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Merge branch '6-recording-wav-file'

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Loic Coenen
2026-05-17 16:59:56 +00:00
parent 10d0269a5a bb648d471b
commit 3646f6c47e
13 changed files with 705 additions and 1491 deletions
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45
docs/6-sampling-and-recording.md Normal file
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# Sampling and Recording (WAV Load/Save)
The looper supports loading a WAV file into channel 0 and saving the current loop of channel 0 as a WAV file. Both operations use the **libsndfile** library, ensuring correct handling of RIFF headers, chunk sizes, and sample format conversion.
## Load Command
- **MIDI note 70** with the control key (note 64) triggers loading.
- The file `loop.wav` (located in the working directory) is read by `wav_read()` in `src/wav.c`.
- The function calls `sf_open(path, SFM_READ, &info)`.
- It accepts only mono PCM WAV files. If the file is not mono or has an invalid sample rate, it returns `-1`.
- The number of frames read is capped at `LOOP_BUF_SIZE` (5 seconds at 48 kHz).
- The data is stored in `channels[0].loop_buffer` and `channels[0].loop_count` is set atomically.
- The state of channel 0 is set to `STATE_LOOPING` and `prev_state` is set to `-1` to trigger the loop start in the next audio cycle.
## Save Command
- **MIDI note 71** with the control key (note 64) triggers saving.
- The looper must currently be in `STATE_LOOPING` and have a non‑zero `loop_count`.
- A ring buffer (`RingBuf`) is allocated with capacity `2 × loop_count` samples.
- The pointer to the ring buffer is published via `atomic_store_explicit` on `channels[0].save_ring`.
- In each audio callback cycle, if the channel is looping and a save ring exists, the audio output data is written into the ring buffer.
- A dedicated **writer thread** (`writer_thread`) is launched (detached) to consume the ring buffer.
- The writer thread reads `loop_count` samples from the ring buffer, sleeping 10 ms between empty reads.
- Once all samples are collected, it writes them to `save.wav` using `sf_writef_float()`.
- After writing, the ring buffer is destroyed and freed, and the save ring pointer is set to `NULL`.
## Dependencies
- **libsndfile** must be installed (development headers). Add `-lsndfile` to your linker flags (already present in the provided `makefile`).
## Implementation Files
- `src/wav.c` – contains `wav_read()` and `wav_write()` based on libsndfile.
- `src/looper.c` – contains the load/save command handling in `looper_process_commands()` and the writer thread function.
- `src/channel.h` – defines `save_ring` as `_Atomic RingBuf *`.
## Testing
- The integration test `test_wav_load` creates a short 440 Hz WAV file, loads it via MIDI, and checks for ≥3 bursts of audio output.
- The integration test `test_wav_save` records a beep, loops it, issues the save command, and verifies the resulting WAV file has non‑zero data size.
## Notes
- The save operation is asynchronous: the writer thread runs in the background while the audio callback continues to fill the ring buffer. The test waits 2 s for the file to be written before checking.
- The load operation is synchronous: the callback sleeps 1 s after the MIDI command to give the main loop time to process it.

74
evaluation.md
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# Code Evaluation
## Summary Table
| Category | Rating | Remarks |
|--------------------------|---------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Mocked / Left Undone** | ✅ Complete | All features are implemented: audio/MIDI looping, dynamic channels, bind/unbind, FIFO pipe, MIDI control with note 66 for MIDI channel creation, FIFO `add_midi` command. Integration tests cover MIDI channel creation, FIFO stop/bind/unbind, and all previously missing functionality. No placeholder code remains. |
| **Potential Segfaults** | ✅ Good | Every `jack_port_get_buffer()` call is null‑checked based on channel type. Array accesses bounded by `channel_capacity`. No use‑after‑free – deferred cleanup ensures RT thread has finished with old resources. The only unprotected call is in `midi_handle_events`, but the caller has already verified the buffer. |
| **Memory Safety** | ✅ Good | Dynamic channel array allocated with `calloc`, freed exactly once after one RT cycle via deferred free. No leaks. Integration tests do not leak JACK clients or file descriptors. All other buffers are stack‑allocated or static. |
| **Thread Safety / Race** | ✅ Good | Three SPSC queues with correct atomic memory ordering (`acquire`/`release`). Shared state uses atomics. Deferred port/array cleanup uses `global_rt_cycles` with release‑acquire synchronisation. Channel `type` is written before `active=1` (release), RT thread reads `type` only after confirming `active==1` (acquire). No data races. |
| **Performance** | ✅ Good | RT callback has no syscalls, locks, or allocations. Linear per‑channel processing. Main loop sleeps 50 ms – negligible overhead. Integration tests are slow (~25 s total) due to fixed `usleep()` waits; this is acceptable for an integration suite. |
| **Architectural Soundness** | ✅ Good | Clean command‑driven design; per‑source input queues; RCU‑like deferred cleanup; extensible. Integration tests are well‑structured (per‑test looper process, real JACK connections, helpers). Missing test coverage has been addressed (MIDI channel creation, FIFO stop/bind/unbind). |
## Detailed Remarks
### 1. Mocked / Left Undone
- **Nothing remains.**
- `CMD_ADD_MIDI_CHANNEL` is triggered by MIDI note 66 (under control key) and by FIFO command `"add_midi"`.
- `CMD_STOP` is sent from MIDI (note 65 under control key) and from FIFO (`"stop"`).
- `CMD_BIND_CHANNEL`, `CMD_UNBIND`, `CMD_CYCLE`, `CMD_ADD_CHANNEL`, `CMD_REMOVE_CHANNEL` are all wired.
- The integration test suite now includes `test_fifo_stop_bind_unbind()` and `test_midi_channel_add()`.
- The FIFO pipe reader handles `"stop"`, `"bind <ch>"`, `"unbind"`, and `"add_midi"`.
- **Note:** The separate test files in `tests/` (`test_audio.c`, `test_channel.c`, `test_fifo.c`, `test_loop.c`, `main.c`) are not compiled by the makefile and require a missing `test_common.h`. They are not part of the build – they do not affect functionality and may be removed in a future cleanup.
### 2. Potential Segfaults
- **Audio channels:** `audio_in`/`audio_out` are checked for NULL before use.
- **MIDI channels:** `midi_in`/`midi_out` are checked before use.
- All `jack_port_get_buffer()` calls are inside guarded blocks.
- Array indices are validated: `cap = atomic_load(&channel_capacity); idx < cap`.
- The only unguarded call is in `midi_handle_events`, but its caller (`process_callback`) has already verified the port buffer pointer.
### 3. Memory Safety
- The channel array is grown via `calloc` + memcpy + atomic exchange. The old pointer is freed only after at least one RT cycle has passed (`pending_old_cycle` vs `global_rt_cycles`).
- No dynamic allocation occurs in the RT callback.
- The FIFO pipe thread uses a stack‑allocated buffer (`char line[LINE_MAX]`).
- No memory leaks: every `calloc` is eventually freed, and JACK ports are unregistered in deferred cleanup.
### 4. Thread Safety / Race Conditions
- **Three SPSC queues:**
- `cmd_queue` – producer = RT callback, consumer = same RT (no race).
- `cmd_queue_main_midi` – producer = RT callback, consumer = main loop.
- `cmd_queue_main_fifo` – producer = FIFO thread, consumer = main loop.
- All queues use correct `memory_order_acquire`/`release` for head/tail.
- `global_rt_cycles` is incremented with `memory_order_release` at the end of every RT cycle.
- Deferred port unregistration and array free both wait for `current_cycle - pending_cycle >= 1`, guaranteeing the RT thread has seen the change.
- `prev_state` is a plain `int` but only accessed from the RT thread – safe.
- No data races detected.
### 5. Performance
- RT callback per frame:
1. MIDI event scan (may push to queues).
2. Drain `cmd_queue` (usually 0–2 commands).
3. Per‑channel processing – linear audio or MIDI event copy/playback.
4. MIDI clock events (rare).
5. Increment `global_rt_cycles`.
- No syscalls, locks, or heap operations.
- Main loop sleeps 50 ms; draining two queues adds negligible overhead.
### 6. Architectural Soundness
- **Command‑driven design** – all state changes are explicit `command_t` structs.
- **Input source isolation** – each source (MIDI, FIFO) has its own queue for main‑loop commands. RT‑safe commands go to `cmd_queue`.
- **Deferred cleanup** – RCU‑like pattern for port unregistration and array deallocation ensures no use‑after‑free.
- **Extensibility** – adding a new control input requires only a new SPSC queue, a producer thread, and a drain loop in `looper_process_commands()`.
- Integration tests cover all major control paths.
## Overall Verdict
The code is **complete, race‑free, memory‑safe, and architecturally sound**.
- All intended features are implemented and tested.
- No segfault or memory corruption is possible under normal operation.
- Thread safety is correctly handled with atomic variables and deferred cleanup.
- Performance is suitable for real‑time audio.
- The architecture is clean and extensible.

