Files
mediadevices/pkg/driver/microphone/microphone_windows.go
2020-10-29 00:04:12 -07:00

348 lines
8.5 KiB
Go

package microphone
import (
"errors"
"golang.org/x/sys/windows"
"io"
"time"
"unsafe"
"github.com/pion/mediadevices/pkg/driver"
"github.com/pion/mediadevices/pkg/io/audio"
"github.com/pion/mediadevices/pkg/prop"
"github.com/pion/mediadevices/pkg/wave"
)
const (
// bufferNumber * prop.Audio.Latency is the maximum blockable duration
// to get data without dropping chunks.
bufferNumber = 5
)
// Windows APIs
var (
winmm = windows.NewLazySystemDLL("Winmm.dll")
waveInOpen = winmm.NewProc("waveInOpen")
waveInStart = winmm.NewProc("waveInStart")
waveInStop = winmm.NewProc("waveInStop")
waveInReset = winmm.NewProc("waveInReset")
waveInClose = winmm.NewProc("waveInClose")
waveInPrepareHeader = winmm.NewProc("waveInPrepareHeader")
waveInAddBuffer = winmm.NewProc("waveInAddBuffer")
waveInUnprepareHeader = winmm.NewProc("waveInUnprepareHeader")
)
type buffer struct {
waveHdr
data []int16
}
func newBuffer(samples int) *buffer {
b := make([]int16, samples)
return &buffer{
waveHdr: waveHdr{
// Sharing Go memory with Windows C API without reference.
// Make sure that the lifetime of the buffer struct is longer
// than the final access from cbWaveIn.
lpData: uintptr(unsafe.Pointer(&b[0])),
dwBufferLength: uint32(samples * 2),
},
data: b,
}
}
type microphone struct {
hWaveIn windows.Pointer
buf map[uintptr]*buffer
chBuf chan *buffer
closed chan struct{}
}
func init() {
// TODO: enum devices
driver.GetManager().Register(&microphone{}, driver.Info{
Label: "default",
DeviceType: driver.Microphone,
})
}
func (m *microphone) Open() error {
m.chBuf = make(chan *buffer)
m.buf = make(map[uintptr]*buffer)
m.closed = make(chan struct{})
return nil
}
func (m *microphone) cbWaveIn(hWaveIn windows.Pointer, uMsg uint, dwInstance, dwParam1, dwParam2 *int32) uintptr {
switch uMsg {
case MM_WIM_DATA:
b := m.buf[uintptr(unsafe.Pointer(dwParam1))]
m.chBuf <- b
case MM_WIM_OPEN:
case MM_WIM_CLOSE:
close(m.chBuf)
}
return 0
}
func (m *microphone) Close() error {
if m.hWaveIn == nil {
return nil
}
close(m.closed)
ret, _, _ := waveInStop.Call(
uintptr(unsafe.Pointer(m.hWaveIn)),
)
if err := errWinmm[ret]; err != nil {
return err
}
// All enqueued buffers are marked done by waveInReset.
ret, _, _ = waveInReset.Call(
uintptr(unsafe.Pointer(m.hWaveIn)),
)
if err := errWinmm[ret]; err != nil {
return err
}
for _, buf := range m.buf {
// Detach buffers from waveIn API.
ret, _, _ := waveInUnprepareHeader.Call(
uintptr(unsafe.Pointer(m.hWaveIn)),
uintptr(unsafe.Pointer(&buf.waveHdr)),
uintptr(unsafe.Sizeof(buf.waveHdr)),
)
if err := errWinmm[ret]; err != nil {
return err
}
}
// Now, it's ready to free the buffers.
// As microphone struct still has reference to the buffers,
// they will be GC-ed once microphone is reopened or unreferenced.
ret, _, _ = waveInClose.Call(
uintptr(unsafe.Pointer(m.hWaveIn)),
)
if err := errWinmm[ret]; err != nil {
return err
}
<-m.chBuf
m.hWaveIn = nil
return nil
}
func (m *microphone) AudioRecord(p prop.Media) (audio.Reader, error) {
for i := 0; i < bufferNumber; i++ {
b := newBuffer(
int(uint64(p.Latency) * uint64(p.SampleRate) / uint64(time.Second)),
)
// Map the buffer by its data head address to restore access to the Go struct
// in callback function. Don't resize the buffer after it.
m.buf[uintptr(unsafe.Pointer(&b.waveHdr))] = b
}
waveFmt := &waveFormatEx{
wFormatTag: WAVE_FORMAT_PCM,
nChannels: uint16(p.ChannelCount),
nSamplesPerSec: uint32(p.SampleRate),
nAvgBytesPerSec: uint32(p.SampleRate * p.ChannelCount * 2),
nBlockAlign: uint16(p.ChannelCount * 2),
wBitsPerSample: 16,
}
ret, _, _ := waveInOpen.Call(
uintptr(unsafe.Pointer(&m.hWaveIn)),
WAVE_MAPPER,
uintptr(unsafe.Pointer(waveFmt)),
windows.NewCallback(m.cbWaveIn),
0,
CALLBACK_FUNCTION,
)
if err := errWinmm[ret]; err != nil {
return nil, err
}
for _, buf := range m.buf {
// Attach buffers to waveIn API.
ret, _, _ := waveInPrepareHeader.Call(
uintptr(unsafe.Pointer(m.hWaveIn)),
uintptr(unsafe.Pointer(&buf.waveHdr)),
uintptr(unsafe.Sizeof(buf.waveHdr)),
)
if err := errWinmm[ret]; err != nil {
return nil, err
}
}
for _, buf := range m.buf {
// Enqueue buffers.
