NuPlayer: pull more video buffers in advance in GenericSource

pull 4 video buffers at a time, and start pulling when we're down
to 1 buffers to avoid starving the decoder.

bug: 22320866
Change-Id: I10914dc092f3830ecb6296e2d9ebf9064ff7a5dc

2 files changed, 18 insertions, 0 deletions

diff --git a/media/libstagefright/mpeg2ts/AnotherPacketSource.cpp b/media/libstagefright/mpeg2ts/AnotherPacketSource.cpp
index 0878a1b..cabde32 100644
--- a/media/libstagefright/mpeg2ts/AnotherPacketSource.cpp
+++ b/media/libstagefright/mpeg2ts/AnotherPacketSource.cpp
@@ -394,6 +394,20 @@ bool AnotherPacketSource::hasDataBufferAvailable(status_t *finalResult) {
     return false;
 }
 
+size_t AnotherPacketSource::getAvailableBufferCount(status_t *finalResult) {
+    Mutex::Autolock autoLock(mLock);
+
+    *finalResult = OK;
+    if (!mEnabled) {
+        return 0;
+    }
+    if (!mBuffers.empty()) {
+        return mBuffers.size();
+    }
+    *finalResult = mEOSResult;
+    return 0;
+}
+
 int64_t AnotherPacketSource::getBufferedDurationUs(status_t *finalResult) {
     Mutex::Autolock autoLock(mLock);
     *finalResult = mEOSResult;
diff --git a/media/libstagefright/mpeg2ts/AnotherPacketSource.h b/media/libstagefright/mpeg2ts/AnotherPacketSource.h
index eb9dc9b..28a0e89 100644
--- a/media/libstagefright/mpeg2ts/AnotherPacketSource.h
+++ b/media/libstagefright/mpeg2ts/AnotherPacketSource.h
@@ -49,6 +49,10 @@ struct AnotherPacketSource : public MediaSource {
     // Returns true if we have packets that's not discontinuities
     bool hasDataBufferAvailable(status_t *finalResult);
 
+    // Returns the number of available buffers. finalResult is always OK
+    // if this method returns non-0, or the final result if it returns 0.
+    size_t getAvailableBufferCount(status_t *finalResult);
+
     // Returns the difference between the last and the first queued
     // presentation timestamps since the last discontinuity (if any).
     int64_t getBufferedDurationUs(status_t *finalResult);