output/alsa: moved code to alsa_output_setup_format()

src/output/alsa_plugin.c

@@ -216,89 +216,54 @@ byteswap_bitformat(snd_pcm_format_t fmt)
 	default: return SND_PCM_FORMAT_UNKNOWN;
 	}
 }
+
 /**
- * Set up the snd_pcm_t object which was opened by the caller.  Set up
- * the configured settings and the audio format.
+ * Configure a sample format, and probe other formats if that fails.
  */
-static bool
-alsa_setup(struct alsa_data *ad, struct audio_format *audio_format,
-	   snd_pcm_format_t bitformat,
-	   GError **error)
+static int
+alsa_output_setup_format(snd_pcm_t *pcm, snd_pcm_hw_params_t *hwparams,
+			 struct audio_format *audio_format)
 {
-	snd_pcm_hw_params_t *hwparams;
-	snd_pcm_sw_params_t *swparams;
-	unsigned int sample_rate = audio_format->sample_rate;
-	unsigned int channels = audio_format->channels;
-	snd_pcm_uframes_t alsa_buffer_size;
-	snd_pcm_uframes_t alsa_period_size;
-	int err;
-	const char *cmd = NULL;
-	int retry = MPD_ALSA_RETRY_NR;
-	unsigned int period_time, period_time_ro;
-	unsigned int buffer_time;
-
-	period_time_ro = period_time = ad->period_time;
-configure_hw:
-	/* configure HW params */
-	snd_pcm_hw_params_alloca(&hwparams);
-	cmd = "snd_pcm_hw_params_any";
-	err = snd_pcm_hw_params_any(ad->pcm, hwparams);
-	if (err < 0)
-		goto error;
-
-	if (ad->use_mmap) {
-		err = snd_pcm_hw_params_set_access(ad->pcm, hwparams,
-						   SND_PCM_ACCESS_MMAP_INTERLEAVED);
-		if (err < 0) {
-			g_warning("Cannot set mmap'ed mode on ALSA device \"%s\":  %s\n",
-				  alsa_device(ad), snd_strerror(-err));
-			g_warning("Falling back to direct write mode\n");
-			ad->use_mmap = false;
-		} else
-			ad->writei = snd_pcm_mmap_writei;
-	}
+	snd_pcm_format_t bitformat = get_bitformat(audio_format);
+	if (bitformat == SND_PCM_FORMAT_UNKNOWN) {
+		/* sample format is not supported by this plugin -
+		   fall back to 16 bit samples */
 
-	if (!ad->use_mmap) {
-		cmd = "snd_pcm_hw_params_set_access";
-		err = snd_pcm_hw_params_set_access(ad->pcm, hwparams,
-						   SND_PCM_ACCESS_RW_INTERLEAVED);
-		if (err < 0)
-			goto error;
-		ad->writei = snd_pcm_writei;
+		audio_format->format = SAMPLE_FORMAT_S16;
+		bitformat = SND_PCM_FORMAT_S16;
 	}
 
-	err = snd_pcm_hw_params_set_format(ad->pcm, hwparams, bitformat);
+	int err = snd_pcm_hw_params_set_format(pcm, hwparams, bitformat);
 	if (err == -EINVAL &&
 	    byteswap_bitformat(bitformat) != SND_PCM_FORMAT_UNKNOWN) {
-		err = snd_pcm_hw_params_set_format(ad->pcm, hwparams,
+		err = snd_pcm_hw_params_set_format(pcm, hwparams,
 						   byteswap_bitformat(bitformat));
 		if (err == 0) {
-			g_debug("ALSA device \"%s\": converting format %s to reverse-endian",
-				alsa_device(ad),
+			g_debug("converting format %s to reverse-endian",
 				sample_format_to_string(audio_format->format));
 			audio_format->reverse_endian = 1;
 		}
 	}
+
 	if (err == -EINVAL && (audio_format->format == SAMPLE_FORMAT_S24_P32 ||
 			       audio_format->format == SAMPLE_FORMAT_S16)) {
 		/* fall back to 32 bit, let pcm_convert.c do the conversion */
-		err = snd_pcm_hw_params_set_format(ad->pcm, hwparams,
+		err = snd_pcm_hw_params_set_format(pcm, hwparams,
 						   SND_PCM_FORMAT_S32);
 		if (err == 0) {
-			g_debug("ALSA device \"%s\": converting format %s to 32 bit\n",
-				alsa_device(ad),
+			g_debug("converting format %s to 32 bit\n",
 				sample_format_to_string(audio_format->format));
 			audio_format->format = SAMPLE_FORMAT_S32;
 		}
 	}
+
 	if (err == -EINVAL && (audio_format->format == SAMPLE_FORMAT_S24_P32 ||
 			       audio_format->format == SAMPLE_FORMAT_S16)) {
 		/* fall back to 32 bit, let pcm_convert.c do the conversion */
-		err = snd_pcm_hw_params_set_format(ad->pcm, hwparams,
+		err = snd_pcm_hw_params_set_format(pcm, hwparams,
 						   byteswap_bitformat(SND_PCM_FORMAT_S32));
 		if (err == 0) {
-			g_debug("ALSA device \"%s\": converting format %s to 32 bit backward-endian\n",
-				alsa_device(ad),
+			g_debug("converting format %s to 32 bit backward-endian\n",
 				sample_format_to_string(audio_format->format));
 			audio_format->format = SAMPLE_FORMAT_S32;
 			audio_format->reverse_endian = 1;
@@ -307,28 +272,81 @@ configure_hw:
 
