feat: add Gemini text-to-speech service

feat: add Gemini text-to-speech service

Author: osolmaz

docs/source/api.rst

@@ -46,6 +46,10 @@ Speech services
    :members:
    :show-inheritance:
 
+.. automodule:: manim_voiceover.services.gemini
+   :members:
+   :show-inheritance:
+
 
 Defaults
 ~~~~~~~~

docs/source/services.rst

@@ -42,6 +42,11 @@ Manim Voiceover defines the :py:class:`~~base.SpeechService` class for adding ne
      - No
      - No
      - It's a free API subsidized by Google, so there is a likelihood it may stop working in the future.
+   * - :py:class:`~gemini.GeminiService`
+     - Very good, human-like
+     - No
+     - Yes
+     - Requires a Gemini API key or Google Cloud ADC, and Python 3.10 or newer.
    * - :py:class:`~openai.OpenAIService`
      - Very good, human-like
      - No
@@ -118,6 +123,39 @@ Install Manim Voiceover with the ``gtts`` extra in order to use :py:class:`~gtts
 
 Refer to the `example usage <https://github.com/ManimCommunity/manim-voiceover/blob/main/examples/gtts-example.py>`__ to get started.
 
+:py:class:`~gemini.GeminiService`
+*********************************
+
+`Gemini text-to-speech <https://ai.google.dev/gemini-api/docs/speech-generation>`__ provides controllable text-to-speech through the Google Gen AI SDK. It requires an internet connection and Python 3.10 or newer.
+
+Install Manim Voiceover with the ``gemini`` extra in order to use :py:class:`~gemini.GeminiService`:
+
+.. code:: sh
+
+   pip install "manim-voiceover[gemini]"
+
+For Gemini Developer API authentication, create a file called ``.env``
+that contains your API key in the same directory where you call Manim.
+
+.. code:: sh
+
+   GEMINI_API_KEY="..." # insert the API key here
+
+Gemini uses API-key authentication by default:
+
+.. code:: python
+
+   self.set_speech_service(GeminiService(voice="Kore"))
+
+For Google Cloud Vertex AI authentication, use Application Default
+Credentials and set ``auth_mode="adc"``:
+
+.. code:: python
+
+   self.set_speech_service(
+       GeminiService(voice="Kore", auth_mode="adc", project="my-project-id")
+   )
+
 :py:class:`~openai.OpenAIService`
 *************************************
 `OpenAI <https://platform.openai.com/docs/api-reference/audio/createSpeech/>`__ provides a text-to-speech service. It is through an API, so it requires an internet connection to work. It also requires an API key to use. Register for one `here <https://platform.openai.com/>`__.

examples/voiceover-demo.py

@@ -1,21 +1,48 @@
 from manim import *
-import pygments.styles as code_styles
 from manim_voiceover import VoiceoverScene
 
-from manim_voiceover.services.azure import AzureService
+from manim_voiceover.services.gemini import GeminiService
 
-code_style = code_styles.get_style_by_name("one-dark")
+code_style = "one-dark"
+
+SCENE_HEADER_LINES = (1, 2)
+SET_SERVICE_LINE = 3
+GEMINI_SERVICE_LINE = 4
+GEMINI_VOICE_LINE = 5
+GEMINI_AUTH_LINE = 6
+SERVICE_CLOSE_LINES = (7, 8)
+CIRCLE_SETUP_LINES = (9, 10)
+VOICEOVER_CONTEXT_LINE = 11
+VOICEOVER_PLAY_LINE = 12
+SHIFT_CONTEXT_LINE = 14
+SHIFT_DURATION_LINE = 15
+
+
+def demo_code_block(code_string):
+    return Code(
+        code_string=code_string,
+        add_line_numbers=False,
+        formatter_style=code_style,
+        background="window",
+        language="python",
+        paragraph_config={"font": "Menlo"},
+    )
+
+
+def code_lines(code_block, start, end=None):
+    if end is None:
+        return code_block.code_lines[start - 1]
+    return code_block.code_lines[start - 1 : end]
+
+
+def code_line_range(code_block, line_range):
+    return code_lines(code_block, line_range[0], line_range[1])
 
 
 class VoiceoverDemo(VoiceoverScene):
     def construct(self):
-        # Initialize speech synthesis using Azure's TTS API
-        self.set_speech_service(
-            AzureService(
-                voice="en-US-AriaNeural",
-                style="newscast-casual",  # global_speed=1.15
-            )
-        )
+        # Initialize speech synthesis using Gemini's TTS API
+        self.set_speech_service(GeminiService(voice="Kore", auth_mode="adc"))
         banner = ManimBanner().scale(0.5)
 
         with self.voiceover(text="Hey Manim Community!"):
@@ -31,20 +58,15 @@ def construct(self):
         self.wait(tracker.get_remaining_duration(buff=-1))
         self.play(FadeOut(banner))
 
-        demo_code = Code(
-            code='''tracker = self.add_voiceover_text(
+        demo_code = demo_code_block(
+            '''tracker = self.add_voiceover_text(
     """AI generated voices have become realistic
         enough for use in most content. Using neural
         text-to-speech frees you from the painstaking
         process of recording and manually syncing
         audio to your video."""
 )
-self.play(Write(demo_code), run_time=tracker.duration)''',
-            insert_line_no=False,
-            style=code_style,
-            background="window",
-            font="Consolas",
-            language="python",
+self.play(Write(demo_code), run_time=tracker.duration)'''