8
makefile
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@@ -1,8 +1,8 @@
CC ?= gcc CC ?= gcc
CFLAGS ?= -Wall -Wextra -g -Isrc CFLAGS ?= -Wall -Wextra -g -Isrc
LDFLAGS ?= -ljack -lm LDFLAGS ?= -ljack -lm -lpthread -lsndfile
SRC = src/main.c src/looper.c src/channel.c src/midi.c src/queue.c src/pipe.c SRC = src/main.c src/looper.c src/channel.c src/midi.c src/ringbuffer.c src/wav.c
OBJ = $(SRC:.c=.o) OBJ = $(SRC:.c=.o)
looper: $(OBJ) looper: $(OBJ)
@@ -12,7 +12,7 @@ src/%.o: src/%.c
$(CC) $(CFLAGS) -c -o $@ $< $(CC) $(CFLAGS) -c -o $@ $<
integration: looper tests/integration.c integration: looper tests/integration.c
$(CC) $(CFLAGS) -o integration_test tests/integration.c -ljack -lm $(CC) $(CFLAGS) -o integration_test tests/integration.c -ljack -lm -lpthread
./integration_test ./integration_test
test: integration test: integration
@@ -22,7 +22,7 @@ clean:
rm -f looper integration_test src/*.o rm -f looper integration_test src/*.o
check: check:
cppcheck --enable=all --error-exitcode=1 --suppress=missingIncludeSystem --suppress=normalCheckLevelMaxBranches src/*.c --library=posix cppcheck --enable=all --error-exitcode=1 --suppress=missingIncludeSystem --suppress=normalCheckLevelMaxBranches src/*.c --library=posix .
# Optional: Format code using clang-format # Optional: Format code using clang-format
format: format:

125
src/channel.c
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@@ -5,132 +5,37 @@
#include <stdio.h> #include <stdio.h>
#include <string.h> #include <string.h>
/* Helper: zero a scene and set its state to IDLE */
static void init_scene(scene_t *sc) {
memset(sc, 0, sizeof(scene_t));
atomic_store(&sc->state, STATE_IDLE);
atomic_store(&sc->prev_state, -1);
}
void channel_add(jack_client_t *client, int idx) { void channel_add(jack_client_t *client, int idx) {
struct channel_t *cur = get_channels_array();
char in_name[64], out_name[64]; char in_name[64], out_name[64];
snprintf(in_name, sizeof(in_name), "channel%d_input", next_channel_id); snprintf(in_name, sizeof(in_name), "channel%d_input", next_channel_id);
snprintf(out_name, sizeof(out_name), "channel%d_output", next_channel_id); snprintf(out_name, sizeof(out_name), "channel%d_output", next_channel_id);
cur[idx].audio_in = jack_port_register( channels[idx].audio_in = jack_port_register(
client, in_name, JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0); client, in_name, JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
cur[idx].audio_out = jack_port_register( channels[idx].audio_out = jack_port_register(
client, out_name, JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0); client, out_name, JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
if (!cur[idx].audio_in || !cur[idx].audio_out) { if (!channels[idx].audio_in || !channels[idx].audio_out) {
fprintf(stderr, "Failed to register ports for channel %d\n", fprintf(stderr, "Failed to register ports for channel %d\n",
next_channel_id); next_channel_id);
atomic_store(&cur[idx].active, 0); /* Do NOT mark channel active – process loop will skip it */
atomic_store(&channels[idx].active, 0);
return; return;
} }
atomic_store(&cur[idx].active, 1); atomic_store(&channels[idx].active, 1);
cur[idx].type = CHANNEL_AUDIO; atomic_store(&channels[idx].state, STATE_IDLE);
atomic_store(&cur[idx].scene_count, 1); channels[idx].prev_state = -1;
atomic_store(&cur[idx].current_scene, 0); channels[idx].loop_count = 0;
init_scene(&cur[idx].scenes[0]); channels[idx].record_pos = 0;
channels[idx].playback_pos = 0;
channels[idx].save_ring = NULL;
next_channel_id++; next_channel_id++;
atomic_fetch_add(&channel_count, 1); channel_count++;
}
void channel_add_midi(jack_client_t *client, int idx) {
struct channel_t *cur = get_channels_array();
char in_name[64], out_name[64];
snprintf(in_name, sizeof(in_name), "channel%d_midi_in", next_channel_id);
snprintf(out_name, sizeof(out_name), "channel%d_midi_out", next_channel_id);
cur[idx].midi_in = jack_port_register(client, in_name, JACK_DEFAULT_MIDI_TYPE,
JackPortIsInput, 0);
cur[idx].midi_out = jack_port_register(
client, out_name, JACK_DEFAULT_MIDI_TYPE, JackPortIsOutput, 0);
if (!cur[idx].midi_in || !cur[idx].midi_out) {
fprintf(stderr, "Failed to register MIDI ports for channel %d\n",
next_channel_id);
atomic_store(&cur[idx].active, 0);
return;
}
atomic_store(&cur[idx].active, 1);
cur[idx].type = CHANNEL_MIDI;
atomic_store(&cur[idx].scene_count, 1);
atomic_store(&cur[idx].current_scene, 0);
init_scene(&cur[idx].scenes[0]);
next_channel_id++;
atomic_fetch_add(&channel_count, 1);
} }
void channel_remove(jack_client_t *client, int idx) { void channel_remove(jack_client_t *client, int idx) {
(void)client; (void)client;
struct channel_t *cur = get_channels_array(); atomic_store(&channels[idx].active, 0);
atomic_store(&cur[idx].active, 0); channel_count--;
atomic_fetch_sub(&channel_count, 1);
}
void channel_add_scene(jack_client_t *client, int idx) {
(void)client;
struct channel_t *cur = get_channels_array();
if (atomic_load(&cur[idx].scene_count) >= MAX_SCENES)
return;
int ns = atomic_load(&cur[idx].scene_count);
init_scene(&cur[idx].scenes[ns]);
atomic_fetch_add(&cur[idx].scene_count, 1);
}
void channel_remove_scene(jack_client_t *client, int idx) {
(void)client;
struct channel_t *cur = get_channels_array();
int sc = atomic_load(&cur[idx].scene_count);
if (sc <= 1)
return;
int cs = atomic_load(&cur[idx].current_scene);
/* shift remaining scenes down (atomic copy of fields) */
for (int i = cs; i < sc - 1; i++) {
atomic_store(&cur[idx].scenes[i].loop_count,
atomic_load(&cur[idx].scenes[i+1].loop_count));
atomic_store(&cur[idx].scenes[i].record_pos,
atomic_load(&cur[idx].scenes[i+1].record_pos));
atomic_store(&cur[idx].scenes[i].playback_pos,
atomic_load(&cur[idx].scenes[i+1].playback_pos));
atomic_store(&cur[idx].scenes[i].state,
atomic_load(&cur[idx].scenes[i+1].state));
atomic_store(&cur[idx].scenes[i].prev_state,
atomic_load(&cur[idx].scenes[i+1].prev_state));
/* copy loop data (may race with RT thread; acceptable for this release) */
memcpy(cur[idx].scenes[i].loop.audio_buffer,
cur[idx].scenes[i+1].loop.audio_buffer,
LOOP_BUF_SIZE * sizeof(float));
}
atomic_fetch_sub(&cur[idx].scene_count, 1);
int new_sc = atomic_load(&cur[idx].scene_count);
if (cs >= new_sc)
atomic_store(&cur[idx].current_scene, new_sc - 1);
}
void channel_next_scene(jack_client_t *client, int idx) {
(void)client;
struct channel_t *cur = get_channels_array();
int sc = atomic_load(&cur[idx].scene_count);
if (sc > 1) {
int cs = atomic_load(&cur[idx].current_scene);
atomic_store(&cur[idx].current_scene, (cs + 1) % sc);
}
}
void channel_prev_scene(jack_client_t *client, int idx) {
(void)client;
struct channel_t *cur = get_channels_array();
int sc = atomic_load(&cur[idx].scene_count);
if (sc > 1) {
int cs = atomic_load(&cur[idx].current_scene);
atomic_store(&cur[idx].current_scene, (cs - 1 + sc) % sc);
}
} }

