Add LKMA-209 synthetic ground-truth recordings

artifacts/lkma-193a/ground-truth/v21/report.json

@@ -0,0 +1,8 @@
+{
+  "source": "synthetic-spandsp",
+  "note": "Generated by spandsp FSK TX - not a real hardware capture. Replace with lab recording when USB FXO rig is available.",
+  "sampleRate": 8000,
+  "channels": 1,
+  "bitDepth": 16,
+  "durationSeconds": 30
+}

artifacts/lkma-193a/ground-truth/v22bis/report.json

@@ -0,0 +1,8 @@
+{
+  "source": "synthetic-spandsp",
+  "note": "V.22bis placeholder silence. Generated by the synthetic spandsp artifact generator; replace with lab recording when USB FXO rig is available.",
+  "sampleRate": 8000,
+  "channels": 1,
+  "bitDepth": 16,
+  "durationSeconds": 30
+}

tools/generate-lkma-193a-groundtruth.c

@@ -0,0 +1,257 @@
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#include <spandsp.h>
+
+#define SAMPLE_RATE 8000
+#define CHANNELS 1
+#define BITS_PER_SAMPLE 16
+#define DURATION_SECONDS 30
+#define TOTAL_SAMPLES (SAMPLE_RATE * DURATION_SECONDS)
+#define BLOCK_SAMPLES 160
+#define V21_MARK_BITS 150
+
+typedef struct {
+    int bit_index;
+} v21_bits_t;
+
+static int make_dirs(const char *path);
+static int write_wav_header(FILE *file, uint32_t samples);
+static int write_silence_wav(const char *path);
+static int write_v21_wav(const char *path);
+static int copy_file(const char *from, const char *to);
+static int write_report(const char *path, const char *note);
+static int get_v21_bit(void *user_data);
+
+int main(void) {
+    if (make_dirs("artifacts/lkma-193a/ground-truth/v21") != 0 ||
+        make_dirs("artifacts/lkma-193a/ground-truth/v22bis") != 0) {
+        return 1;
+    }
+
+    if (write_v21_wav("artifacts/lkma-193a/groundtruth-v21.wav") != 0 ||
+        copy_file("artifacts/lkma-193a/groundtruth-v21.wav",
+                  "artifacts/lkma-193a/ground-truth/v21/inbound.wav") != 0 ||
+        write_silence_wav("artifacts/lkma-193a/ground-truth/v21/outbound.wav") != 0 ||
+        write_report(
+            "artifacts/lkma-193a/ground-truth/v21/report.json",
+            "Generated by spandsp FSK TX - not a real hardware capture. Replace with lab recording when USB FXO rig is available."
+        ) != 0 ||
+        write_silence_wav("artifacts/lkma-193a/ground-truth/v22bis/inbound.wav") != 0 ||
+        write_silence_wav("artifacts/lkma-193a/ground-truth/v22bis/outbound.wav") != 0 ||
+        write_report(
+            "artifacts/lkma-193a/ground-truth/v22bis/report.json",
+            "V.22bis placeholder silence. Generated by the synthetic spandsp artifact generator; replace with lab recording when USB FXO rig is available."
+        ) != 0) {
+        return 1;
+    }
+
+    return 0;
+}
+
+static int make_dirs(const char *path) {
+    char partial[512];
+    size_t length = strlen(path);
+
+    if (length >= sizeof(partial)) {
+        fprintf(stderr, "path too long: %s\n", path);
+        return -1;
+    }
+
+    for (size_t index = 0; index <= length; index++) {
+        partial[index] = path[index];
+        if (path[index] != '/' && path[index] != '\0') {
+            continue;
+        }
+
+        partial[index] = '\0';
+        if (partial[0] != '\0' && mkdir(partial, 0775) != 0 && errno != EEXIST) {
+            fprintf(stderr, "mkdir %s: %s\n", partial, strerror(errno));
+            return -1;
+        }
+        partial[index] = path[index];
+    }
+    return 0;
+}
+
+static int write_u16_le(FILE *file, uint16_t value) {
+    uint8_t bytes[2] = {
+        (uint8_t) (value & 0xff),
+        (uint8_t) ((value >> 8) & 0xff)
+    };
+    return fwrite(bytes, 1, sizeof(bytes), file) == sizeof(bytes) ? 0 : -1;
+}
+
+static int write_u32_le(FILE *file, uint32_t value) {
+    uint8_t bytes[4] = {
+        (uint8_t) (value & 0xff),
+        (uint8_t) ((value >> 8) & 0xff),
+        (uint8_t) ((value >> 16) & 0xff),
+        (uint8_t) ((value >> 24) & 0xff)
+    };
+    return fwrite(bytes, 1, sizeof(bytes), file) == sizeof(bytes) ? 0 : -1;
+}
+
+static int write_i16_le(FILE *file, int16_t value) {
+    return write_u16_le(file, (uint16_t) value);
+}
+
+static int write_wav_header(FILE *file, uint32_t samples) {
+    const uint16_t block_align = CHANNELS * (BITS_PER_SAMPLE / 8);
+    const uint32_t byte_rate = SAMPLE_RATE * block_align;
+    const uint32_t data_bytes = samples * block_align;
+
+    return fwrite("RIFF", 1, 4, file) == 4 &&
+           write_u32_le(file, 36 + data_bytes) == 0 &&
+           fwrite("WAVEfmt ", 1, 8, file) == 8 &&
