# Scope and requirements

The [draft statement of work](https://sam.gov/api/prod/opps/v3/opportunities/resources/files/34eacfe92b1a46228b9f90674c4c60e1/download) describes software for producing NLS digital talking books through two input routes. The engineering proposal is to share the downstream production system between those routes.

The draft background describes approximately **3,000 DTBs produced annually** in the existing operation. That is context, not a numerical throughput acceptance target for the new system. [SOW §1](https://sam.gov/api/prod/opps/v3/opportunities/resources/files/34eacfe92b1a46228b9f90674c4c60e1/download).

## The two required input routes

| Route | Core work | Important boundary |
|---|---|---|
| Existing commercial audiobook | Ingest audio and metadata, identify divisions, create required supplemental speech, and construct the DTB. | Proposed handling: preserve the supplied narration through approved mastering/conversion. A transcript supports analysis rather than replacing the recording. |
| Electronic text | Ingest EPUB, Word, RTF, or plain text; recover structure; generate speech; construct the DTB. | Preserve the source and document any change to its spoken form. |

The commercial route explicitly accepts **WAV, MP3, OPUS and FLAC**, and requires AMR-WB+ conversion with MP3 encoding optional. The text route requires **WAV and AMR-WB+** outputs, with MP3 encoding optional. These routes and formats come from SOW §§3.1–3.2. Scanned-book OCR is not an explicit core input in the draft. Treat it as a potential extension that needs scope agreement. A raw scan also creates recognition errors that the current text-first workflow would otherwise avoid.

## Requirements and proposed evidence

The first two columns summarize the draft; the last is a proposed way to demonstrate completion, not a Government-approved acceptance checklist.

| Area | Draft requirement or concern | Proposed evidence |
|---|---|---|
| Outputs | NLS-compatible DTBs, navigation, metadata, required audio and related files; §§3.1–3.2 | A reference book from each input route, validator results, and playback observations. |
| Processing | Batch operation and automation with useful operator control | Repeatable batch run, failed-job recovery, and an exception-review demonstration. |
| Integration | Work within the Library's AWS environment and interfaces | Deployment in the approved environment and a traced delivery to the agreed destination. |
| Security | Federal security requirements referenced through Section H; §3.6 | An agreed controls matrix after the missing section is supplied. |
| Compatibility and testing | Library playback environment; §§3.11, 3.13 | Test records for the agreed hardware, applications, and protected packages. |
| Ownership and continuity | Non-subscription delivery and Library ownership; §§2, 3.12 | Deliverable inventory, reproducible deployment, and dependency/voice-license records. |
| Documentation and support | Technical documentation, training/support and warranty obligations | Manuals, deployment runbook, handover exercise, support process and warranty terms. |

Use the [full SOW](https://sam.gov/api/prod/opps/v3/opportunities/resources/files/34eacfe92b1a46228b9f90674c4c60e1/download) as the authority for exact wording; this table is a reading aid. The [milestones page](roadmap.md) captures the concrete schedule terms.

## Why local inference is the proposed default

The ownership and non-subscription language favors a system that can keep running without a required commercial speech API. The proposal is to deliver application code, approved model artifacts, configurations, and deployment machinery into the Library's environment.

That is an architectural interpretation, not a finding that every hosted service is forbidden or that open weights automatically satisfy the contract. AWS infrastructure still costs money. Third-party code, model weights, voice recordings, and commercial components each need their own rights assessment. Library ownership of delivered work does not erase third-party licenses.

## Scope boundaries to settle

Agree which languages, book types, complex tables, equations, poetry, footnotes, and mixed-language passages are included in acceptance. Agree whether page navigation is required only when authoritative page references exist. Decide whether “various multimedia types” means an initial audio-plus-navigation product or additional full-text outputs. See [open decisions](decisions.md).

## A practical traceability record

For each accepted requirement, record its source section and edition, implementation component, test procedure, evidence artifact, and acceptance status. Keep this separate from model confidence scores. A model saying that a book looks correct is not proof of contractual acceptance.

Example proposal: the requirement for a valid navigation target maps to the compiler's reference checker, a deliberate broken-target test, and a playback test that reaches the expected chapter. This connects a rule to observable behavior.