add windows DirectShow support

Author: noriah

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2021 noriah vix ([email protected])
+Copyright (c) 2022 noriah vix ([email protected])
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -17,8 +17,9 @@
 ## it supports audio backends
 - PortAudio (linux/macOS/*windblows**)
 - PulseAudio (parec/FFmpeg)
-- AVFoundation (FFmpeg)
-- ALSA (FFmpeg)
+- AVFoundation (macOS FFmpeg)
+- DirectShow (windblows FFmpeg)
+- ALSA (linux/FFmpeg)
 
 ## it depends on
 

fft/fftw.go

@@ -1,5 +1,4 @@
-//go:build cgo
-// +build cgo
+//go:build cgo && !windows
 
 package fft
 

fft/gonum.go

@@ -1,5 +1,4 @@
-//go:build !cgo
-// +build !cgo
+//go:build !cgo || windows
 
 package fft
 

input/ffmpeg/alsa.go

@@ -1,3 +1,5 @@
+//go:build linux
+
 package ffmpeg
 
 import (

input/ffmpeg/avfoundation.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package ffmpeg
 
 import (

input/ffmpeg/dshow.go

@@ -0,0 +1,136 @@
+//go:build windows
+
+package ffmpeg
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os/exec"
+	"strings"
+
+	"github.com/noriah/catnip/input"
+	"github.com/noriah/catnip/input/common/execread"
+)
+
+func init() {
+	input.RegisterBackend("ffmpeg-dshow", DShow{})
+}
+
+func NewWindowsSession(b FFmpegBackend, cfg input.SessionConfig) (*execread.Session, error) {
+	args := []string{"ffmpeg", "-hide_banner", "-loglevel", "panic"}
+	args = append(args,
+		"-f", "dshow", "-audio_buffer_size", "20",
+		"-sample_rate", fmt.Sprintf("%.0f", cfg.SampleRate),
+		"-channels", fmt.Sprintf("%d", cfg.FrameSize),
+		// "-sample_size", fmt.Sprintf("%d", 16),
+	)
+	args = append(args, b.InputArgs()...)
+	args = append(args, "-f", "f64le", "-")
+
+	return execread.NewSession(args, false, cfg)
+}
+
+// DShow is the DirectShow input for FFmpeg on Windows.
+type DShow struct{}
+
+func (p DShow) Init() error {
+	return nil
+}
+
+func (p DShow) Close() error {
+	return nil
+}
+
+// Devices returns a list of dshow devices.
+func (p DShow) Devices() ([]input.Device, error) {
+	cmd := exec.Command(
+		"ffmpeg", "-hide_banner", "-loglevel", "info",
+		"-f", "dshow", "-list_devices", "true",
+		"-i", "",
+	)
+
+	o, _ := cmd.CombinedOutput()
+
+	audio := true
+	var devices []input.Device
+
+	var scanner = bufio.NewScanner(bytes.NewReader(o))
+
+	for scanner.Scan() {
+		text := scanner.Text()
+
+		// Trim away the prefix.
+		if strings.HasPrefix(text, "[dshow") {
+			parts := strings.SplitN(text, "] ", 2)
+			if len(parts) == 2 {
+				text = parts[1][1:]
+			}
+		}
+
+		// If we're not scanning a device (which starts with a square bracket)
+		// anymore, then we stop.
+		if strings.HasPrefix(text, ":") {
+			audio = false
+			continue
+		}
+
+		// If we're not under the audio section yet, then skip.
+		if !audio {
+			continue
+		}
+
+		// Parse.
+		parts := strings.SplitN(text, "\" (", 2)
+		if len(parts) != 2 {
+			continue
+		}
+
+		if !strings.HasPrefix(parts[1], "audio") {
+			continue
+		}
+
+		devices = append(devices, DShowDevice{
+			Name: parts[0],
+		})
+	}
+
+	if len(devices) == 0 {
+		// This is completely for visual.
+		var lines = strings.Split(string(o), "\n")
+		for i, line := range lines {
+			lines[i] = "\t" + line
+		}
+		var output = strings.Join(lines, "\n")
+
+		return nil, fmt.Errorf("no devices found; ffmpeg output:\n%s", output)
+	}
+
+	return devices, nil
+}
+
+func (p DShow) DefaultDevice() (input.Device, error) {
+	return DShowDevice{"no default device"}, nil
+}
+
+func (p DShow) Start(cfg input.SessionConfig) (input.Session, error) {
+	dv, ok := cfg.Device.(DShowDevice)
+	if !ok {
+		return nil, fmt.Errorf("invalid device type %T", cfg.Device)
+	}
+
+	return NewWindowsSession(dv, cfg)
+}
+
+type DShowDevice struct {
+	Name string
+}
+
+func (d DShowDevice) InputArgs() []string {
+	input := fmt.Sprintf("audio=%s", d.Name)
+	return []string{"-i", input}
+}
+
+func (d DShowDevice) String() string {
+	return fmt.Sprintf("%s", d.Name)
+}

portaudio.go

@@ -1,5 +1,4 @@
-//go:build cgo && !noportaudio
-// +build cgo,!noportaudio
+//go:build (cgo && !windows && !noportaudio) || (cgo && windows && enablePortaudio)
 
 package main