 	if (err == -EINVAL && audio_format->format != SAMPLE_FORMAT_S16) {
 		/* fall back to 16 bit, let pcm_convert.c do the conversion */
-		err = snd_pcm_hw_params_set_format(ad->pcm, hwparams,
+		err = snd_pcm_hw_params_set_format(pcm, hwparams,
 						   SND_PCM_FORMAT_S16);
 		if (err == 0) {
-			g_debug("ALSA device \"%s\": converting format %s to 16 bit\n",
-				alsa_device(ad),
+			g_debug("converting format %s to 16 bit\n",
 				sample_format_to_string(audio_format->format));
 			audio_format->format = SAMPLE_FORMAT_S16;
 		}
 	}
+
 	if (err == -EINVAL && audio_format->format != SAMPLE_FORMAT_S16) {
 		/* fall back to 16 bit, let pcm_convert.c do the conversion */
-		err = snd_pcm_hw_params_set_format(ad->pcm, hwparams,
+		err = snd_pcm_hw_params_set_format(pcm, hwparams,
 						   byteswap_bitformat(SND_PCM_FORMAT_S16));
 		if (err == 0) {
-			g_debug("ALSA device \"%s\": converting format %s to 16 bit backward-endian\n",
-				alsa_device(ad),
+			g_debug("converting format %s to 16 bit backward-endian\n",
 				sample_format_to_string(audio_format->format));
 			audio_format->format = SAMPLE_FORMAT_S16;
 			audio_format->reverse_endian = 1;
 		}
 	}
 
+	return err;
+}
+
+/**
+ * Set up the snd_pcm_t object which was opened by the caller.  Set up
+ * the configured settings and the audio format.
+ */
+static bool
+alsa_setup(struct alsa_data *ad, struct audio_format *audio_format,
+	   GError **error)
+{
+	snd_pcm_hw_params_t *hwparams;
+	snd_pcm_sw_params_t *swparams;
+	unsigned int sample_rate = audio_format->sample_rate;
+	unsigned int channels = audio_format->channels;
+	snd_pcm_uframes_t alsa_buffer_size;
+	snd_pcm_uframes_t alsa_period_size;
+	int err;
+	const char *cmd = NULL;
+	int retry = MPD_ALSA_RETRY_NR;
+	unsigned int period_time, period_time_ro;
+	unsigned int buffer_time;
+
+	period_time_ro = period_time = ad->period_time;
+configure_hw:
+	/* configure HW params */
+	snd_pcm_hw_params_alloca(&hwparams);
+	cmd = "snd_pcm_hw_params_any";
+	err = snd_pcm_hw_params_any(ad->pcm, hwparams);
+	if (err < 0)
+		goto error;
+
+	if (ad->use_mmap) {
+		err = snd_pcm_hw_params_set_access(ad->pcm, hwparams,
+						   SND_PCM_ACCESS_MMAP_INTERLEAVED);
+		if (err < 0) {
+			g_warning("Cannot set mmap'ed mode on ALSA device \"%s\":  %s\n",
+				  alsa_device(ad), snd_strerror(-err));
+			g_warning("Falling back to direct write mode\n");
+			ad->use_mmap = false;
+		} else
+			ad->writei = snd_pcm_mmap_writei;
+	}
+
+	if (!ad->use_mmap) {
+		cmd = "snd_pcm_hw_params_set_access";
+		err = snd_pcm_hw_params_set_access(ad->pcm, hwparams,
+						   SND_PCM_ACCESS_RW_INTERLEAVED);
+		if (err < 0)
+			goto error;
+		ad->writei = snd_pcm_writei;
+	}
+
+	err = alsa_output_setup_format(ad->pcm, hwparams, audio_format);
 	if (err < 0) {
 		g_set_error(error, alsa_output_quark(), err,
 			    "ALSA device \"%s\" does not support format %s: %s",
@@ -455,19 +473,9 @@ static bool
 alsa_open(void *data, struct audio_format *audio_format, GError **error)
 {
 	struct alsa_data *ad = data;
-	snd_pcm_format_t bitformat;
 	int err;
 	bool success;
 
-	bitformat = get_bitformat(audio_format);
-	if (bitformat == SND_PCM_FORMAT_UNKNOWN) {
-		/* sample format is not supported by this plugin -
-		   fall back to 16 bit samples */
-
-		audio_format->format = SAMPLE_FORMAT_S16;
-		bitformat = SND_PCM_FORMAT_S16;
-	}
-
 	err = snd_pcm_open(&ad->pcm, alsa_device(ad),
 			   SND_PCM_STREAM_PLAYBACK, ad->mode);
 	if (err < 0) {
@@ -477,7 +485,7 @@ alsa_open(void *data, struct audio_format *audio_format, GError **error)
 		return false;
 	}
 
-	success = alsa_setup(ad, audio_format, bitformat, error);
+	success = alsa_setup(ad, audio_format, error);
 	if (!success) {
 		snd_pcm_close(ad->pcm);
 		return false;