Is this the final solution to the audio crackling problem? increase pts by number of samples and add dummy audio frames between

This commit is contained in:
dec05eba 2022-09-20 20:11:56 +02:00
parent a668cac2bb
commit f810161203
2 changed files with 53 additions and 78 deletions

View File

@ -483,7 +483,7 @@ static AVCodecContext* create_audio_codec_context(AVFormatContext *av_format_con
#endif
codec_context->time_base.num = 1;
codec_context->time_base.den = AV_TIME_BASE;
codec_context->time_base.den = codec_context->sample_rate;
codec_context->framerate.num = fps;
codec_context->framerate.den = 1;
@ -1462,11 +1462,12 @@ int main(int argc, char **argv) {
av_opt_set_sample_fmt(swr, "out_sample_fmt", AV_SAMPLE_FMT_FLTP, 0);
swr_init(swr);
int64_t pts = 0;
const double target_audio_hz = 1.0 / (double)audio_track.codec_context->sample_rate;
while(running) {
void *sound_buffer;
int sound_buffer_size = sound_device_read_next_chunk(&audio_track.sound_device, &sound_buffer);
if(sound_buffer_size < 0)
sound_buffer = empty_audio;
int ret = av_frame_make_writable(audio_track.frame);
if (ret < 0) {
@ -1474,15 +1475,42 @@ int main(int argc, char **argv) {
break;
}
// TODO: Instead of converting audio, get float audio from alsa. Or does alsa do conversion internally to get this format?
swr_convert(swr, &audio_track.frame->data[0], audio_track.frame->nb_samples, (const uint8_t**)&sound_buffer, audio_track.sound_device.frames);
audio_track.frame->pts = (clock_get_monotonic_seconds() - start_time_pts) * AV_TIME_BASE;
const double this_audio_frame_time = clock_get_monotonic_seconds();
const int64_t expected_frames = std::round((this_audio_frame_time - start_time_pts) / target_audio_hz);
const int64_t num_missing_frames = std::max(0L, (expected_frames - pts) / audio_track.frame->nb_samples);
// Jesus is there a better way to do this? I JUST WANT TO KEEP VIDEO AND AUDIO SYNCED HOLY FUCK I WANT TO KILL MYSELF NOW.
// THIS PIECE OF SHIT WANTS EMPTY FRAMES OTHERWISE VIDEO PLAYS TOO FAST TO KEEP UP WITH AUDIO OR THE AUDIO PLAYS TOO EARLY.
// BUT WE CANT USE DELAYS TO GIVE DUMMY DATA BECAUSE PULSEAUDIO MIGHT GIVE AUDIO A BIG DELAYED!!!
if(num_missing_frames >= 5) {
// TODO:
//audio_track.frame->data[0] = empty_audio;
swr_convert(swr, &audio_track.frame->data[0], audio_track.frame->nb_samples, (const uint8_t**)&empty_audio, audio_track.sound_device.frames);
// TODO: Check if duplicate frame can be saved just by writing it with a different pts instead of sending it again
for(int i = 0; i < num_missing_frames; ++i) {
audio_track.frame->pts = pts;
pts += audio_track.frame->nb_samples;
ret = avcodec_send_frame(audio_track.codec_context, audio_track.frame);
if(ret >= 0){
receive_frames(audio_track.codec_context, audio_track.stream_index, audio_track.stream, audio_track.frame, av_format_context, record_start_time, frame_data_queue, replay_buffer_size_secs, frames_erased, *write_output_mutex);
} else {
fprintf(stderr, "Failed to encode audio!\n");
}
}
}
ret = avcodec_send_frame(audio_track.codec_context, audio_track.frame);
if(ret >= 0){
receive_frames(audio_track.codec_context, audio_track.stream_index, audio_track.stream, audio_track.frame, av_format_context, record_start_time, frame_data_queue, replay_buffer_size_secs, frames_erased, *write_output_mutex);
} else {
fprintf(stderr, "Failed to encode audio!\n");
if(sound_buffer_size >= 0) {
// TODO: Instead of converting audio, get float audio from alsa. Or does alsa do conversion internally to get this format?
swr_convert(swr, &audio_track.frame->data[0], audio_track.frame->nb_samples, (const uint8_t**)&sound_buffer, audio_track.sound_device.frames);
audio_track.frame->pts = pts;
pts += audio_track.frame->nb_samples;
ret = avcodec_send_frame(audio_track.codec_context, audio_track.frame);
if(ret >= 0){
receive_frames(audio_track.codec_context, audio_track.stream_index, audio_track.stream, audio_track.frame, av_format_context, record_start_time, frame_data_queue, replay_buffer_size_secs, frames_erased, *write_output_mutex);
} else {
fprintf(stderr, "Failed to encode audio!\n");
}
}
}

