Speaker Adapter for Custom Voice#

Speaker adapter is a TTS technology that allows us to fine-tune datasets with duration close to 30 minutes on a model trained with larger data with satisfactory results. Using Adapters reduces the FastPitch training time significantly.

Download the Models#

Download the pretrained models that we will be fine-tuning.

## Download fastpitch pretrained model.
ngc registry model download-version "nvidia/riva/tts_fastpitch_speaker_adapter_ipa:trainable_v1.0"
## Download hifiGan pretrained model.
ngc registry model download-version "nvidia/riva/tts_en_hifigan_adapter:trainable_v1.0"

Fine-Tune the Existing Model#

After we have downloaded the models, we can use them to fine-tune the model to a new voice. Use the tutorial for fine-tuning speaker adapter models. The tutorial already has the recipe and recommended hyperparameters for fine-tuning, however, we will need to update the following parameters in section Set-finetuning-params:

pretrained_fastpitch_checkpoint="<Path to pretrained FastPitch.nemo ckpt, downloaded from ngc in previous section.>"
finetuned_hifigan_on_multispeaker_checkpoint="<Path to pretrained HifiGan.nemo ckpt, downloaded from ngc in previous section.>"
use_ipa=True ##Set this to true, since we will do finetuning based on an IPA pretrained model.

Generate the Riva Checkpoint#

After the fine-tuning finishes, we will have .nemo checkpoints. We use .nemo checkpoints to generate a .riva checkpoint. The processes of converting .nemo to .riva is documented in creating Riva files. We generate .riva checkpoints for both HiFi-GAN and FastPitch. Sample commands to generate .riva include:
- FastPitch: nemo2riva --key tlt_encode --out FastPitch.riva FastPitch.nemo
- HiFi-GAN: nemo2riva --key tlt_encode --out HifiGan.riva HifiGan.nemo

Generate RMIR#

We should now have a .riva checkpoint for both HiFi-GAN and FastPitch. We next use riva-build from the riva_servicemaker container to create a deployable RMIR checkpoint. Refer to the Riva documentation for more details. We can also use the sample command below with the appropriate values to generate the RMIR:

wget -o ipa.txt https://github.com/NVIDIA/NeMo/blob/main/scripts/tts_dataset_files/ipa_cmudict-0.7b_nv23.01.txt
riva-build speech_synthesis \
    <rmir_filename>:<key> \
    <riva_fastpitch_file>:<key> \
    <riva_hifigan_file>:<key> \
    --num_speakers=1 \
    --phone_set=ipa \
    --phone_dictionary_file=ipa.txt \
    --sample_rate 44100 \
    --voice_name <voice_name> \


We now have everything we need to deploy our model. We can use tts_deploy from Riva to deploy our model.