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Phase 22: add non-destructive audio splitting, clip gain and fades, and cached waveforms

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Johannes Findeisen 2026-10-27 15:46:41 +01:00
commit 01d8c1d661
23 changed files with 650 additions and 18 deletions
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docs/PROJECT_FORMAT.md
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@ -1,4 +1,4 @@
# Project format v7 (reads v1–v6)
# Project format v8 (reads v1–v7)
Phases 5–15 use a bounded text format implemented in C99 without a parser library.
The extension is `.xtc`. File operations run exclusively on the control thread.
@ -151,7 +151,7 @@ discrete-mode compatibility are checked on control-thread compilation. Versions
## Phase 18: version 7 and project folders
Current writer emits v7; readers migrate v1–v6. Record ordering and field bounds
Phase 18 introduced v7; its readers migrated v1–v6. Record ordering and field bounds
are otherwise unchanged from v6. v7 ASSET may contain a relative path, interpreted
against the actual containing directory of the named project file (resolved on
the control thread), never the launch working directory. Opening a symlink to a project uses the
@ -189,3 +189,29 @@ truncation and deterministic byte mutations, malformed plugin metadata, interrup
writers and write-limit failures. ASan/UBSan/static analysis additionally audit the
bounded parser. This is regression/fault-injection coverage, not exhaustive fuzzing
or a claim of power-cut qualification.
## Phase 22: version 8 audio clip settings
Current writer emits v8 and reads v1–v7 with unity clip gain and no explicit
clip fades. After **every** clip's `MIDI` record (including silent and MIDI
clips), v8 requires:
```text
AUDIO gain_float32_hex_bits fade_in_ticks fade_out_ticks
```
Gain is finite, linear and within 0..4. Fade durations are unsigned decimal,
0..source_length_tick; zero disables that explicit fade. MIDI clips require
gain exactly 1 and both fades zero. Invalid or missing AUDIO records reject the
whole candidate. All v7 media-folder rules and atomic-save guarantees remain.
Older applications reject v8 rather than silently stripping clip settings.
Rebuild C/C++ consumers against the extended `xtc_clip_info` public struct;
this development release does not promise an unchanged struct binary layout.
Fades follow the audible trimmed clip boundaries, in current-tempo ticks, with
sample endpoints defined in AUDIO_FILES.md. Duplicating retains settings and
source references; splitting keeps the original ID on the left, gives the right
a fresh ID/source offset, retains outer explicit fades and clears inner ones.
No waveform cache or source audio is serialized. Checked-in v1–v7 migrations,
v8 exact roundtrips, malformed new metadata and byte-mutation tests cover the
format change (`make test test-portability test-audio-editing`).