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1 /*
2  * Copyright (C) 2009 Google Inc.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 #ifndef ANDROID_TTS_H
17 #define ANDROID_TTS_H
18 
19 #include <sys/cdefs.h>
20 
21 // This header defines the interface used by the Android platform
22 // to access Text-To-Speech functionality in shared libraries that implement
23 // speech synthesis and the management of resources associated with the
24 // synthesis.
25 
26 // The shared library must contain a function named "android_getTtsEngine"
27 // that returns an 'android_tts_engine_t' instance.
28 
29 #ifdef __cplusplus
30 extern "C" {
31 #endif
32 
33 #define ANDROID_TTS_ENGINE_PROPERTY_CONFIG "engineConfig"
34 #define ANDROID_TTS_ENGINE_PROPERTY_PITCH  "pitch"
35 #define ANDROID_TTS_ENGINE_PROPERTY_RATE   "rate"
36 #define ANDROID_TTS_ENGINE_PROPERTY_VOLUME "volume"
37 
38 typedef enum {
39     ANDROID_TTS_SUCCESS                 = 0,
40     ANDROID_TTS_FAILURE                 = -1,
41     ANDROID_TTS_FEATURE_UNSUPPORTED     = -2,
42     ANDROID_TTS_VALUE_INVALID           = -3,
43     ANDROID_TTS_PROPERTY_UNSUPPORTED    = -4,
44     ANDROID_TTS_PROPERTY_SIZE_TOO_SMALL = -5,
45     ANDROID_TTS_MISSING_RESOURCES       = -6
46 } android_tts_result_t;
47 
48 typedef enum {
49     ANDROID_TTS_LANG_COUNTRY_VAR_AVAILABLE = 2,
50     ANDROID_TTS_LANG_COUNTRY_AVAILABLE    = 1,
51     ANDROID_TTS_LANG_AVAILABLE            = 0,
52     ANDROID_TTS_LANG_MISSING_DATA         = -1,
53     ANDROID_TTS_LANG_NOT_SUPPORTED        = -2
54 } android_tts_support_result_t;
55 
56 typedef enum {
57     ANDROID_TTS_SYNTH_DONE              = 0,
58     ANDROID_TTS_SYNTH_PENDING           = 1
59 } android_tts_synth_status_t;
60 
61 typedef enum {
62     ANDROID_TTS_CALLBACK_HALT           = 0,
63     ANDROID_TTS_CALLBACK_CONTINUE       = 1
64 } android_tts_callback_status_t;
65 
66 // Supported audio formats
67 //
68 // NOTE: This is duplicated in compat/include/TtsEngine.h
69 // Please make changes there as well.
70 typedef enum {
71     ANDROID_TTS_AUDIO_FORMAT_INVALID    = -1,
72     ANDROID_TTS_AUDIO_FORMAT_DEFAULT    = 0,
73     ANDROID_TTS_AUDIO_FORMAT_PCM_16_BIT = 1,
74     ANDROID_TTS_AUDIO_FORMAT_PCM_8_BIT  = 2,
75 } android_tts_audio_format_t;
76 
77 
78 /* An android_tts_engine_t object can be anything, but must have,
79  * as its first field, a pointer to a table of functions.
80  *
81  * See the full definition of struct android_tts_engine_t_funcs_t
82  * below for details.
83  */
84 typedef struct android_tts_engine_funcs_t  android_tts_engine_funcs_t;
85 
86 typedef struct {
87     android_tts_engine_funcs_t *funcs;
88 } android_tts_engine_t;
89 
90 #if __ANDROID_API__ >= 13
91 /* This function must be located in the TTS Engine shared library
92  * and must return the address of an android_tts_engine_t library.
93  */
94 extern android_tts_engine_t *android_getTtsEngine();
95 
96 /* Including the old version for legacy support (Froyo compatibility).
97  * This should return the same thing as android_getTtsEngine.
98  */
99 extern "C" android_tts_engine_t *getTtsEngine();
100 #endif /* __ANDROID_API__ >= 13 */
101 
102 // A callback type used to notify the framework of new synthetized
103 // audio samples, status will be SYNTH_DONE for the last sample of
104 // the last request, of SYNTH_PENDING otherwise.
105 //
106 // This is passed by the framework to the engine through the
107 // 'engine_init' function (see below).