+           write_u32_le(file, 16) == 0 &&
+           write_u16_le(file, 1) == 0 &&
+           write_u16_le(file, CHANNELS) == 0 &&
+           write_u32_le(file, SAMPLE_RATE) == 0 &&
+           write_u32_le(file, byte_rate) == 0 &&
+           write_u16_le(file, block_align) == 0 &&
+           write_u16_le(file, BITS_PER_SAMPLE) == 0 &&
+           fwrite("data", 1, 4, file) == 4 &&
+           write_u32_le(file, data_bytes) == 0 ? 0 : -1;
+}
+
+static int write_silence_wav(const char *path) {
+    FILE *file = fopen(path, "wb");
+    if (!file) {
+        fprintf(stderr, "open %s: %s\n", path, strerror(errno));
+        return -1;
+    }
+    if (write_wav_header(file, TOTAL_SAMPLES) != 0) {
+        fclose(file);
+        fprintf(stderr, "write header %s failed\n", path);
+        return -1;
+    }
+    for (int sample = 0; sample < TOTAL_SAMPLES; sample++) {
+        if (write_i16_le(file, 0) != 0) {
+            fclose(file);
+            fprintf(stderr, "write sample %s failed\n", path);
+            return -1;
+        }
+    }
+    return fclose(file);
+}
+
+static int write_v21_wav(const char *path) {
+    FILE *file = fopen(path, "wb");
+    if (!file) {
+        fprintf(stderr, "open %s: %s\n", path, strerror(errno));
+        return -1;
+    }
+
+    if (write_wav_header(file, TOTAL_SAMPLES) != 0) {
+        fclose(file);
+        fprintf(stderr, "write header %s failed\n", path);
+        return -1;
+    }
+
+    v21_bits_t bits = {0};
+    fsk_tx_state_t *tx = fsk_tx_init(NULL, &preset_fsk_specs[FSK_V21CH1], get_v21_bit, &bits);
+    if (!tx) {
+        fclose(file);
+        fprintf(stderr, "fsk_tx_init failed\n");
+        return -1;
+    }
+
+    int16_t samples[BLOCK_SAMPLES];
+    int remaining = TOTAL_SAMPLES;
+    while (remaining > 0) {
+        int count = remaining > BLOCK_SAMPLES ? BLOCK_SAMPLES : remaining;
+        int generated = fsk_tx(tx, samples, count);
+        if (generated != count) {
+            fsk_tx_free(tx);
+            fclose(file);
+            fprintf(stderr, "fsk_tx generated %d of %d samples\n", generated, count);
+            return -1;
+        }
+        for (int index = 0; index < generated; index++) {
+            if (write_i16_le(file, samples[index]) != 0) {
+                fsk_tx_free(tx);
+                fclose(file);
+                fprintf(stderr, "write sample %s failed\n", path);
+                return -1;
+            }
+        }
+        remaining -= generated;
+    }
+
+    fsk_tx_free(tx);
+    return fclose(file);
+}
+
+static int copy_file(const char *from, const char *to) {
+    FILE *source = fopen(from, "rb");
+    if (!source) {
+        fprintf(stderr, "open %s: %s\n", from, strerror(errno));
+        return -1;
+    }
+    FILE *target = fopen(to, "wb");
+    if (!target) {
+        fclose(source);
+        fprintf(stderr, "open %s: %s\n", to, strerror(errno));
+        return -1;
+    }
+
+    uint8_t buffer[8192];
+    size_t count;
+    while ((count = fread(buffer, 1, sizeof(buffer), source)) > 0) {
+        if (fwrite(buffer, 1, count, target) != count) {
+            fclose(source);
+            fclose(target);
+            fprintf(stderr, "write %s failed\n", to);
+            return -1;
+        }
+    }
+
+    int read_error = ferror(source);
+    int close_source = fclose(source);
+    int close_target = fclose(target);
+    return read_error || close_source || close_target ? -1 : 0;
+}
+
+static int write_report(const char *path, const char *note) {
+    FILE *file = fopen(path, "wb");
+    if (!file) {
+        fprintf(stderr, "open %s: %s\n", path, strerror(errno));
+        return -1;
+    }
+
+    int ok = fprintf(
+        file,
+        "{\n"
+        "  \"source\": \"synthetic-spandsp\",\n"
+        "  \"note\": \"%s\",\n"
+        "  \"sampleRate\": 8000,\n"
+        "  \"channels\": 1,\n"
+        "  \"bitDepth\": 16,\n"
+        "  \"durationSeconds\": 30\n"
+        "}\n",
+        note
+    ) > 0;
+
+    return fclose(file) == 0 && ok ? 0 : -1;
+}
+
+static int get_v21_bit(void *user_data) {
+    static const uint8_t pattern[] = {0xff, 0x01, 0x7e};
+    v21_bits_t *bits = (v21_bits_t *) user_data;
+    int bit;
+
+    if (bits->bit_index < V21_MARK_BITS) {
+        bit = 1;
+    } else {
+        int payload_bit = bits->bit_index - V21_MARK_BITS;
+        uint8_t byte = pattern[(payload_bit / 8) % (int) (sizeof(pattern) / sizeof(pattern[0]))];
+        bit = (byte >> (payload_bit % 8)) & 1;
+    }
+    bits->bit_index++;
+    return bit;
+}