1 files changed, 142 insertions, 0 deletions
diff --git a/media/libstagefright/VideoSourceDownSampler.cpp b/media/libstagefright/VideoSourceDownSampler.cpp
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+++ b/media/libstagefright/VideoSourceDownSampler.cpp
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+/*
+ * Copyright (C) 2010 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 "VideoSourceDownSampler"
+
+#include <media/stagefright/VideoSourceDownSampler.h>
+#include <media/stagefright/MediaBuffer.h>
+#include <media/stagefright/MediaDebug.h>
+#include <media/stagefright/MetaData.h>
+#include <media/stagefright/YUVImage.h>
+#include <media/stagefright/YUVCanvas.h>
+#include "OMX_Video.h"
+
+namespace android {
+
+VideoSourceDownSampler::VideoSourceDownSampler(const sp<MediaSource> &videoSource,
+        int32_t width, int32_t height) {
+    LOGV("Construct VideoSourceDownSampler");
+    CHECK(width > 0);
+    CHECK(height > 0);
+
+    mRealVideoSource = videoSource;
+    mWidth = width;
+    mHeight = height;
+
+    mMeta = new MetaData(*(mRealVideoSource->getFormat()));
+    CHECK(mMeta->findInt32(kKeyWidth, &mRealSourceWidth));
+    CHECK(mMeta->findInt32(kKeyHeight, &mRealSourceHeight));
+
+    if ((mWidth != mRealSourceWidth) || (mHeight != mRealSourceHeight)) {
+        // Change meta data for width and height.
+        CHECK(mWidth <= mRealSourceWidth);
+        CHECK(mHeight <= mRealSourceHeight);
+
+        mNeedDownSampling = true;
+        computeDownSamplingParameters();
+        mMeta->setInt32(kKeyWidth, mWidth);
+        mMeta->setInt32(kKeyHeight, mHeight);
+    } else {
+        mNeedDownSampling = false;
+    }
+}
+
+VideoSourceDownSampler::~VideoSourceDownSampler() {
+}
+
+void VideoSourceDownSampler::computeDownSamplingParameters() {
+    mDownSampleSkipX = mRealSourceWidth / mWidth;
+    mDownSampleSkipY = mRealSourceHeight / mHeight;
+
+    mDownSampleOffsetX = mRealSourceWidth - mDownSampleSkipX * mWidth;
+    mDownSampleOffsetY = mRealSourceHeight - mDownSampleSkipY * mHeight;
+}
+
+void VideoSourceDownSampler::downSampleYUVImage(
+        const MediaBuffer &sourceBuffer, MediaBuffer **buffer) const {
+    // find the YUV format
+    int32_t srcFormat;
+    CHECK(mMeta->findInt32(kKeyColorFormat, &srcFormat));
+    YUVImage::YUVFormat yuvFormat;
+    if (srcFormat == OMX_COLOR_FormatYUV420SemiPlanar) {
+        yuvFormat = YUVImage::YUV420SemiPlanar;
+    } else if (srcFormat == OMX_COLOR_FormatYUV420Planar) {
+        yuvFormat = YUVImage::YUV420Planar;
+    }
+
+    // allocate mediaBuffer for down sampled image and setup a canvas.
+    *buffer = new MediaBuffer(YUVImage::bufferSize(yuvFormat, mWidth, mHeight));
+    YUVImage yuvDownSampledImage(yuvFormat,
+            mWidth, mHeight,
+            (uint8_t *)(*buffer)->data());
+    YUVCanvas yuvCanvasDownSample(yuvDownSampledImage);
+
+    YUVImage yuvImageSource(yuvFormat,
+            mRealSourceWidth, mRealSourceHeight,
+            (uint8_t *)sourceBuffer.data());
+    yuvCanvasDownSample.downsample(mDownSampleOffsetX, mDownSampleOffsetY,
+            mDownSampleSkipX, mDownSampleSkipY,
+            yuvImageSource);
+}
+
+status_t VideoSourceDownSampler::start(MetaData *params) {
+    LOGV("start");
+    return mRealVideoSource->start();
+}
+
+status_t VideoSourceDownSampler::stop() {
+    LOGV("stop");
+    return mRealVideoSource->stop();
+}
+
+sp<MetaData> VideoSourceDownSampler::getFormat() {
+    LOGV("getFormat");
+    return mMeta;
+}
+
+status_t VideoSourceDownSampler::read(
+        MediaBuffer **buffer, const ReadOptions *options) {
+    LOGV("read");
+    MediaBuffer *realBuffer;
+    status_t err = mRealVideoSource->read(&realBuffer, options);
+
+    if (mNeedDownSampling) {
+        downSampleYUVImage(*realBuffer, buffer);
+
+        int64_t frameTime;
+        realBuffer->meta_data()->findInt64(kKeyTime, &frameTime);
+        (*buffer)->meta_data()->setInt64(kKeyTime, frameTime);
+
+        // We just want this buffer to be deleted when the encoder releases it.
+        // So don't add a reference to it and set the observer to NULL.
+        (*buffer)->setObserver(NULL);
+
+        // The original buffer is no longer required. Release it.
+        realBuffer->release();
+    } else {
+        *buffer = realBuffer;
+    }
+
+    return err;
+}
+
+status_t VideoSourceDownSampler::pause() {
+    LOGV("pause");
+    return mRealVideoSource->pause();
+}
+
+}  // namespace android