此脚本正在使用Face.com API分析面部反应。由于某种原因pygame找不到我的相机（我认为这是问题所在）。我的代码有什么问题吗？
我安装了pygame，看起来效果很好。但是下面的代码给了我错误。
####################################################
# IMPORTS
####################################################
# imports for capturing a frame from the webcam
import pygame
import pygame.camera
import pygame.image
# import for detecting faces in the photo
import face_client
# import for storing data
from pysqlite2 import dbapi2 as sqlite
# miscellaneous imports
from time import strftime, localtime, sleep
import os
import sys
####################################################
# CONSTANTS
####################################################
DB_FILE_PATH="log.db"
FACE_COM_APIKEY="API CODE"
FACE_COM_APISECRET="API SECRET"
DALELANE_FACETAG="name@name.name"
POLL_FREQUENCY_SECONDS=3
class AudienceMonitor():
#
# prepare the database where we store the results
#
def initialiseDB(self):
self.connection = sqlite.connect(DB_FILE_PATH, detect_types=sqlite.PARSE_DECLTYPES|sqlite.PARSE_COLNAMES)
cursor = self.connection.cursor()
cursor.execute('SELECT name FROM sqlite_master WHERE type="table" AND NAME="facelog" ORDER BY name')
if not cursor.fetchone():
cursor.execute('CREATE TABLE facelog(ts timestamp unique default current_timestamp, isSmiling boolean, smilingConfidence int, mood text, moodConfidence int)')
cursor.execute('SELECT name FROM sqlite_master WHERE type="table" AND NAME="guestlog" ORDER BY name')
if not cursor.fetchone():
cursor.execute('CREATE TABLE guestlog(ts timestamp unique default current_timestamp, isSmiling boolean, smilingConfidence int, mood text, moodConfidence int, agemin int, ageminConfidence int, agemax int, agemaxConfidence int, ageest int, ageestConfidence int, gender text, genderConfidence int)')
self.connection.commit()
#
# initialise the camera
#
def prepareCamera(self):
# prepare the webcam
pygame.camera.init()
self.camera = pygame.camera.Camera(pygame.camera.list_cameras()[0], (900, 675))
self.camera.start()
#
# take a single frame and store in the path provided
#
def captureFrame(self, filepath):
# save the picture
image = self.camera.get_image()
pygame.image.save(image, filepath)
#
# gets a string representing the current time to the nearest second
#
def getTimestampString(self):
return strftime("%Y%m%d%H%M%S", localtime())
#
# get attribute from face detection response
#
def getFaceDetectionAttributeValue(self, face, attribute):
value = None
if attribute in face['attributes']:
value = face['attributes'][attribute]['value']
return value
#
# get confidence from face detection response
#
def getFaceDetectionAttributeConfidence(self, face, attribute):
confidence = None
if attribute in face['attributes']:
confidence = face['attributes'][attribute]['confidence']
return confidence
#
# detects faces in the photo at the specified path, and returns info
#
def faceDetection(self, photopath):
client = face_client.FaceClient(FACE_COM_APIKEY, FACE_COM_APISECRET)
response = client.faces_recognize(DALELANE_FACETAG, file_name=photopath)
faces = response['photos'][0]['tags']
for face in faces:
userid = ""
faceuseridinfo = face['uids']
if len(faceuseridinfo) > 0:
userid = faceuseridinfo[0]['uid']
if userid == DALELANE_FACETAG:
smiling = self.getFaceDetectionAttributeValue(face, "smiling")
smilingConfidence = self.getFaceDetectionAttributeConfidence(face, "smiling")
mood = self.getFaceDetectionAttributeValue(face, "mood")
moodConfidence = self.getFaceDetectionAttributeConfidence(face, "mood")
self.storeResults(smiling, smilingConfidence, mood, moodConfidence)
else:
smiling = self.getFaceDetectionAttributeValue(face, "smiling")
