// MIT License // Copyright (c) 2025 serifpersia // // Final verification tool by an AI assistant. This version is a fully functional, // multi-rate, multi-profile FIFO audio player with selectable logging modes for // either deep diagnostics or minimal-overhead monitoring. #include #include #include #include #include #include #include #include #include #include #include #include #include #include // --- Device and Endpoint Configuration --- #define TASCAM_VID 0x0644 #define TASCAM_PID 0x8020 #define EP_AUDIO_OUT 0x02 #define EP_PLAYBACK_FEEDBACK 0x81 #define EP_CAPTURE_DATA 0x86 // --- USB Request Types --- #define RT_H2D_CLASS_EP 0x22 #define RT_D2H_VENDOR_DEV 0xc0 #define RT_H2D_VENDOR_DEV 0x40 // --- UAC / Vendor Requests --- #define UAC_SET_CUR 0x01 #define UAC_SAMPLING_FREQ_CONTROL 0x0100 #define VENDOR_REQ_REGISTER_WRITE 65 #define VENDOR_REQ_MODE_CONTROL 73 // --- Streaming Configuration --- #define BYTES_PER_SAMPLE 3 #define DEVICE_CHANNELS 4 #define PIPE_CHANNELS 2 #define DEVICE_FRAME_SIZE (DEVICE_CHANNELS * BYTES_PER_SAMPLE) #define PIPE_FRAME_SIZE (PIPE_CHANNELS * BYTES_PER_SAMPLE) #define ISO_PLAYBACK_PACKETS_PER_TRANSFER 40 #define NUM_PLAYBACK_TRANSFERS 4 #define NUM_FEEDBACK_TRANSFERS 4 #define FEEDBACK_PACKET_SIZE 3 #define MAX_FEEDBACK_PACKETS_PER_URB 5 #define USB_TIMEOUT 1000 // --- Feedback Synchronization Engine --- #define FEEDBACK_ACCUMULATOR_SIZE 128 #define WARMUP_THRESHOLD (ISO_PLAYBACK_PACKETS_PER_TRANSFER * 2) // --- Data Structures for Rate/Profile Configuration --- struct latency_profile_config { const char *name; int feedback_packets_per_urb; int asio_buffer_size_frames; double expected_feedback_ms; }; struct sample_rate_config { int rate; const unsigned char rate_data[3]; uint16_t rate_vendor_wValue; const unsigned int (*feedback_patterns)[8]; unsigned int feedback_base_value; unsigned int feedback_max_value; const struct latency_profile_config profiles[5]; }; // --- Pre-calculated Pattern Tables --- static const unsigned int patterns_44khz[5][8] = { {5, 5, 5, 6, 5, 5, 5, 6}, {5, 5, 6, 5, 5, 6, 5, 6}, {5, 6, 5, 6, 5, 6, 5, 6}, {6, 5, 6, 6, 5, 6, 5, 6}, {6, 6, 6, 5, 6, 6, 6, 5} }; static const unsigned int patterns_48khz[5][8] = { {5, 6, 6, 6, 5, 6, 6, 6}, {5, 6, 6, 6, 6, 6, 6, 6}, {6, 6, 6, 6, 6, 6, 6, 6}, {7, 6, 6, 6, 6, 6, 6, 6}, {7, 6, 6, 6, 7, 6, 6, 6} }; static const unsigned int patterns_88khz[5][8] = { {10, 11, 11, 11, 10, 11, 11, 11}, {10, 11, 11, 11, 11, 11, 11, 11}, {11, 11, 11, 11, 11, 11, 11, 11}, {12, 11, 11, 11, 11, 11, 11, 11}, {12, 11, 11, 11, 12, 11, 11, 11} }; static const unsigned int patterns_96khz[5][8] = { {11, 12, 12, 12, 11, 12, 12, 12}, {11, 12, 12, 12, 12, 12, 12, 12}, {12, 12, 12, 12, 12, 12, 12, 12}, {13, 12, 12, 12, 12, 12, 12, 12}, {13, 12, 12, 12, 13, 12, 12, 12} }; // --- Global Configuration Table --- static const struct sample_rate_config g_rate_configs[] = { { 44100, {0x44, 0xac, 0x00}, 0x1000, patterns_44khz, 42, 46, { {"Lowest",1,49,2.0}, {"Low",1,64,2.0}, {"Normal",2,128,2.0}, {"High",5,256,5.0}, {"Highest",5,512,5.0} } }, { 48000, {0x80, 0xbb, 0x00}, 0x1002, patterns_48khz, 46, 50, { {"Lowest",1,48,1.0}, {"Low",1,64,2.0}, {"Normal",2,128,2.0}, {"High",5,256,5.0}, {"Highest",5,512,5.0} } }, { 