         ).rescale_to_fit(12, 0)
 
         tracker = self.add_voiceover_text(
@@ -80,14 +102,13 @@ def construct(self):
         with self.voiceover(text="I would go on, but you get the idea."):
             self.play(FadeOut(circle))
 
-        demo_code2 = Code(
-            code="""class VoiceoverDemo(VoiceoverScene):
+        demo_code2 = demo_code_block(
+            """class VoiceoverDemo(VoiceoverScene):
     def construct(self):
         self.set_speech_service(
-            AzureService(
-                voice="en-US-AriaNeural",
-                style="newscast-casual",
-                global_speed=1.15
+            GeminiService(
+                voice="Kore",
+                auth_mode="adc",
             )
         )
         circle = Circle()
@@ -96,64 +117,51 @@ def construct(self):
             self.play(Create(circle))
 
         with self.voiceover(text="Let's shift it to the left 2 units.") as tracker:
-            self.play(circle.animate.shift(2 * LEFT), run_time=tracker.duration)""",
-            insert_line_no=False,
-            style=code_style,
-            background="window",
-            font="Consolas",
-            language="python",
+            self.play(circle.animate.shift(2 * LEFT), run_time=tracker.duration)"""
         ).rescale_to_fit(12, 0)
 
         with self.voiceover(text="Let's see how the API works!"):
-            self.play(FadeIn(demo_code2.background_mobject))
+            self.play(FadeIn(demo_code2.background))
 
-        with self.voiceover(
-            text="First, we create a scene using the Voiceover Scene class from the plugin."
-        ):
-            self.play(FadeIn(demo_code2.code[:2]))
+        with self.voiceover(text="First, we create a scene using the Voiceover Scene class from the plugin."):
+            self.play(FadeIn(code_line_range(demo_code2, SCENE_HEADER_LINES)))
 
-        with self.voiceover(
-            text="Then, we initialize the voiceover by setting the appropriate speech synthesizer."
-        ):
-            self.play(FadeIn(demo_code2.code[2]))
+        with self.voiceover(text="Then, we initialize the voiceover by setting the appropriate speech synthesizer."):
+            self.play(FadeIn(code_lines(demo_code2, SET_SERVICE_LINE)))
 
-        with self.voiceover(text="In this example, we use Azure Text-to-speech."):
-            self.play(FadeIn(demo_code2.code[3]))
+        with self.voiceover(text="In this example, we use Gemini text-to-speech."):
+            self.play(FadeIn(code_lines(demo_code2, GEMINI_SERVICE_LINE)))
 
-        with self.voiceover(
-            text="We use the English speaking neural voice called Aria."
-        ):
-            self.play(FadeIn(demo_code2.code[4]))
+        with self.voiceover(text="We use the prebuilt Gemini voice called Kore."):
+            self.play(FadeIn(code_lines(demo_code2, GEMINI_VOICE_LINE)))
 
-        with self.voiceover(text='We use the style called "newscast casual".'):
-            self.play(FadeIn(demo_code2.code[5]))
+        with self.voiceover(text="We authenticate with Application Default Credentials."):
+            self.play(FadeIn(code_lines(demo_code2, GEMINI_AUTH_LINE)))
 
         with self.voiceover(
-            text="""Finally, we give an option to speed up the voiceover
-            playback fifteen percent, because the default is a bit too slow."""
+            text="""Finally, Gemini returns audio that Manim Voiceover stores
+            in the local voiceover cache for reuse."""
         ):
-            self.play(FadeIn(demo_code2.code[6:9]))
+            self.play(FadeIn(code_line_range(demo_code2, SERVICE_CLOSE_LINES)))
 
-        with self.voiceover(
-            text="""With the configuration out of the way, it is time to animate."""
-        ):
+        with self.voiceover(text="""With the configuration out of the way, it is time to animate."""):
             pass
 
         with self.voiceover(text="""Let's initialize the circle object."""):
-            self.play(FadeIn(demo_code2.code[9:11]))
+            self.play(FadeIn(code_line_range(demo_code2, CIRCLE_SETUP_LINES)))
 
         with self.voiceover(
             text="""Then, we need to tell the scene to start narrating,
             by calling the function "self-dot-voiceover"."""
         ):
-            self.play(FadeIn(demo_code2.code[11]))
+            self.play(FadeIn(code_lines(demo_code2, VOICEOVER_CONTEXT_LINE)))
 
         with self.voiceover(
             text="""By wrapping our animation inside a "with-statement",
             we ensure that once it finishes playing, it will also wait for
             the voiceover playback to finish."""
         ):
-            self.play(FadeIn(demo_code2.code[12]))
+            self.play(FadeIn(code_lines(demo_code2, VOICEOVER_PLAY_LINE)))
 
         with self.voiceover(
             text="""This is extremely convenient, and let's you chain
@@ -164,79 +172,61 @@ def construct(self):
         with self.voiceover(
             text="""We just need to repeat the same pattern with self-dot-voiceover and with-statements. Here is something cool."""