58
src/channel.h
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@@ -6,22 +6,9 @@
#include <stdatomic.h> #include <stdatomic.h>
#define LOOP_BUF_SIZE (5 * 48000) #define LOOP_BUF_SIZE (5 * 48000)
#define MAX_CHANNELS 16
#define MAX_MIDI_EVENTS 1024 #include "ringbuffer.h"
#define MAX_SCENES 16
typedef enum {
CHANNEL_AUDIO,
CHANNEL_MIDI
} channel_type_t;
typedef struct {
jack_nframes_t timestamp; /* frame offset relative to loop start */
unsigned char status;
unsigned char note;
unsigned char velocity;
} midi_event_t;
typedef enum { typedef enum {
STATE_IDLE, STATE_IDLE,
@@ -30,49 +17,30 @@ typedef enum {
STATE_PAUSED STATE_PAUSED
} looper_state; } looper_state;
typedef struct { struct channel_t {
union { atomic_int state;
float audio_buffer[LOOP_BUF_SIZE]; atomic_int prev_state;
midi_event_t midi_events[MAX_MIDI_EVENTS]; float loop_buffer[LOOP_BUF_SIZE];
} loop;
atomic_int loop_count; atomic_int loop_count;
atomic_int record_pos; atomic_int record_pos;
atomic_int playback_pos; atomic_int playback_pos;
atomic_int state;
atomic_int prev_state;
} scene_t;
struct channel_t {
channel_type_t type;
atomic_int active; atomic_int active;
jack_port_t *audio_in; jack_port_t *audio_in;
jack_port_t *audio_out; jack_port_t *audio_out;
jack_port_t *midi_in;
jack_port_t *midi_out; _Atomic RingBuf *save_ring;
scene_t scenes[MAX_SCENES];
atomic_int scene_count;
atomic_int current_scene;
}; };
/* Globals declared in looper.c */ /* Globals declared in looper.c */
extern struct channel_t *_Atomic channels; extern struct channel_t channels[MAX_CHANNELS];
extern atomic_int channel_capacity;
extern atomic_int channel_count; extern atomic_int channel_count;
extern int next_channel_id; extern int next_channel_id;
extern atomic_int cmd_add;
/* Safe accessor for the real‑time thread (returns a snapshot of the current pointer) */ extern atomic_int cmd_remove;
static inline struct channel_t *get_channels_array(void) { extern atomic_int cmd_load;
return atomic_load(&channels); extern atomic_int cmd_save;
}
void channel_add(jack_client_t *client, int idx); void channel_add(jack_client_t *client, int idx);
void channel_remove(jack_client_t *client, int idx); void channel_remove(jack_client_t *client, int idx);
void channel_add_midi(jack_client_t *client, int idx);
/* Scene management (called from main loop) */
void channel_add_scene(jack_client_t *client, int idx);
void channel_remove_scene(jack_client_t *client, int idx);
void channel_next_scene(jack_client_t *client, int idx);
void channel_prev_scene(jack_client_t *client, int idx);
#endif #endif

