Allocate buffers before calling start on its source in OMXCodec::start() for encoder case

o This makes it possible to configure the source to use the same number of input buffers
  as requested by the video encoder, before the source starts. As a result, hardcoded
  number of video buffers for camera source, for instance, can be avoided.

o related-to-bug: 6920805

Change-Id: I13d2c308dce34967768cd407f02988e92ef10a89

2 files changed, 18 insertions, 5 deletions

diff --git a/include/media/stagefright/MetaData.h b/include/media/stagefright/MetaData.h
index 3c25a14..e91904c 100644
--- a/include/media/stagefright/MetaData.h
+++ b/include/media/stagefright/MetaData.h
@@ -111,6 +111,7 @@ enum {
     kKeyTrackTimeStatus   = 'tktm',  // int64_t
 
     kKeyNotRealTime       = 'ntrt',  // bool (int32_t)
+    kKeyNumBuffers        = 'nbbf',  // int32_t
 
     // Ogg files can be tagged to be automatically looping...
     kKeyAutoLoop          = 'autL',  // bool (int32_t)
diff --git a/media/libstagefright/OMXCodec.cpp b/media/libstagefright/OMXCodec.cpp
index 2f5e9a4..dabb0e7 100755
--- a/media/libstagefright/OMXCodec.cpp
+++ b/media/libstagefright/OMXCodec.cpp
@@ -3623,11 +3623,6 @@ status_t OMXCodec::start(MetaData *meta) {
         }
         params->setInt64(kKeyTime, startTimeUs);
     }
-    status_t err = mSource->start(params.get());
-
-    if (err != OK) {
-        return err;
-    }
 
     mCodecSpecificDataIndex = 0;
     mInitialBufferSubmit = true;
@@ -3640,6 +3635,23 @@ status_t OMXCodec::start(MetaData *meta) {
     mFilledBuffers.clear();
     mPaused = false;
 
+    status_t err;
+    if (mIsEncoder) {
+        // Calling init() before starting its source so that we can configure,
+        // if supported, the source to use exactly the same number of input
+        // buffers as requested by the encoder.
+        if ((err = init()) != OK) {
+            return err;
+        }
+
+        params->setInt32(kKeyNumBuffers, mPortBuffers[kPortIndexInput].size());
+        return mSource->start(params.get());
+    }
+
+    // Decoder case
+    if ((err = mSource->start(params.get())) != OK) {
+        return err;
+    }
     return init();
 }