Audio LMs scene is heating up! 🔥 @FixieAI Ultravox 0.4.1 - 8B model approaching GPT4o level, pick any LLM, train an adapter with Whisper as Audio Encoder, profit 💥
Bonus: MIT licensed checkpoints
> Pre-trained on Llama3.1-8b/ 70b backbone as well as the encoder part of whisper-large-v3-turbo
> Only the multi-modal adapter is trained, while Whisper encoder and LLM are kept frozen
> Use knowledge-distillation loss where Ultravox is trying to match the logits of the LLM backbone
GG @FixieAI - Play with it directly on the space and checkout the models on the hub 🤗
Fuck yeah! MaskGCT - New open SoTA Text to Speech model! 🔥
> Zero-shot voice cloning
> Emotional TTS
> Trained on 100K hours of data
> Long form synthesis
> Variable speed synthesis
> Bilingual - Chinese & English
> Available on Hugging Face
Fully non-autoregressive architecture:
> Stage 1: Predicts semantic tokens from text, using tokens extracted from a speech self-supervised learning (SSL) model
> Stage 2: Predicts acoustic tokens conditioned on the semantic tokens.
Synthesised: "Would you guys personally like to have a fake fireplace, an electric one, in your house? Or would you rather have a real fireplace? Let me know down below. Okay everybody, that's all for today's video and I hope you guys learned a bunch of furniture vocabulary!"
> Trained on 100K hours of data
> Zero-shot voice cloning
> Speed control (based on total duration)
> Emotion based synthesis
> Long-form synthesis
> Supports code-switching
> Best part: CC-BY license (commercially permissive)🔥
Diffusion based architecture:
> Non-Autoregressive + Flow Matching with DiT
> Uses ConvNeXt to refine text representation, alignment
Synthesised: I was, like, talking to my friend, and she’s all, um, excited about her, uh, trip to Europe, and I’m just, like, so jealous, right? (Happy emotion)
Apple spilled the beans on Apple Intelligence Foundation Models (notes below):
Architecture:
> Dense - decoder only transformer architecture
> RMSNorm & Query/ Key normalization
> GQA (w/ 8 KV heads)
> SwiGLU activation & RoPE (base_freq=500K for long context)
Pre-training & Tokenisation:
> Webpages crawled through the Applebot (web crawl)
> Code & Math datasets (publicaly licensed)
> BPE tokenizer w/ 100K vocab for server & 49K for on-device
Three step pre-training:
>Core (consumes most of the compute budget)
AFM-server - 6.3T tokens + 4096 seq length
AFM-on-device - initialised from a pruned 6.4B server model, trained for full 6.3T tokens along with distillation loss
- Continued (down-weight lower quality data and increase code, math, licensed data weight)
1T tokens, w/ 8192 seq length
no distillation loss for AFM-on-device in this phase
- Context-lengthening with long sequence + synthetic data
100B tokens, w/ 32768 seq length
Training Infrastructure:
> Pre-trained v4 & v5p TPU clusters
> Using AXLearn (JAX) with a combination of tensor, fsdp, and seq parallelism
> AFM Server trained on 8192 TPUv4 chips
> AFM On-device trained on 2048 TPUv5p chips
Post Training:
> Hybrid data - synthetic + human annotated
> Synthetic data for Mathematics (problem rephrase & reversion + evolution), Tool use and coding
> RLHF: Iterative Teaching Committee - Refresh online human preference data collection using a diverse set of best performing model
> For above, collect pairwise human preference on responses sampled from the comittee
Deployment:
> Adapters for each task, adapter values represented using 16-bits, loaded on-the-fly based on the task
> Quantised under 4-bit-per-weight (3.7 bpw), use accuracy recovering adapters for regaining the lost performance
> Accuracy recovery adapter trains on 10B tokens across different ranks, 8, 16, 32
> Some layers (unimportant) pushed to 2-bit
Evaluation:
> On-device: SoTA in IFEval and competitive with Gemma 7B on AlpacaEval 2.0
> Server: SoTA in IFEval, comparable to Mixtral 8x22B in Arena Hard
> Competitve with GPT 4/ Gemini 1.5 on Tools/ function calling, writing (summarisation, composition) benchmarks
> On-device beats L3 8B on Math
The report is quite feature packed, quite enjoyed skimming through it. Thanks Apple for being so open about your practices and spilling the beans on what would power the next gen of on-device ML.