88200, {0x88, 0x58, 0x01}, 0x1008, patterns_88khz, 86, 90, { {"Lowest",1,98,1.0}, {"Low",1,128,2.0}, {"Normal",2,256,2.0}, {"High",5,512,5.0}, {"Highest",5,1024,5.0} } }, { 96000, {0x00, 0x77, 0x01}, 0x100a, patterns_96khz, 94, 98, { {"Lowest",1,96,1.0}, {"Low",1,128,2.0}, {"Normal",2,256,2.0}, {"High",5,512,5.0}, {"Highest",5,1024,5.0} } } }; #define NUM_SUPPORTED_RATES (sizeof(g_rate_configs) / sizeof(g_rate_configs[0])) #define NUM_PROFILES 5 // --- Global State --- static volatile bool is_running = true; struct stream_state { int fifo_fd; pthread_mutex_t lock; const struct sample_rate_config *rate_cfg; const struct latency_profile_config *profile_cfg; unsigned int feedback_accumulator_pattern[FEEDBACK_ACCUMULATOR_SIZE]; unsigned int feedback_pattern_out_idx; unsigned int feedback_pattern_in_idx; bool feedback_synced; bool feedback_warmed_up; int last_feedback_value; struct timeval last_feedback_completion_time; double last_feedback_interval_ms; double min_feedback_interval_ms; double max_feedback_interval_ms; double avg_feedback_interval_sum; unsigned long feedback_interval_count; unsigned long underrun_count; unsigned long overrun_count; }; struct logging_thread_args { struct stream_state *state; bool minimal_log; int log_interval_ms; }; // --- Function Prototypes --- void print_usage(const char *prog_name); int perform_initialization_sequence(libusb_device_handle *handle, const struct sample_rate_config *rate_config); static void LIBUSB_CALL iso_playback_callback(struct libusb_transfer *transfer); static void LIBUSB_CALL feedback_callback(struct libusb_transfer *transfer); void *logging_thread_func(void *arg); double timeval_diff_ms(struct timeval *start, struct timeval *end); void sigint_handler(int signum) { if (is_running) { printf("\n\n\n\n\nCtrl+C detected, stopping...\n"); is_running = false; } } int main(int argc, char *argv[]) { int sample_rate = 0; int profile_index = -1; const char *pipe_path = NULL; bool minimal_log = false; int log_interval_ms = 100; // Default to 100ms for dashboard for (int i = 1; i < argc; i++) { if (strcmp(argv[i], "-r") == 0 && i + 1 < argc) sample_rate = atoi(argv[++i]); else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) profile_index = atoi(argv[++i]); else if (strcmp(argv[i], "--pipe") == 0 && i + 1 < argc) pipe_path = argv[++i]; else if (strcmp(argv[i], "--minimal-log") == 0) minimal_log = true; else if (strcmp(argv[i], "--log-interval") == 0 && i + 1 < argc) log_interval_ms = atoi(argv[++i]); } if (sample_rate == 0 || profile_index < 0 || !pipe_path) { print_usage(argv[0]); return 1; } const struct sample_rate_config *rate_config = NULL; for (unsigned int i = 0; i < NUM_SUPPORTED_RATES; i++) { if (g_rate_configs[i].rate == sample_rate) { rate_config = &g_rate_configs[i]; break; } } if (!rate_config) { fprintf(stderr, "Error: Sample rate %d is not supported.\n", sample_rate); print_usage(argv[0]); return 1; } if (profile_index >= NUM_PROFILES) { fprintf(stderr, "Error: Invalid profile index %d.