切换摄像头可以通过改变 getMediaStream 的约束条件来实现。
前置摄像头：
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| constraints = {
audio: true,
video: {
facingMode: "user"
}
}
|
后置摄像头：
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| constraints = {
audio: true,
video: {
facingMode: {
exact: "environment"
}
}
}
|
切换摄像头：
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| async function switchCamera() {
localStream.getTracks().forEach(track => {
track.stop();
});
constraints.video.facingMode = constraints.video.facingMode === "user" ? {exact: "environment"} : "user";
localStream = await getMediaStream(constraints).catch(() => {console.error("获取视频流失败")});
localVideo.value.srcObject = localStream;
localVideo.value.play();
localStream.getTracks().forEach(track => {
pc.getSenders().forEach(sender => {
sender.replaceTrack(track);
});
});
}
|
切换摄像头时，先把本地视频流停掉，然后根据约束条件获取新的视频流。
获取到新的视频流之后，为了在保持视频不断的情况下将其传到远端，可以用 RTCRtpSender.replaceTrack() 方法。