stagefright: Remove additional deep-copy of encoder buffers

MPEG4Writer makes a copy of encoded buffer to avoid holding on
to the read buffer. This is not needed with MediaCodecSource,
as the encoded-output buffer is already copied to a heap buffer.
This saves a copy and some power.
However, cloning the buffer is still needed for upstream sources
that cannot afford to keep the buffers with writer up until they
are released.
So, pass a hint in buffer's metadata to indicate if it is OK
to delay the release and not copy the buffer

Change-Id: Ib59ac29ebc6ce4afd6fc272688a8260438ab1517

3 files changed, 22 insertions, 9 deletions

diff --git a/media/libavextensions/stagefright/AVExtensions.h b/media/libavextensions/stagefright/AVExtensions.h
index 9c712e4..17ea475 100644
--- a/media/libavextensions/stagefright/AVExtensions.h
+++ b/media/libavextensions/stagefright/AVExtensions.h
@@ -161,6 +161,9 @@ struct AVUtils {
 
     virtual bool useQCHWEncoder(const sp<AMessage> &, AString &) { return false; }
 
+    virtual bool canDeferRelease(const sp<MetaData> &/*meta*/) { return false; }
+    virtual void setDeferRelease(sp<MetaData> &/*meta*/) {}
+
     struct HEVCMuxer {
 
         virtual bool reassembleHEVCCSD(const AString &mime, sp<ABuffer> csd0, sp<MetaData> &meta);
diff --git a/media/libstagefright/MPEG4Writer.cpp b/media/libstagefright/MPEG4Writer.cpp
index 94f40b4..cb9df29 100644
--- a/media/libstagefright/MPEG4Writer.cpp
+++ b/media/libstagefright/MPEG4Writer.cpp
@@ -2284,15 +2284,23 @@ status_t MPEG4Writer::Track::threadEntry() {
             continue;
         }
 
-        // Make a deep copy of the MediaBuffer and Metadata and release
-        // the original as soon as we can
-        MediaBuffer *copy = new MediaBuffer(buffer->range_length());
-        memcpy(copy->data(), (uint8_t *)buffer->data() + buffer->range_offset(),
-                buffer->range_length());
-        copy->set_range(0, buffer->range_length());
-        meta_data = new MetaData(*buffer->meta_data().get());
-        buffer->release();
-        buffer = NULL;
+        MediaBuffer *copy = NULL;
+        // Check if the upstream source hints it is OK to hold on to the
+        // buffer without releasing immediately and avoid cloning the buffer
+        if (AVUtils::get()->canDeferRelease(buffer->meta_data())) {
+            copy = buffer;
+            meta_data = new MetaData(*buffer->meta_data().get());
+        } else {
+            // Make a deep copy of the MediaBuffer and Metadata and release
+            // the original as soon as we can
+            copy = new MediaBuffer(buffer->range_length());
+            memcpy(copy->data(), (uint8_t *)buffer->data() + buffer->range_offset(),
+                    buffer->range_length());
+            copy->set_range(0, buffer->range_length());
+            meta_data = new MetaData(*buffer->meta_data().get());
+            buffer->release();
+            buffer = NULL;
+        }
 
         if (mIsAvc || mIsHEVC) StripStartcode(copy);
 
diff --git a/media/libstagefright/MediaCodecSource.cpp b/media/libstagefright/MediaCodecSource.cpp
index dbd9cb0..925be14 100644
--- a/media/libstagefright/MediaCodecSource.cpp
+++ b/media/libstagefright/MediaCodecSource.cpp
@@ -759,6 +759,8 @@ void MediaCodecSource::onMessageReceived(const sp<AMessage> &msg) {
 
             MediaBuffer *mbuf = new MediaBuffer(outbuf->size());
             memcpy(mbuf->data(), outbuf->data(), outbuf->size());
+            sp<MetaData> meta = mbuf->meta_data();
+            AVUtils::get()->setDeferRelease(meta);
 
             if (!(flags & MediaCodec::BUFFER_FLAG_CODECCONFIG)) {
                 if (mIsVideo) {