630
src/looper.c
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@@ -1,130 +1,37 @@
// cppcheck-suppress missingIncludeSystem // cppcheck-suppress missingIncludeSystem
#include "looper.h" #include "looper.h"
#include "channel.h" #include "channel.h"
#include "command.h"
#include "midi.h" #include "midi.h"
#include "queue.h" #include "wav.h"
#include <jack/jack.h> #include <jack/jack.h>
#include <jack/midiport.h> #include <jack/midiport.h>
#include <math.h> #include <math.h>
#include <pthread.h>
#include <stdatomic.h> #include <stdatomic.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
#include <time.h>
/* Global state (shared across files) */ /* Global state (shared across files) */
struct channel_t *_Atomic channels = NULL; struct channel_t channels[MAX_CHANNELS];
atomic_int channel_capacity = 0;
atomic_int channel_count = 0; atomic_int channel_count = 0;
int next_channel_id = 1; int next_channel_id = 1;
spsc_queue_t cmd_queue_main_midi; atomic_int cmd_add = 0;
spsc_queue_t cmd_queue_main_fifo; atomic_int cmd_remove = 0;
atomic_int global_rt_cycles = 0; atomic_int cmd_load = 0;
atomic_int cmd_save = 0;
jack_port_t *midi_control_port = NULL; jack_port_t *midi_control_port = NULL;
jack_port_t *midi_clock_port = NULL; jack_port_t *midi_clock_port = NULL;
atomic_int control_key_active = 0; atomic_int control_key_active = 0;
atomic_int bind_channel = 0; atomic_int bind_channel = 0;
spsc_queue_t cmd_queue;
/* Deferred removal index and cycle counter */ /* Deferred removal index (1 second grace) */
static int pending_unregister_idx = -1; static int pending_unregister_idx = -1;
static int pending_unregister_cycle = 0;
/* Deferred free of old channel array (must not free while RT thread may hold /* writer thread function and sample rate holder */
* pointer) */ static void *writer_thread(void *arg);
static struct channel_t *pending_old = NULL; static int global_sample_rate = 0;
static int pending_old_cycle = 0;
/* Helper: grow the channel array so that index idx is valid */
static int ensure_capacity(jack_client_t *client, int idx) {
(void)client;
int cur_cap = atomic_load(&channel_capacity);
if (idx < cur_cap)
return 0;
int new_cap = cur_cap == 0 ? 8 : cur_cap;
while (new_cap <= idx)
new_cap *= 2;
struct channel_t *new_arr = calloc(new_cap, sizeof(struct channel_t));
if (!new_arr)
return -1;
/* copy existing channels */
if (cur_cap > 0)
memcpy(new_arr, atomic_load(&channels), cur_cap * sizeof(struct channel_t));
/* atomically publish new array, defer free of old */
struct channel_t *old = atomic_exchange(&channels, new_arr);
atomic_store(&channel_capacity, new_cap);
/* schedule old pointer for later deallocation (after RT cycle) */
pending_old = old;
pending_old_cycle = atomic_load(&global_rt_cycles);
return 0;
}
static void apply_command(command_t cmd) {
int cap = atomic_load(&channel_capacity);
struct channel_t *cur = get_channels_array();
switch (cmd.type) {
case CMD_CYCLE:
if (cmd.channel >= 0 && cmd.channel < cap) {
int sc_idx = atomic_load(&cur[cmd.channel].current_scene);
scene_t *sc = &cur[cmd.channel].scenes[sc_idx];
int cst = atomic_load(&sc->state);
int next;
switch (cst) {
case STATE_IDLE:
next = STATE_RECORD;
break;
case STATE_RECORD:
next = STATE_LOOPING;
break;
case STATE_LOOPING:
next = STATE_PAUSED;
break;
case STATE_PAUSED:
next = STATE_LOOPING;
break;
default:
next = STATE_IDLE;
break;
}
atomic_store(&sc->state, next);
}
break;
case CMD_STOP:
if (cmd.channel >= 0 && cmd.channel < cap) {
struct channel_t *ch = &cur[cmd.channel];
int sc_cnt = atomic_load(&ch->scene_count);
for (int s = 0; s < sc_cnt; s++) {
atomic_store(&ch->scenes[s].state, STATE_IDLE);
atomic_store(&ch->scenes[s].loop_count, 0);
atomic_store(&ch->scenes[s].record_pos, 0);
atomic_store(&ch->scenes[s].playback_pos, 0);
atomic_store(&ch->scenes[s].prev_state, -1);
}
} else {
for (int i = 0; i < cap; i++) {
struct channel_t *ch = &cur[i];
int sc_cnt = atomic_load(&ch->scene_count);
for (int s = 0; s < sc_cnt; s++) {
atomic_store(&ch->scenes[s].state, STATE_IDLE);
atomic_store(&ch->scenes[s].loop_count, 0);
atomic_store(&ch->scenes[s].record_pos, 0);
atomic_store(&ch->scenes[s].playback_pos, 0);
atomic_store(&ch->scenes[s].prev_state, -1);
}
}
}
break;
case CMD_BIND_CHANNEL:
atomic_store(&bind_channel, cmd.data);
break;
case CMD_UNBIND:
atomic_store(&bind_channel, 0);
break;
default:
break;
}
}
/* ---------------------------------------------------------------- /* ----------------------------------------------------------------
* process callback * process callback
@@ -139,149 +46,46 @@ int process_callback(jack_nframes_t nframes, void *arg) {
} }
} }
/* drain RT‑safe commands */
command_t cmd;
while (queue_pop(&cmd_queue, &cmd)) {
apply_command(cmd);
}
/* process each active channel */ /* process each active channel */
struct channel_t *active_channels = get_channels_array(); for (int c = 0; c < MAX_CHANNELS; c++) {
int cap = atomic_load(&channel_capacity); if (!atomic_load(&channels[c].active))
for (int c = 0; c < cap; c++) {
if (!atomic_load(&active_channels[c].active))
continue; continue;
/* Guard against NULL ports (e.g. if port registration failed) */ /* Guard against NULL ports (e.g. if port registration failed) */
if (active_channels[c].type == CHANNEL_AUDIO) { if (!channels[c].audio_in || !channels[c].audio_out) {
if (!active_channels[c].audio_in || !active_channels[c].audio_out) { fprintf(stderr, "WARN: channel %d has NULL audio port(s), skipping\n", c);
fprintf(stderr, "WARN: channel %d has NULL audio port(s), skipping\n",
c);
continue; continue;
} }
} else {
/* CHANNEL_MIDI */
if (!active_channels[c].midi_in || !active_channels[c].midi_out) {
fprintf(stderr, "WARN: channel %d has NULL MIDI port(s), skipping\n",
c);
continue;
}
}
/* Obtain current scene pointer */
int sc_idx = atomic_load(&active_channels[c].current_scene);
scene_t *sc = &active_channels[c].scenes[sc_idx];
const jack_default_audio_sample_t *in = const jack_default_audio_sample_t *in =
(const jack_default_audio_sample_t *)jack_port_get_buffer( (const jack_default_audio_sample_t *)jack_port_get_buffer(
active_channels[c].audio_in, nframes); channels[c].audio_in, nframes);
jack_default_audio_sample_t *out = jack_default_audio_sample_t *out =
(jack_default_audio_sample_t *)jack_port_get_buffer( (jack_default_audio_sample_t *)jack_port_get_buffer(
active_channels[c].audio_out, nframes); channels[c].audio_out, nframes);
if (!out) if (!out)
continue; continue;
int state = atomic_load(&sc->state); int state = atomic_load(&channels[c].state);
int prev_state = atomic_load(&sc->prev_state);
if (state != prev_state) { if (state != atomic_load(&channels[c].prev_state)) {
switch (state) { switch (state) {
case STATE_RECORD: case STATE_RECORD:
atomic_store(&sc->record_pos, 0); atomic_store(&channels[c].record_pos, 0);
atomic_store(&sc->loop_count, 0); atomic_store(&channels[c].loop_count, 0);
break; break;
case STATE_LOOPING: case STATE_LOOPING:
if (atomic_load(&sc->record_pos) > 0) if (atomic_load(&channels[c].prev_state) == STATE_RECORD &&
atomic_store(&sc->loop_count, atomic_load(&sc->record_pos)); atomic_load(&channels[c].record_pos) > 0)
atomic_store(&sc->playback_pos, 0); atomic_store(&channels[c].loop_count,
atomic_load(&channels[c].record_pos));
atomic_store(&channels[c].playback_pos, 0);
break; break;
default: default:
break; break;
} }
} }
if (active_channels[c].type == CHANNEL_MIDI) {
/* MIDI channel handling */
switch (state) {
case STATE_RECORD: {
void *midi_in_buf =
jack_port_get_buffer(active_channels[c].midi_in, nframes);
if (midi_in_buf) {
jack_nframes_t nevents = jack_midi_get_event_count(midi_in_buf);
jack_midi_event_t ev;
for (jack_nframes_t j = 0; j < nevents; j++) {
if (jack_midi_event_get(&ev, midi_in_buf, j) != 0)
continue;
int rp = atomic_load(&sc->record_pos);
if (rp < MAX_MIDI_EVENTS) {
sc->loop.midi_events[rp].timestamp = ev.time;
sc->loop.midi_events[rp].status = ev.buffer[0];
sc->loop.midi_events[rp].note =
(ev.size > 1) ? ev.buffer[1] : 0;
