res_speech: allow speech to translate input channel

* Allow res_speech to translate the input channel if the
  format is translatable to a format suppored by the
  speech provider.

Resolves: #129

UserNote: res_speech now supports translation of an input channel
to a format supported by the speech provider, provided a translation
path is available between the source format and provider capabilites.

diff --git a/res/res_speech.c b/res/res_speech.c
index 2438e7953cf44f4c75b01b2b1dea924c425a2176..c173bd00ddcc31098f244770959ba0204030e42f 100644 (file)
--- a/res/res_speech.c
+++ b/res/res_speech.c
@@ -37,6 +37,7 @@
 #include "asterisk/term.h"
 #include "asterisk/speech.h"
 #include "asterisk/format_cache.h"
+#include "asterisk/translate.h"
 
 static AST_RWLIST_HEAD_STATIC(engines, ast_speech_engine);
 static struct ast_speech_engine *default_engine = NULL;
@@ -183,6 +184,7 @@ struct ast_speech *ast_speech_new(const char *engine_name, const struct ast_form
        struct ast_speech *new_speech = NULL;
        struct ast_format_cap *joint;
        RAII_VAR(struct ast_format *, best, NULL, ao2_cleanup);
+       RAII_VAR(struct ast_format *, best_translated, NULL, ao2_cleanup);
 
        /* Try to find the speech recognition engine that was requested */
        if (!(engine = ast_speech_find_engine(engine_name)))
@@ -201,7 +203,16 @@ struct ast_speech *ast_speech_new(const char *engine_name, const struct ast_form
                if (ast_format_cap_iscompatible_format(engine->formats, ast_format_slin) != AST_FORMAT_CMP_NOT_EQUAL) {
                        best = ao2_bump(ast_format_slin);
                } else {
-                       return NULL;
+                       /*
+                        * If there is no overlap and the engine does not support slin, find the best
+                        * format to translate to and set that as the 'best' input format for the engine.
+                        * API consumer is responsible for translating to this format.
+                        * Safe to cast cap as ast_translator_best_choice does not modify the caps
+                        */
+                       if (ast_translator_best_choice(engine->formats, (struct ast_format_cap *)cap, &best, &best_translated)) {
+                               /* No overlapping formats and no translatable formats */
+                               return NULL;
+                       }
                }
        }