From 2692a7d22c0b691f7f27f969c91e7af05c8ede7d Mon Sep 17 00:00:00 2001 From: dec05eba Date: Sun, 14 Apr 2024 00:02:47 +0200 Subject: Testing audio latency compensation --- include/sound.hpp | 2 +- src/main.cpp | 9 ++++++--- src/sound.cpp | 19 +++++++++++++++---- 3 files changed, 22 insertions(+), 8 deletions(-) diff --git a/include/sound.hpp b/include/sound.hpp index 731e787..c0d0465 100644 --- a/include/sound.hpp +++ b/include/sound.hpp @@ -55,7 +55,7 @@ void sound_device_close(SoundDevice *device); Returns the next chunk of audio into @buffer. Returns the number of frames read, or a negative value on failure. */ -int sound_device_read_next_chunk(SoundDevice *device, void **buffer, double timeout_sec); +int sound_device_read_next_chunk(SoundDevice *device, void **buffer, double timeout_sec, double *latency_sec); std::vector get_pulseaudio_inputs(); diff --git a/src/main.cpp b/src/main.cpp index 5aacd8b..eb90e91 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -2417,12 +2417,15 @@ int main(int argc, char **argv) { while(running) { void *sound_buffer; int sound_buffer_size = -1; + double latency_seconds = 0.0; + const double time_before_read = clock_get_monotonic_seconds(); if(audio_device.sound_device.handle) - sound_buffer_size = sound_device_read_next_chunk(&audio_device.sound_device, &sound_buffer, timeout_sec); + sound_buffer_size = sound_device_read_next_chunk(&audio_device.sound_device, &sound_buffer, 1.0, &latency_seconds); const bool got_audio_data = sound_buffer_size >= 0; - - const double this_audio_frame_time = clock_get_monotonic_seconds() - paused_time_offset; + const double time_after_read = clock_get_monotonic_seconds(); + latency_seconds = time_after_read - time_before_read; // TODO: Remove this + const double this_audio_frame_time = (time_after_read - paused_time_offset) - latency_seconds; if(paused) { if(got_audio_data) diff --git a/src/sound.cpp b/src/sound.cpp index 485548b..8be32b2 100644 --- a/src/sound.cpp +++ b/src/sound.cpp @@ -41,6 +41,7 @@ struct pa_handle { size_t output_index, output_length; int operation_success; + double latency_seconds; }; static void pa_sound_device_free(pa_handle *s) { @@ -79,8 +80,9 @@ static pa_handle* pa_sound_device_new(const char *server, p->read_data = NULL; p->read_length = 0; p->read_index = 0; + p->latency_seconds = 0.0; - const int buffer_size = attr->maxlength; + const int buffer_size = attr->fragsize; void *buffer = malloc(buffer_size); if(!buffer) { fprintf(stderr, "failed to allocate buffer for audio\n"); @@ -161,6 +163,9 @@ static int pa_sound_device_read(pa_handle *p, double timeout_seconds) { bool success = false; int r = 0; int *rerror = &r; + pa_usec_t latency = 0; + int negative = 0; + CHECK_DEAD_GOTO(p, rerror, fail); while (p->output_index < p->output_length) { @@ -193,6 +198,10 @@ static int pa_sound_device_read(pa_handle *p, double timeout_seconds) { CHECK_DEAD_GOTO(p, rerror, fail); continue; } + + if(pa_stream_get_latency(p->stream, &latency, &negative) >= 0) { + p->latency_seconds = (negative ? -(int64_t)latency : (int64_t)latency) * 0.000001; + } } const size_t space_free_in_output_buffer = p->output_length - p->output_index; @@ -255,8 +264,8 @@ int sound_device_get_by_name(SoundDevice *device, const char *device_name, const buffer_attr.tlength = -1; buffer_attr.prebuf = -1; buffer_attr.minreq = -1; - buffer_attr.maxlength = period_frame_size * audio_format_to_get_bytes_per_sample(audio_format) * num_channels; // 2/4 bytes/sample, @num_channels channels - buffer_attr.fragsize = buffer_attr.maxlength; + buffer_attr.maxlength = -1; + buffer_attr.fragsize = period_frame_size * audio_format_to_get_bytes_per_sample(audio_format) * num_channels; // 2/4 bytes/sample, @num_channels channels int error = 0; pa_handle *handle = pa_sound_device_new(nullptr, description, device_name, description, &ss, &buffer_attr, &error); @@ -276,13 +285,15 @@ void sound_device_close(SoundDevice *device) { device->handle = NULL; } -int sound_device_read_next_chunk(SoundDevice *device, void **buffer, double timeout_sec) { +int sound_device_read_next_chunk(SoundDevice *device, void **buffer, double timeout_sec, double *latency_sec) { pa_handle *pa = (pa_handle*)device->handle; if(pa_sound_device_read(pa, timeout_sec) < 0) { //fprintf(stderr, "pa_simple_read() failed: %s\n", pa_strerror(error)); + *latency_sec = 0.0; return -1; } *buffer = pa->output_data; + *latency_sec = pa->latency_seconds; return device->frames; } -- cgit v1.2.3