waveform visualization plugin

meson.build

@@ -336,6 +336,7 @@ if conf.has('USE_QT')
     'Stream Tuner (experimental)': get_variable('have_streamtuner', false),
     'VU Meter': get_option('vumeter'),
     'X11 Global Hotkeys': get_variable('have_qthotkey', false),
+    'Waveform': true,
   }, section: 'Qt Support')
 endif
 

meson_options.txt

@@ -199,3 +199,5 @@ option('spectrum-analyzer', type: 'boolean', value: true,
        description: 'Whether the Spectrum Analyzer (2D) plugin is enabled')
 option('vumeter', type: 'boolean', value: true,
        description: 'Whether the VU Meter visualization plugin is enabled')
+option('waveform', type: 'boolean', value: true,
+       description: 'Whether the Waveform visualization plugin is enabled')

src/meson.build

@@ -190,6 +190,10 @@ if conf.has('USE_QT')
   if get_option('vumeter')
     subdir('vumeter-qt')
   endif
+
+  if get_option('waveform')
+    subdir('waveform-qt')
+  endif
 endif
 
 
@@ -258,6 +262,8 @@ if conf.has('USE_GTK')
   if get_option('vumeter')
     subdir('vumeter')
   endif
+
+  # TODO: add waveform for GTK
 endif
 
 

src/waveform-qt/Makefile

@@ -0,0 +1,13 @@
+PLUGIN = waveform-qt${PLUGIN_SUFFIX}
+
+SRCS = waveform_qt.cc waveform_qt_widget.cc
+
+include ../../buildsys.mk
+include ../../extra.mk
+
+plugindir := ${plugindir}/${VISUALIZATION_PLUGIN_DIR}
+
+LD = ${CXX}
+CFLAGS += ${PLUGIN_CFLAGS}
+CPPFLAGS += ${PLUGIN_CPPFLAGS} -I../.. ${QT_CFLAGS}
+LIBS += -lm ${QT_LIBS}

src/waveform-qt/meson.build

@@ -0,0 +1,17 @@
+avformat_dep   = dependency('libavformat')
+avcodec_dep    = dependency('libavcodec')
+avutil_dep     = dependency('libavutil')
+swresample_dep = dependency('libswresample')
+threads_dep    = dependency('threads')
+shared_module('waveform-qt',
+  'track_peaks.cc',
+  'preload.cc',
+  'track_state.cc',
+  'waveform_widget.cc',
+  'settings.cc',
+  'waveform_plugin.cc',
+  dependencies: [audacious_dep, qt_dep, avformat_dep, avcodec_dep, avutil_dep, swresample_dep, threads_dep],
+  name_prefix: '',
+  install: true,
+  install_dir: visualization_plugin_dir
+)

src/waveform-qt/preload.cc

@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2026 0000xFFFF.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "preload.h"
+
+#include <atomic>
+#include <cstdlib>
+#include <cstring>
+#include <thread>
+#include <vector>
+
+#include <libaudcore/audstrings.h>
+#include <libaudcore/playlist.h>
+
+std::atomic<bool> g_preload_running{false};
+std::atomic<int> g_preload_total{0};
+std::atomic<int> g_preload_done{0};
+
+bool preload_one_file(const char * filename, TrackPeaks * out)
+{
+    TrackPeaks local;
+    TrackPeaks * peaks = out ? out : &local;
+
+    char * cpath = cache_path_for(filename);
+
+    bool ok = load_cache(cpath, peaks);
+    if (!ok)
+    {
+        StringBuf local_path = uri_to_filename(filename);
+        const char * decode_path =
+            local_path ? (const char *)local_path : filename;
+
+        ok = decode_peaks(decode_path, peaks);
+        if (ok)
+            save_cache(cpath, peaks);
+    }
+
+    delete[] cpath;
+    return ok;
+}
+
+/* Filenames are snapshotted on the calling (UI) thread -- Playlist's
+ * API is not meant to be called from worker threads -- then handed off
+ * to the worker pool below, so a beefier machine churns through the
+ * playlist proportionally faster. */
+void run_playlist_preload()
+{
+    if (g_preload_running.exchange(true))
+        return; /* already running */
+
+    Playlist pl = Playlist::active_playlist();
+    int n = pl.n_entries();
+
+    g_preload_total = n;
+    g_preload_done = 0;
+
+    if (n <= 0)
+    {
+        g_preload_running = false;
+        return;
+    }
+
+    auto * filenames = new std::vector<char *>();
+    filenames->reserve(n);
+    for (int i = 0; i < n; i++)
+    {
+        String fn = pl.entry_filename(i);
+        filenames->push_back(strdup(fn ? (const char *)fn : ""));
+    }
+
+    std::thread([filenames]() {
+        unsigned n_threads = std::thread::hardware_concurrency();
+        if (n_threads == 0)
+            n_threads = 2; /* hardware_concurrency() can return 0; fall back */
+
+        size_t total = filenames->size();
+        if (n_threads > total)
+            n_threads = (unsigned)total;
+
+        std::atomic<size_t> next_idx{0};
+
+        std::vector<std::thread> workers;
+        workers.reserve(n_threads);
+        for (unsigned t = 0; t < n_threads; t++)
+        {
+            workers.emplace_back([filenames, &next_idx, total]() {
+                for (;;)
+                {
+                    size_t idx = next_idx.fetch_add(1);
+                    if (idx >= total)
+                        break;
+
+                    const char * fn = (*filenames)[idx];
+                    if (fn && fn[0])
+                        preload_one_file(fn);
+
+                    g_preload_done.fetch_add(1);
+                }
+            });
+        }
+
+        for (auto & w : workers)
+            w.join();
+
+        for (char * fn : *filenames)
+            free(fn);
+        delete filenames;
+
+        g_preload_running = false;
+    }).detach();
+}