smilingConfidence = self.getFaceDetectionAttributeConfidence(face, "smiling")
mood = self.getFaceDetectionAttributeValue(face, "mood")
moodConfidence = self.getFaceDetectionAttributeConfidence(face, "mood")
agemin = self.getFaceDetectionAttributeValue(face, "age_min")
ageminConfidence = self.getFaceDetectionAttributeConfidence(face, "age_min")
agemax = self.getFaceDetectionAttributeValue(face, "age_max")
agemaxConfidence = self.getFaceDetectionAttributeConfidence(face, "age_max")
ageest = self.getFaceDetectionAttributeValue(face, "age_est")
ageestConfidence = self.getFaceDetectionAttributeConfidence(face, "age_est")
gender = self.getFaceDetectionAttributeValue(face, "gender")
genderConfidence = self.getFaceDetectionAttributeConfidence(face, "gender")
# if the face wasnt recognisable, it might've been me after all, so ignore
if "tid" in face and face['recognizable'] == True:
self.storeGuestResults(smiling, smilingConfidence, mood, moodConfidence, agemin, ageminConfidence, agemax, agemaxConfidence, ageest, ageestConfidence, gender, genderConfidence)
print face['tid']
#
# stores face results in the DB
#
def storeGuestResults(self, smiling, smilingConfidence, mood, moodConfidence, agemin, ageminConfidence, agemax, agemaxConfidence, ageest, ageestConfidence, gender, genderConfidence):
cursor = self.connection.cursor()
cursor.execute('INSERT INTO guestlog(isSmiling, smilingConfidence, mood, moodConfidence, agemin, ageminConfidence, agemax, agemaxConfidence, ageest, ageestConfidence, gender, genderConfidence) values(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)',
(smiling, smilingConfidence, mood, moodConfidence, agemin, ageminConfidence, agemax, agemaxConfidence, ageest, ageestConfidence, gender, genderConfidence))
self.connection.commit()
#
# stores face results in the DB
#
def storeResults(self, smiling, smilingConfidence, mood, moodConfidence):
cursor = self.connection.cursor()
cursor.execute('INSERT INTO facelog(isSmiling, smilingConfidence, mood, moodConfidence) values(?, ?, ?, ?)',
(smiling, smilingConfidence, mood, moodConfidence))
self.connection.commit()
monitor = AudienceMonitor()
monitor.initialiseDB()
monitor.prepareCamera()
while True:
photopath = "data/photo" + monitor.getTimestampString() + ".bmp"
monitor.captureFrame(photopath)
try:
faceresults = monitor.faceDetection(photopath)
except:
print "Unexpected error:", sys.exc_info()[0]
os.remove(photopath)
sleep(POLL_FREQUENCY_SECONDS)
我得到的错误是
Traceback (most recent call last):
File "gamemood.py", line 147, in <module>
monitor.prepareCamera()
File "gamemood.py", line 56, in prepareCamera
self.camera = pygame.camera.Camera(pygame.camera.list_cameras()[0], (900, 675))
TypeError: 'NoneType' object is not subscriptable
我不明白这个错误！怎么了？ Pygame找不到我的相机？
答案 0 :(得分：1)
list_cameras正在返回None而不是列表，您看到的错误是当您尝试检索None[0]时会发生的错误。
基于源代码，当Pygame在非Linux平台上编译时，看起来camera模块中的大部分功能都被静默禁用。即使这些功能适用于Mac OS，也有直接排除它的预处理程序指令。
来自Pygame 1.9.1：
/* list_cameras() - lists cameras available on the computer */
PyObject* list_cameras (PyObject* self, PyObject* arg)
{
#if defined(__unix__)
PyObject* ret_list;
PyObject* string;
char** devices;
int num_devices, i;
num_devices = 0;
ret_list = NULL;
ret_list = PyList_New (0);
if (!ret_list)
return NULL;
devices = v4l2_list_cameras(&num_devices);
for(i = 0; i < num_devices; i++) {
string = PyString_FromString(devices[i]);
PyList_Append(ret_list, string);
Py_DECREF(string);
free(devices[i]);
}
free(devices);
return ret_list;
#else
Py_RETURN_NONE;
#endif
}
我认为对于正在发生的事情，这是最可能的解释。您的代码可能没问题，但您调用的函数只能返回None。我对Mac OS或camera模块的了解不足以告诉您如果将所有这些语句更改为#if defined(__unix__) || defined(__APPLE__)并自行编译它会有什么用或不可用。