stagefright: Resurrect PCM offload

 * Forward-port the open-source code from L which was moved to closed-source
   in M. This is being done out of necessity- the architecture chosen by
   Qualcomm is not optimal and doesn't work well with a singular
   codebase which attempts to service a large number of devices.
 * This patch brings in the code to support PCM offload (AudioFlinger
   bypass). This allows for playback of high resolution clips without
   decimation stages, and enables reduced power consumption for audio
   pipelines which take advantage of the Hexagon DSP (effects).

Change-Id: I0ef15fc3df538ab723f3c12ce0ed71d0e607c99e

1 files changed, 11 insertions, 1 deletions

diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerDecoderPassThrough.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerDecoderPassThrough.cpp
index 937936d..0b50d0d 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerDecoderPassThrough.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerDecoderPassThrough.cpp
@@ -53,7 +53,8 @@ NuPlayer::DecoderPassThrough::DecoderPassThrough(
       mPendingAudioErr(OK),
       mPendingBuffersToDrain(0),
       mCachedBytes(0),
-      mComponentName("pass through decoder") {
+      mComponentName("pass through decoder"),
+      mPCMFormat(AUDIO_FORMAT_INVALID) {
     ALOGW_IF(renderer == NULL, "expect a non-NULL renderer");
 }
 
@@ -75,6 +76,15 @@ void NuPlayer::DecoderPassThrough::onConfigure(const sp<AMessage> &format) {
     // The audio sink is already opened before the PassThrough decoder is created.
     // Opening again might be relevant if decoder is instantiated after shutdown and
     // format is different.
+    sp<MetaData> audioMeta = mSource->getFormatMeta(true /* audio */);
+    if (AVNuUtils::get()->isRAWFormat(audioMeta)) {
+        mPCMFormat = AVNuUtils::get()->getKeyPCMFormat(audioMeta);
+        if (mPCMFormat != AUDIO_FORMAT_INVALID) {
+            AVNuUtils::get()->setPCMFormat(format, mPCMFormat);
+            AVNuUtils::get()->updateAudioBitWidth(mPCMFormat, format);
+        }
+    }
+
     status_t err = mRenderer->openAudioSink(
             format, true /* offloadOnly */, hasVideo,
             AUDIO_OUTPUT_FLAG_NONE /* flags */, NULL /* isOffloaded */, mSource->isStreaming());