Create streamer.py

streamer.py

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+from queue import Queue
+from transformers.generation.streamers import BaseStreamer
+from typing import Optional
+from parler_tts import ParlerTTSForConditionalGeneration
+import numpy as np
+import math
+import torch
+
+
+class ParlerTTSStreamer(BaseStreamer):
+    def __init__(
+        self,
+        model: ParlerTTSForConditionalGeneration,
+        device: Optional[str] = None,
+        play_steps: Optional[int] = 10,
+        stride: Optional[int] = None,
+        timeout: Optional[float] = None,
+    ):
+        """
+        Streamer that stores playback-ready audio in a queue, to be used by a downstream application as an iterator. This is
+        useful for applications that benefit from accessing the generated audio in a non-blocking way (e.g. in an interactive
+        Gradio demo).
+        Parameters:
+            model (`ParlerTTSForConditionalGeneration`):
+                The Parler-TTS model used to generate the audio waveform.
+            device (`str`, *optional*):
+                The torch device on which to run the computation. If `None`, will default to the device of the model.
+            play_steps (`int`, *optional*, defaults to 10):
+                The number of generation steps with which to return the generated audio array. Using fewer steps will
+                mean the first chunk is ready faster, but will require more codec decoding steps overall. This value
+                should be tuned to your device and latency requirements.
+            stride (`int`, *optional*):
+                The window (stride) between adjacent audio samples. Using a stride between adjacent audio samples reduces
+                the hard boundary between them, giving smoother playback. If `None`, will default to a value equivalent to
+                play_steps // 6 in the audio space.
+            timeout (`int`, *optional*):
+                The timeout for the audio queue. If `None`, the queue will block indefinitely. Useful to handle exceptions
+                in `.generate()`, when it is called in a separate thread.
+        """
+        self.decoder = model.decoder
+        self.audio_encoder = model.audio_encoder
+        self.generation_config = model.generation_config
+        self.device = device if device is not None else model.device
+
+        # variables used in the streaming process
+        self.play_steps = play_steps
+        if stride is not None:
+            self.stride = stride
+        else:
+            hop_length = math.floor(self.audio_encoder.config.sampling_rate / self.audio_encoder.config.frame_rate)
+            self.stride = hop_length * (play_steps - self.decoder.num_codebooks) // 6
+        self.token_cache = None
+        self.to_yield = 0
+
+        # varibles used in the thread process
+        self.audio_queue = Queue()
+        self.stop_signal = None
+        self.timeout = timeout
+
+    def apply_delay_pattern_mask(self, input_ids):
+        # build the delay pattern mask for offsetting each codebook prediction by 1 (this behaviour is specific to Parler)
+        _, delay_pattern_mask = self.decoder.build_delay_pattern_mask(
+            input_ids[:, :1],
+            bos_token_id=self.generation_config.bos_token_id,
+            pad_token_id=self.generation_config.decoder_start_token_id,
+            max_length=input_ids.shape[-1],
+        )
+        # apply the pattern mask to the input ids
+        input_ids = self.decoder.apply_delay_pattern_mask(input_ids, delay_pattern_mask)
+
+        # revert the pattern delay mask by filtering the pad token id
+        mask = (delay_pattern_mask != self.generation_config.bos_token_id) & (delay_pattern_mask != self.generation_config.pad_token_id)
+        input_ids = input_ids[mask].reshape(1, self.decoder.num_codebooks, -1)
+        # append the frame dimension back to the audio codes
+        input_ids = input_ids[None, ...]
+
+        # send the input_ids to the correct device
+        input_ids = input_ids.to(self.audio_encoder.device)
+
+        decode_sequentially = (
+            self.generation_config.bos_token_id in input_ids
+            or self.generation_config.pad_token_id in input_ids
+            or self.generation_config.eos_token_id in input_ids
+        )
+        if not decode_sequentially:
+            output_values = self.audio_encoder.decode(
+                input_ids,
+                audio_scales=[None],
+            )
+        else:
+            sample = input_ids[:, 0]
+            sample_mask = (sample >= self.audio_encoder.config.codebook_size).sum(dim=(0, 1)) == 0
+            sample = sample[:, :, sample_mask]
+            output_values = self.audio_encoder.decode(sample[None, ...], [None])
+
+        audio_values = output_values.audio_values[0, 0]
+        return audio_values.cpu().float().numpy()
+
+    def put(self, value):
+        batch_size = value.shape[0] // self.decoder.num_codebooks
+        if batch_size > 1:
+            raise ValueError("ParlerTTSStreamer only supports batch size 1")
+
+        if self.token_cache is None:
+            self.token_cache = value
+        else:
+            self.token_cache = torch.concatenate([self.token_cache, value[:, None]], dim=-1)
+
+        if self.token_cache.shape[-1] % self.play_steps == 0:
+            audio_values = self.apply_delay_pattern_mask(self.token_cache)
+            self.on_finalized_audio(audio_values[self.to_yield : -self.stride])
+            self.to_yield += len(audio_values) - self.to_yield - self.stride
+
+    def end(self):
+        """Flushes any remaining cache and appends the stop symbol."""
+        if self.token_cache is not None:
+            audio_values = self.apply_delay_pattern_mask(self.token_cache)
+        else:
+            audio_values = np.zeros(self.to_yield)
+
+        self.on_finalized_audio(audio_values[self.to_yield :], stream_end=True)
+
+    def on_finalized_audio(self, audio: np.ndarray, stream_end: bool = False):
+        """Put the new audio in the queue. If the stream is ending, also put a stop signal in the queue."""
+        self.audio_queue.put(audio, timeout=self.timeout)
+        if stream_end:
+            self.audio_queue.put(self.stop_signal, timeout=self.timeout)
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        value = self.audio_queue.get(timeout=self.timeout)
+        if not isinstance(value, np.ndarray) and value == self.stop_signal:
+            raise StopIteration()
+        else:
+            return value