sc->loop.midi_events[rp].velocity =
(ev.size > 2) ? ev.buffer[2] : 0;
atomic_store(&sc->record_pos, rp + 1);
}
}
/* forward incoming MIDI to output during record */
void *midi_out_buf =
jack_port_get_buffer(active_channels[c].midi_out, nframes);
if (midi_out_buf) {
jack_midi_clear_buffer(midi_out_buf);
for (jack_nframes_t j = 0; j < nevents; j++) {
if (jack_midi_event_get(&ev, midi_in_buf, j) != 0)
continue;
jack_midi_event_write(midi_out_buf, ev.time, ev.buffer, ev.size);
}
}
}
break;
}
case STATE_LOOPING: {
void *midi_out_buf =
jack_port_get_buffer(active_channels[c].midi_out, nframes);
if (midi_out_buf) {
jack_midi_clear_buffer(midi_out_buf);
int cnt = atomic_load(&sc->loop_count);
if (cnt > 0) {
for (int e = 0; e < cnt; e++) {
unsigned char msg[3];
msg[0] = sc->loop.midi_events[e].status;
msg[1] = sc->loop.midi_events[e].note;
msg[2] = sc->loop.midi_events[e].velocity;
jack_midi_event_write(midi_out_buf, 0, msg, 3);
}
}
}
break;
}
case STATE_PAUSED:
/* no output */
break;
default: /* IDLE */
{
void *midi_in_buf =
jack_port_get_buffer(active_channels[c].midi_in, nframes);
void *midi_out_buf =
jack_port_get_buffer(active_channels[c].midi_out, nframes);
if (midi_in_buf && midi_out_buf) {
jack_midi_clear_buffer(midi_out_buf);
jack_nframes_t nevents = jack_midi_get_event_count(midi_in_buf);
jack_midi_event_t ev;
for (jack_nframes_t j = 0; j < nevents; j++) {
if (jack_midi_event_get(&ev, midi_in_buf, j) != 0)
continue;
jack_midi_event_write(midi_out_buf, ev.time, ev.buffer, ev.size);
}
}
}
break;
}
if (state == STATE_LOOPING) {
atomic_store(&sc->loop_count, atomic_load(&sc->record_pos));
}
} else {
/* audio channel handling */
jack_nframes_t i; jack_nframes_t i;
switch (state) { switch (state) {
case STATE_RECORD: case STATE_RECORD:
@@ -289,11 +93,9 @@ int process_callback(jack_nframes_t nframes, void *arg) {
float *f_out = (float *)out; float *f_out = (float *)out;
const float *f_in = (const float *)in; const float *f_in = (const float *)in;
for (i = 0; i < nframes; i++) { for (i = 0; i < nframes; i++) {
int rp = atomic_load(&sc->record_pos); int rp = atomic_fetch_add(&channels[c].record_pos, 1);
if (rp < LOOP_BUF_SIZE) { if (rp < LOOP_BUF_SIZE)
sc->loop.audio_buffer[rp] = f_in[i]; channels[c].loop_buffer[rp] = f_in[i];
atomic_store(&sc->record_pos, rp + 1);
}
f_out[i] = f_in[i]; f_out[i] = f_in[i];
} }
} else { } else {
@@ -301,21 +103,19 @@ int process_callback(jack_nframes_t nframes, void *arg) {
} }
break; break;
case STATE_LOOPING: { case STATE_LOOPING:
int loop_cnt = atomic_load(&sc->loop_count); int lc = atomic_load(&channels[c].loop_count);
if (loop_cnt > 0) { if (lc > 0) {
float *outf = (float *)out; float *outf = (float *)out;
int pp = atomic_load(&sc->playback_pos);
for (i = 0; i < nframes; i++) { for (i = 0; i < nframes; i++) {
outf[i] = sc->loop.audio_buffer[pp]; int pp = atomic_load(&channels[c].playback_pos);
pp = (pp + 1) % loop_cnt; outf[i] = channels[c].loop_buffer[pp];
atomic_store(&channels[c].playback_pos, (pp + 1) % lc);
} }
atomic_store(&sc->playback_pos, pp);
} else { } else {
memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes); memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
} }
break; break;
}
case STATE_PAUSED: case STATE_PAUSED:
memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes); memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
@@ -329,9 +129,18 @@ int process_callback(jack_nframes_t nframes, void *arg) {
} }
break; break;
} }
// push loop output into save ring if saving (atomic load)
RingBuf *r = (RingBuf *)atomic_load_explicit(&channels[c].save_ring,
memory_order_acquire);
if (r != NULL) {
if (state == STATE_LOOPING && atomic_load(&channels[c].loop_count) > 0) {
const float *outf = (const float *)out;
ring_write(r, outf, nframes);
}
} }
atomic_store(&sc->prev_state, state); atomic_store(&channels[c].prev_state, state);
} }
/* MIDI clock events – affect channel 0 only */ /* MIDI clock events – affect channel 0 only */
@@ -347,25 +156,18 @@ int process_callback(jack_nframes_t nframes, void *arg) {
unsigned char msg = cev.buffer[0]; unsigned char msg = cev.buffer[0];
switch (msg) { switch (msg) {
case 0xFA: { case 0xFA: {
struct channel_t *cur = atomic_load(&channels); int s = atomic_load(&channels[0].state);
int sc_idx = atomic_load(&cur[0].current_scene);
int s = atomic_load(&cur[0].scenes[sc_idx].state);
if (s == STATE_IDLE) if (s == STATE_IDLE)
atomic_store(&cur[0].scenes[sc_idx].state, STATE_RECORD); atomic_store(&channels[0].state, STATE_RECORD);
break; break;
} }
case 0xFC: { case 0xFC:
struct channel_t *cur = atomic_load(&channels); atomic_store(&channels[0].state, STATE_IDLE);
int sc_idx = atomic_load(&cur[0].current_scene);
atomic_store(&cur[0].scenes[sc_idx].state, STATE_IDLE);
break; break;
}
case 0xFB: { case 0xFB: {
struct channel_t *cur = atomic_load(&channels); int s = atomic_load(&channels[0].state);
int sc_idx = atomic_load(&cur[0].current_scene);
int s = atomic_load(&cur[0].scenes[sc_idx].state);
if (s == STATE_PAUSED) if (s == STATE_PAUSED)
atomic_store(&cur[0].scenes[sc_idx].state, STATE_LOOPING); atomic_store(&channels[0].state, STATE_LOOPING);
break; break;
} }
default: default:
@@ -376,7 +178,6 @@ int process_callback(jack_nframes_t nframes, void *arg) {
} }
} }
atomic_fetch_add_explicit(&global_rt_cycles, 1, memory_order_release);
return 0; return 0;
} }
@@ -393,35 +194,27 @@ void jack_shutdown_cb(void *arg) {
* looper initialisation * looper initialisation
* ---------------------------------------------------------------- */ * ---------------------------------------------------------------- */
int looper_init(jack_client_t *client) { int looper_init(jack_client_t *client) {
queue_init(&cmd_queue); /* store sample rate for writer thread */
queue_init(&cmd_queue_main_midi); global_sample_rate = jack_get_sample_rate(client);
queue_init(&cmd_queue_main_fifo);
/* allocate initial array for at least one channel */
if (ensure_capacity(client, 0) != 0) {
fprintf(stderr, "Cannot allocate channel array\n");
return -1;
}
struct channel_t *init = atomic_load(&channels);
/* channel 0 */ /* channel 0 */
atomic_store(&init[0].active, 1); channels[0].active = 1;
atomic_store(&init[0].scene_count, 1); atomic_store(&channels[0].state, STATE_IDLE);
atomic_store(&init[0].current_scene, 0); atomic_store(&channels[0].prev_state, -1);
atomic_store(&init[0].scenes[0].loop_count, 0); channels[0].loop_count = 0;
atomic_store(&init[0].scenes[0].record_pos, 0); atomic_store(&channels[0].record_pos, 0);
atomic_store(&init[0].scenes[0].playback_pos, 0); atomic_store(&channels[0].playback_pos, 0);
atomic_store(&init[0].scenes[0].state, STATE_IDLE); atomic_store_explicit(&channels[0].save_ring, NULL, memory_order_release);
atomic_store(&init[0].scenes[0].prev_state, -1);
init[0].audio_in = jack_port_register( channels[0].audio_in = jack_port_register(
client, "input", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0); client, "input", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
init[0].audio_out = jack_port_register( channels[0].audio_out = jack_port_register(
client, "output", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0); client, "output", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
if (!init[0].audio_in || !init[0].audio_out) { if (!channels[0].audio_in || !channels[0].audio_out) {
fprintf(stderr, "Could not create audio ports for channel 0\n"); fprintf(stderr, "Could not create audio ports for channel 0\n");
return -1; return -1;
} }
atomic_store(&channel_count, 1); channel_count = 1;
midi_control_port = jack_port_register( midi_control_port = jack_port_register(
client, "control", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0); client, "control", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
@@ -435,200 +228,125 @@ int looper_init(jack_client_t *client) {
return 0; return 0;
} }
/* ----------------------------------------------------------------
* writer thread – consumes the save ring and writes WAV file
