用Python的Django框架完成视频处理任务的教程

$scope.upload_slide = (upload_slide_form) ->  file = document.getElementById("slide_file").files[0]  reader = new FileReader()  reader.readAsDataURL file  reader.onload = (event) ->   result = event.target.result   fileName = document.getElementById("slide_file").files[0].name   $.post "/world/upload_slide",    data: result    name: fileName    room_id: $scope.room.id    (response_data) ->     if response_data.success? is not yes      console.error "There was an error uploading the file", response_data     else      console.log "Upload successful", response_data  reader.onloadstart = ->   console.log "onloadstart"  reader.onprogress = (event) ->   console.log "onprogress", event.total, event.loaded, (event.loaded / event.total) * 100  reader.onabort = ->   console.log "onabort"  reader.onerror = ->   console.log "onerror"  reader.onloadend = (event) ->   console.log "onloadend", event

$ pip install 'Django>=1.5.2' 'django-celery>=3.0.21' /  'django-storages>=1.1.8' 'lxml>=3.2.3' 'python-magic>=0.4.3'我建立了两个模块：SlideUploadQueue 用来储存每一次上传的数据，SlideVideoMedia 则是用来储存每个要上传影片的数据。 class SlideUploadQueue(models.Model):  created_by = models.ForeignKey(User)  created_time = models.DateTimeField(db_index=True)  original_file = models.FileField(    upload_to=filename_sanitiser, blank=True, default='')  media_type = models.ForeignKey(MediaType)  encoding_com_tracking_code = models.CharField(    default='', max_length=24, blank=True)   STATUS_AWAITING_DATA = 0  STATUS_AWAITING_PROCESSING = 1  STATUS_PROCESSING = 2  STATUS_AWAITING_3RD_PARTY_PROCESSING = 5  STATUS_FINISHED = 3  STATUS_FAILED = 4   STATUS_LIST = (    (STATUS_AWAITING_DATA, 'Awaiting Data'),    (STATUS_AWAITING_PROCESSING, 'Awaiting processing'),    (STATUS_PROCESSING, 'Processing'),    (STATUS_AWAITING_3RD_PARTY_PROCESSING,      'Awaiting 3rd-party processing'),    (STATUS_FINISHED, 'Finished'),    (STATUS_FAILED, 'Failed'),  )   status = models.PositiveSmallIntegerField(    default=STATUS_AWAITING_DATA, choices=STATUS_LIST)   class Meta:    verbose_name = 'Slide'    verbose_name_plural = 'Slide upload queue'   def save(self, *args, **kwargs):    if not self.created_time:      self.created_time = /        datetime.utcnow().replace(tzinfo=pytz.utc)     return super(SlideUploadQueue, self).save(*args, **kwargs)   def __unicode__(self):    if self.id is None:      return 'new <SlideUploadQueue>'    return '<SlideUploadQueue> %d' % self.id class SlideVideoMedia(models.Model):  converted_file = models.FileField(    upload_to=filename_sanitiser, blank=True, default='')   FORMAT_MP4 = 0  FORMAT_WEBM = 1  FORMAT_OGG = 2  FORMAT_FL9 = 3  FORMAT_THUMB = 4   supported_formats = (    (FORMAT_MP4, 'MPEG 4'),    (FORMAT_WEBM, 'WebM'),    (FORMAT_OGG, 'OGG'),    (FORMAT_FL9, 'Flash 9 Video'),    (FORMAT_THUMB, 'Thumbnail'),  )   mime_types = (    (FORMAT_MP4, 'video/mp4'),    (FORMAT_WEBM, 'video/webm'),    (FORMAT_OGG, 'video/ogg'),    (FORMAT_FL9, 'video/mp4'),    (FORMAT_THUMB, 'image/jpeg'),  )   format = models.PositiveSmallIntegerField(    default=FORMAT_MP4, choices=supported_formats)   class Meta:    verbose_name = 'Slide video'    verbose_name_plural = 'Slide videos'   def __unicode__(self):    if self.id is None:      return 'new <SlideVideoMedia>'    return '<SlideVideoMedia> %d' % self.id

def filename_sanitiser(instance, filename):  folder = instance.__class__.__name__.lower()  ext = 'jpg'   if '.' in filename:    t_ext = filename.split('.')[-1].strip().lower()     if t_ext != '':      ext = t_ext   return '%s/%s.%s' % (folder, str(uuid.uuid4()), ext)

