ALSAInput::ALSAInput(const char *device, unsigned sample_rate, unsigned num_channels, audio_callback_t audio_callback)
: device(device), sample_rate(sample_rate), num_channels(num_channels), audio_callback(audio_callback)
{
- die_on_error(device, snd_pcm_open(&pcm_handle,device, SND_PCM_STREAM_CAPTURE, 0));
+ die_on_error(device, snd_pcm_open(&pcm_handle, device, SND_PCM_STREAM_CAPTURE, 0));
// Set format.
snd_pcm_hw_params_t *hw_params;
snd_pcm_hw_params_alloca(&hw_params);
- die_on_error("snd_pcm_hw_params_any()", snd_pcm_hw_params_any(pcm_handle, hw_params));
- die_on_error("snd_pcm_hw_params_set_access()", snd_pcm_hw_params_set_access(pcm_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED));
- 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);
- die_on_error("snd_pcm_hw_params_set_format()", snd_pcm_hw_params_set_format_mask(pcm_handle, hw_params, format_mask));
- die_on_error("snd_pcm_hw_params_set_rate_near()", snd_pcm_hw_params_set_rate_near(pcm_handle, hw_params, &sample_rate, 0));
- die_on_error("snd_pcm_hw_params_set_channels()", snd_pcm_hw_params_set_channels(pcm_handle, hw_params, num_channels));
+ if (!set_base_params(device, pcm_handle, hw_params, &sample_rate)) {
+ exit(1);
+ }
die_on_error("snd_pcm_hw_params_set_channels()", snd_pcm_hw_params_set_channels(pcm_handle, hw_params, num_channels));
die_on_error("snd_pcm_nonblock()", snd_pcm_nonblock(pcm_handle, 1));
die_on_error("snd_pcm_prepare()", snd_pcm_prepare(pcm_handle));
-
}
ALSAInput::~ALSAInput()
const int64_t prev_pts = frames_to_pts(num_frames_output);
const int64_t pts = frames_to_pts(num_frames_output + frames);
- audio_callback(buffer.get(), frames, audio_format, pts - prev_pts);
+ bool success;
+ do {
+ if (should_quit) return;
+ success = audio_callback(buffer.get(), frames, audio_format, pts - prev_pts);
+ } while (!success);
num_frames_output += frames;
}
}
}
}
+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;
+}
+
+vector<ALSAInput::Device> ALSAInput::enumerate_devices()
+{
+ vector<Device> ret;
+
+ // Enumerate all cards.
+ for (int card_index = -1; snd_card_next(&card_index) == 0 && card_index >= 0; ) {
+ char address[256];
+ snprintf(address, sizeof(address), "hw:%d", card_index);
+
+ snd_ctl_t *ctl;
+ int err = snd_ctl_open(&ctl, address, 0);
+ if (err < 0) {
+ printf("%s: %s\n", address, snd_strerror(err));
+ continue;
+ }
+ snd_ctl_card_info_t *card_info;
+ snd_ctl_card_info_alloca(&card_info);
+ snd_ctl_card_info(ctl, card_info);
+
+ string card_name = snd_ctl_card_info_get_name(card_info);
+
+ // Enumerate all devices on this card.
+ for (int dev_index = -1; snd_ctl_pcm_next_device(ctl, &dev_index) == 0 && dev_index >= 0; ) {
+ snd_pcm_info_t *pcm_info;
+ snd_pcm_info_alloca(&pcm_info);
+ snd_pcm_info_set_device(pcm_info, dev_index);
+ snd_pcm_info_set_subdevice(pcm_info, 0);
+ snd_pcm_info_set_stream(pcm_info, SND_PCM_STREAM_CAPTURE);
+ if (snd_ctl_pcm_info(ctl, pcm_info) < 0) {
+ // Not available for capture.
+ continue;
+ }
+
+ snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
+
+ unsigned num_channels = 0;
+
+ // Find all channel maps for this device, and pick out the one
+ // with the most channels.
+ snd_pcm_chmap_query_t **cmaps = snd_pcm_query_chmaps_from_hw(card_index, dev_index, 0, SND_PCM_STREAM_CAPTURE);
+ if (cmaps != nullptr) {
+ for (snd_pcm_chmap_query_t **ptr = cmaps; *ptr; ++ptr) {
+ num_channels = max(num_channels, (*ptr)->map.channels);
+ }
+ snd_pcm_free_chmaps(cmaps);
+ }
+ if (num_channels == 0) {
+ // Device had no channel maps. We need to open it to query.
+ snd_pcm_t *pcm_handle;
+ int err = snd_pcm_open(&pcm_handle, address, SND_PCM_STREAM_CAPTURE, 0);
+ if (err < 0) {
+ // TODO: When we go to hotplug support, we should support some
+ // retry here, as the device could legitimately be busy.
+ printf("%s: %s\n", address, snd_strerror(err));
+ continue;
+ }
+ snd_pcm_hw_params_t *hw_params;
+ snd_pcm_hw_params_alloca(&hw_params);
+ unsigned sample_rate;
+ if (!set_base_params(address, pcm_handle, hw_params, &sample_rate)) {
+ snd_pcm_close(pcm_handle);
+ continue;
+ }
+ err = snd_pcm_hw_params_get_channels_max(hw_params, &num_channels);
+ if (err < 0) {
+ fprintf(stderr, "[%s] snd_pcm_hw_params_get_channels_max(): %s\n",
+ address, snd_strerror(err));
+ snd_pcm_close(pcm_handle);
+ continue;
+ }
+ snd_pcm_close(pcm_handle);
+ }
+
+ if (num_channels == 0) {
+ printf("%s: No channel maps with channels\n", address);
+ continue;
+ }
+
+ Device dev;
+ dev.address = address;
+ dev.name = card_name;
+ dev.info = snd_pcm_info_get_name(pcm_info);
+ dev.num_channels = num_channels;
+
+ ret.push_back(dev);
+ }
+ snd_ctl_close(ctl);
+ }
+
+ return ret;
+}