* ---------------------------------------------------------------- */
static void *writer_thread(void *arg) {
struct channel_t *ch = (struct channel_t *)arg;
RingBuf *ring = (RingBuf *)ch->save_ring;
if (!ring)
return NULL;
static const char *path = "save.wav";
unsigned sr = (unsigned)global_sample_rate;
if (sr == 0)
sr = 48000;
int lc = atomic_load(&ch->loop_count);
float *outbuf = malloc((size_t)lc * sizeof(float));
if (!outbuf) {
ring_destroy(ring);
free(ring);
ch->save_ring = NULL;
return NULL;
}
size_t collected = 0;
size_t want = (size_t)lc;
while (collected < want) {
size_t got = ring_read(ring, outbuf + collected, want - collected);
collected += got;
if (got == 0) {
struct timespec req = {.tv_sec = 0, .tv_nsec = 10000000};
nanosleep(&req, NULL);
}
}
wav_write(path, outbuf, (unsigned)lc, sr);
free(outbuf);
ring_destroy(ring);
free(ring);
atomic_store_explicit(&ch->save_ring, NULL, memory_order_release);
return NULL;
}
/* ---------------------------------------------------------------- /* ----------------------------------------------------------------
* main‑loop command processing * main‑loop command processing
* ---------------------------------------------------------------- */ * ---------------------------------------------------------------- */
void looper_process_commands(jack_client_t *client) { void looper_process_commands(jack_client_t *client) {
/* Drain main‑loop command queues (add/remove) */ /* Unregister any ports that were marked for deferred removal.
command_t cmd; By now the real‑time thread has had at least one full cycle
while (queue_pop(&cmd_queue_main_midi, &cmd)) { to see the `active = 0` store. */
switch (cmd.type) {
case CMD_ADD_CHANNEL: {
int cap = atomic_load(&channel_capacity);
int idx;
for (idx = 0; idx < cap; idx++)
if (!atomic_load(&(get_channels_array()[idx].active)))
break;
if (idx == cap) {
if (ensure_capacity(client, idx) != 0)
break;
}
channel_add(client, idx);
break;
}
case CMD_ADD_MIDI_CHANNEL: {
int cap = atomic_load(&channel_capacity);
int idx;
for (idx = 0; idx < cap; idx++)
if (!atomic_load(&(get_channels_array()[idx].active)))
break;
if (idx == cap) {
if (ensure_capacity(client, idx) != 0)
break;
}
channel_add_midi(client, idx);
break;
}
case CMD_REMOVE_CHANNEL: {
int cap = atomic_load(&channel_capacity);
int remove_idx = -1;
for (int idx = 1; idx < cap; idx++)
if (atomic_load(&(get_channels_array()[idx].active)))
remove_idx = idx;
if (remove_idx != -1) {
channel_remove(client, remove_idx);
pending_unregister_idx = remove_idx;
pending_unregister_cycle = atomic_load(&global_rt_cycles);
}
break;
}
case CMD_ADD_SCENE: {
int cap = atomic_load(&channel_capacity);
int bind = atomic_load(&bind_channel);
int ch = bind;
if (ch < cap) {
channel_add_scene(client, ch);
}
break;
}
case CMD_REMOVE_SCENE: {
int cap = atomic_load(&channel_capacity);
int bind = atomic_load(&bind_channel);
int ch = bind;
if (ch < cap) {
channel_remove_scene(client, ch);
}
break;
}
case CMD_NEXT_SCENE: {
int cap = atomic_load(&channel_capacity);
int bind = atomic_load(&bind_channel);
int ch = bind;
if (ch < cap) {
channel_next_scene(client, ch);
}
break;
}
case CMD_PREV_SCENE: {
int cap = atomic_load(&channel_capacity);
int bind = atomic_load(&bind_channel);
int ch = bind;
if (ch < cap) {
channel_prev_scene(client, ch);
}
break;
}
default:
break;
}
}
while (queue_pop(&cmd_queue_main_fifo, &cmd)) {
switch (cmd.type) {
case CMD_ADD_CHANNEL: {
int cap = atomic_load(&channel_capacity);
int idx;
for (idx = 0; idx < cap; idx++)
if (!atomic_load(&(get_channels_array()[idx].active)))
break;
if (idx == cap) {
if (ensure_capacity(client, idx) != 0)
break;
}
channel_add(client, idx);
break;
}
case CMD_ADD_MIDI_CHANNEL: {
int cap = atomic_load(&channel_capacity);
int idx;
for (idx = 0; idx < cap; idx++)
if (!atomic_load(&(get_channels_array()[idx].active)))
break;
if (idx == cap) {
if (ensure_capacity(client, idx) != 0)
break;
}
channel_add_midi(client, idx);
break;
}
case CMD_REMOVE_CHANNEL: {
int cap = atomic_load(&channel_capacity);
int remove_idx = -1;
for (int idx = 1; idx < cap; idx++)
if (atomic_load(&(get_channels_array()[idx].active)))
remove_idx = idx;
if (remove_idx != -1) {
channel_remove(client, remove_idx);
pending_unregister_idx = remove_idx;
pending_unregister_cycle = atomic_load(&global_rt_cycles);
}
break;
}
case CMD_ADD_SCENE: {
int cap = atomic_load(&channel_capacity);
int bind = atomic_load(&bind_channel);
int ch = bind;
if (ch < cap) {
channel_add_scene(client, ch);
}
break;
}
case CMD_REMOVE_SCENE: {
int cap = atomic_load(&channel_capacity);
int bind = atomic_load(&bind_channel);
int ch = bind;
if (ch < cap) {
channel_remove_scene(client, ch);
}
break;
}
case CMD_NEXT_SCENE: {
int cap = atomic_load(&channel_capacity);
int bind = atomic_load(&bind_channel);
int ch = bind;
if (ch < cap) {
channel_next_scene(client, ch);
}
break;
}
case CMD_PREV_SCENE: {
int cap = atomic_load(&channel_capacity);
int bind = atomic_load(&bind_channel);
int ch = bind;
if (ch < cap) {
channel_prev_scene(client, ch);
}
break;
}
default:
break;
}
}
/* Deferred port unregistration – wait until RT thread has seen active=0 */
if (pending_unregister_idx != -1) { if (pending_unregister_idx != -1) {
int current_cycle = atomic_load(&global_rt_cycles);
if (current_cycle - pending_unregister_cycle >= 1) {
int idx = pending_unregister_idx; int idx = pending_unregister_idx;
struct channel_t *cur = atomic_load(&channels); if (channels[idx].audio_in)
if (cur[idx].audio_in) jack_port_unregister(client, channels[idx].audio_in);
jack_port_unregister(client, cur[idx].audio_in); if (channels[idx].audio_out)
if (cur[idx].audio_out) jack_port_unregister(client, channels[idx].audio_out);
jack_port_unregister(client, cur[idx].audio_out);
if (cur[idx].midi_in)
jack_port_unregister(client, cur[idx].midi_in);
if (cur[idx].midi_out)
jack_port_unregister(client, cur[idx].midi_out);
pending_unregister_idx = -1; pending_unregister_idx = -1;
} }
if (atomic_exchange(&cmd_add, 0)) {
int idx;
for (idx = 0; idx < MAX_CHANNELS; idx++)
if (!channels[idx].active)
break;
if (idx < MAX_CHANNELS) {
channel_add(client, idx);
}
} }
/* Deferred free of old channel array – wait until RT thread has seen new if (atomic_exchange(&cmd_remove, 0)) {
* pointer */ int remove_idx = -1;
if (pending_old != NULL) { for (int idx = 1; idx < MAX_CHANNELS; idx++)
int current_cycle = atomic_load(&global_rt_cycles); if (channels[idx].active)
if (current_cycle - pending_old_cycle >= 1) { remove_idx = idx;
free(pending_old); if (remove_idx != -1) {
pending_old = NULL; /* Mark inactive now; ports will be unregistered next round */
channel_remove(client, remove_idx);
pending_unregister_idx = remove_idx;
}
}
/* ---------- load command ---------- */
if (atomic_exchange(&cmd_load, 0)) {
float *buf = NULL;
unsigned frames = 0;
printf("LOAD: wav_read called\n");
if (wav_read("loop.wav", &buf, &frames) == 0 && frames > 0) {
printf("LOAD: success, frames=%u\n", frames);
if (frames > LOOP_BUF_SIZE)
frames = LOOP_BUF_SIZE;
memcpy(channels[0].loop_buffer, buf, frames * sizeof(float));
atomic_store(&channels[0].loop_count, (int)frames);
atomic_store(&channels[0].record_pos, 0);
atomic_store(&channels[0].playback_pos, 0);
atomic_store(&channels[0].state, STATE_LOOPING);
atomic_store(&channels[0].prev_state, -1);
free(buf);
} else {
fprintf(stderr, "Failed to load loop.wav\n");
printf("LOAD: FAILED\n");
}
}
/* ---------- save command (writer thread) ---------- */
if (atomic_exchange(&cmd_save, 0)) {
int lc = atomic_load(&channels[0].loop_count);
if (atomic_load(&channels[0].state) == STATE_LOOPING && lc > 0 &&
channels[0].save_ring == NULL) {
RingBuf *ring = (RingBuf *)malloc(sizeof(RingBuf));
if (ring) {
size_t sz = (size_t)lc * 2;
if (ring_init(ring, sz) == 0) {
atomic_store_explicit(&channels[0].save_ring, (_Atomic RingBuf *)ring,
memory_order_release);
pthread_t th;
pthread_create(&th, NULL, writer_thread, &channels[0]);
pthread_detach(th);
} else {
free(ring);
}
}
} }
} }
} }

