Add support for ALSA devices that have no channel maps.

[nageru] / alsa_input.cpp

diff --git a/alsa_input.cpp b/alsa_input.cpp
index 22daf760b026cb8c27cd8b4604ab41488667f345..87adb4ab2427c705a1a1682b9fad24ba7e309abf 100644 (file)
--- a/alsa_input.cpp
+++ b/alsa_input.cpp
@@ -6,21 +6,14 @@ using namespace std;
 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));
 
@@ -125,7 +118,11 @@ void ALSAInput::capture_thread_func()
 
                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;
        }
 }
@@ -143,6 +140,37 @@ void ALSAInput::die_on_error(const char *func_name, int err)
        }
 }
 
+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;
@@ -178,15 +206,43 @@ vector<ALSAInput::Device> ALSAInput::enumerate_devices()
 
                        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);
-                       unsigned num_channels = 0;
-                       for (snd_pcm_chmap_query_t **ptr = cmaps; *ptr; ++ptr) {
-                               num_channels = max(num_channels, (*ptr)->map.channels);
+                       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);
                        }
-
-                       snd_pcm_free_chmaps(cmaps);
 
                        if (num_channels == 0) {
                                printf("%s: No channel maps with channels\n", address);