * sample_index,
                         sample_size, sizeof(*sample_size)) < (ssize_t)sizeof(*sample_size)) {
                 return ERROR_IO;
@@ -375,7 +375,7 @@
         case 16:
         {
             uint16_t x;
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         mSampleSizeOffset + 12 + 2 * sample_index,
                         &x, sizeof(x)) < (ssize_t)sizeof(x)) {
                 return ERROR_IO;
@@ -388,7 +388,7 @@
         case 8:
         {
             uint8_t x;
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         mSampleSizeOffset + 12 + sample_index,
                         &x, sizeof(x)) < (ssize_t)sizeof(x)) {
                 return ERROR_IO;
@@ -403,7 +403,7 @@
             CHECK_EQ(mSampleSizeFieldSize, 4);
 
             uint8_t x;
-            if (mDataSource->read_at(
+            if (mDataSource->readAt(
                         mSampleSizeOffset + 12 + sample_index / 2,
                         &x, sizeof(x)) < (ssize_t)sizeof(x)) {
                 return ERROR_IO;
@@ -554,7 +554,7 @@
     uint32_t right = mNumSyncSamples;
     while (left < right) {
         uint32_t mid = (left + right) / 2;
-        if (mDataSource->read_at(
+        if (mDataSource->readAt(
                     mSyncSampleOffset + 8 + (mid - 1) * 4, &x, 4) != 4) {
             return ERROR_IO;
         }
@@ -597,7 +597,7 @@
 
     for (size_t i = 0; i < numSamplesToScan; ++i) {
         uint32_t x;
-        if (mDataSource->read_at(
+        if (mDataSource->readAt(
                     mSyncSampleOffset + 8 + i * 4, &x, 4) != 4) {
             return ERROR_IO;
         }