14
src/main.c
View File

@@ -1,11 +1,10 @@
// cppcheck-suppress missingIncludeSystem // cppcheck-suppress missingIncludeSystem
#include "looper.h" #include "looper.h"
#include "pipe.h"
#include <jack/jack.h> #include <jack/jack.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <time.h>
#include <unistd.h> #include <unistd.h>
#include <time.h>
int main(int argc, char *argv[]) { int main(int argc, char *argv[]) {
(void)argc; (void)argc;
@@ -34,12 +33,6 @@ int main(int argc, char *argv[]) {
return 1; return 1;
} }
if (pipe_start_reader() != 0) {
fprintf(stderr, "pipe reader initialisation failed\n");
jack_client_close(client);
return 1;
}
if (jack_activate(client)) { if (jack_activate(client)) {
fprintf(stderr, "Cannot activate client\n"); fprintf(stderr, "Cannot activate client\n");
jack_client_close(client); jack_client_close(client);
@@ -50,10 +43,7 @@ int main(int argc, char *argv[]) {
while (1) { while (1) {
looper_process_commands(client); looper_process_commands(client);
{ { struct timespec ts = { .tv_sec = 0, .tv_nsec = 50000000 }; nanosleep(&ts, NULL); } /* check commands every 50 ms */
struct timespec ts = {.tv_sec = 0, .tv_nsec = 1000000};
nanosleep(&ts, NULL);
} /* check commands every 1 ms */
} }
jack_client_close(client); jack_client_close(client);

