--- /dev/null
+#include "alsa_input.h"
+
+#include <alsa/error.h>
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <cstdint>
+
+#include "alsa_pool.h"
+#include "bmusb/bmusb.h"
+#include "timebase.h"
+
+using namespace std;
+using namespace std::chrono;
+using namespace std::placeholders;
+
+#define RETURN_ON_ERROR(msg, expr) do { \
+ int err = (expr); \
+ if (err < 0) { \
+ fprintf(stderr, "[%s] " msg ": %s\n", device.c_str(), snd_strerror(err)); \
+ if (err == -ENODEV) return CaptureEndReason::DEVICE_GONE; \
+ return CaptureEndReason::OTHER_ERROR; \
+ } \
+} while (false)
+
+#define RETURN_FALSE_ON_ERROR(msg, expr) do { \
+ int err = (expr); \
+ if (err < 0) { \
+ fprintf(stderr, "[%s] " msg ": %s\n", device.c_str(), snd_strerror(err)); \
+ return false; \
+ } \
+} while (false)
+
+#define WARN_ON_ERROR(msg, expr) do { \
+ int err = (expr); \
+ if (err < 0) { \
+ fprintf(stderr, "[%s] " msg ": %s\n", device.c_str(), snd_strerror(err)); \
+ } \
+} while (false)
+
+ALSAInput::ALSAInput(const char *device, unsigned sample_rate, unsigned num_channels, audio_callback_t audio_callback, ALSAPool *parent_pool, unsigned internal_dev_index)
+ : device(device),
+ sample_rate(sample_rate),
+ num_channels(num_channels),
+ audio_callback(audio_callback),
+ parent_pool(parent_pool),
+ internal_dev_index(internal_dev_index)
+{
+}
+
+bool ALSAInput::open_device()
+{
+ RETURN_FALSE_ON_ERROR("snd_pcm_open()", snd_pcm_open(&pcm_handle, device.c_str(), SND_PCM_STREAM_CAPTURE, 0));
+
+ // Set format.
+ snd_pcm_hw_params_t *hw_params;
+ snd_pcm_hw_params_alloca(&hw_params);
+ if (!set_base_params(device.c_str(), pcm_handle, hw_params, &sample_rate)) {
+ return false;
+ }
+
+ RETURN_FALSE_ON_ERROR("snd_pcm_hw_params_set_channels()", snd_pcm_hw_params_set_channels(pcm_handle, hw_params, num_channels));
+
+ // Fragment size of 64 samples (about 1 ms at 48 kHz; a frame at 60
+ // fps/48 kHz is 800 samples.) We ask for 64 such periods in our buffer
+ // (~85 ms buffer); more than that, and our jitter is probably so high
+ // that the resampling queue can't keep up anyway.
+ // The entire thing with periods and such is a bit mysterious to me;
+ // seemingly I can get 96 frames at a time with no problems even if
+ // the period size is 64 frames. And if I set num_periods to e.g. 1,
+ // I can't have a big buffer.
+ num_periods = 16;
+ int dir = 0;
+ RETURN_FALSE_ON_ERROR("snd_pcm_hw_params_set_periods_near()", snd_pcm_hw_params_set_periods_near(pcm_handle, hw_params, &num_periods, &dir));
+ period_size = 64;
+ dir = 0;
+ RETURN_FALSE_ON_ERROR("snd_pcm_hw_params_set_period_size_near()", snd_pcm_hw_params_set_period_size_near(pcm_handle, hw_params, &period_size, &dir));
+ buffer_frames = 64 * 64;
+ RETURN_FALSE_ON_ERROR("snd_pcm_hw_params_set_buffer_size_near()", snd_pcm_hw_params_set_buffer_size_near(pcm_handle, hw_params, &buffer_frames));
+ RETURN_FALSE_ON_ERROR("snd_pcm_hw_params()", snd_pcm_hw_params(pcm_handle, hw_params));
+ //snd_pcm_hw_params_free(hw_params);
+
+ // Figure out which format the card actually chose.
