1 files changed, 353 insertions, 0 deletions
diff --git a/media/libstagefright/AMRExtractor.cpp b/media/libstagefright/AMRExtractor.cpp
new file mode 100644
index 0000000..03dcbf9
--- /dev/null
+++ b/media/libstagefright/AMRExtractor.cpp
@@ -0,0 +1,353 @@
+/*
+ * Copyright (C) 2009 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 "AMRExtractor"
+#include <utils/Log.h>
+
+#include "include/AMRExtractor.h"
+
+#include <media/stagefright/foundation/ADebug.h>
+#include <media/stagefright/DataSource.h>
+#include <media/stagefright/MediaBufferGroup.h>
+#include <media/stagefright/MediaDefs.h>
+#include <media/stagefright/MediaErrors.h>
+#include <media/stagefright/MediaSource.h>
+#include <media/stagefright/MetaData.h>
+#include <utils/String8.h>
+
+namespace android {
+
+class AMRSource : public MediaSource {
+public:
+    AMRSource(const sp<DataSource> &source,
+              const sp<MetaData> &meta,
+              bool isWide,
+              const off64_t *offset_table,
+              size_t offset_table_length);
+
+    virtual status_t start(MetaData *params = NULL);
+    virtual status_t stop();
+
+    virtual sp<MetaData> getFormat();
+
+    virtual status_t read(
+            MediaBuffer **buffer, const ReadOptions *options = NULL);
+
+protected:
+    virtual ~AMRSource();
+
+private:
+    sp<DataSource> mDataSource;
+    sp<MetaData> mMeta;
+    bool mIsWide;
+
+    off64_t mOffset;
+    int64_t mCurrentTimeUs;
+    bool mStarted;
+    MediaBufferGroup *mGroup;
+
+    off64_t mOffsetTable[OFFSET_TABLE_LEN];
+    size_t mOffsetTableLength;
+
+    AMRSource(const AMRSource &);
+    AMRSource &operator=(const AMRSource &);
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+static size_t getFrameSize(bool isWide, unsigned FT) {
+    static const size_t kFrameSizeNB[16] = {
+        95, 103, 118, 134, 148, 159, 204, 244,
+        39, 43, 38, 37, // SID
+        0, 0, 0, // future use
+        0 // no data
+    };
+    static const size_t kFrameSizeWB[16] = {
+        132, 177, 253, 285, 317, 365, 397, 461, 477,
+        40, // SID
+        0, 0, 0, 0, // future use
+        0, // speech lost
+        0 // no data
+    };
+
+    if (FT > 15 || (isWide && FT > 9 && FT < 14) || (!isWide && FT > 11 && FT < 15)) {
+        ALOGE("illegal AMR frame type %d", FT);
+        return 0;
+    }
+
+    size_t frameSize = isWide ? kFrameSizeWB[FT] : kFrameSizeNB[FT];
+
+    // Round up bits to bytes and add 1 for the header byte.
+    frameSize = (frameSize + 7) / 8 + 1;
+
+    return frameSize;
+}
+
+static status_t getFrameSizeByOffset(const sp<DataSource> &source,
+        off64_t offset, bool isWide, size_t *frameSize) {
+    uint8_t header;
+    if (source->readAt(offset, &header, 1) < 1) {
+        return ERROR_IO;
+    }
+
+    unsigned FT = (header >> 3) & 0x0f;
+
+    *frameSize = getFrameSize(isWide, FT);
+    if (*frameSize == 0) {
+        return ERROR_MALFORMED;
+    }
+    return OK;
+}
+
+AMRExtractor::AMRExtractor(const sp<DataSource> &source)
+    : mDataSource(source),
+      mInitCheck(NO_INIT),
+      mOffsetTableLength(0) {
+    String8 mimeType;
+    float confidence;
+    if (!SniffAMR(mDataSource, &mimeType, &confidence, NULL)) {
+        return;
+    }
+
+    mIsWide = (mimeType == MEDIA_MIMETYPE_AUDIO_AMR_WB);
+
+    mMeta = new MetaData;
+    mMeta->setCString(
+            kKeyMIMEType, mIsWide ? MEDIA_MIMETYPE_AUDIO_AMR_WB
+                                  : MEDIA_MIMETYPE_AUDIO_AMR_NB);
+
+    mMeta->setInt32(kKeyChannelCount, 1);
+    mMeta->setInt32(kKeySampleRate, mIsWide ? 16000 : 8000);
+
+    off64_t offset = mIsWide ? 9 : 6;
+    off64_t streamSize;
+    size_t frameSize, numFrames = 0;
+    int64_t duration = 0;
+
+    if (mDataSource->getSize(&streamSize) == OK) {
+         while (offset < streamSize) {
+            if (getFrameSizeByOffset(source, offset, mIsWide, &frameSize) != OK) {
+                return;
+            }
+
+            if ((numFrames % 50 == 0) && (numFrames / 50 < OFFSET_TABLE_LEN)) {
+                CHECK_EQ(mOffsetTableLength, numFrames / 50);
+                mOffsetTable[mOffsetTableLength] = offset - (mIsWide ? 9: 6);
+                mOffsetTableLength ++;
+            }
+
+            offset += frameSize;
+            duration += 20000;  // Each frame is 20ms
+            numFrames ++;
+        }
+
+        mMeta->setInt64(kKeyDuration, duration);
+    }
+
+    mInitCheck = OK;
+}
+
+AMRExtractor::~AMRExtractor() {
+}
+
+sp<MetaData> AMRExtractor::getMetaData() {
