app.py

import gradio as gr
import librosa
import soundfile
import tempfile
import os
import uuid
import json

from nemo.collections.asr.models import ASRModel
from nemo.utils import logging

from align import main, AlignmentConfig, ASSFileConfig


SAMPLE_RATE = 16000

logging.setLevel(logging.INFO)


def get_audio_data_and_duration(file):
	data, sr = librosa.load(file)

	if sr != SAMPLE_RATE:
		data = librosa.resample(data, orig_sr=sr, target_sr=SAMPLE_RATE)

	# monochannel
	data = librosa.to_mono(data)

	duration = librosa.get_duration(y=data, sr=SAMPLE_RATE)
	return data, duration


def get_char_tokens(text, model):
	tokens = []
	for character in text:
		if character in model.decoder.vocabulary:
			tokens.append(model.decoder.vocabulary.index(character))
	else:
		tokens.append(len(model.decoder.vocabulary))  # return unk token (same as blank token)

	return tokens


def get_S_prime_and_T(text, model_name, model, audio_duration):

	# estimate T
	if "citrinet" in model_name or "_fastconformer_" in model_name:
		output_timestep_duration = 0.08
	elif "_conformer_" in model_name:
		output_timestep_duration = 0.04
	elif "quartznet" in model_name:
		output_timestep_duration = 0.02
	else:
		raise RuntimeError("unexpected model name")

	T = int(audio_duration / output_timestep_duration) + 1

	# calculate S_prime =  num tokens + num repetitions
	if hasattr(model, 'tokenizer'):
		all_tokens = model.tokenizer.text_to_ids(text)
	elif hasattr(model.decoder, "vocabulary"):  # i.e. tokenization is simply character-based
		all_tokens = get_char_tokens(text, model)
	else:
		raise RuntimeError("cannot obtain tokens from this model")

	n_token_repetitions = 0
	for i_tok in range(1, len(all_tokens)):
		if all_tokens[i_tok] == all_tokens[i_tok - 1]:
			n_token_repetitions += 1

	S_prime = len(all_tokens) + n_token_repetitions

	return S_prime, T


def delete_mp4s_except_given_filepath(filepath):
	files_in_dir = os.listdir()
	mp4_files_in_dir = [x for x in files_in_dir if x.endswith(".mp4")]
	for mp4_file in mp4_files_in_dir:
		if mp4_file != filepath:
			os.remove(mp4_file)


def align(Microphone, File_Upload, text, split_on_newline, progress=gr.Progress()):
	# Create utt_id,  specify output_video_filepath and delete any MP4s
	# that are not that filepath. These stray MP4s can be created
	# if a user refreshes or exits the page while this 'align' function is executing.
	# This deletion will not delete any other users' video as long as this 'align' function
	# is run one at a time.
	utt_id = uuid.uuid4()
	output_video_filepath = f"{utt_id}.mp4"
	delete_mp4s_except_given_filepath(output_video_filepath)

	output_info = ""
	ass_text=""

	progress(0, desc="Validating input")

	# decide which of Mic / File_Upload is used as input & do error handling
	if (Microphone is not None) and (File_Upload is not None):
		raise gr.Error("Please use either the microphone or file upload input - not both")
	elif (Microphone is None) and (File_Upload is None):
		raise gr.Error("You have to either use the microphone or upload an audio file")
	elif Microphone is not None:
		file = Microphone
	else:
		file = File_Upload

	# check audio is not too long
	audio_data, duration = get_audio_data_and_duration(file)

	# loading model
	progress(0.1, desc="Loading speech recognition model")
	model_name = "ayymen/stt_zgh_fastconformer_ctc_small"
	model = ASRModel.from_pretrained(model_name)

	if text:  # check input text is not too long compared to audio
		S_prime, T = get_S_prime_and_T(text, model_name, model, duration)

		if S_prime > T:
			raise gr.Error(
				f"The number of tokens in the input text is too long compared to the duration of the audio."
				f" This model can handle {T} tokens + token repetitions at most. You have provided {S_prime} tokens + token repetitions. "
				f" (Adjacent tokens that are not in the model's vocabulary are also counted as a token repetition.)"
			)

	with tempfile.TemporaryDirectory() as tmpdir:
		audio_path = os.path.join(tmpdir, f'{utt_id}.wav')
		soundfile.write(audio_path, audio_data, SAMPLE_RATE)

		# getting the text if it hasn't been provided
		if not text:
			progress(0.2, desc="Transcribing audio")
			text = model.transcribe([audio_path])[0]
			if 'hybrid' in model_name:
				text = text[0]

			if text == "":
				raise gr.Error(
					"ERROR: the ASR model did not detect any speech in the input audio. Please upload audio with speech."
				)

			output_info += (
				"You did not enter any input text, so the ASR model's transcription will be used:\n"
				"--------------------------\n"
				f"{text}\n"
				"--------------------------\n"
				f"You could try pasting the transcription into the text input box, correcting any"
				" transcription errors, and clicking 'Submit' again."
			)

