X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=nageru%2Falsa_input.cpp;h=511dda95738cd63b2dcdd30ff1ae67f5bc318ff6;hb=f9024d141398e69e7b4011becd3ebbe37eaa1776;hp=08a67f7fa7837ccabeb18a414eeaacf61d404bb3;hpb=9b7d691b4cc5db7dbfc18c82e86c1207fcac4722;p=nageru

diff --git a/nageru/alsa_input.cpp b/nageru/alsa_input.cpp
index 08a67f7..511dda9 100644
--- a/nageru/alsa_input.cpp
+++ b/nageru/alsa_input.cpp
@@ -9,7 +9,7 @@
 
 #include "alsa_pool.h"
 #include "bmusb/bmusb.h"
-#include "timebase.h"
+#include "shared/timebase.h"
 
 using namespace std;
 using namespace std::chrono;
@@ -111,6 +111,9 @@ bool ALSAInput::open_device()
 	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_set_tstamp_mode", snd_pcm_sw_params_set_tstamp_mode(pcm_handle, sw_params, SND_PCM_TSTAMP_ENABLE));
+	RETURN_FALSE_ON_ERROR("snd_pcm_sw_params_set_tstamp_type", snd_pcm_sw_params_set_tstamp_type(pcm_handle, sw_params, SND_PCM_TSTAMP_TYPE_MONOTONIC));
+
 	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));
@@ -171,6 +174,14 @@ void ALSAInput::stop_capture_thread()
 
 void ALSAInput::capture_thread_func()
 {
+	if (!done_init) {
+		char thread_name[16];
+		snprintf(thread_name, sizeof(thread_name), "ALSA_C_%d", internal_dev_index);
+		pthread_setname_np(pthread_self(), thread_name);
+
+		done_init = true;
+	}
+
 	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
@@ -221,7 +232,8 @@ ALSAInput::CaptureEndReason ALSAInput::do_capture()
 	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;
+	snd_pcm_status_t *status;
+	snd_pcm_status_alloca(&status);
 	while (!should_quit.should_quit()) {
 		int ret = snd_pcm_wait(pcm_handle, /*timeout=*/100);
 		if (ret == 0) continue;  // Timeout.
@@ -233,7 +245,14 @@ ALSAInput::CaptureEndReason ALSAInput::do_capture()
 		}
 		RETURN_ON_ERROR("snd_pcm_wait()", ret);
 
-		snd_pcm_sframes_t frames = snd_pcm_readi(pcm_handle, buffer.get(), buffer_frames);
+		ret = snd_pcm_status(pcm_handle, status);
+		RETURN_ON_ERROR("snd_pcm_status()", ret);
+
+		snd_pcm_sframes_t avail = snd_pcm_status_get_avail(status);
+		snd_htimestamp_t alsa_ts;
+		snd_pcm_status_get_htstamp(status, &alsa_ts);
+
+		snd_pcm_sframes_t frames = snd_pcm_readi(pcm_handle, buffer.get(), avail);
 		if (frames == -EPIPE) {
 			fprintf(stderr, "[%s] ALSA overrun\n", device.c_str());
 			snd_pcm_prepare(pcm_handle);
@@ -246,21 +265,13 @@ ALSAInput::CaptureEndReason ALSAInput::do_capture()
 		}
 		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();
+		// NOTE: This assumes steady_clock::time_point is the same as clock_gettime(CLOCK_MONOTONIC).
+		const steady_clock::time_point ts = steady_clock::time_point(seconds(alsa_ts.tv_sec) + nanoseconds(alsa_ts.tv_nsec));
 		bool success;
 		do {
 			if (should_quit.should_quit()) return CaptureEndReason::REQUESTED_QUIT;
-			success = audio_callback(buffer.get(), frames, audio_format, pts - prev_pts, now);
+			success = audio_callback(buffer.get(), frames, audio_format, ts);
 		} 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;
-}
-