Fix a software decoder freeze issue

OpenCore's software decoders are all using 2 output buffers.
Holding more than 1 buffer in the video MIO can lead to starvation
and playback freeze.

bug - 2478420

2 files changed, 9 insertions, 8 deletions

diff --git a/android/android_surface_output.cpp b/android/android_surface_output.cpp
index 5538f8c15..9f0ad3208 100644
--- a/android/android_surface_output.cpp
+++ b/android/android_surface_output.cpp
@@ -48,7 +48,7 @@ OSCL_EXPORT_REF AndroidSurfaceOutput::AndroidSurfaceOutput() :
     mPvPlayer = NULL;
     mEmulation = false;
     iEosReceived = false;
-    mNumberOfFramesToHold = 2;
+    mNumberOfFramesToHold = 1;
 }
 
 status_t AndroidSurfaceOutput::set(PVPlayer* pvPlayer, const sp<ISurface>& surface, bool emulation)
diff --git a/android/android_surface_output.h b/android/android_surface_output.h
index f8ca4ff76..5f0f734c3 100644
--- a/android/android_surface_output.h
+++ b/android/android_surface_output.h
@@ -315,14 +315,15 @@ protected:
     bool iIsMIOConfigured;
 
     /*
-     * The value of mNumberOfFramesToHold is hardware/platform specific.
-     * 1. On non-overlay based platforms, its value it set to 2
-     *    so as to avoid potential tearings oberved during video playback.
-     * 2. On overlay-based platforms, its value should be overwritten.
-     *    We have observed video decoder starvation when a value other than 1.
+     * The value of mNumberOfFramesToHold is decoder specific.
+     *
+     * Please make sure that the number of unique output buffers from the decoder
+     * (either hardware or software) is not less than 1 +  mNumberOfFramesToHold;
+     * otherwise, we will have starvation.
+     *
+     * On some platforms, mNumberOfFramesToHold needs to set to more than 1 (such as
+     * 2) in order to workaround a tearing issue from SF during video playback.
      *
-     * We set the default value to 2 in this class. Please change its value
-     * accordingly in the derived class.
      */
     int mNumberOfFramesToHold;