From 1f24b30fe4b5d8e4050d30c92cf81cfa599cf991 Mon Sep 17 00:00:00 2001
From: Andreas Huber <andih@google.com>
Date: Thu, 10 Jun 2010 11:12:39 -0700
Subject: [PATCH] Support "pausing" of MediaSources with the effect that they
 no longer pull on their upstream source until a subsequent read-with-seek.

Change-Id: Ie4153a10ab36c1135f5fcfb572958129d886bcc3
---
 include/media/stagefright/MediaSource.h |  8 ++++++++
 include/media/stagefright/OMXCodec.h    |  4 ++++
 media/libstagefright/OMXCodec.cpp       | 20 +++++++++++++++++++-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/include/media/stagefright/MediaSource.h b/include/media/stagefright/MediaSource.h
index 96d57e724d211..9cc94c8391aae 100644
--- a/include/media/stagefright/MediaSource.h
+++ b/include/media/stagefright/MediaSource.h
@@ -20,6 +20,7 @@
 
 #include <sys/types.h>
 
+#include <media/stagefright/MediaErrors.h>
 #include <utils/RefBase.h>
 
 namespace android {
@@ -83,6 +84,13 @@ struct MediaSource : public RefBase {
         int64_t mLatenessUs;
     };
 
+    // Causes this source to suspend pulling data from its upstream source
+    // until a subsequent read-with-seek. Currently only supported by
+    // OMXCodec.
+    virtual status_t pause() {
+        return ERROR_UNSUPPORTED;
+    }
+
 protected:
     virtual ~MediaSource();
 
diff --git a/include/media/stagefright/OMXCodec.h b/include/media/stagefright/OMXCodec.h
index 3fbb4697379a3..c95fc021b1401 100644
--- a/include/media/stagefright/OMXCodec.h
+++ b/include/media/stagefright/OMXCodec.h
@@ -52,6 +52,8 @@ struct OMXCodec : public MediaSource,
     virtual status_t read(
             MediaBuffer **buffer, const ReadOptions *options = NULL);
 
+    virtual status_t pause();
+
     void on_message(const omx_message &msg);
 
     // from MediaBufferObserver
@@ -144,6 +146,8 @@ private:
     Mutex mLock;
     Condition mAsyncCompletion;
 
+    bool mPaused;
+
     // A list of indices into mPortStatus[kPortIndexOutput] filled with data.
     List<size_t> mFilledBuffers;
     Condition mBufferFilled;
diff --git a/media/libstagefright/OMXCodec.cpp b/media/libstagefright/OMXCodec.cpp
index 14682af042a56..6be41b449920b 100644
--- a/media/libstagefright/OMXCodec.cpp
+++ b/media/libstagefright/OMXCodec.cpp
@@ -1145,7 +1145,8 @@ OMXCodec::OMXCodec(
       mNoMoreOutputData(false),
       mOutputPortSettingsHaveChanged(false),
       mSeekTimeUs(-1),
-      mLeftOverBuffer(NULL) {
+      mLeftOverBuffer(NULL),
+      mPaused(false) {
     mPortStatus[kPortIndexInput] = ENABLED;
     mPortStatus[kPortIndexOutput] = ENABLED;
 
@@ -1735,6 +1736,9 @@ void OMXCodec::onCmdComplete(OMX_COMMANDTYPE cmd, OMX_U32 data) {
                     CODEC_LOGV("Finished flushing both ports, now continuing from"
                          " seek-time.");
 
+                    // We implicitly resume pulling on our upstream source.
+                    mPaused = false;
+
                     drainInputBuffers();
                     fillOutputBuffers();
                 }
@@ -2034,6 +2038,10 @@ void OMXCodec::drainInputBuffer(BufferInfo *info) {
         return;
     }
 
+    if (mPaused) {
+        return;
+    }
+
     status_t err;
 
     bool signalEOS = false;
@@ -2554,6 +2562,7 @@ status_t OMXCodec::start(MetaData *) {
     mOutputPortSettingsHaveChanged = false;
     mSeekTimeUs = -1;
     mFilledBuffers.clear();
+    mPaused = false;
 
     return init();
 }
@@ -2660,6 +2669,7 @@ status_t OMXCodec::read(
             // There's no reason to trigger the code below, there's
             // nothing to flush yet.
             seeking = false;
+            mPaused = false;
         }
 
         drainInputBuffers();
@@ -3220,6 +3230,14 @@ void OMXCodec::initOutputFormat(const sp<MetaData> &inputFormat) {
     }
 }
 
+status_t OMXCodec::pause() {
+    Mutex::Autolock autoLock(mLock);
+
+    mPaused = true;
+
+    return OK;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 status_t QueryCodecs(