android - reversa - Habilite la cámara trasera con HTML5

manual para instalar camara de reversa

Question

Estoy trabajando en un proyecto con MVC ASP.Net 4 HTML5 (el navegador predeterminado es google-chrome v29.0.1547.57) Puedo interactuar con estas herramientas y tomar fotografías, pero solo con la cámara frontal, ¿cómo podría habilitar la cámara trasera? la característica de la tableta: Samsung Galaxy Tab 2 Espero que me puedas ayudar

Answer 1

Consulte https://simpl.info/getusermedia/sources/ que muestra cómo puede seleccionar fuentes usando

MediaStreamTrack.getSources(gotSources);

Luego puede seleccionar la fuente y pasarla como opcional en getUserMedia

var constraints = {
audio: {
optional: [{sourceId: audioSource}]
},
video: {
optional: [{sourceId: videoSource}]
}
};
navigator.getUserMedia(constraints, successCallback, errorCallback);

Ahora está completamente disponible en Chrome estable y móvil (a partir de v30)

Answer 2

En Chrome en mi Samsung S8 puedo usar "facingMode" = "environment" para tomar videos de la "cámara trasera". El valor predeterminado parece ser "usuario" (la cámara frontal)

en TypeScript:

 const video = document.getElementById("video");
const constraints = {
advanced: [{
facingMode: "environment"
}]
};
navigator.mediaDevices
.getUserMedia({
video: constraints
})
.then((stream) => {
video.src = window.URL.createObjectURL(stream);
video.play();
});

ref: MediaTrackConstraints/facingMode

Answer 3

La última vez que desarrollé ese código, aquí está la versión que uso: llamas directamente a la función whichCamera en tu código y especias qué cámara "usuario", "entorno" o "computadora" si estás corriendo en una computadora.

`//----------------------------------------------------------------------
// whichCamera(Type)
// For smartphone or tablet :
// Start the type={user,environment} camera.
// For computer it''s simple :
// type = "computer".
//----------------------------------------------------------------------
var streamSrc, cameraType;
function whichCamera(type){
var cameraFacing;
cameraType = type;
if( type == "user")
cameraFacing = 0;
else if( type == "environment")
cameraFacing = 1;
else if( type == "computer"){
cameraFacing = 2;
}
console.log(type+" index : "+cameraFacing);
// Here we list all media devices, in order to choose between
// the front and the rear camera.
// videoDevices[0] : user Camera
// videoDevices[1] : environment Camera
// Then set the video resolution.
navigator.mediaDevices.enumerateDevices()
.then(devices => {
var videoDevices, videoDeviceIndex, constraints;
// Initialize the array wich will contain all video resources IDs.
// Most of devices have two video resources (Front & Rear Camera).
videoDevices = [0,0];
// Simple index to browse the videa resources array (videoDevices).
videoDeviceIndex = 0;
// devices.forEach(), this function will detect all media resources (Audio, Video) of the device
// where we run the application.
devices.forEach(function(device) {
console.log(device.kind + ": " + device.label +
" id = " + device.deviceId);
// If the kind of the media resource is video,
if (device.kind == "videoinput") {
// then we save it on the array videoDevices.
videoDevices[videoDeviceIndex++] = device.deviceId;
console.log(device.deviceId+" = "+videoDevices[videoDeviceIndex-1]);
}
});
console.log("Camera facing ="+cameraFacing+" ID = "+videoDevices[videoDeviceIndex-1]);
// Here we specified which camera we start,
// videoDevices[0] : Front Camera
// videoDevices[1] : Back Camera
if( cameraFacing != "computer"){
constraints = { deviceId: { exact: videoDevices[cameraFacing] }};
return navigator.mediaDevices.getUserMedia({ video:
constraints,
width: { min: 1280, ideal: 1600, max: 1920 },
height: { min: 720, ideal: 1200, max: 1080 }
}
);
}else
return navigator.mediaDevices.getUserMedia({ video: true });
})
// Then we retrieve the link to the video stream.
.then(stream => {
if (window.webkitURL) {
video.src = window.webkitURL.createObjectURL(stream);
localMediaStream = stream;
console.log(localMediaStream +" = "+ stream)
} else if (video.mozSrcObject !== undefined) {
video.mozSrcObject = stream;
console.log(video.mozSrcObject +" = "+ stream)
} else if (video.srcObject !== undefined) {
video.srcObject = stream;
console.log(video.srcObject +" = "+ stream)
} else {
video.src = stream;
console.log(video.src +" = "+ stream)
}
streamSrc = stream;
})
.catch(e => console.error(e));
}

Answer 4

Se puede encontrar una demostración en https://webrtc.github.io/samples/src/content/devices/input-output/ . Esto permitirá el acceso a la cámara delantera y trasera.

Muchas demostraciones que encontrará dependen de la función obsoleta:

MediaStreamTrack.getSources()

A partir de Chrome 45 y FireFox 39, deberá usar la función:

MediaDevices.enumerateDevices()

Ejemplo:

if (!navigator.mediaDevices || !navigator.mediaDevices.enumerateDevices) {
console.log("enumerateDevices() not supported.");
return;
}
// List cameras and microphones.
navigator.mediaDevices.enumerateDevices()
.then(function(devices) {
devices.forEach(function(device) {
console.log(device.kind + ": " + device.label +
" id = " + device.deviceId);
});
})
.catch(function(err) {
console.log(err.name + ": " + error.message);
});

Se puede encontrar documentación adicional aquí: https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/enumerateDevices

Answer 5

 //----------------------------------------------------------------------
// Here we list all media devices, in order to choose between
// the front and the back camera.
// videoDevices[0] : Front Camera
// videoDevices[1] : Back Camera
// I used an array to save the devices ID
// which i get using devices.forEach()
// Then set the video resolution.
//----------------------------------------------------------------------
navigator.mediaDevices.enumerateDevices()
.then(devices => {
var videoDevices = [0,0];
var videoDeviceIndex = 0;
devices.forEach(function(device) {
console.log(device.kind + ": " + device.label +
" id = " + device.deviceId);
if (device.kind == "videoinput") {
videoDevices[videoDeviceIndex++] = device.deviceId;
}
});
var constraints = {width: { min: 1024, ideal: 1280, max: 1920 },
height: { min: 776, ideal: 720, max: 1080 },
deviceId: { exact: videoDevices[1] }
};
return navigator.mediaDevices.getUserMedia({ video: constraints });
})
.then(stream => {
if (window.webkitURL) {
video.src = window.webkitURL.createObjectURL(stream);
localMediaStream = stream;
} else if (video.mozSrcObject !== undefined) {
video.mozSrcObject = stream;
} else if (video.srcObject !== undefined) {
video.srcObject = stream;
} else {
video.src = stream;
}})
.catch(e => console.error(e));