Speech to text streaming support (#4140)

### 🛠 Summary

CVS-181778
CVS-185048

- Streaming support for speech2text endpoint
- Disconnection support for both speech2text and text2speech
- bugfixing

### 🧪 Checklist

- [x] Unit tests added.
- [ ] The documentation updated.
- [x] Change follows security best practices.
``

---------

Co-authored-by: Michal Kulakowski <michalkulakowski@intel.com>

Author: michalkulakowski

demos/common/export_models/export_model.py

@@ -134,8 +134,14 @@ def add_common_arguments(parser):
   name: "S2tExecutor"
   input_side_packet: "STT_NODE_RESOURCES:s2t_servable"
   calculator: "S2tCalculator"
+  input_stream: "LOOPBACK:loopback"
   input_stream: "HTTP_REQUEST_PAYLOAD:input"
+  output_stream: "LOOPBACK:loopback"
   output_stream: "HTTP_RESPONSE_PAYLOAD:output"
+  input_stream_info: {
+    tag_index: 'LOOPBACK:0',
+    back_edge: true
+  }
   node_options: {
     [type.googleapis.com / mediapipe.S2tCalculatorOptions]: {
       models_path: "{{model_path}}",
@@ -144,6 +150,16 @@ def add_common_arguments(parser):
       enable_word_timestamps: {% if not enable_word_timestamps %}false{% else %}true{% endif%},
     }
   }
+  input_stream_handler {
+    input_stream_handler: "SyncSetInputStreamHandler",
+    options {
+      [mediapipe.SyncSetInputStreamHandlerOptions.ext] {
+        sync_set {
+          tag_index: "LOOPBACK:0"
+        }
+      }
+    }
+  }
 }
 """
 

src/BUILD

@@ -52,6 +52,16 @@ cc_library(
     copts = COMMON_STATIC_LIBS_COPTS,
 )
 
+ovms_cc_library(
+    name = "executor_base",
+    hdrs = ["executor_base.hpp"],
+    deps = [
+        "//src:libovmslogging",
+    ],
+    visibility = ["//visibility:public"],
+    alwayslink = 1,
+)
+
 cc_shared_library(
     name = "ovms_shared",
     dynamic_deps = [],
@@ -1354,6 +1364,12 @@ ovms_cc_library(
 )
 
 
+ovms_cc_library(
+    name = "sse_utils",
+    hdrs = ["sse_utils.hpp"],
+    visibility = ["//visibility:public"],
+)
+
 ovms_cc_library(
     name = "libovmsstatus",
     hdrs = ["status.hpp",],
@@ -2367,6 +2383,7 @@ cc_test(
                 "test/llm/visual_language_model/initialization_test.cpp",
                 "test/audio/text2speech_test.cpp",
                 "test/audio/speech2text_test.cpp",
+                "test/audio/s2t_streaming_test.cpp",
             ],
             "//:disable_mediapipe" : [
                 "test/disabled_mediapipe_test.cpp",

src/audio/speech_to_text/BUILD

@@ -19,7 +19,50 @@ load("//:common_settings.bzl", "ovms_cc_library")
 
 ovms_cc_library(
     name = "s2t_servable",
-    hdrs = ["s2t_servable.hpp"],
+    srcs = ["s2t_servable.cpp"],
+    hdrs = [
+        "s2t_executor.hpp",
+        "s2t_servable.hpp",
+    ],
+    deps = [
+        "//src:executor_base",
+        "//src:httppayload",
+        "//src:libovmslogging",
+        "//src:libmodelconfigjsonparser",
+        "//src:libovmsstring_utils",
+        "s2t_calculator_cc_proto",
+        "@com_google_absl//absl/status",
+        "//third_party:genai",
+    ],
+    visibility = ["//visibility:public"],
+    alwayslink = 1,
+)
+
+ovms_cc_library(
+    name = "s2t_streaming_handler",
+    srcs = [
+        "s2t_streaming_handler.cpp",
+        "streaming_text_queue.cpp",
+    ],
+    hdrs = [
+        "s2t_streaming_handler.hpp",
+        "streaming_text_queue.hpp",
+    ],
+    deps = [
+        "@mediapipe//mediapipe/framework:calculator_framework",
+        "//src:httppayload",
+        "//src:libovmsclient_connection",
+        "//src:libovmslogging",
+        "//src:libovmsstring_utils",
+        "//src:libovmsstatus",
+        "//src:libmodelconfigjsonparser",
+        "//src:sse_utils",
+        "//src/port:rapidjson_stringbuffer",
+        "//src/port:rapidjson_writer",
+        ":s2t_servable",
+        "s2t_calculator_cc_proto",
+        "//third_party:genai",
+    ],
     visibility = ["//visibility:public"],
     alwayslink = 1,
 )
@@ -37,11 +80,11 @@ ovms_cc_library(
         "//src/port:rapidjson_stringbuffer",
         "//src/port:rapidjson_writer",
         ":s2t_servable",
+        ":s2t_streaming_handler",
         "//third_party:genai",
         "//src/audio:audio_utils",
         "//src:libmodelconfigjsonparser",
         "//src/mediapipe_internal:node_initializer",
-        "//src:libovmsstring_utils",
     ],
     visibility = ["//visibility:public"],
     alwayslink = 1,