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Sheldon Lee 2024-10-10 20:53:49 +08:00
parent 7cc2f28241
commit 0b8f5a5620
3 changed files with 52 additions and 13 deletions
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14
README.md Normal file
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@ -0,0 +1,14 @@
Make run to compile and run
```
make run
```
I'm using the whole new pipewire + wireplumber audio stack, which has
compatibility with pulse audio.
Seems like there is ``SDL_AUDIODRIVER=alsa`` environment variable that SDL can
use. I don't think my code works with this enabled.
[Maybe related GitHub issue](https://github.com/libsdl-org/SDL/issues/9706)
I'm using SDL2 version 2.28.5. Downgrading from 2.30.7 seems to make it work a
bit better, but still not consistent.

1
example-test-code/README.md Normal file
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@ -0,0 +1 @@
Some code here is from ChatGPT

50
main.c
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@ -5,7 +5,9 @@
#include <stdio.h>
#include "log.h"
/*
* INFO: I will mark places to look at with INFO:
*/
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
@ -52,7 +54,7 @@ int text_texture_load(text_texture* text_texture, char* string);
int text_texture_render(text_texture* text_texture, int x, int y);
int text_texture_free(text_texture* text_texture);
/*
* Audio
* Audio INFO: audio related declarations and callback here.
*/
int num_devices = 0;
@ -107,23 +109,24 @@ int main(int argc, char* argv[])
text_texture_load(&state_text_texture, char_buffer);
SDL_Event event;
int running = 1;
while (running) {
while (1) {
while (SDL_PollEvent(&event)) {
SDL_Keycode keysym = event.key.keysym.sym;
switch (event.type) {
case SDL_QUIT:
running = 0;
goto cleanup;
break;
case SDL_KEYDOWN:
// INFO: main state logic here.
handle_input(&event, &state);
break;
}
}
// INFO: more state logic here. I check the buffer write position here
handle_task(&state);
sprintf(char_buffer, default_fmt, state.device_index);
@ -153,6 +156,9 @@ int main(int argc, char* argv[])
SDL_RenderPresent(renderer);
}
cleanup:
SDL_CloseAudioDevice(state.recording_device_id);
SDL_CloseAudioDevice(state.playback_device_id);
text_texture_free(&display_text_texture);
for (int i = 0; i < num_devices; i++) {
text_texture_free(&device_textures[i]);
@ -166,17 +172,24 @@ void handle_input(SDL_Event* event, state* state)
{
SDL_Keycode keysym = event->key.keysym.sym;
switch (state->application_state) {
// INFO: init of recording audio device here
case SELECTING_DEVICE:
switch (keysym) {
case SDLK_y:
case SDLK_RETURN:
// INFO: init audio device here and below
// Here it initialises everytime you press enter or y, and
// unpauses device immediately. Seems to work mor consistently
SDL_CloseAudioDevice(state->recording_device_id);
state->recording_device_id = audio_recording_init(state->device_index, NULL);
state->recording_device_id =
audio_recording_init(state->device_index, NULL);
if (state->device_index == -1 || !state->recording_device_id) break;
recording_buffer_position = 0;
// INFO: calling this should unpause the device and start calling the callback
SDL_PauseAudioDevice(state->recording_device_id, 0);
/*SDL_UnlockAudioDevice(state->recording_device_id);*/
// INFO: state change looks like this here
state->application_state = RECORDING;
break;
case SDLK_ESCAPE:
@ -188,6 +201,12 @@ void handle_input(SDL_Event* event, state* state)
if (device_index_new == -1) break;
if (state->device_index != -1 && device_index_new == -1) break;
state->device_index = device_index_new;
// INFO: inititialising here seems to be less consistent. When I
// spam enter or y after initialising here, Sometimes I see
// callback being called sometimes not.
/*SDL_CloseAudioDevice(state->recording_device_id);*/
/*state->recording_device_id = audio_recording_init(state->device_index, NULL);*/
break;
case RECORDING:
@ -203,7 +222,7 @@ void handle_input(SDL_Event* event, state* state)
break;
}
break;
// INFO: init of playback audio device here. Can't seem to get it to play / call callback
case RECORDED:
switch (keysym) {
case SDLK_y:
@ -243,6 +262,7 @@ void handle_task(state* state)
break;
case RECORDING:
// INFO: check buffer position here and stop if reaces the end
SDL_LockAudioDevice(state->recording_device_id);
/*printf("buf pos: %u\n", recording_buffer_position);*/
if (recording_buffer_position >= recording_buffer_position_max) {
@ -259,6 +279,7 @@ void handle_task(state* state)
break;
case PLAYBACK:
// INFO:
SDL_LockAudioDevice(state->playback_device_id);
if (recording_buffer_position >= recording_buffer_position_max) {
SDL_UnlockAudioDevice(state->playback_device_id);
@ -421,9 +442,11 @@ int text_texture_free(text_texture* text_texture)
SDL_DestroyTexture(text_texture->texture);
return 1;
}
// INFO: device init here
// Most of the audio stuff I copied from an example
SDL_AudioDeviceID audio_recording_init(int index, void* userdata)
{
// INFO: audio spec and callback
SDL_zero(recording_spec);
recording_spec.freq = 44100;
recording_spec.format = AUDIO_F32;
@ -441,6 +464,7 @@ SDL_AudioDeviceID audio_recording_init(int index, void* userdata)
unsigned int bytes_per_sample = received_recording_spec.channels * (SDL_AUDIO_BITSIZE(received_recording_spec.format)/8);
unsigned int bytes_per_second = received_recording_spec.freq * bytes_per_sample;
// INFO: I just copied example where they allocated 1 second worth of buffer so it doesn't die
recording_buffer_size = RECORDING_BUFFER_SECONDS * bytes_per_second;
recording_buffer_position_max = MAX_RECORDING_SECONDS * bytes_per_second;
@ -449,14 +473,14 @@ SDL_AudioDeviceID audio_recording_init(int index, void* userdata)
return device_id;
}
// INFO:
SDL_AudioDeviceID audio_playback_init(void* userdata)
{
if (!recording_buffer) {
printf("Audio buffer not initialized");
return 0;
}
// INFO: audio spec and callback
SDL_zero(playback_spec);
playback_spec.freq = 44100;
playback_spec.format = AUDIO_F32;
@ -488,7 +512,7 @@ void audio_buffer_destroy()
recording_buffer_size = 0;
recording_buffer_position = 0;
}
// INFO: callback here
void audio_recording_callback(void* userdata, Uint8* stream, int len)
{
memcpy(&recording_buffer[recording_buffer_position], stream, len);
@ -498,7 +522,7 @@ void audio_recording_callback(void* userdata, Uint8* stream, int len)
printf(string, "Record pos: %u %u\n", recording_buffer_position, len);
log_message(LOG_INFO, string);
}
// INFO:
void audio_playback_callback(void* userdata, Uint8* stream, int len)
{
memcpy(stream, &recording_buffer[recording_buffer_position], len);