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Use omx-dsp 0.21.0 instead of private copies of omx_lin_to_db_d and omx_db_to_lin #87
Description
The LV2 measurers convert levels to dB with their own 20 * log10(...) and one dB-to-linear pow, where omx-dsp has the functions and plugin-qualify already builds against it (omx-dsp >= 0.18.0). Operator rule, 2026-10-16: "If it is in the lib we should use it in plugins and every dependency."
Found by a sweep of every FreeMixer repo against omx-dsp main (0f23bed), plugin-qualify main 6198927.
The copies
| where | replace with | bit-identical? |
|---|---|---|
native/lv2-measure.c:880, :898, :899, :900, :901, :1124: 20.0 * log10(rms...) |
omx_lin_to_db_d(x, 0.0) (<omxdsp/omx_units.h>), inside the existing > 0 ? ... : -999.0 guards |
yes: the library's body is 20.0 * log10(lin > floor ? lin : floor) |
native/lv2-host-probe.c:88: 20.0 * log10(mag < 1e-12 ? 1e-12 : mag) |
omx_lin_to_db_d(mag, 1e-12) |
yes for every finite mag; a NaN differs (the library floors it, the copy keeps NaN) |
native/lv2-host-probe.c:66: pow(10.0, HOT_EXCESS_DB / 20.0) |
omx_db_to_lin |
no, only equivalent: the library is float, powf(10, db * 0.05f), and has no double twin. Replacing it moves the probe's stimulus by float rounding. Decision for the operator: either omx-dsp adds omx_db_to_lin_d and this line takes it verbatim, or the line stays and goes on the allowlist. Do not switch it in the verbatim commit. |
Not copies: native/fixtures/synth.c (MIDI note to Hz, no library twin), level_db_at in lv2-host-probe.c (a single-bin DFT; the library has the full FFT only), tools/benchmark.py (Python).
Acceptance
- One change set: the call switch, the deletion of the inline conversions, and the floor raised to omx-dsp >= 0.21.0 (packaging/plugin-qualify.spec BuildRequires, debian/control, the version
make depsfetches). Same batch, each commit naming the others. - Verbatim: no rename, no cleanup, no behaviour change in the replacing commit; improvements are separate commits after.
- Proof that nothing moved: the measurer's printed readings on the qualification corpus are byte-identical before and after; oracles and goldens green at the nine rates (32 to 192 kHz).
- A grep proof in the change:
git grep -n 'log10\|pow(10' native/*.cprints only lines that are on the allowlist with a reason.
Full sweep: ~/.local/share/omx/third/dsp-copies/sweep.md (r1).
Activity
omx-dsp floor 0.21.0 (#87)
lv2-measure: the dB readings are omx-dsp's omx_lin_to_db_d (#87)
lv2-host-probe: level_db_at reads omx-dsp's omx_lin_to_db_d (#87)
lv2-host-probe: level_db_at reads omx-dsp's omx_lin_to_db_d (#87)
lv2-host-probe: a NaN level stays NaN and is a failed claim, never th…
test: native/*.c holds no log10 or pow(10, ...) of its own but one na…