av/revid/audio-input_test.go

package revid

import (
	"bytes"
	"errors"
	"io/ioutil"
	"testing"
	"time"

	"bitbucket.org/ausocean/av/codec/codecutil"
	"github.com/yobert/alsa"
)

// Check that a device exists with the given config parameters.
func checkDevice(ac *AudioConfig) error {
	cards, err := alsa.OpenCards()
	if err != nil {
		return errors.New("no audio cards found")
	}
	defer alsa.CloseCards(cards)
	var testDev *alsa.Device
	for _, card := range cards {
		devices, err := card.Devices()
		if err != nil {
			continue
		}
		for _, dev := range devices {
			if dev.Type != alsa.PCM || !dev.Record {
				continue
			}
			testDev = dev
			break
		}
	}
	if testDev == nil {
		return errors.New("no suitable device found")
	}
	err = testDev.Open()
	if err != nil {
		return err
	}
	_, err = testDev.NegotiateChannels(2)
	if err != nil {
		return err
	}
	foundRate := false
	for i := 0; i < len(Rates) && !foundRate; i++ {
		if Rates[i] < ac.SampleRate {
			continue
		}
		if Rates[i]%ac.SampleRate == 0 {
			_, err = testDev.NegotiateRate(Rates[i])
			if err == nil {
				foundRate = true
			}
		}
	}
	if !foundRate {
		_, err = testDev.NegotiateRate(defaultSampleRate)
		if err != nil {
			return err
		}
	}
	var aFmt alsa.FormatType
	switch ac.BitDepth {
	case 16:
		aFmt = alsa.S16_LE
	case 32:
		aFmt = alsa.S32_LE
	default:
		return errors.New("unsupported bitdepth")
	}
	_, err = testDev.NegotiateFormat(aFmt)
	if err != nil {
		return err
	}
	_, err = testDev.NegotiateBufferSize(8192, 16384)
	if err != nil {
		return err
	}
	if err = testDev.Prepare(); err != nil {
		return err
	}
	if testDev != nil {
		testDev.Close()
	}
	return nil
}

func TestAudio(t *testing.T) {
	// We want to open a device with a standard configuration.
	ac := &AudioConfig{
		SampleRate: 8000,
		Channels:   1,
		RecPeriod:  1,
		BitDepth:   16,
		Codec:      ADPCM,
	}

	// Skip if there are no suitable devices to test with.
	err := checkDevice(ac)
	if err != nil {
		t.Error(err)
	}

	// Create a new audioDevice, start, read/lex, and then stop it.
	ai, err := NewAudioDevice(ac)
	if err != nil {
		t.Error(err)
	}
	dst := bytes.NewBuffer(make([]byte, 0))
	err = ai.Start()
	if err != nil {
		t.Error(err)
	}
	num := 3 // How many 'ac.RecPeriod's to record.
	go codecutil.LexBytes(dst, ai, time.Duration(ac.RecPeriod*float64(time.Second)), ai.ChunkSize())
	time.Sleep(time.Millisecond * 1000 * time.Duration(num))
	ai.Stop()
	err = ioutil.WriteFile("./testout", dst.Bytes(), 0644)
}