         ):
-            self.play(FadeIn(demo_code2.code[14]))
+            self.play(FadeIn(code_lines(demo_code2, SHIFT_CONTEXT_LINE)))
 
         with self.voiceover(
             text="""We can retrieve the duration of the generated voiceover programmatically, and then use it to define for how long an animation should play."""
         ):
-            self.play(FadeIn(demo_code2.code[15]))
+            self.play(FadeIn(code_lines(demo_code2, SHIFT_DURATION_LINE)))
 
-        demo_code3 = Code(
-            code="""class VoiceoverDemo(VoiceoverScene):
+        demo_code3 = demo_code_block(
+            """class VoiceoverDemo(VoiceoverScene):
     def construct(self):
         self.set_speech_service(
-            AzureService(
-                voice="en-US-AriaNeural",
-                style="newscast-casual",
-                global_speed=1.15
+            GeminiService(
+                voice="Kore",
+                auth_mode="adc",
             )
         )
         # self.set_speech_service(
         #     StitcherService("my_voice_recording.mp3")
         # )
-        """,
-            insert_line_no=False,
-            style=code_style,
-            background="window",
-            font="Consolas",
-            language="python",
+        """
         ).scale(0.85)
 
         demo_code4 = (
-            Code(
-                code="""class VoiceoverDemo(VoiceoverScene):
+            demo_code_block(
+                """class VoiceoverDemo(VoiceoverScene):
     def construct(self):
         # self.set_speech_service(
-        #     AzureService(
-        #         voice="en-US-AriaNeural",
-        #         style="newscast-casual",
-        #         global_speed=1.15
+        #     GeminiService(
+        #         voice="Kore",
+        #         auth_mode="adc",
         #     )
         # )
         # self.set_speech_service(
         #     StitcherService("my_voice_recording.mp3")
         # )
-        """,
-                insert_line_no=False,
-                style=code_style,
-                background="window",
-                font="Consolas",
-                language="python",
+        """
             )
             .scale(0.85)
             .align_to(demo_code3, LEFT)
         )
 
         demo_code5 = (
-            Code(
-                code="""class VoiceoverDemo(VoiceoverScene):
+            demo_code_block(
+                """class VoiceoverDemo(VoiceoverScene):
     def construct(self):
         # self.set_speech_service(
-        #     AzureService(
-        #         voice="en-US-AriaNeural",
-        #         style="newscast-casual",
-        #         global_speed=1.15
+        #     GeminiService(
+        #         voice="Kore",
+        #         auth_mode="adc",
         #     )
         # )
         self.set_speech_service(
             StitcherService("my_voice_recording.mp3")
         )
-        """,
-                insert_line_no=False,
-                style=code_style,
-                background="window",
-                font="Consolas",
-                language="python",
+        """
             )
             .scale(0.85)
             .align_to(demo_code3, LEFT)
@@ -258,31 +248,21 @@ def construct(self):
             self.wait()
             self.play(FadeOut(text1, text2, arrow))
 
-        with self.voiceover(
-            text="To do that, you record an MP3 of the final text of your video."
-        ):
+        with self.voiceover(text="To do that, you record an MP3 of the final text of your video."):
             self.play(FadeIn(demo_code3))
 
         with self.voiceover(
             text="""Manim-voiceover then splits your audio automatically and replaces the AI generated voice with your real recording."""
         ):
-            self.play(FadeOut(demo_code3.code), FadeIn(demo_code4.code))
-            self.play(FadeOut(demo_code4.code), FadeIn(demo_code5.code))
+            self.play(FadeOut(demo_code3.code_lines), FadeIn(demo_code4.code_lines))
+            self.play(FadeOut(demo_code4.code_lines), FadeIn(demo_code5.code_lines))
 
         self.wait(2)
 
-        with self.voiceover(
-            text="""Manim-voiceover makes it much easier to do voiceovers for Manim projects."""
-        ):
-            self.play(FadeOut(demo_code5.code, demo_code3.background_mobject))
+        with self.voiceover(text="""Manim-voiceover makes it much easier to do voiceovers for Manim projects."""):
+            self.play(FadeOut(demo_code5.code_lines, demo_code3.background))
 
-        with self.voiceover(
-            text="Visit the GitHub repo to start using it in your project."
-        ):
-            self.play(
-                FadeIn(
-                    Tex(r"\texttt{https://github.com/ManimCommunity/manim-voiceover}")
-                )
-            )
+        with self.voiceover(text="Visit the GitHub repo to start using it in your project."):
+            self.play(FadeIn(Tex(r"\texttt{https://github.com/ManimCommunity/manim-voiceover}")))
 
         self.wait(5)