Function parse_diffusion_head_config

src/models/vibevoice/assets.cpp:145–174

}

int64_t require_acoustic_vae_dim(const engine::io::json::Value & root) {
    // VibeVoice-7B's config.json spells this key "acostic_vae_dim".
    for (const char * key : {"acoustic_vae_dim", "acostic_vae_dim"}) {
        if (const auto * value = root.find(key); value != nullptr) {
            return value->as_i64();
        }
    }
    throw std::runtime_error("VibeVoice config is missing acoustic_vae_dim");
}

VibeVoiceConfig parse_config(const assets::ResourceBundle & resources) {
    const auto root = resources.parse_json("config");
    VibeVoiceConfig config;
    config.model_type = json::optional_string(root, "model_type", "");
    if (config.model_type != "vibevoice") {
        throw std::runtime_error("VibeVoice config model_type mismatch");
    }
    config.torch_dtype = json::optional_string(root, "torch_dtype", config.torch_dtype);
    config.acoustic_vae_dim = require_acoustic_vae_dim(root);
    config.semantic_vae_dim = json::require_i64(root, "semantic_vae_dim");
    config.acoustic_tokenizer = parse_tokenizer_config(root.require("acoustic_tokenizer_config"), "acoustic tokenizer");
    config.semantic_tokenizer = parse_tokenizer_config(root.require("semantic_tokenizer_config"), "semantic tokenizer");
    config.decoder = parse_decoder_config(root.require("decoder_config"));
    // VibeVoice-7B carries tie_word_embeddings at the top level, unlike the 1.5B decoder config.
    config.decoder.tie_word_embeddings =
        json::optional_bool(root, "tie_word_embeddings", config.decoder.tie_word_embeddings);
    config.diffusion_head = parse_diffusion_head_config(root.require("diffusion_head_config"));
    engine::io::require_positive(config.acoustic_vae_dim, "acoustic_vae_dim");
    engine::io::require_positive(config.semantic_vae_dim, "semantic_vae_dim");
    if (config.acoustic_vae_dim != config.acoustic_tokenizer.vae_dim) {
        throw std::runtime_error("VibeVoice acoustic_vae_dim does not match acoustic tokenizer vae_dim");
    }
    if (config.semantic_vae_dim != config.semantic_tokenizer.vae_dim) {