+ RETURN_FALSE_ON_ERROR("snd_pcm_hw_params_current()", snd_pcm_hw_params_current(pcm_handle, hw_params));
+ snd_pcm_format_t chosen_format;
+ RETURN_FALSE_ON_ERROR("snd_pcm_hw_params_get_format()", snd_pcm_hw_params_get_format(hw_params, &chosen_format));
+
+ audio_format.num_channels = num_channels;
+ audio_format.bits_per_sample = 0;
+ switch (chosen_format) {
+ case SND_PCM_FORMAT_S16_LE:
+ audio_format.bits_per_sample = 16;
+ break;
+ case SND_PCM_FORMAT_S24_LE:
+ audio_format.bits_per_sample = 24;
+ break;
+ case SND_PCM_FORMAT_S32_LE:
+ audio_format.bits_per_sample = 32;
+ break;
+ default:
+ assert(false);
+ }
+ audio_format.sample_rate = sample_rate;
+ //printf("num_periods=%u period_size=%u buffer_frames=%u sample_rate=%u bits_per_sample=%d\n",
+ // num_periods, unsigned(period_size), unsigned(buffer_frames), sample_rate, audio_format.bits_per_sample);
+
+ buffer.reset(new uint8_t[buffer_frames * num_channels * audio_format.bits_per_sample / 8]);
+
+ snd_pcm_sw_params_t *sw_params;
+ snd_pcm_sw_params_alloca(&sw_params);
+ RETURN_FALSE_ON_ERROR("snd_pcm_sw_params_current()", snd_pcm_sw_params_current(pcm_handle, sw_params));
+ RETURN_FALSE_ON_ERROR("snd_pcm_sw_params_set_start_threshold", snd_pcm_sw_params_set_start_threshold(pcm_handle, sw_params, num_periods * period_size / 2));
+ RETURN_FALSE_ON_ERROR("snd_pcm_sw_params()", snd_pcm_sw_params(pcm_handle, sw_params));
+
+ RETURN_FALSE_ON_ERROR("snd_pcm_nonblock()", snd_pcm_nonblock(pcm_handle, 1));
+ RETURN_FALSE_ON_ERROR("snd_pcm_prepare()", snd_pcm_prepare(pcm_handle));
+ return true;
+}
+
+bool ALSAInput::set_base_params(const char *device_name, snd_pcm_t *pcm_handle, snd_pcm_hw_params_t *hw_params, unsigned *sample_rate)
+{
+ int err;
+ err = snd_pcm_hw_params_any(pcm_handle, hw_params);
+ if (err < 0) {
+ fprintf(stderr, "[%s] snd_pcm_hw_params_any(): %s\n", device_name, snd_strerror(err));
+ return false;
+ }
+ err = snd_pcm_hw_params_set_access(pcm_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
+ if (err < 0) {
+ fprintf(stderr, "[%s] snd_pcm_hw_params_set_access(): %s\n", device_name, snd_strerror(err));
+ return false;
+ }
+ snd_pcm_format_mask_t *format_mask;
+ snd_pcm_format_mask_alloca(&format_mask);
+ snd_pcm_format_mask_set(format_mask, SND_PCM_FORMAT_S16_LE);
+ snd_pcm_format_mask_set(format_mask, SND_PCM_FORMAT_S24_LE);
+ snd_pcm_format_mask_set(format_mask, SND_PCM_FORMAT_S32_LE);
+ err = snd_pcm_hw_params_set_format_mask(pcm_handle, hw_params, format_mask);
+ if (err < 0) {
+ fprintf(stderr, "[%s] snd_pcm_hw_params_set_format_mask(): %s\n", device_name, snd_strerror(err));
+ return false;
+ }
+ err = snd_pcm_hw_params_set_rate_near(pcm_handle, hw_params, sample_rate, 0);
+ if (err < 0) {
+ fprintf(stderr, "[%s] snd_pcm_hw_params_set_rate_near(): %s\n", device_name, snd_strerror(err));
+ return false;
+ }
+ return true;
+}
+
+ALSAInput::~ALSAInput()
+{
+ if (pcm_handle) {
+ WARN_ON_ERROR("snd_pcm_close()", snd_pcm_close(pcm_handle));
+ }
+}
+
+void ALSAInput::start_capture_thread()
+{
+ assert(!device.empty());
+ should_quit.unquit();
+ capture_thread = thread(&ALSAInput::capture_thread_func, this);
+}
+
+void ALSAInput::stop_capture_thread()
+{
+ should_quit.quit();
+ capture_thread.join();
+}
+
+void ALSAInput::capture_thread_func()
+{
+ parent_pool->set_card_state(internal_dev_index, ALSAPool::Device::State::STARTING);
+
+ // If the device hasn't been opened already, we need to do so
+ // before we can capture.
