Merge "Another attempt for fixing AAC+/eAAC+ related issue" into gingerbread
diff --git a/media/libstagefright/codecs/aacdec/AACDecoder.cpp b/media/libstagefright/codecs/aacdec/AACDecoder.cpp
index c5b51c0..e4ed5e6 100644
--- a/media/libstagefright/codecs/aacdec/AACDecoder.cpp
+++ b/media/libstagefright/codecs/aacdec/AACDecoder.cpp
@@ -123,6 +123,8 @@
mAnchorTimeUs = 0;
mNumSamplesOutput = 0;
mStarted = true;
+ mNumDecodedBuffers = 0;
+ mUpsamplingFactor = 2;
return OK;
}
@@ -207,22 +209,65 @@
Int decoderErr = PVMP4AudioDecodeFrame(mConfig, mDecoderBuf);
- // Check on the sampling rate to see whether it is changed.
- int32_t sampleRate;
- CHECK(mMeta->findInt32(kKeySampleRate, &sampleRate));
- if (mConfig->samplingRate != sampleRate) {
- mMeta->setInt32(kKeySampleRate, mConfig->samplingRate);
- LOGW("Sample rate was %d, but now is %d",
- sampleRate, mConfig->samplingRate);
- buffer->release();
- mInputBuffer->release();
- mInputBuffer = NULL;
- return INFO_FORMAT_CHANGED;
+ /*
+ * AAC+/eAAC+ streams can be signalled in two ways: either explicitly
+ * or implicitly, according to MPEG4 spec. AAC+/eAAC+ is a dual
+ * rate system and the sampling rate in the final output is actually
+ * doubled compared with the core AAC decoder sampling rate.
+ *
+ * Explicit signalling is done by explicitly defining SBR audio object
+ * type in the bitstream. Implicit signalling is done by embedding
+ * SBR content in AAC extension payload specific to SBR, and hence
+ * requires an AAC decoder to perform pre-checks on actual audio frames.
+ *
+ * Thus, we could not say for sure whether a stream is
+ * AAC+/eAAC+ until the first data frame is decoded.
+ */
+ if (++mNumDecodedBuffers <= 2) {
+ LOGV("audio/extended audio object type: %d + %d",
+ mConfig->audioObjectType, mConfig->extendedAudioObjectType);
+ LOGV("aac+ upsampling factor: %d desired channels: %d",
+ mConfig->aacPlusUpsamplingFactor, mConfig->desiredChannels);
+
+ CHECK(mNumDecodedBuffers > 0);
+ if (mNumDecodedBuffers == 1) {
+ mUpsamplingFactor = mConfig->aacPlusUpsamplingFactor;
+ // Check on the sampling rate to see whether it is changed.
+ int32_t sampleRate;
+ CHECK(mMeta->findInt32(kKeySampleRate, &sampleRate));
+ if (mConfig->samplingRate != sampleRate) {
+ mMeta->setInt32(kKeySampleRate, mConfig->samplingRate);
+ LOGW("Sample rate was %d Hz, but now is %d Hz",
+ sampleRate, mConfig->samplingRate);
+ buffer->release();
+ mInputBuffer->release();
+ mInputBuffer = NULL;
+ return INFO_FORMAT_CHANGED;
+ }
+ } else { // mNumDecodedBuffers == 2
+ if (mConfig->extendedAudioObjectType == MP4AUDIO_AAC_LC ||
+ mConfig->extendedAudioObjectType == MP4AUDIO_LTP) {
+ if (mUpsamplingFactor == 2) {
+ // The stream turns out to be not aacPlus mode anyway
+ LOGW("Disable AAC+/eAAC+ since extended audio object type is %d",
+ mConfig->extendedAudioObjectType);
+ mConfig->aacPlusEnabled = 0;
+ }
+ } else {
+ if (mUpsamplingFactor == 1) {
+ // aacPlus mode does not buy us anything, but to cause
+ // 1. CPU load to increase, and
+ // 2. a half speed of decoding
+ LOGW("Disable AAC+/eAAC+ since upsampling factor is 1");
+ mConfig->aacPlusEnabled = 0;
+ }
+ }
+ }
}
size_t numOutBytes =
mConfig->frameLength * sizeof(int16_t) * mConfig->desiredChannels;
- if (mConfig->aacPlusUpsamplingFactor == 2) {
+ if (mUpsamplingFactor == 2) {
if (mConfig->desiredChannels == 1) {
memcpy(&mConfig->pOutputBuffer[1024], &mConfig->pOutputBuffer[2048], numOutBytes * 2);
}
diff --git a/media/libstagefright/include/AACDecoder.h b/media/libstagefright/include/AACDecoder.h
index 200f93c..886a3b7 100644
--- a/media/libstagefright/include/AACDecoder.h
+++ b/media/libstagefright/include/AACDecoder.h
@@ -53,6 +53,8 @@
int64_t mAnchorTimeUs;
int64_t mNumSamplesOutput;
status_t mInitCheck;
+ int64_t mNumDecodedBuffers;
+ int32_t mUpsamplingFactor;
MediaBuffer *mInputBuffer;