View File

@ -20,7 +20,6 @@
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <cmath>
#include <pulse/pulseaudio.h>
@ -28,29 +27,6 @@
#include <pulse/xmalloc.h>
#include <pulse/error.h>
#define CHECK_DEAD_GOTO(p, rerror, label) \
do { \
if (!(p)->context || !PA_CONTEXT_IS_GOOD(pa_context_get_state((p)->context)) || \
!(p)->stream || !PA_STREAM_IS_GOOD(pa_stream_get_state((p)->stream))) { \
if (((p)->context && pa_context_get_state((p)->context) == PA_CONTEXT_FAILED) || \
((p)->stream && pa_stream_get_state((p)->stream) == PA_STREAM_FAILED)) { \
if (rerror) \
*(rerror) = pa_context_errno((p)->context); \
} else \
if (rerror) \
*(rerror) = PA_ERR_BADSTATE; \
goto label; \
} \
} while(false);
static double clock_get_monotonic_seconds() {
struct timespec ts;
ts.tv_sec = 0;
ts.tv_nsec = 0;
clock_gettime(CLOCK_MONOTONIC, &ts);
return (double)ts.tv_sec + (double)ts.tv_nsec * 0.000000001;
}
static int sound_device_index = 0;
struct pa_handle {
@ -154,59 +130,30 @@ fail:
return NULL;
}
static void pa_sound_device_mainloop_timed(pa_handle *p, int64_t timeout_ms) {
const double start_time = clock_get_monotonic_seconds();
while((clock_get_monotonic_seconds() - start_time) * 1000.0 < timeout_ms) {
pa_mainloop_prepare(p->mainloop, 1 * 1000);
pa_mainloop_poll(p->mainloop);
pa_mainloop_dispatch(p->mainloop);
}
}
// Returns a negative value on failure. Always blocks a time specified matching the sampling rate of the audio.
// Returns a negative value on failure or if no data is available at the moment
static int pa_sound_device_read(pa_handle *p, void *data, size_t length) {
assert(p);
int r = 0;
int *rerror = &r;
bool retry = true;
pa_mainloop_iterate(p->mainloop, 0, NULL);
const int64_t timeout_ms = std::round((1000.0 / (double)pa_stream_get_sample_spec(p->stream)->rate) * 1000.0);
pa_mainloop_prepare(p->mainloop, timeout_ms * 1000);
pa_mainloop_poll(p->mainloop);
pa_mainloop_dispatch(p->mainloop);
CHECK_DEAD_GOTO(p, rerror, fail);
if(pa_stream_readable_size(p->stream) < length)
return -1;
while(true) {
if(pa_stream_readable_size(p->stream) < length) {
if(!retry)
break;
int r = pa_stream_peek(p->stream, &p->read_data, &p->read_length);
if(r != 0)
return -1;
retry = false;
pa_sound_device_mainloop_timed(p, timeout_ms);
continue;
}
r = pa_stream_peek(p->stream, &p->read_data, &p->read_length);
if(r != 0) {
if(retry)
pa_sound_device_mainloop_timed(p, timeout_ms);
return -1;
}
if(p->read_length < length || !p->read_data) {
pa_stream_drop(p->stream);
if(retry)
pa_sound_device_mainloop_timed(p, timeout_ms);
return -1;
}
memcpy(data, p->read_data, length);
if(p->read_length < length || !p->read_data) {
pa_stream_drop(p->stream);
return 0;
return -1;
}
fail:
return -1;
memcpy(data, p->read_data, length);
pa_stream_drop(p->stream);
return 0;
}
int sound_device_get_by_name(SoundDevice *device, const char *name, unsigned int num_channels, unsigned int period_frame_size) {