+ while (!should_quit.should_quit() && pcm_handle == nullptr) {
+ if (!open_device()) {
+ fprintf(stderr, "[%s] Waiting one second and trying again...\n",
+ device.c_str());
+ should_quit.sleep_for(seconds(1));
+ }
+ }
+
+ if (should_quit.should_quit()) {
+ // Don't call free_card(); that would be a deadlock.
+ if (pcm_handle) {
+ WARN_ON_ERROR("snd_pcm_close()", snd_pcm_close(pcm_handle));
+ }
+ pcm_handle = nullptr;
+ return;
+ }
+
+ // Do the actual capture. (Termination condition within loop.)
+ for ( ;; ) {
+ switch (do_capture()) {
+ case CaptureEndReason::REQUESTED_QUIT:
+ // Don't call free_card(); that would be a deadlock.
+ WARN_ON_ERROR("snd_pcm_close()", snd_pcm_close(pcm_handle));
+ pcm_handle = nullptr;
+ return;
+ case CaptureEndReason::DEVICE_GONE:
+ parent_pool->free_card(internal_dev_index);
+ WARN_ON_ERROR("snd_pcm_close()", snd_pcm_close(pcm_handle));
+ pcm_handle = nullptr;
+ return;
+ case CaptureEndReason::OTHER_ERROR:
+ parent_pool->set_card_state(internal_dev_index, ALSAPool::Device::State::STARTING);
+ fprintf(stderr, "[%s] Sleeping one second and restarting capture...\n",
+ device.c_str());
+ should_quit.sleep_for(seconds(1));
+ break;
+ }
+ }
+}
+
+ALSAInput::CaptureEndReason ALSAInput::do_capture()
+{
+ parent_pool->set_card_state(internal_dev_index, ALSAPool::Device::State::STARTING);
+ RETURN_ON_ERROR("snd_pcm_start()", snd_pcm_start(pcm_handle));
+ parent_pool->set_card_state(internal_dev_index, ALSAPool::Device::State::RUNNING);
+
+ uint64_t num_frames_output = 0;
+ while (!should_quit.should_quit()) {
+ int ret = snd_pcm_wait(pcm_handle, /*timeout=*/100);
+ if (ret == 0) continue; // Timeout.
+ if (ret == -EPIPE) {
+ fprintf(stderr, "[%s] ALSA overrun\n", device.c_str());
+ snd_pcm_prepare(pcm_handle);
+ snd_pcm_start(pcm_handle);
+ continue;
+ }
+ RETURN_ON_ERROR("snd_pcm_wait()", ret);
+
+ snd_pcm_sframes_t frames = snd_pcm_readi(pcm_handle, buffer.get(), buffer_frames);
+ if (frames == -EPIPE) {
+ fprintf(stderr, "[%s] ALSA overrun\n", device.c_str());
+ snd_pcm_prepare(pcm_handle);
+ snd_pcm_start(pcm_handle);
+ continue;
+ }
+ if (frames == 0) {
+ fprintf(stderr, "snd_pcm_readi() returned 0\n");
+ break;
+ }
+ RETURN_ON_ERROR("snd_pcm_readi()", frames);
+
+ const int64_t prev_pts = frames_to_pts(num_frames_output);
+ const int64_t pts = frames_to_pts(num_frames_output + frames);
+ const steady_clock::time_point now = steady_clock::now();
+ bool success;
+ do {
+ if (should_quit.should_quit()) return CaptureEndReason::REQUESTED_QUIT;
+ success = audio_callback(buffer.get(), frames, audio_format, pts - prev_pts, now);
+ } while (!success);
+ num_frames_output += frames;
+ }
+ return CaptureEndReason::REQUESTED_QUIT;
+}
+
+int64_t ALSAInput::frames_to_pts(uint64_t n) const
+{
+ return (n * TIMEBASE) / sample_rate;
+}
+
projects / nageru / blobdiff