        # split text on new lines if requested
		if split_on_newline:
			text = "|".join(list(filter(None, text.split("\n"))))

		data = {
			"audio_filepath": audio_path,
			"text": text,
		}
		manifest_path = os.path.join(tmpdir, f"{utt_id}_manifest.json")
		with open(manifest_path, 'w') as fout:
			fout.write(f"{json.dumps(data)}\n")

		# run alignment
		if "|" in text:
			resegment_text_to_fill_space = False
		else:
			resegment_text_to_fill_space = True

		alignment_config = AlignmentConfig(
			pretrained_name=model_name,
			manifest_filepath=manifest_path,
			output_dir=f"{tmpdir}/nfa_output/",
			audio_filepath_parts_in_utt_id=1,
			batch_size=1,
			use_local_attention=True,
			additional_segment_grouping_separator="|",
			# transcribe_device='cpu',
			# viterbi_device='cpu',
			save_output_file_formats=["ass", "ctm"],
			ass_file_config=ASSFileConfig(
				fontsize=45,
				resegment_text_to_fill_space=resegment_text_to_fill_space,
				max_lines_per_segment=4,
			),
		)

		progress(0.5, desc="Aligning audio")

		main(alignment_config)

		progress(0.95, desc="Saving generated alignments")


		# make video file from the word-level ASS file
		ass_file_for_video = f"{tmpdir}/nfa_output/ass/words/{utt_id}.ass"

		with open(ass_file_for_video, "r") as ass_file:
			ass_text = ass_file.read()

		ffmpeg_command = (
			f"ffmpeg -y -i {audio_path} "
			"-f lavfi -i color=c=white:s=1280x720:r=50 "
			"-crf 1 -shortest -vcodec libx264 -pix_fmt yuv420p "
			f"-vf 'ass={ass_file_for_video}' "
			f"{output_video_filepath}"
		)

		os.system(ffmpeg_command)

		# save ASS file
		ass_path = "word_level.ass"
		with open(ass_path, "w", encoding="utf-8") as f:
			f.write(ass_text)

		# save word-level CTM file
		with open(f"{tmpdir}/nfa_output/ctm/words/{utt_id}.ctm", "r") as word_ctm_file:
			word_ctm_text = word_ctm_file.read()

		word_ctm_path = "word_level.ctm"
		with open(word_ctm_path, "w", encoding="utf-8") as f:
			f.write(word_ctm_text)

		# save segment-level CTM file
		with open(f"{tmpdir}/nfa_output/ctm/segments/{utt_id}.ctm", "r") as segment_ctm_file:
			segment_ctm_text = segment_ctm_file.read()

		segment_ctm_path = "segment_level.ctm"
		with open(segment_ctm_path, "w", encoding="utf-8") as f:
			f.write(segment_ctm_text)

	return output_video_filepath, gr.update(value=output_info, visible=True if output_info else False), output_video_filepath, gr.update(value=ass_path, visible=True), gr.update(value=word_ctm_path, visible=True), gr.update(value=segment_ctm_path, visible=True)


def delete_non_tmp_video(video_path):
	if video_path:
		if os.path.exists(video_path):
			os.remove(video_path)
	return None


with gr.Blocks(title="NeMo Forced Aligner", theme="huggingface") as demo:
	non_tmp_output_video_filepath = gr.State([])

	with gr.Row():
		with gr.Column():
			gr.Markdown("# NeMo Forced Aligner")
			gr.Markdown(
				"Demo for [NeMo Forced Aligner](https://github.com/NVIDIA/NeMo/tree/main/tools/nemo_forced_aligner) (NFA). "
				"Upload audio in Tamazight and (optionally) the text spoken in the audio to generate a video where each part of the text will be highlighted as it is spoken. ",
			)
			gr.Markdown("You can also download CTM and ASS files to add subtitles to your videos. ")

	with gr.Row():

		with gr.Column(scale=1):
			gr.Markdown("## Input")
			mic_in = gr.Audio(sources=["microphone"], type='filepath', label="Microphone input")
			audio_file_in = gr.Audio(sources=["upload"], type='filepath', label="File upload")
			ref_text = gr.Textbox(
				label="[Optional] The reference text. Use '|' separators to specify which text will appear together. "
				"Leave this field blank to use an ASR model's transcription as the reference text instead."
			)
			split_on_newline = gr.Checkbox(
				True,
                label="Separate text on new lines",
            )

			submit_button = gr.Button("Submit")

		with gr.Column(scale=1):
			gr.Markdown("## Output")
			video_out = gr.Video(label="Output Video")
			text_out = gr.Textbox(label="Output Info", visible=False)
			ass_file = gr.File(label="ASS File", visible=False)
			word_ctm_file = gr.File(label="Word-level CTM File", visible=False)
			segment_ctm_file = gr.File(label="Segment-level CTM File", visible=False)
			gr.Markdown("You can use this [space](https://huggingface.co/spaces/Tamazight-NLP/CTM-to-SRT) to convert CTM files to SRT format.")

