daniel/reasampler
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Q-W1 pt2: core/shell/app relocation + sub-namespaces; one concrete ui::Rect (LTRB fork retired); slot_map split from bank_book; BankIndex→BankModel; 59/59 green

Browse Source
This commit is contained in:
Daniel Harvey
2026-07-28 20:48:56 -04:00
parent 67a41728f3
commit 847936f813
222 changed files with 2247 additions and 2079 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/core/audio/peaks.cpp
+126
View File
@@ -0,0 +1,126 @@
#include "core/audio/peaks.h"
#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdint>
// peaks implementation.
//
// One linear pass per channel. The frame->bin partition is computed with integer
// arithmetic so it is exact for any frameCount / binCount pairing: bin b owns the
// half-open frame span [b*frameCount/binCount, (b+1)*frameCount/binCount). That
// span formula distributes the remainder deterministically (earlier bins get the
// extra frames) with no rounding drift and no dropped tail — the last bin's end is
// always exactly frameCount.
namespace reasampler::audio {
Envelope computeEnvelope(const std::vector<AudioSample>& interleaved,
std::size_t channelCount,
std::size_t frameCount,
std::size_t binCount) {
Envelope envelope(channelCount);
if (channelCount == 0) {
return envelope; // no channels -> no envelopes
}
// Never read past what the buffer actually holds, even if the caller's
// frameCount overstates the buffer (defensive: no OOB on a short buffer).
const std::size_t availableFrames = interleaved.size() / channelCount;
const std::size_t frames = std::min(frameCount, availableFrames);
for (std::size_t ch = 0; ch < channelCount; ++ch) {
ChannelEnvelope& bins = envelope[ch];
bins.assign(binCount, MinMax{}); // empty/degenerate bins default to {0,0}
for (std::size_t b = 0; b < binCount; ++b) {
// Half-open frame span for this bin: [b*frames/binCount, (b+1)*frames/binCount).
// Guard against size_t overflow in b*frames and (b+1)*frames: binCount is
// caller-controlled and unbounded, so when b >= SIZE_MAX/frames either
// multiplication could wrap. Any such bin is unreachable in practice
// (allocating that many MinMax entries would OOM first), but we guard
// explicitly to eliminate UB.
if (frames > 0 && b >= SIZE_MAX / frames) {
continue; // b*frames or (b+1)*frames would overflow; span is empty
}
const std::size_t begin = (b * frames) / binCount;
const std::size_t end = ((b + 1) * frames) / binCount;
if (begin >= end) {
continue; // empty span (binCount > frames) -> keep {0,0}
}
const AudioSample first = interleaved[begin * channelCount + ch];
AudioSample lo = first;
AudioSample hi = first;
for (std::size_t f = begin + 1; f < end; ++f) {
const AudioSample s = interleaved[f * channelCount + ch];
lo = std::min(lo, s);
hi = std::max(hi, s);
}
bins[b] = MinMax{lo, hi};
}
}
return envelope;
}
MinMax columnMinMax(const ChannelEnvelope& bins, int columnCount, int col) {
const int nbins = static_cast<int>(bins.size());
if (columnCount <= 0 || nbins == 0) return MinMax{};
// Clamp col to [0, columnCount-1].
if (col < 0) col = 0;
if (col >= columnCount) col = columnCount - 1;
// Half-open bin range for this column, mirroring computeEnvelope's exact partition.
// 64-bit products: col*nbins can exceed int range for a large oversampled envelope
// (same overflow discipline as computeEnvelope's frame-span arithmetic above).
const std::int64_t begin64 = (static_cast<std::int64_t>(col) * nbins) / columnCount;
const std::int64_t end64 =
(static_cast<std::int64_t>(col) + 1) * nbins / columnCount;
// col <= columnCount-1 guarantees begin64 <= (columnCount-1)*nbins/columnCount < nbins.
const int colBinBegin = static_cast<int>(begin64);
// When the column spans no full bin (more columns than bins), use the enclosing bin
// so no column is left empty.