108 //
109 // The callback for synthesis completed takes:
110 // @param [inout] void *&       - The userdata pointer set in the original
111 //                                 synth call
112 // @param [in]    uint32_t      - Track sampling rate in Hz
113 // @param [in]    uint32_t      - The audio format
114 // @param [in]    int           - The number of channels
115 // @param [inout] int8_t *&     - A buffer of audio data only valid during the
116 //                                execution of the callback
117 // @param [inout] size_t  &     - The size of the buffer
118 // @param [in] tts_synth_status - indicate whether the synthesis is done, or
119 //                                 if more data is to be synthesized.
120 // @return TTS_CALLBACK_HALT to indicate the synthesis must stop,
121 //         TTS_CALLBACK_CONTINUE to indicate the synthesis must continue if
122 //            there is more data to produce.
123 typedef android_tts_callback_status_t (*android_tts_synth_cb_t)
124             (void **pUserData,
125              uint32_t trackSamplingHz,
126              android_tts_audio_format_t audioFormat,
127              int channelCount,
128              int8_t **pAudioBuffer,
129              size_t *pBufferSize,
130              android_tts_synth_status_t status);
131 
132 
133 // The table of function pointers that the android_tts_engine_t must point to.
134 // Note that each of these functions will take a handle to the engine itself
135 // as their first parameter.
136 //
137 
138 struct android_tts_engine_funcs_t {
139     // reserved fields, ignored by the framework
140     // they must be placed here to ensure binary compatibility
141     // of legacy binary plugins.
142     void *reserved[2];
143 
144     // Initialize the TTS engine and returns whether initialization succeeded.
145     // @param synthDoneCBPtr synthesis callback function pointer
146     // @return TTS_SUCCESS, or TTS_FAILURE
147     android_tts_result_t (*init)
148             (void *engine,
149              android_tts_synth_cb_t synthDonePtr,
150              const char *engineConfig);
151 
152     // Shut down the TTS engine and releases all associated resources.
153     // @return TTS_SUCCESS, or TTS_FAILURE
154     android_tts_result_t (*shutdown)
155             (void *engine);
156 
157     // Interrupt synthesis and flushes any synthesized data that hasn't been
158     // output yet. This will block until callbacks underway are completed.
159     // @return TTS_SUCCESS, or TTS_FAILURE
160     android_tts_result_t (*stop)
161             (void *engine);
162 
163     // Returns the level of support for the language, country and variant.
164     // @return TTS_LANG_COUNTRY_VAR_AVAILABLE if the language, country and variant are supported,
165     //            and the corresponding resources are correctly installed
166     //         TTS_LANG_COUNTRY_AVAILABLE if the language and country are supported and the
167     //             corresponding resources are correctly installed, but there is no match for
168     //             the specified variant
169     //         TTS_LANG_AVAILABLE if the language is supported and the
170     //             corresponding resources are correctly installed, but there is no match for
171     //             the specified country and variant
172     //         TTS_LANG_MISSING_DATA if the required resources to provide any level of support
173     //             for the language are not correctly installed
174     //         TTS_LANG_NOT_SUPPORTED if the language is not supported by the TTS engine.
175     android_tts_support_result_t (*isLanguageAvailable)
176             (void *engine,
177              const char *lang,
178              const char *country,
179              const char *variant);
180 
181     // Load the resources associated with the specified language. The loaded
182     // language will only be used once a call to setLanguage() with the same
183     // language value is issued. Language and country values are coded according to the ISO three
184     // letter codes for languages and countries, as can be retrieved from a java.util.Locale
185     // instance. The variant value is encoded as the variant string retrieved from a
186     // java.util.Locale instance built with that variant data.
187     // @param lang pointer to the ISO three letter code for the language
188     // @param country pointer to the ISO three letter code for the country
189     // @param variant pointer to the variant code
190     // @return TTS_SUCCESS, or TTS_FAILURE
191     android_tts_result_t (*loadLanguage)
192             (void *engine,
193              const char *lang,
194              const char *country,
195              const char *variant);
196 
197     // Load the resources associated with the specified language, country and Locale variant.
198     // The loaded language will only be used once a call to setLanguageFromLocale() with the same
199     // language value is issued. Language and country values are coded according to the ISO three
200     // letter codes for languages and countries, as can be retrieved from a java.util.Locale
201     // instance. The variant value is encoded as the variant string retrieved from a
202     // java.util.Locale instance built with that variant data.
