revid, alsa: reorder audio setup

device/alsa/alsa.go

@@ -437,6 +437,10 @@ func (d *ALSA) formatBuffer() pcm.Buffer {
 	return formatted
 }
 
+func (d *ALSA) DataSize() int {
+	return pcm.DataSize(d.SampleRate, d.Channels, d.BitDepth, d.RecPeriod, d.Codec)
+}
+
 // nearestPowerOfTwo finds and returns the nearest power of two to the given integer.
 // If the lower and higher power of two are the same distance, it returns the higher power.
 // For negative values, 1 is returned.

revid/audio_linux.go

@@ -29,13 +29,32 @@ import (
 	"strconv"
 
 	"bitbucket.org/ausocean/av/codec/codecutil"
-	"bitbucket.org/ausocean/av/codec/pcm"
 	"bitbucket.org/ausocean/av/container/mts"
 	"bitbucket.org/ausocean/av/device/alsa"
 	"bitbucket.org/ausocean/utils/logger"
 )
 
 func (r *Revid) setupAudio() error {
+	// Create new ALSA device.
+	d := alsa.New(r.cfg.Logger)
+	r.input = d
+
+	// Configure ALSA device.
+	r.cfg.Logger.Log(logger.Debug, "configuring input device")
+	err := r.input.Set(r.cfg)
+	if err != nil {
+		r.cfg.Logger.Log(logger.Warning, "errors from configuring input device", "errors", err)
+	}
+	r.cfg.Logger.Log(logger.Info, "input device configured")
+
+	// Set revid's lexer.
+	l, err := codecutil.NewByteLexer(d.DataSize())
+	if err != nil {
+		return err
+	}
+	r.lexTo = l.Lex
+
+	// Add metadata.
 	mts.Meta.Add("sampleRate", strconv.Itoa(int(r.cfg.SampleRate)))
 	mts.Meta.Add("channels", strconv.Itoa(int(r.cfg.Channels)))
 	mts.Meta.Add("period", fmt.Sprintf("%.6f", r.cfg.RecPeriod))
@@ -50,13 +69,5 @@ func (r *Revid) setupAudio() error {
 		r.cfg.Logger.Log(logger.Fatal, "no audio codec set in config")
 	}
 
-	r.input = alsa.New(r.cfg.Logger)
-
-	l, err := codecutil.NewByteLexer(pcm.DataSize(r.cfg.SampleRate, r.cfg.Channels, r.cfg.BitDepth, r.cfg.RecPeriod, r.cfg.InputCodec))
-	if err != nil {
-		return err
-	}
-	r.lexTo = l.Lex
-
 	return nil
 }

revid/revid.go

@@ -392,6 +392,12 @@ func (r *Revid) setupPipeline(mtsEnc func(dst io.WriteCloser, rate float64) (io.
 		}
 	}
 
+	// input.Set does not need to be called for InputAudio since it is called
+	// in setupAudio above, so we can return here.
+	if r.cfg.Input == config.InputAudio {
+		return nil
+	}
+
 	// Configure the input device. We know that defaults are set, so no need to
 	// return error, but we should log.
 	r.cfg.Logger.Log(logger.Debug, "configuring input device")