const int scanEnd = (end64 > begin64) ? static_cast<int>(end64) : colBinBegin + 1;
const int clampedEnd = (scanEnd <= nbins) ? scanEnd : nbins;
MinMax result = bins[static_cast<std::size_t>(colBinBegin)];
for (int b = colBinBegin + 1; b < clampedEnd; ++b) {
const MinMax& mm = bins[static_cast<std::size_t>(b)];
if (mm.min < result.min) result.min = mm.min;
if (mm.max > result.max) result.max = mm.max;
}
return result;
}
std::size_t lastFrameAboveThreshold(const std::vector<AudioSample>& interleaved,
std::size_t channelCount,
std::size_t frameCount,
AudioSample linearThreshold) {
if (channelCount == 0) return kNoFrameAboveThreshold;
// Clamp to what the buffer actually holds — a caller frameCount that overstates
// the buffer must never read past the end (mirror of computeEnvelope's guard).
const std::size_t availableFrames = interleaved.size() / channelCount;
const std::size_t frames = std::min(frameCount, availableFrames);
if (frames == 0) return kNoFrameAboveThreshold;
// Scan backward: the first frame (from the end) whose loudest channel exceeds the
// threshold is the last audible frame. `f` runs frames..1 so `f-1` never wraps.
for (std::size_t f = frames; f > 0; --f) {
const std::size_t frame = f - 1;
const std::size_t base = frame * channelCount;
AudioSample peak = 0.0f;
for (std::size_t c = 0; c < channelCount; ++c) {
const AudioSample a = std::fabs(interleaved[base + c]);
peak = std::max(peak, a);
}
if (peak > linearThreshold) return frame;
}
return kNoFrameAboveThreshold;
}
} // namespace reasampler::audio
src/core/audio/peaks.h
+122
View File
@@ -0,0 +1,122 @@
#pragma once
// peaks — waveform min/max envelope (thumbnail) computation from raw interleaved
// PCM. We compute our own thumbnails from the captured file rather than depending
// on REAPER's peak API: we own the file format, so this is simpler, testable, and
// dependency-free. A future bank panel (M5) calls this at whatever bin resolution
// the panel width dictates and draws one min/max envelope per channel.
//
// PURE MODULE (CLAUDE.md §load-bearing split): NO REAPER types, NO SWELL, NO
// vendor/ includes. Standard library only. Builds and unit-tests without REAPER.
#include <cstddef>
#include <vector>
namespace reasampler::audio {
// Canonical in-memory audio-sample type. `float` is REAPER's native audio buffer
// format (its render/PCM_source callbacks hand back interleaved 32-bit float), so
// peaks consumes that directly with no lossy conversion. If a capture ever lands
// as a different depth, the caller converts to float at the boundary — the
// thumbnail core stays single-typed.
//
// NAMED AudioSample, not `Sample`: `reasampler::Sample` is already bank_model's
// metadata struct. A `using Sample = float` here would collide at namespace scope
// wherever both headers are visible (the bank_panel module includes both). The
// audio-domain name also reads more precisely — this is one PCM sample value.
using AudioSample = float;
// One bin of a channel's envelope: the extremes of every sample that fell in it.
// min <= max always. For an empty bin (more bins than frames), both are 0.
struct MinMax {
AudioSample min = 0.0f;
AudioSample max = 0.0f;
bool operator==(const MinMax& o) const { return min == o.min && max == o.max; }
};
// One channel's envelope: exactly `binCount` bins, in time order.
using ChannelEnvelope = std::vector<MinMax>;
// Per-channel envelopes: outer index is channel (channelCount entries, order
// preserved — never mixed or folded), inner is that channel's bins.
using Envelope = std::vector<ChannelEnvelope>;
// Computes a per-channel min/max envelope from interleaved PCM.
//
// interleaved frame-interleaved samples: [f0c0, f0c1, ..., f1c0, f1c1, ...].
// Size must be >= frameCount * channelCount; extra is ignored.
// channelCount channels per frame (the stride). Each channel is enveloped
// INDEPENDENTLY — no averaging, no stereo fold (precision
// invariant: channel count preserved).
// frameCount frames (samples-per-channel) to consider.
// binCount requested bins per channel. Honored exactly for any frameCount.