+    sp<MetaData> meta = new MetaData;
+
+    if (mInitCheck != OK) {
+        return meta;
+    }
+
+    meta->setCString(kKeyMIMEType, mIsWide ? "audio/amr-wb" : "audio/amr");
+
+    return meta;
+}
+
+size_t AMRExtractor::countTracks() {
+    return mInitCheck == OK ? 1 : 0;
+}
+
+sp<MediaSource> AMRExtractor::getTrack(size_t index) {
+    if (mInitCheck != OK || index != 0) {
+        return NULL;
+    }
+
+    return new AMRSource(mDataSource, mMeta, mIsWide,
+            mOffsetTable, mOffsetTableLength);
+}
+
+sp<MetaData> AMRExtractor::getTrackMetaData(size_t index, uint32_t flags) {
+    if (mInitCheck != OK || index != 0) {
+        return NULL;
+    }
+
+    return mMeta;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+AMRSource::AMRSource(
+        const sp<DataSource> &source, const sp<MetaData> &meta,
+        bool isWide, const off64_t *offset_table, size_t offset_table_length)
+    : mDataSource(source),
+      mMeta(meta),
+      mIsWide(isWide),
+      mOffset(mIsWide ? 9 : 6),
+      mCurrentTimeUs(0),
+      mStarted(false),
+      mGroup(NULL),
+      mOffsetTableLength(offset_table_length) {
+    if (mOffsetTableLength > 0 && mOffsetTableLength <= OFFSET_TABLE_LEN) {
+        memcpy ((char*)mOffsetTable, (char*)offset_table, sizeof(off64_t) * mOffsetTableLength);
+    }
+}
+
+AMRSource::~AMRSource() {
+    if (mStarted) {
+        stop();
+    }
+}
+
+status_t AMRSource::start(MetaData *params) {
+    CHECK(!mStarted);
+
+    mOffset = mIsWide ? 9 : 6;
+    mCurrentTimeUs = 0;
+    mGroup = new MediaBufferGroup;
+    mGroup->add_buffer(new MediaBuffer(128));
+    mStarted = true;
+
+    return OK;
+}
+
+status_t AMRSource::stop() {
+    CHECK(mStarted);
+
+    delete mGroup;
+    mGroup = NULL;
+
+    mStarted = false;
+    return OK;
+}
+
+sp<MetaData> AMRSource::getFormat() {
+    return mMeta;
+}
+
+status_t AMRSource::read(
+        MediaBuffer **out, const ReadOptions *options) {
+    *out = NULL;
+
+    int64_t seekTimeUs;
+    ReadOptions::SeekMode mode;
+    if (options && options->getSeekTo(&seekTimeUs, &mode)) {
+        size_t size;
+        int64_t seekFrame = seekTimeUs / 20000ll;  // 20ms per frame.
+        mCurrentTimeUs = seekFrame * 20000ll;
+
+        int index = seekFrame / 50;
+        if (index >= mOffsetTableLength) {
+            index = mOffsetTableLength - 1;
+        }
+
+        mOffset = mOffsetTable[index] + (mIsWide ? 9 : 6);
+
+        for (int i = 0; i< seekFrame - index * 50; i++) {
+            status_t err;
+            if ((err = getFrameSizeByOffset(mDataSource, mOffset,
+                            mIsWide, &size)) != OK) {
+                return err;
+            }
+            mOffset += size;
+        }
+    }
+
+    uint8_t header;
+    ssize_t n = mDataSource->readAt(mOffset, &header, 1);
+
+    if (n < 1) {
+        return ERROR_END_OF_STREAM;
+    }
+
+    if (header & 0x83) {
+        // Padding bits must be 0.
+
+        ALOGE("padding bits must be 0, header is 0x%02x", header);
+
+        return ERROR_MALFORMED;
+    }
+
+    unsigned FT = (header >> 3) & 0x0f;
+
+    size_t frameSize = getFrameSize(mIsWide, FT);
+    if (frameSize == 0) {
+        return ERROR_MALFORMED;
+    }
+
+    MediaBuffer *buffer;
+    status_t err = mGroup->acquire_buffer(&buffer);
+    if (err != OK) {
+        return err;
+    }
+
+    n = mDataSource->readAt(mOffset, buffer->data(), frameSize);
+
+    if (n != (ssize_t)frameSize) {
+        buffer->release();
+        buffer = NULL;
+
+        return ERROR_IO;
+    }
+
+    buffer->set_range(0, frameSize);
+    buffer->meta_data()->setInt64(kKeyTime, mCurrentTimeUs);
+    buffer->meta_data()->setInt32(kKeyIsSyncFrame, 1);
+
+    mOffset += frameSize;
+    mCurrentTimeUs += 20000;  // Each frame is 20ms
+
+    *out = buffer;
+
+    return OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+bool SniffAMR(
+        const sp<DataSource> &source, String8 *mimeType, float *confidence,
+        sp<AMessage> *) {
+    char header[9];
+
+    if (source->readAt(0, header, sizeof(header)) != sizeof(header)) {
+        return false;
+    }
+
+    if (!memcmp(header, "#!AMR\n", 6)) {
+        *mimeType = MEDIA_MIMETYPE_AUDIO_AMR_NB;
+        *confidence = 0.5;
+
+        return true;
+    } else if (!memcmp(header, "#!AMR-WB\n", 9)) {
+        *mimeType = MEDIA_MIMETYPE_AUDIO_AMR_WB;
+        *confidence = 0.5;
+
+        return true;
+    }
+
+    return false;
+}
+
+}  // namespace android