The purpose of this patch is to add a C-based ABI that can be exposed by the NDK
for developers wanting to write a TTS Engine. This replaces the C++ ABI that is
currently under frameworks/base/include/tts/TtsEngine.h but is *binary* compatible
with it.
As a consequence, the svox pico plugin under external/svox/pico/tts/, which
links against tts/TtsEngine.h can be loaded by the TTS service properly.
Another patch would modify the pico tts to use <android/tts.h>, then we will
be able to get rid of <tts/TtsEngine.h> in the source tree.
Change-Id: I16844cef9b5b006cc32655a29e4f9f193c8c1a91
The AudioTrack that plays the synthesized audio data should only be
started when the first synthesis request is sent, not after the
initialization of the engine.
The track volume should be initialized to it nominal level. Volumes
above 1 do not provide amplification, so setting the volume to 2 is
not necessary.
if it was synthesing to a file, the latter can be deleted without
still being written to.
Clear the hashmap of SpeechItem to be stopped (mKillList) when the speech
queue is empty.
Merge commit '0950c5de864d1ad83ed96efc5c2d1569b4d36188' into eclair
* commit '0950c5de864d1ad83ed96efc5c2d1569b4d36188':
Fix bug 2046705 where the output of the speech synthesizer is too low.
The language files for the SVOX Pico engine result in the output of
the synthesizer to be too soft, and barely audible on a phone speaker.
The change implements a low shelf filter on the output of the synthesis
and a drastic amplification. This works as intended because the
synthesized data contains too much energy in the lower frequencies that
is wasted on a phone speaker. Once filtered out, they leave room for
amplication to address the volume issue.
Initial commit for review.
Integrated comments after patch set 1 review.
Fixed lockup in AudioFlinger::ThreadBase::exit()
Fixed lockup when playing tone with AudioPlocyService startTone()
so it can be recreated when the service is initialized.
In the interface with the native synthesizer library, close the lib
in the finalizer, delete the global ref to the SynthProxy java object.
for all current TextToSpeech instances by only caching the language
value so it is used with each subsequent utterance for this instance.
Synchronize calls to the engine around a global mutex since the engine
isn't thread-safe, except for the stop() call which is meant to interrupt
the synthesis loop.