@verify_auth_token@return_jsondef upload_slide(request):  file_data = request.POST.get('data', '')  file_data = base64.b64decode(file_data.split(';base64,')[1])  description = magic.from_buffer(file_data)

slide_upload = SlideUploadQueue()...slide_upload.status = SlideUploadQueue.STATUS_AWAITING_PROCESSINGslide_upload.save()slide_upload.original_file./  save('anything.%s' % file_ext, ContentFile(file_data))slide_upload.save() task = ConvertRawSlideToSlide()task.delay(slide_upload)

class ConvertRawSlideToSlide(Task):  queue = 'backend_convert_raw_slides'  ...  def _handle_video(self, slide_upload):    mp4 = {      'output': 'mp4',      'size': '320x240',      'bitrate': '256k',      'audio_bitrate': '64k',      'audio_channels_number': '2',      'keep_aspect_ratio': 'yes',      'video_codec': 'mpeg4',      'profile': 'main',      'vcodecparameters': 'no',      'audio_codec': 'libfaac',      'two_pass': 'no',      'cbr': 'no',      'deinterlacing': 'no',      'keyframe': '300',      'audio_volume': '100',      'file_extension': 'mp4',      'hint': 'no',    }     webm = {      'output': 'webm',      'size': '320x240',      'bitrate': '256k',      'audio_bitrate': '64k',      'audio_sample_rate': '44100',      'audio_channels_number': '2',      'keep_aspect_ratio': 'yes',      'video_codec': 'libvpx',      'profile': 'baseline',      'vcodecparameters': 'no',      'audio_codec': 'libvorbis',      'two_pass': 'no',      'cbr': 'no',      'deinterlacing': 'no',      'keyframe': '300',      'audio_volume': '100',      'preset': '6',      'file_extension': 'webm',      'acbr': 'no',    }     ogg = {      'output': 'ogg',      'size': '320x240',      'bitrate': '256k',      'audio_bitrate': '64k',      'audio_sample_rate': '44100',      'audio_channels_number': '2',      'keep_aspect_ratio': 'yes',      'video_codec': 'libtheora',      'profile': 'baseline',      'vcodecparameters': 'no',      'audio_codec': 'libvorbis',      'two_pass': 'no',      'cbr': 'no',      'deinterlacing': 'no',      'keyframe': '300',      'audio_volume': '100',      'file_extension': 'ogg',      'acbr': 'no',    }     flv = {      'output': 'fl9',      'size': '320x240',      'bitrate': '256k',      'audio_bitrate': '64k',      'audio_channels_number': '2',      'keep_aspect_ratio': 'yes',      'video_codec': 'libx264',      'profile': 'high',      'vcodecparameters': 'no',      'audio_codec': 'libfaac',      'two_pass': 'no',      'cbr': 'no',      'deinterlacing': 'no',      'keyframe': '300',      'audio_volume': '100',      'file_extension': 'mp4',    }     thumbnail = {      'output': 'thumbnail',      'time': '5',      'video_codec': 'mjpeg',      'keep_aspect_ratio': 'yes',      'file_extension': 'jpg',    }     encoder = Encoding(settings.ENCODING_API_USER_ID,      settings.ENCODING_API_USER_KEY)    resp = encoder.add_media(source=[slide_upload.original_file.url],      formats=[mp4, webm, ogg, flv, thumbnail])     media_id = None     if resp is not None and resp.get('response') is not None:      media_id = resp.get('response').get('MediaID')     if media_id is None:      slide_upload.status = SlideUploadQueue.STATUS_FAILED      slide_upload.save()      log.error('Unable to communicate with encoding.com')      return False     slide_upload.encoding_com_tracking_code = media_id    slide_upload.status = /      SlideUploadQueue.STATUS_AWAITING_3RD_PARTY_PROCESSING    slide_upload.save()    return True

