1 files changed, 148 insertions, 0 deletions
diff --git a/media/libstagefright/MediaClock.cpp b/media/libstagefright/MediaClock.cpp
new file mode 100644
index 0000000..433f555
--- /dev/null
+++ b/media/libstagefright/MediaClock.cpp
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 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 "MediaClock"
+#include <utils/Log.h>
+
+#include <media/stagefright/MediaClock.h>
+
+#include <media/stagefright/foundation/ADebug.h>
+#include <media/stagefright/foundation/ALooper.h>
+
+namespace android {
+
+MediaClock::MediaClock()
+    : mAnchorTimeMediaUs(-1),
+      mAnchorTimeRealUs(-1),
+      mMaxTimeMediaUs(INT64_MAX),
+      mStartingTimeMediaUs(-1),
+      mPlaybackRate(1.0) {
+}
+
+MediaClock::~MediaClock() {
+}
+
+void MediaClock::setStartingTimeMedia(int64_t startingTimeMediaUs) {
+    Mutex::Autolock autoLock(mLock);
+    mStartingTimeMediaUs = startingTimeMediaUs;
+}
+
+void MediaClock::clearAnchor() {
+    Mutex::Autolock autoLock(mLock);
+    mAnchorTimeMediaUs = -1;
+    mAnchorTimeRealUs = -1;
+}
+
+void MediaClock::updateAnchor(
+        int64_t anchorTimeMediaUs,
+        int64_t anchorTimeRealUs,
+        int64_t maxTimeMediaUs) {
+    if (anchorTimeMediaUs < 0 || anchorTimeRealUs < 0) {
+        ALOGW("reject anchor time since it is negative.");
+        return;
+    }
+
+    Mutex::Autolock autoLock(mLock);
+    int64_t nowUs = ALooper::GetNowUs();
+    int64_t nowMediaUs =
+        anchorTimeMediaUs + (nowUs - anchorTimeRealUs) * (double)mPlaybackRate;
+    if (nowMediaUs < 0) {
+        ALOGW("reject anchor time since it leads to negative media time.");
+        return;
+    }
+    mAnchorTimeRealUs = nowUs;
+    mAnchorTimeMediaUs = nowMediaUs;
+    mMaxTimeMediaUs = maxTimeMediaUs;
+}
+
+void MediaClock::updateMaxTimeMedia(int64_t maxTimeMediaUs) {
+    Mutex::Autolock autoLock(mLock);
+    mMaxTimeMediaUs = maxTimeMediaUs;
+}
+
+void MediaClock::setPlaybackRate(float rate) {
+    CHECK_GE(rate, 0.0);
+    Mutex::Autolock autoLock(mLock);
+    if (mAnchorTimeRealUs == -1) {
+        mPlaybackRate = rate;
+        return;
+    }
+
+    int64_t nowUs = ALooper::GetNowUs();
+    mAnchorTimeMediaUs += (nowUs - mAnchorTimeRealUs) * (double)mPlaybackRate;
+    if (mAnchorTimeMediaUs < 0) {
+        ALOGW("setRate: anchor time should not be negative, set to 0.");
+        mAnchorTimeMediaUs = 0;
+    }
+    mAnchorTimeRealUs = nowUs;
+    mPlaybackRate = rate;
+}
+
+status_t MediaClock::getMediaTime(
+        int64_t realUs, int64_t *outMediaUs, bool allowPastMaxTime) const {
+    if (outMediaUs == NULL) {
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock autoLock(mLock);
+    return getMediaTime_l(realUs, outMediaUs, allowPastMaxTime);
+}
+
+status_t MediaClock::getMediaTime_l(
+        int64_t realUs, int64_t *outMediaUs, bool allowPastMaxTime) const {
+    if (mAnchorTimeRealUs == -1) {
+        return NO_INIT;
+    }
+
+    int64_t mediaUs = mAnchorTimeMediaUs
+            + (realUs - mAnchorTimeRealUs) * (double)mPlaybackRate;
+    if (mediaUs > mMaxTimeMediaUs && !allowPastMaxTime) {
+        mediaUs = mMaxTimeMediaUs;
+    }
+    if (mediaUs < mStartingTimeMediaUs) {
+        mediaUs = mStartingTimeMediaUs;
+    }
+    if (mediaUs < 0) {
+        mediaUs = 0;
+    }
+    *outMediaUs = mediaUs;
+    return OK;
+}
+
+status_t MediaClock::getRealTimeFor(
+        int64_t targetMediaUs, int64_t *outRealUs) const {
+    if (outRealUs == NULL) {
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock autoLock(mLock);
+    if (mPlaybackRate == 0.0) {
+        return NO_INIT;
+    }
+
+    int64_t nowUs = ALooper::GetNowUs();
+    int64_t nowMediaUs;
+    status_t status =
+            getMediaTime_l(nowUs, &nowMediaUs, true /* allowPastMaxTime */);
+    if (status != OK) {
+        return status;
+    }
+    *outRealUs = (targetMediaUs - nowMediaUs) / (double)mPlaybackRate + nowUs;
+    return OK;
+}
+
+}  // namespace android