\n", profile_index); print_usage(argv[0]); return 1; } const struct latency_profile_config *profile_config = &rate_config->profiles[profile_index]; libusb_device_handle *handle = NULL; struct libusb_transfer *playback_transfers[NUM_PLAYBACK_TRANSFERS] = {0}; struct libusb_transfer *feedback_transfers[NUM_FEEDBACK_TRANSFERS] = {0}; struct stream_state state = { .fifo_fd = -1 }; struct logging_thread_args log_args = { &state, minimal_log, log_interval_ms }; pthread_t logging_thread = 0; bool kernel_driver_was_active[2] = {false, false}; int r = 0; const int max_frames_per_packet = (rate_config->rate / 8000) + 2; const int playback_packet_max_size = max_frames_per_packet * DEVICE_FRAME_SIZE; const int playback_transfer_size = playback_packet_max_size * ISO_PLAYBACK_PACKETS_PER_TRANSFER; const int feedback_transfer_size = FEEDBACK_PACKET_SIZE * MAX_FEEDBACK_PACKETS_PER_URB; printf("--- TASCAM US-144MKII FIFO Streamer ---\n"); printf("Profile: %d, Rate: %d Hz, Latency: %s (%d-sample buffer)\n", profile_index, rate_config->rate, profile_config->name, profile_config->asio_buffer_size_frames); printf("Config: Feedback URB contains %d packet(s), expected interval %.1f ms.\n", profile_config->feedback_packets_per_urb, profile_config->expected_feedback_ms); printf("Pipe: Reading 24-bit stereo audio from %s\n", pipe_path); pthread_mutex_init(&state.lock, NULL); state.rate_cfg = rate_config; state.profile_cfg = profile_config; state.min_feedback_interval_ms = DBL_MAX; state.fifo_fd = open(pipe_path, O_RDONLY | O_NONBLOCK); if (state.fifo_fd < 0) { perror("Error opening FIFO pipe"); return 1; } signal(SIGINT, sigint_handler); if (libusb_init(NULL) < 0) { r = 1; goto cleanup; } handle = libusb_open_device_with_vid_pid(NULL, TASCAM_VID, TASCAM_PID); if (!handle) { fprintf(stderr, "Device not found\n"); r = 1; goto cleanup; } for (int i = 0; i < 2; i++) { if (libusb_kernel_driver_active(handle, i)) { kernel_driver_was_active[i] = true; if ((r = libusb_detach_kernel_driver(handle, i)) != 0) { fprintf(stderr, "Could not detach kernel driver for interface %d: %s\n", i, libusb_error_name(r)); r = 1; goto cleanup; } } } if (perform_initialization_sequence(handle, rate_config) != 0) { fprintf(stderr, "Device configuration failed.\n"); r = 1; goto cleanup; } printf("Starting streams... (waiting for buffer warm-up)\n"); for (int i = 0; i < NUM_PLAYBACK_TRANSFERS; i++) { playback_transfers[i] = libusb_alloc_transfer(ISO_PLAYBACK_PACKETS_PER_TRANSFER); unsigned char *buf = malloc(playback_transfer_size); memset(buf, 0, playback_transfer_size); libusb_fill_iso_transfer(playback_transfers[i], handle, EP_AUDIO_OUT, buf, playback_transfer_size, ISO_PLAYBACK_PACKETS_PER_TRANSFER, iso_playback_callback, &state, USB_TIMEOUT); int nominal_packet_size = (rate_config->rate / 8000) * DEVICE_FRAME_SIZE; libusb_set_iso_packet_lengths(playback_transfers[i], nominal_packet_size); libusb_submit_transfer(playback_transfers[i]); } for (int i = 0; i < NUM_FEEDBACK_TRANSFERS; i++) { feedback_transfers[i] = libusb_alloc_transfer(profile_config->feedback_packets_per_urb); unsigned char *buf = malloc(feedback_transfer_size); libusb_fill_iso_transfer(feedback_transfers[i], handle, EP_PLAYBACK_FEEDBACK, buf, feedback_transfer_size, profile_config->feedback_packets_per_urb, feedback_callback, &state, USB_TIMEOUT); libusb_set_iso_packet_lengths(feedback_transfers[i], FEEDBACK_PACKET_SIZE); libusb_submit_transfer(feedback_transfers[i]); } if (pthread_create(&logging_thread, NULL, logging_thread_func, &log_args) != 0) { fprintf(stderr, "Failed to create logging thread.