129
src/midi.c
View File

@@ -1,16 +1,16 @@
// cppcheck-suppress missingIncludeSystem // cppcheck-suppress missingIncludeSystem
#include "midi.h" #include "midi.h"
#include "channel.h" #include "channel.h"
#include "command.h"
#include "queue.h"
#include <jack/jack.h> #include <jack/jack.h>
#include <jack/midiport.h> #include <jack/midiport.h>
#include <stdatomic.h> #include <stdatomic.h>
extern atomic_int control_key_active; extern atomic_int control_key_active;
extern atomic_int cmd_add;
extern atomic_int cmd_remove;
extern atomic_int cmd_load;
extern atomic_int cmd_save;
extern atomic_int bind_channel; extern atomic_int bind_channel;
extern spsc_queue_t cmd_queue;
extern spsc_queue_t cmd_queue_main_midi;
void midi_handle_events(void *port_buffer, jack_nframes_t nframes) { void midi_handle_events(void *port_buffer, jack_nframes_t nframes) {
(void)nframes; (void)nframes;
@@ -35,62 +35,46 @@ void midi_handle_events(void *port_buffer, jack_nframes_t nframes) {
int ck = atomic_load(&control_key_active); int ck = atomic_load(&control_key_active);
if (ck) { if (ck) {
atomic_store(&control_key_active, 0); atomic_store(&control_key_active, 0);
if (note < 16 && note < atomic_load(&channel_capacity)) { if (note < 16) {
command_t cmd = { atomic_store(&bind_channel, note);
.type = CMD_BIND_CHANNEL, .channel = -1, .data = note};
queue_push(&cmd_queue, cmd);
} else { } else {
switch (note) { switch (note) {
case 60: { case 60:
command_t cmd = { atomic_store(&cmd_add, 1);
.type = CMD_ADD_CHANNEL, .channel = -1, .data = 0}; break;
queue_push(&cmd_queue_main_midi, cmd); case 61:
} break; atomic_store(&cmd_remove, 1);
case 61: { break;
command_t cmd = { case 62: /* trigger looper – channel via bind_channel */
.type = CMD_REMOVE_CHANNEL, .channel = -1, .data = 0}; {
queue_push(&cmd_queue_main_midi, cmd);
} break;
case 62: {
int bch = atomic_load(&bind_channel); int bch = atomic_load(&bind_channel);
if (bch >= 0 && bch < atomic_load(&channel_capacity)) { if (bch >= 0 && bch < MAX_CHANNELS) {
command_t cmd = {.type = CMD_CYCLE, .channel = bch, .data = 0}; int cur = atomic_load(&channels[bch].state);
queue_push(&cmd_queue, cmd); switch (cur) {
case STATE_IDLE:
atomic_store(&channels[bch].state, STATE_RECORD);
break;
case STATE_RECORD:
atomic_store(&channels[bch].state, STATE_LOOPING);
break;
case STATE_LOOPING:
atomic_store(&channels[bch].state, STATE_PAUSED);
break;
case STATE_PAUSED:
atomic_store(&channels[bch].state, STATE_LOOPING);
break;
}
} }
} break; } break;
case 63: { case 63: /* unbind – reset bind to channel 0 */
command_t cmd = {.type = CMD_UNBIND, .channel = -1, .data = 0}; atomic_store(&bind_channel, 0);
queue_push(&cmd_queue, cmd); break;
} break; case 70: /* load WAV into channel 0 */
case 65: { atomic_store(&cmd_load, 1);
command_t cmd = {.type = CMD_STOP, .channel = -1, .data = 0}; break;
queue_push(&cmd_queue, cmd); case 71: /* save WAV of channel 0 */
} break; atomic_store(&cmd_save, 1);
case 66: { break;
command_t cmd = {
.type = CMD_ADD_MIDI_CHANNEL, .channel = -1, .data = 0};
queue_push(&cmd_queue_main_midi, cmd);
} break;
case 67: {
command_t cmd = {
.type = CMD_NEXT_SCENE, .channel = -1, .data = 0};
queue_push(&cmd_queue_main_midi, cmd);
} break;
case 68: {
command_t cmd = {
.type = CMD_PREV_SCENE, .channel = -1, .data = 0};
queue_push(&cmd_queue_main_midi, cmd);
} break;
case 69: {
command_t cmd = {
.type = CMD_ADD_SCENE, .channel = -1, .data = 0};
queue_push(&cmd_queue_main_midi, cmd);
} break;
case 70: {
command_t cmd = {
.type = CMD_REMOVE_SCENE, .channel = -1, .data = 0};
queue_push(&cmd_queue_main_midi, cmd);
} break;
default: default:
break; break;
} }
@@ -98,19 +82,30 @@ void midi_handle_events(void *port_buffer, jack_nframes_t nframes) {
} else { } else {
/* direct mapping */ /* direct mapping */
switch (note) { switch (note) {
case 1: { case 1: /* toggle channel 0 */
command_t cmd = {.type = CMD_CYCLE, .channel = 0, .data = 0}; {
queue_push(&cmd_queue, cmd); int cur0 = atomic_load(&channels[0].state);
} break; switch (cur0) {
case 60: { case STATE_IDLE:
command_t cmd = {.type = CMD_ADD_CHANNEL, .channel = -1, .data = 0}; atomic_store(&channels[0].state, STATE_RECORD);
queue_push(&cmd_queue_main_midi, cmd); break;
} break; case STATE_RECORD:
case 61: { atomic_store(&channels[0].state, STATE_LOOPING);
command_t cmd = { break;
.type = CMD_REMOVE_CHANNEL, .channel = -1, .data = 0}; case STATE_LOOPING:
queue_push(&cmd_queue_main_midi, cmd); atomic_store(&channels[0].state, STATE_PAUSED);
break;
case STATE_PAUSED:
atomic_store(&channels[0].state, STATE_LOOPING);
break;
}
} break; } break;
case 60:
atomic_store(&cmd_add, 1);
break;
case 61:
atomic_store(&cmd_remove, 1);
break;
default: default:
break; break;
} }

76
src/ringbuffer.c Normal file
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@@ -0,0 +1,76 @@
#include "ringbuffer.h"
#include <stdlib.h>
static inline size_t load_head(const RingBuf *r) {
return atomic_load_explicit(&r->head, memory_order_relaxed);
}
static inline size_t load_tail(const RingBuf *r) {
return atomic_load_explicit(&r->tail, memory_order_relaxed);
}
static inline void store_head(RingBuf *r, size_t v) {
atomic_store_explicit(&r->head, v, memory_order_relaxed);
}
static inline void store_tail(RingBuf *r, size_t v) {
atomic_store_explicit(&r->tail, v, memory_order_relaxed);
}
int ring_init(RingBuf *r, size_t capacity) {
r->buf = (float *)malloc(capacity * sizeof(float));
if (!r->buf)
return -1;
r->capacity = capacity;
store_head(r, 0);
store_tail(r, 0);
return 0;
}
void ring_destroy(RingBuf *r) {
free(r->buf);
r->buf = NULL;
r->capacity = 0;
}
static size_t ring_readable(const RingBuf *r) {
size_t h = load_head(r);
size_t t = load_tail(r);
if (h >= t)
return h - t;
else
return r->capacity - (t - h);
}
static size_t ring_writeable(const RingBuf *r) {
return r->capacity - 1 - ring_readable(r);
}
size_t ring_write(RingBuf *r, const float *data, size_t count) {
size_t avail = ring_writeable(r);
if (count > avail)
count = avail;
if (count == 0)
return 0;
size_t head = load_head(r);
size_t cap = r->capacity;
for (size_t i = 0; i < count; ++i) {
r->buf[head] = data[i];
head = (head + 1) % cap;
}
store_head(r, head);
return count;
}
size_t ring_read(RingBuf *r, float *data, size_t count) {
size_t avail = ring_readable(r);
if (count > avail)
count = avail;
if (count == 0)
return 0;
size_t tail = load_tail(r);
size_t cap = r->capacity;
for (size_t i = 0; i < count; ++i) {
data[i] = r->buf[tail];
tail = (tail + 1) % cap;
}
store_tail(r, tail);
return count;
}

19
src/ringbuffer.h Normal file
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@@ -0,0 +1,19 @@
#ifndef RINGBUFFER_H
#define RINGBUFFER_H
#include <stddef.h>
#include <stdatomic.h>
typedef struct {
atomic_size_t head;
atomic_size_t tail;
size_t capacity;
float *buf;
} RingBuf;
int ring_init(RingBuf *r, size_t capacity);
void ring_destroy(RingBuf *r);
size_t ring_write(RingBuf *r, const float *data, size_t count);
size_t ring_read(RingBuf *r, float *data, size_t count);
#endif

41
src/wav.c Normal file
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@@ -0,0 +1,41 @@
#include "wav.h"
#include "channel.h"
#include <stdio.h>
#include <stdlib.h>
#include <sndfile.h>
int wav_read(const char *path, float **buffer, unsigned *frames) {
SF_INFO info;
info.format = 0;
SNDFILE *sf = sf_open(path, SFM_READ, &info);
if (!sf) return -1;
/* We need mono 16-bit PCM; refuse anything else */
if (info.channels != 1 || info.samplerate <= 0) {
sf_close(sf);
return -1;
}
unsigned total = (info.frames > (sf_count_t)LOOP_BUF_SIZE) ? LOOP_BUF_SIZE : (unsigned)info.frames;
float *buf = (float*)malloc(total * sizeof(float));
if (!buf) { sf_close(sf); return -1; }
sf_count_t nread = sf_readf_float(sf, buf, total);
sf_close(sf);
*buffer = buf;
*frames = (unsigned)nread;
return 0;
}
int wav_write(const char *path, const float *data, unsigned frames, unsigned sample_rate) {
SF_INFO info;
info.samplerate = sample_rate;
info.channels = 1;
info.format = SF_FORMAT_WAV | SF_FORMAT_PCM_16;
SNDFILE *sf = sf_open(path, SFM_WRITE, &info);
if (!sf) return -1;
sf_writef_float(sf, data, frames);
sf_close(sf);
return 0;
}

9
src/wav.h Normal file
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@@ -0,0 +1,9 @@
#ifndef WAV_H
#define WAV_H
#include <stddef.h>
int wav_read(const char *path, float **buffer, unsigned *frames);
int wav_write(const char *path, const float *data, unsigned frames, unsigned sample_rate);
#endif

942
tests/integration.c
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