ret, _, _ := waveInAddBuffer.Call(
uintptr(unsafe.Pointer(m.hWaveIn)),
uintptr(unsafe.Pointer(&buf.waveHdr)),
uintptr(unsafe.Sizeof(buf.waveHdr)),
)
if err := errWinmm[ret]; err != nil {
return nil, err
}
}
ret, _, _ = waveInStart.Call(
uintptr(unsafe.Pointer(m.hWaveIn)),
)
if err := errWinmm[ret]; err != nil {
return nil, err
}
// TODO: detect microphone device disconnection and return EOF
reader := audio.ReaderFunc(func() (wave.Audio, func(), error) {
b, ok := <-m.chBuf
if !ok {
return nil, func() {}, io.EOF
}
select {
case <-m.closed:
default:
// Re-enqueue used buffer.
ret, _, _ := waveInAddBuffer.Call(
uintptr(unsafe.Pointer(m.hWaveIn)),
uintptr(unsafe.Pointer(&b.waveHdr)),
uintptr(unsafe.Sizeof(b.waveHdr)),
)
if err := errWinmm[ret]; err != nil {
return nil, func() {}, err
}
}
a := wave.NewInt16Interleaved(
wave.ChunkInfo{
Channels: p.ChannelCount,
Len: (int(b.waveHdr.dwBytesRecorded) / 2) / p.ChannelCount,
},
)
j := 0
for i := 0; i < a.Size.Len; i++ {
for ch := 0; ch < a.Size.Channels; ch++ {
a.SetInt16(i, ch, wave.Int16Sample(b.data[j]))
j++
}
}
return a, func() {}, nil
})
return reader, nil
}
func (m *microphone) Properties() []prop.Media {
// TODO: Get actual properties
monoProp := prop.Media{
Audio: prop.Audio{
SampleRate: 48000,
Latency: time.Millisecond * 20,
ChannelCount: 1,
},
}
stereoProp := monoProp
stereoProp.ChannelCount = 2
return []prop.Media{monoProp, stereoProp}
}
// Windows API structures
type waveFormatEx struct {
wFormatTag uint16
nChannels uint16
nSamplesPerSec uint32
nAvgBytesPerSec uint32
nBlockAlign uint16
wBitsPerSample uint16
cbSize uint16
}
type waveHdr struct {
lpData uintptr
dwBufferLength uint32
dwBytesRecorded uint32
dwUser *uint32
dwFlags uint32
dwLoops uint32
lpNext *waveHdr
reserved *uint32
}
// Windows consts
const (
MMSYSERR_NOERROR = 0
MMSYSERR_ERROR = 1
MMSYSERR_BADDEVICEID = 2
MMSYSERR_NOTENABLED = 3
MMSYSERR_ALLOCATED = 4
MMSYSERR_INVALHANDLE = 5
MMSYSERR_NODRIVER = 6
MMSYSERR_NOMEM = 7
MMSYSERR_NOTSUPPORTED = 8
MMSYSERR_BADERRNUM = 9
MMSYSERR_INVALFLAG = 10
MMSYSERR_INVALPARAM = 11
MMSYSERR_HANDLEBUSY = 12
MMSYSERR_INVALIDALIAS = 13
MMSYSERR_BADDB = 14
MMSYSERR_KEYNOTFOUND = 15
MMSYSERR_READERROR = 16
MMSYSERR_WRITEERROR = 17
MMSYSERR_DELETEERROR = 18
MMSYSERR_VALNOTFOUND = 19
MMSYSERR_NODRIVERCB = 20
WAVERR_BADFORMAT = 32
WAVERR_STILLPLAYING = 33
WAVERR_UNPREPARED = 34
WAVERR_SYNC = 35
WAVE_MAPPER = 0xFFFF
WAVE_FORMAT_PCM = 1
CALLBACK_NULL = 0
CALLBACK_WINDOW = 0x10000
CALLBACK_TASK = 0x20000
CALLBACK_FUNCTION = 0x30000
CALLBACK_THREAD = CALLBACK_TASK
CALLBACK_EVENT = 0x50000
MM_WIM_OPEN = 0x3BE
MM_WIM_CLOSE = 0x3BF
MM_WIM_DATA = 0x3C0
)
var errWinmm = map[uintptr]error{
MMSYSERR_NOERROR: nil,
MMSYSERR_ERROR: errors.New("error"),
MMSYSERR_BADDEVICEID: errors.New("bad device id"),
MMSYSERR_NOTENABLED: errors.New("not enabled"),
MMSYSERR_ALLOCATED: errors.New("already allocated"),
MMSYSERR_INVALHANDLE: errors.New("invalid handler"),
MMSYSERR_NODRIVER: errors.New("no driver"),
MMSYSERR_NOMEM: errors.New("no memory"),
MMSYSERR_NOTSUPPORTED: errors.New("not supported"),
MMSYSERR_BADERRNUM: errors.New("band error number"),
MMSYSERR_INVALFLAG: errors.New("invalid flag"),
MMSYSERR_INVALPARAM: errors.New("invalid param"),
MMSYSERR_HANDLEBUSY: errors.New("handle busy"),
MMSYSERR_INVALIDALIAS: errors.New("invalid alias"),
MMSYSERR_BADDB: errors.New("bad db"),
MMSYSERR_KEYNOTFOUND: errors.New("key not found"),
MMSYSERR_READERROR: errors.New("read error"),
MMSYSERR_WRITEERROR: errors.New("write error"),
MMSYSERR_DELETEERROR: errors.New("delete error"),
MMSYSERR_VALNOTFOUND: errors.New("value not found"),
MMSYSERR_NODRIVERCB: errors.New("no driver cb"),
WAVERR_BADFORMAT: errors.New("bad format"),
WAVERR_STILLPLAYING: errors.New("still playing"),
WAVERR_UNPREPARED: errors.New("unprepared"),
WAVERR_SYNC: errors.New("sync"),
}