src/waveform-qt/preload.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2026 0000xFFFF.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __PRELOAD_H__
+#define __PRELOAD_H__
+
+#include <atomic>
+
+#include "track_peaks.h"
+
+/* Progress counters, polled by the controls widget's status label. */
+extern std::atomic<bool> g_preload_running;
+extern std::atomic<int> g_preload_total;
+extern std::atomic<int> g_preload_done;
+
+/* Loads peaks for `filename` from cache if possible, otherwise decodes
+ * and writes the cache. If `out` is non-null, the resulting peak data
+ * is copied into it; otherwise it is decoded/loaded and then discarded.
+ * Shared by the bulk preloader and the single-track async loader. */
+bool preload_one_file(const char * filename, TrackPeaks * out = nullptr);
+
+/* Kicks off a background preload of every entry in the active
+ * playlist using a pool of worker threads sized to the number of CPU
+ * cores available. Safe to call repeatedly; a second call while one
+ * is already running is ignored. */
+void run_playlist_preload();
+
+#endif

src/waveform-qt/settings.cc

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2026 0000xFFFF.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "settings.h"
+
+#include <QHBoxLayout>
+#include <QLabel>
+#include <QPushButton>
+#include <QTimer>
+
+#include <libaudcore/i18n.h>
+
+#include "preload.h"
+
+WaveformSettings::WaveformSettings(QWidget * parent) : QWidget(parent)
+{
+    auto * layout = new QHBoxLayout(this);
+    layout->setContentsMargins(4, 2, 4, 2);
+
+    m_button = new QPushButton(_("Preload Playlist Waveforms"), this);
+    m_label = new QLabel(this);
+    m_label->setMinimumWidth(90);
+
+    layout->addWidget(m_button);
+    layout->addWidget(m_label);
+    layout->addStretch(1);
+
+    QObject::connect(m_button, &QPushButton::clicked, this,
+                     []() { run_playlist_preload(); });
+
+    m_timer = new QTimer(this);
+    QObject::connect(m_timer, &QTimer::timeout, this, [this]() { refresh(); });
+    m_timer->start(150);
+
+    refresh();
+}
+
+void WaveformSettings::refresh()
+{
+    bool running = g_preload_running.load();
+    int done = g_preload_done.load();
+    int total = g_preload_total.load();
+
+    m_button->setEnabled(!running);
+
+    if (running)
+        m_label->setText(QString("%1/%2").arg(done).arg(total));
+    else if (total > 0)
+        m_label->setText(QString(_("Done (%1/%2)")).arg(done).arg(total));
+    else
+        m_label->setText(QString());
+}
+
+void * waveform_get_settings_widget() { return new WaveformSettings(); }

src/waveform-qt/settings.h

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2026 0000xFFFF.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __WAVEFORM_CONTROLS_H__
+#define __WAVEFORM_CONTROLS_H__
+
+#include <QWidget>
+
+class QPushButton;
+class QLabel;
+class QTimer;
+
+/* Shown on the plugin's preferences page: a button to preload the
+ * whole playlist's waveforms, and a label that polls preload progress
+ * while it runs. */
+class WaveformSettings : public QWidget
+{
+public:
+    explicit WaveformSettings(QWidget * parent = nullptr);
+
+private:
+    void refresh();
+
+    QPushButton * m_button;
+    QLabel * m_label;
+    QTimer * m_timer;
+};
+
+/* Factory matching the signature WidgetCustomQt() expects in
+ * libaudcore/preferences.h. */
+void * waveform_get_settings_widget();
+
+#endif