	with gr.Row():
		gr.HTML(
			"<p style='text-align: center'>"
				"Tutorial: <a href='https://colab.research.google.com/github/NVIDIA/NeMo/blob/main/tutorials/tools/NeMo_Forced_Aligner_Tutorial.ipynb' target='_blank'>\"How to use NFA?\"</a> 🚀 | "
				"Blog post: <a href='https://nvidia.github.io/NeMo/blogs/2023/2023-08-forced-alignment/' target='_blank'>\"How does forced alignment work?\"</a> 📚 | "
				"NFA <a href='https://github.com/NVIDIA/NeMo/tree/main/tools/nemo_forced_aligner/' target='_blank'>Github page</a> 👩‍💻"
			"</p>"
		)

	submit_button.click(
		fn=align,
		inputs=[mic_in, audio_file_in, ref_text, split_on_newline],
		outputs=[video_out, text_out, non_tmp_output_video_filepath, ass_file, word_ctm_file, segment_ctm_file],
	).then(
		fn=delete_non_tmp_video, inputs=[non_tmp_output_video_filepath], outputs=None,
	)
	example_2 = """ⵜⴰⴽⵟⵟⵓⵎⵜ ⵏ ⵜⵙⴰⴷⵓⴼⵜ.
ⵙ ⵉⵙⵎ ⵏ ⵕⴱⴱⵉ ⴰⵎⴰⵍⵍⴰⵢ ⴰⵎⵙⵎⵓⵍⵍⵓ.
ⴰⵎⵓⵢ ⵉ ⵕⴱⴱⵉ ⵍⵍⵉ ⵎⵓ ⵜⴳⴰ ⵜⵓⵍⵖⵉⵜ ⵜⵉⵏⵏⵙ, ⵕⴱⴱⵉ ⵏ ⵉⵖⵥⵡⴰⵕⵏ, ⴽⵔⴰ ⴳⴰⵏ.
ⴰⵎⴰⵍⵍⴰⵢ ⴰⵎⵙⵎⵓⵍⵍⵓ, ⵖ ⵜⵎⵣⵡⴰⵔⵓⵜ ⵓⵍⴰ ⵖ ⵜⵎⴳⴳⴰⵔⵓⵜ.
ⴰⴳⵍⵍⵉⴷ ⵏ ⵡⴰⵙⵙ ⵏ ⵓⴼⵔⴰ, ⴰⵙⵙ ⵏ ⵓⵙⵙⵃⵙⵓ, ⴽⵔⴰⵉⴳⴰⵜ ⵢⴰⵏ ⴷ ⵎⴰⴷ ⵉⵙⴽⵔ.
ⵀⴰ ⵏⵏ ⴽⵢⵢⵉ ⴽⴰ ⵙ ⵏⵙⵙⵓⵎⴷ, ⴷ ⴽⵢⵢⵉ ⴽⴰ ⴰⴷ ⵏⵎⵎⵜⵔ.
ⵙⵎⵓⵏ ⴰⵖ, ⵜⵎⵍⵜ ⴰⵖ, ⴰⵖⴰⵔⴰⵙ ⵢⵓⵖⴷⵏ.
ⴰⵖⴰⵔⴰⵙ ⵏ ⵖⵡⵉⵍⵍⵉ ⵜⵙⵏⵏⵓⴼⴰⵜ, ⵓⵔ ⴷ ⴰⵢⵜ ⵜⵉⵢⵓⵔⵉ, ⵓⵍⴰ ⵉⵎⵓⴹⴹⴰⵕ."""
	example_3 = "ⴷⴰⴳ ⵓⵢⵍⵅ ⵙ ⵉⴳⵏⵏⴰ|ⵏⵏⴰⵏ ⵉⵢⵉ|ⴳⴳⵯⵣ ⴷ!|ⵏⵏⵉⵅ ⴰⵙⵏ|ⵜⵎⵢⴰⵔⵎ ⴰⵣⴷⴷⵉⵔ|ⵜⵎⵢⴰⵔⵎ ⵜⴰⵍⵍⴰ ⴷ ⵉⵎⵟⵟⴰⵡⵏ"
	examples = gr.Examples(
		examples=[
			["common_voice_zgh_37837257.mp3", "ⵎⵍ ⵉⵢⵉ ⵎⴰⴷ ⴷ ⵜⴻⵜⵜⵎⵓⵏⴷ ⴰⴷ ⴰⴽ ⵎⵍⵖ ⵎⴰⴷ ⵜⴳⵉⴷ"],
			["Voice1410.wav", example_2],
			["Tamazight_For_All.mp3", example_3]
		],
		inputs=[audio_file_in, ref_text]
	)

demo.queue()
demo.launch()