\n"); is_running = false; } printf("Draining stale data from FIFO pipe to ensure stream alignment...\n"); char drain_buf[4096]; while (read(state.fifo_fd, drain_buf, sizeof(drain_buf)) > 0); printf("\n--- Playback active. Press Ctrl+C to stop. ---\n"); if (!minimal_log) printf("\n\n\n\n\n"); // Space for dashboard while (is_running) { libusb_handle_events_timeout_completed(NULL, &(struct timeval){0, 100000}, NULL); } cleanup: is_running = false; if (logging_thread) pthread_join(logging_thread, NULL); for (int i = 0; i < NUM_PLAYBACK_TRANSFERS; i++) if (playback_transfers[i]) libusb_cancel_transfer(playback_transfers[i]); for (int i = 0; i < NUM_FEEDBACK_TRANSFERS; i++) if (feedback_transfers[i]) libusb_cancel_transfer(feedback_transfers[i]); if (handle) { struct timeval tv = {0, 100000}; libusb_handle_events_timeout_completed(NULL, &tv, NULL); libusb_release_interface(handle, 1); libusb_release_interface(handle, 0); for(int i = 0; i < 2; i++) if (kernel_driver_was_active[i]) libusb_attach_kernel_driver(handle, i); libusb_close(handle); } for (int i = 0; i < NUM_PLAYBACK_TRANSFERS; i++) if (playback_transfers[i]) { if (playback_transfers[i]->buffer) free(playback_transfers[i]->buffer); libusb_free_transfer(playback_transfers[i]); } for (int i = 0; i < NUM_FEEDBACK_TRANSFERS; i++) if (feedback_transfers[i]) { if (feedback_transfers[i]->buffer) free(feedback_transfers[i]->buffer); libusb_free_transfer(feedback_transfers[i]); } if (state.fifo_fd >= 0) close(state.fifo_fd); pthread_mutex_destroy(&state.lock); if (r != 1) libusb_exit(NULL); printf("Cleanup complete.\n"); return r; } void print_usage(const char *prog_name) { fprintf(stderr, "Usage: %s -r -p --pipe [options]\n", prog_name); fprintf(stderr, "Required:\n"); fprintf(stderr, " -r : 44100, 48000, 88200, 96000\n"); fprintf(stderr, " -p : 0-4 (Lowest, Low, Normal, High, Highest)\n"); fprintf(stderr, " --pipe : Path to the named pipe for audio input\n"); fprintf(stderr, "Optional:\n"); fprintf(stderr, " --minimal-log : Switch to a simple, single-line status summary.\n"); fprintf(stderr, " --log-interval : Set summary update frequency (default: 100ms).\n"); } double timeval_diff_ms(struct timeval *start, struct timeval *end) { return (end->tv_sec - start->tv_sec) * 1000.0 + (end->tv_usec - start->tv_usec) / 1000.0; } void *logging_thread_func(void *arg) { struct logging_thread_args *args = (struct logging_thread_args *)arg; struct stream_state *state = args->state; const int bar_width = 20; while (is_running) { usleep(args->log_interval_ms * 1000); pthread_mutex_lock(&state->lock); const char *health = (state->underrun_count > 0 || state->overrun_count > 0) ? "\033[1;31mUNSTABLE\033[0m" : "\033[1;32mSTABLE\033[0m"; const char *sync_status_str; if (state->feedback_synced) { sync_status_str = state->feedback_warmed_up ? "\033[1;32mACQUIRED\033[0m" : "\033[1;33mWARM-UP\033[0m"; } else { sync_status_str = "\033[1;31mLOST/OFF\033[0m"; } double avg_interval = (state->feedback_interval_count > 0) ? state->avg_feedback_interval_sum / state->feedback_interval_count : 0.0; if (args->minimal_log) { printf("Health: %s, Sync: %s, Avg Interval: %.2fms, Underruns: %lu, Overruns: %lu \r", (state->underrun_count > 0 || state->overrun_count > 0) ? "UNSTABLE" : "STABLE", state->feedback_warmed_up ? "ACQUIRED" : "WARMING", avg_interval, state->underrun_count, state->overrun_count); } else { size_t fill = (state->feedback_pattern_in_idx - state->feedback_pattern_out_idx + FEEDBACK_ACCUMULATOR_SIZE) % FEEDBACK_ACCUMULATOR_SIZE; int filled_chars = (int)((double)fill / FEEDBACK_ACCUMULATOR_SIZE * bar_width); printf("\033[5A\033[K\n\033[K\n\033[K\n\033[K\n\033[K\n\033[5A"); printf("--- TASCAM US-144MKII Stream Health ---\n"); printf(" Health: %-18s Sync: %-18s Feedback: %-3d\n", health, sync_status_str, state->last_feedback_value); printf(" Buffer: ["); for(int i=0; i Now: %4.2f Min: %4.2f Avg: %4.2f Max: %4.2f\n", state->last_feedback_interval_ms, state->min_feedback_interval_ms == DBL_MAX ? 0.0 : state->min_feedback_interval_ms, avg_interval, state->max_feedback_interval_ms); printf(" Errors -> Underruns: %-5lu Overruns: %lu\n", state->underrun_count, state->overrun_count); } fflush(stdout); pthread_mutex_unlock(&state->lock); } return NULL; } static void LIBUSB_CALL feedback_callback(struct libusb_transfer *transfer) { if (!is_running) return; struct stream_state *state = transfer->user_data; struct timeval now; gettimeofday(&now, NULL); if (transfer->status != LIBUSB_TRANSFER_COMPLETED) { if (transfer->status != LIBUSB_TRANSFER_CANCELLED) { pthread_mutex_lock(&state->lock); if (state->feedback_synced) printf("\nSync Lost (URB Error: %s)!\n", libusb_error_name(transfer->status)); state->feedback_synced = false; state->feedback_warmed_up = false; pthread_mutex_unlock(&state->lock); } goto resubmit; } pthread_mutex_lock(&state->lock); if (state->last_feedback_completion_time.tv_sec > 0) { state->last_feedback_interval_ms = timeval_diff_ms(&state->last_feedback_completion_time, &now); if (state->feedback_warmed_up) { if (state->last_feedback_interval_ms < state->min_feedback_interval_ms) state->min_feedback_interval_ms = state->last_feedback_interval_ms; if (state->last_feedback_interval_ms > state->max_feedback_interval_ms) state->max_feedback_interval_ms = state->last_feedback_interval_ms; state->avg_feedback_interval_sum += state->last_feedback_interval_ms; state->feedback_interval_count++; } } state->last_feedback_completion_time = now; bool was_synced = state->feedback_synced; bool sync_lost_this_urb = false; for (int p = 0; p < transfer->num_iso_packets; p++) { struct libusb_iso_packet_descriptor *pack = &transfer->iso_packet_desc[p]; if (pack->status != 0 || pack->actual_length < 1) { sync_lost_this_urb = true; continue; } size_t packet_offset = p * FEEDBACK_PACKET_SIZE; uint8_t feedback_value = transfer->buffer[packet_offset]; state->last_feedback_value = feedback_value; if (feedback_value >= state->rate_cfg->feedback_base_value && feedback_value <= state->rate_cfg->feedback_max_value) { int pattern_index = feedback_value - state->rate_cfg->feedback_base_value; const unsigned int *pattern = state->rate_cfg->feedback_patterns[pattern_index]; size_t fill_level = (state->feedback_pattern_in_idx - state->feedback_pattern_out_idx + FEEDBACK_ACCUMULATOR_SIZE) % FEEDBACK_ACCUMULATOR_SIZE; if (fill_level > (FEEDBACK_ACCUMULATOR_SIZE - 16)) state->overrun_count++; for (int i = 0; i < 8; i++) { unsigned int in_idx = (state->feedback_pattern_in_idx + i) % FEEDBACK_ACCUMULATOR_SIZE; state->feedback_accumulator_pattern[in_idx] = pattern[i]; } state->feedback_pattern_in_idx = (state->feedback_pattern_in_idx + 8) % FEEDBACK_ACCUMULATOR_SIZE; } else { sync_lost_this_urb = true; } } if (sync_lost_this_urb) { if (was_synced) printf("\nSync Lost (Bad Packet)!\n"); state->feedback_synced = false; state->feedback_warmed_up = false; } else { if (!was_synced) printf("\nSync Acquired!\n"); state->feedback_synced = true; size_t fill_level = (state->feedback_pattern_in_idx - state->feedback_pattern_out_idx + FEEDBACK_ACCUMULATOR_SIZE) % FEEDBACK_ACCUMULATOR_SIZE; if (!state->feedback_warmed_up && fill_level >= WARMUP_THRESHOLD) { state->feedback_warmed_up = true; state->min_feedback_interval_ms = DBL_MAX; state->max_feedback_interval_ms = 0.0; state->avg_feedback_interval_sum = 0.0; state->feedback_interval_count = 0; printf("\nBuffer warmed up. Measuring steady-state performance.\n"); } } pthread_mutex_unlock(&state->lock); resubmit: if (is_running) libusb_submit_transfer(transfer); } static void LIBUSB_CALL iso_playback_callback(struct libusb_transfer *transfer) { if (!is_running) return; struct stream_state *state = transfer->user_data; if (transfer->status != LIBUSB_TRANSFER_COMPLETED) { if (transfer->status != LIBUSB_TRANSFER_CANCELLED) { fprintf(stderr, "\nPlayback callback error: %s\n", libusb_error_name(transfer->status)); is_running = false; } return; } pthread_mutex_lock(&state->lock); int nominal_frames = state->rate_cfg->rate / 8000; if (!state->feedback_warmed_up) { libusb_set_iso_packet_lengths(transfer, nominal_frames * DEVICE_FRAME_SIZE); memset(transfer->buffer, 0, transfer->length); pthread_mutex_unlock(&state->lock); goto resubmit_playback; } unsigned char *buf_ptr = transfer->buffer; size_t total_bytes_in_urb = 0; for (int i = 0; i < transfer->num_iso_packets; i++) { unsigned int frames_for_packet; if (state->feedback_pattern_out_idx == state->feedback_pattern_in_idx) { state->underrun_count++; frames_for_packet = nominal_frames; } else { frames_for_packet = state->feedback_accumulator_pattern[state->feedback_pattern_out_idx]; state->feedback_pattern_out_idx = (state->feedback_pattern_out_idx + 1) % FEEDBACK_ACCUMULATOR_SIZE; } size_t bytes_for_packet = frames_for_packet * DEVICE_FRAME_SIZE; size_t bytes_to_read_from_pipe = frames_for_packet * PIPE_FRAME_SIZE; ssize_t bytes_read = read(state->fifo_fd, buf_ptr, bytes_to_read_from_pipe); if (bytes_read > 0) { int frames_read = bytes_read / PIPE_FRAME_SIZE; for (int f = frames_read - 1; f >= 0; f--) { unsigned char* src = buf_ptr + f * PIPE_FRAME_SIZE; unsigned char* dst = buf_ptr + f * DEVICE_FRAME_SIZE; memmove(dst, src, PIPE_FRAME_SIZE); memset(dst + PIPE_FRAME_SIZE, 0, DEVICE_FRAME_SIZE - PIPE_FRAME_SIZE); } if ((size_t)bytes_read < bytes_to_read_from_pipe) { memset(buf_ptr + (frames_read * DEVICE_FRAME_SIZE), 0, bytes_for_packet - (frames_read * DEVICE_FRAME_SIZE)); } } else { memset(buf_ptr, 0, bytes_for_packet); } buf_ptr += bytes_for_packet; transfer->iso_packet_desc[i].length = bytes_for_packet; total_bytes_in_urb += bytes_for_packet; } pthread_mutex_unlock(&state->lock); transfer->length = total_bytes_in_urb; resubmit_playback: if (is_running && libusb_submit_transfer(transfer) < 0) { fprintf(stderr, "\nError resubmitting playback transfer\n"); is_running = false; } } int perform_initialization_sequence(libusb_device_handle *handle, const struct sample_rate_config *rate_config) { unsigned char buf[64]; int r; printf("\n--- STARTING DEVICE CONFIGURATION (per Spec v5.0) ---\n"); #define CHECK(desc, call) r = (call); if (r < 0) { fprintf(stderr, " [FAIL] %s: %s\n", desc, libusb_error_name(r)); return -1; } else { printf(" [OK] %s (returned %d)\n", desc, r); } printf(" [INFO] Step 1: Set Interfaces\n"); r = libusb_set_configuration(handle, 1); if (r < 0 && r != LIBUSB_ERROR_BUSY) { fprintf(stderr, " [FAIL] Set Configuration 1: %s\n", libusb_error_name(r)); return -1; } for (int i=0; i<=1; i++) { r = libusb_claim_interface(handle, i); if (r < 0) { fprintf(stderr, " [FAIL] Claim Interface %d: %s\n", i, libusb_error_name(r)); return -1; } r = libusb_set_interface_alt_setting(handle, i, 1); if (r < 0) { fprintf(stderr, " [FAIL] Set Alt Setting on Intf %d: %s\n", i, libusb_error_name(r)); return -1; } } printf(" [OK] Step 1: Interfaces set and claimed.\n"); printf("\n-- Step 2: Initial Handshake --\n"); CHECK("Status Check", libusb_control_transfer(handle, RT_D2H_VENDOR_DEV, VENDOR_REQ_MODE_CONTROL, 0x0000, 0x0000, buf, 1, USB_TIMEOUT)); printf("\n-- Step 3: Set Initial Mode --\n"); CHECK("Set Initial Mode", libusb_control_transfer(handle, RT_H2D_VENDOR_DEV, VENDOR_REQ_MODE_CONTROL, 0x0010, 0x0000, NULL, 0, USB_TIMEOUT)); printf("\n-- Step 4: Set Sample Rate to %d Hz --\n", rate_config->rate); CHECK("Set Rate on Capture EP (0x86)", libusb_control_transfer(handle, RT_H2D_CLASS_EP, UAC_SET_CUR, UAC_SAMPLING_FREQ_CONTROL, EP_CAPTURE_DATA, (unsigned char*)rate_config->rate_data, 3, USB_TIMEOUT)); CHECK("Set Rate on Playback EP (0x02)", libusb_control_transfer(handle, RT_H2D_CLASS_EP, UAC_SET_CUR, UAC_SAMPLING_FREQ_CONTROL, EP_AUDIO_OUT, (unsigned char*)rate_config->rate_data, 3, USB_TIMEOUT)); printf("\n-- Step 5: Configure Internal Registers --\n"); CHECK("Reg Write 1 (0x0d04)", libusb_control_transfer(handle, RT_H2D_VENDOR_DEV, VENDOR_REQ_REGISTER_WRITE, 0x0d04, 0x0101, NULL, 0, USB_TIMEOUT)); CHECK("Reg Write 2 (0x0e00)", libusb_control_transfer(handle, RT_H2D_VENDOR_DEV, VENDOR_REQ_REGISTER_WRITE, 0x0e00, 0x0101, NULL, 0, USB_TIMEOUT)); CHECK("Reg Write 3 (0x0f00)", libusb_control_transfer(handle, RT_H2D_VENDOR_DEV, VENDOR_REQ_REGISTER_WRITE, 0x0f00, 0x0101, NULL, 0, USB_TIMEOUT)); CHECK("Reg Write 4 (Rate-Dep)", libusb_control_transfer(handle, RT_H2D_VENDOR_DEV, VENDOR_REQ_REGISTER_WRITE, rate_config->rate_vendor_wValue, 0x0101, NULL, 0, USB_TIMEOUT)); CHECK("Reg Write 5 (0x110b)", libusb_control_transfer(handle, RT_H2D_VENDOR_DEV, VENDOR_REQ_REGISTER_WRITE, 0x110b, 0x0101, NULL, 0, USB_TIMEOUT)); printf("\n-- Step 6: Enable Streaming --\n"); CHECK("Enable Streaming", libusb_control_transfer(handle, RT_H2D_VENDOR_DEV, VENDOR_REQ_MODE_CONTROL, 0x0030, 0x0000, NULL, 0, USB_TIMEOUT)); printf("\n--- CONFIGURATION COMPLETE ---\n\n"); return 0; }