203     // @param lang pointer to the ISO three letter code for the language
204     // @param country pointer to the ISO three letter code for the country
205     // @param variant pointer to the variant code
206     // @return TTS_SUCCESS, or TTS_FAILURE
207     android_tts_result_t (*setLanguage)
208             (void *engine,
209              const char *lang,
210              const char *country,
211              const char *variant);
212 
213     // Retrieve the currently set language, country and variant, or empty strings if none of
214     // parameters have been set. Language and country are represented by their 3-letter ISO code
215     // @param[out]   pointer to the retrieved 3-letter code language value
216     // @param[out]   pointer to the retrieved 3-letter code country value
217     // @param[out]   pointer to the retrieved variant value
218     // @return TTS_SUCCESS, or TTS_FAILURE
219     android_tts_result_t (*getLanguage)
220             (void *engine,
221              char *language,
222              char *country,
223              char *variant);
224 
225     // Notifies the engine what audio parameters should be used for the synthesis.
226     // This is meant to be used as a hint, the engine implementation will set the output values
227     // to those of the synthesis format, based on a given hint.
228     // @param[inout] encoding in: the desired audio sample format
229     //                         out: the format used by the TTS engine
230     // @param[inout] rate in: the desired audio sample rate
231     //                         out: the sample rate used by the TTS engine
232     // @param[inout] channels in: the desired number of audio channels
233     //                         out: the number of channels used by the TTS engine
234     // @return TTS_SUCCESS, or TTS_FAILURE
235     android_tts_result_t (*setAudioFormat)
236             (void *engine,
237              android_tts_audio_format_t* pEncoding,
238              uint32_t* pRate,
239              int* pChannels);
240 
241     // Set a property for the the TTS engine
242     // "size" is the maximum size of "value" for properties "property"
243     // @param property pointer to the property name
244     // @param value    pointer to the property value
245     // @param size     maximum size required to store this type of property
246     // @return         TTS_PROPERTY_UNSUPPORTED, or TTS_SUCCESS, or TTS_FAILURE,
247     //                  or TTS_VALUE_INVALID
248     android_tts_result_t (*setProperty)
249             (void *engine,
250              const char *property,
251              const char *value,
252              const size_t size);
253 
254     // Retrieve a property from the TTS engine
255     // @param        property pointer to the property name
256     // @param[out]   value    pointer to the retrieved language value
257     // @param[inout] iosize   in: stores the size available to store the
258     //                          property value.
259     //                        out: stores the size required to hold the language
260     //                          value if getLanguage() returned
261     //                          TTS_PROPERTY_SIZE_TOO_SMALL, unchanged otherwise
262     // @return TTS_PROPERTY_UNSUPPORTED, or TTS_SUCCESS,
263     //         or TTS_PROPERTY_SIZE_TOO_SMALL
264     android_tts_result_t (*getProperty)
265             (void *engine,
266              const char *property,
267              char *value,
268              size_t *iosize);
269 
270     // Synthesize the text.
271     // As the synthesis is performed, the engine invokes the callback to notify
272     // the TTS framework that it has filled the given buffer, and indicates how
273     // many bytes it wrote. The callback is called repeatedly until the engine
274     // has generated all the audio data corresponding to the text.
275     // Note about the format of the input: the text parameter may use the
276     // following elements
277     // and their respective attributes as defined in the SSML 1.0 specification:
278     //    * lang
279     //    * say-as:
280     //          o interpret-as
281     //    * phoneme
282     //    * voice:
283     //          o gender,
284     //          o age,
285     //          o variant,
286     //          o name
287     //    * emphasis
288     //    * break:
289     //          o strength,
290     //          o time
291     //    * prosody:
292     //          o pitch,
293     //          o contour,
294     //          o range,
295     //          o rate,
296     //          o duration,
297     //          o volume
298     //    * mark
299     // Differences between this text format and SSML are:
300     //    * full SSML documents are not supported
301     //    * namespaces are not supported
302     // Text is coded in UTF-8.
303     // @param text      the UTF-8 text to synthesize
304     // @param userdata  pointer to be returned when the call is invoked
305     // @param buffer    the location where the synthesized data must be written
306     // @param bufferSize the number of bytes that can be written in buffer
307     // @return          TTS_SUCCESS or TTS_FAILURE
308     android_tts_result_t (*synthesizeText)
309             (void *engine,
310              const char *text,
311              int8_t *buffer,
312              size_t bufferSize,
313              void *userdata);
314 };
315 
316 #ifdef __cplusplus
317 }
318 #endif
319 
320 #endif /* ANDROID_TTS_H */
321