//
// Frame->bin partition: frames are split into `binCount` contiguous spans as
// evenly as possible; when frameCount does not divide evenly, the remainder is
// spread one-frame-per-bin across the earliest bins (ceil/floor split), so the
// tail is never dropped and no bin reads out of bounds. When binCount > frameCount
// the trailing empty bins are {0, 0}.
//
// Defined behavior for degenerate input (no UB, no throw):
// binCount == 0 -> per channel: an empty bin vector.
// channelCount == 0 -> an empty envelope (no channels).
// frameCount == 0 -> per channel: binCount bins, all {0, 0}.
Envelope computeEnvelope(const std::vector<AudioSample>& interleaved,
std::size_t channelCount,
std::size_t frameCount,
std::size_t binCount);
// The merged min/max for display column `col` (0-based, of `columnCount` total columns)
// of a pre-computed per-bin ChannelEnvelope: the true extremes of every bin that projects
// to that column. This is the display-side collapse of an envelope computed at HIGHER
// resolution than the drawn width (oversampled bins -> per-pixel-column min/max), so a
// steep transient whose adjacent bins hold disjoint spans (e.g. {0.9,1.0} then
// {-1.0,-0.9}) renders as one gap-free vertical span instead of two separated dots.
//
// Bin->column mapping mirrors computeEnvelope's half-open partition:
// column col owns bins [col*nbins/columnCount, (col+1)*nbins/columnCount).
// When that range is empty (more columns than bins), the enclosing bin
// (col*nbins/columnCount) fills the column — so no column is left empty and no bin is
// ever dropped. columnCount <= 0 or bins.empty() returns {0, 0}; `col` is clamped to
// [0, columnCount-1]. Pure.
MinMax columnMinMax(const ChannelEnvelope& bins, int columnCount, int col);
// Sentinel returned by lastFrameAboveThreshold when NO frame in the scanned range
// peaks above the threshold (pure silence at that level). SIZE_MAX is unambiguous:
// no valid frame index can equal it (a real index is < frameCount <= SIZE_MAX for
// any allocatable buffer), so the caller tests `== kNoFrameAboveThreshold` cleanly.
inline constexpr std::size_t kNoFrameAboveThreshold =
static_cast<std::size_t>(-1);
// Scans interleaved PCM BACKWARD for the last frame whose per-frame peak (the max
// absolute value across all channels of that frame — NO stereo fold, just the
// loudest channel that frame) exceeds `linearThreshold`, returning that frame index.
// Returns kNoFrameAboveThreshold if no frame exceeds it (or on degenerate input).
//
// This is the boundary primitive behind the realtime tail's decay-scan trim
// (docs/product/capture-tail.md §The realtime path): the recorded tail window is
// scanned back from the end for the last frame still above -72 dB, and the file is
// truncated one frame past it. Deliberately a separate primitive from
// computeEnvelope — that answers "the min/max envelope over bins" (a thumbnail),
// this answers "the last frame above a level" (a boundary). Bending the bin-oriented
// envelope to a frame-exact boundary question is a worse fit (spec §option a).
//
// interleaved frame-interleaved samples: [f0c0, f0c1, ..., f1c0, f1c1, ...].
// Must hold >= frameCount * channelCount; extra is ignored, and a
// short buffer is clamped to what it actually holds (no OOB read).
// channelCount channels per frame (the stride). The per-frame test is the max
// |sample| over these channels — the frame is "above" if its
// loudest channel is above the threshold.
// frameCount frames to consider (the scan starts at the last of these).
// linearThreshold the comparison level as a LINEAR amplitude ratio (e.g. the
// -72 dB ratio from render_settings::autoTrimEndRatio), NOT dB.
// A frame counts as above when its peak is STRICTLY > this.
//
// Pure, stdlib-only, unit-tested (a synthetic decaying ramp, silence, all-above,
// and degenerate inputs) so the trim boundary math is locked outside the DAW.
std::size_t lastFrameAboveThreshold(const std::vector<AudioSample>& interleaved,
std::size_t channelCount,
std::size_t frameCount,
AudioSample linearThreshold);
} // namespace reasampler::audio