import httplibfrom lxml import etreeimport urllibfrom xml.parsers.expat import ExpatErrorimport xmltodict ENCODING_API_URL = 'manage.encoding.com:80' class Encoding(object):   def __init__(self, userid, userkey, url=ENCODING_API_URL):    self.url = url    self.userid = userid    self.userkey = userkey   def get_media_info(self, action='GetMediaInfo', ids=[],    headers={'Content-Type': 'application/x-www-form-urlencoded'}):    query = etree.Element('query')     nodes = {      'userid': self.userid,      'userkey': self.userkey,      'action': action,      'mediaid': ','.join(ids),    }     query = self._build_tree(etree.Element('query'), nodes)    results = self._execute_request(query, headers)     return self._parse_results(results)   def get_status(self, action='GetStatus', ids=[], extended='no',    headers={'Content-Type': 'application/x-www-form-urlencoded'}):    query = etree.Element('query')     nodes = {      'userid': self.userid,      'userkey': self.userkey,      'action': action,      'extended': extended,      'mediaid': ','.join(ids),    }     query = self._build_tree(etree.Element('query'), nodes)    results = self._execute_request(query, headers)     return self._parse_results(results)   def add_media(self, action='AddMedia', source=[], notify='', formats=[],    instant='no',    headers={'Content-Type': 'application/x-www-form-urlencoded'}):    query = etree.Element('query')     nodes = {      'userid': self.userid,      'userkey': self.userkey,      'action': action,      'source': source,      'notify': notify,      'instant': instant,    }     query = self._build_tree(etree.Element('query'), nodes)     for format in formats:      format_node = self._build_tree(etree.Element('format'), format)      query.append(format_node)     results = self._execute_request(query, headers)    return self._parse_results(results)   def _build_tree(self, node, data):    for k, v in data.items():      if isinstance(v, list):        for item in v:          element = etree.Element(k)          element.text = item          node.append(element)      else:        element = etree.Element(k)        element.text = v        node.append(element)     return node   def _execute_request(self, xml, headers, path='', method='POST'):    params = urllib.urlencode({'xml': etree.tostring(xml)})     conn = httplib.HTTPConnection(self.url)    conn.request(method, path, params, headers)    response = conn.getresponse()    data = response.read()    conn.close()    return data   def _parse_results(self, results):    try:      return xmltodict.parse(results)    except ExpatError, e:      print 'Error parsing encoding.com response'      print e      return None

class CheckUpOnThirdParties(PeriodicTask):  run_every = timedelta(seconds=settings.THIRD_PARTY_CHECK_UP_INTERVAL)  ...  def _handle_encoding_com(self, slides):    format_lookup = {      'mp4': SlideVideoMedia.FORMAT_MP4,      'webm': SlideVideoMedia.FORMAT_WEBM,      'ogg': SlideVideoMedia.FORMAT_OGG,      'fl9': SlideVideoMedia.FORMAT_FL9,      'thumbnail': SlideVideoMedia.FORMAT_THUMB,    }     encoder = Encoding(settings.ENCODING_API_USER_ID,      settings.ENCODING_API_USER_KEY)     job_ids = [item.encoding_com_tracking_code for item in slides]    resp = encoder.get_status(ids=job_ids)     if resp is None:      log.error('Unable to check up on encoding.com')      return False

if resp.get('response') is None:  log.error('Unable to get response node from encoding.com')  return False resp_id = resp.get('response').get('id') if resp_id is None:  log.error('Unable to get media id from encoding.com')  return False slide = SlideUploadQueue.objects.filter(  status=SlideUploadQueue.STATUS_AWAITING_3RD_PARTY_PROCESSING,  encoding_com_tracking_code=resp_id) if len(slide) != 1:  log.error('Unable to find a single record for %s' % resp_id)  return False resp_status = resp.get('response').get('status') if resp_status is None:  log.error('Unable to get status from encoding.com')  return False if resp_status != u'Finished':  log.debug("%s isn't finished, will check back later" % resp_id)  return True formats = resp.get('response').get('format') if formats is None:  log.error("No output formats were found. Something's wrong.")  return False for format in formats:  try:    assert format.get('status') == u'Finished', /    "%s is not finished. Something's wrong." % format.get('id')     output = format.get('output')    assert output in ('mp4', 'webm', 'ogg', 'fl9',      'thumbnail'), 'Unknown output format %s' % output     s3_dest = format.get('s3_destination')    assert 'http://encoding.com.result.s3.amazonaws.com/'/      in s3_dest, 'Suspicious S3 url: %s' % s3_dest     https_link = /      'https://s3.amazonaws.com/encoding.com.result/%s' %/      s3_dest.split('/')[-1]    file_ext = https_link.split('.')[-1].strip()     assert len(file_ext) > 0,/      'Unable to get file extension from %s' % https_link     count = SlideVideoMedia.objects.filter(slide_upload=slide,      format=format_lookup[output]).count()     if count != 0:      print 'There is already a %s file for this slide' % output      continue     content = self.download_content(https_link)     assert content is not None,/      'There is no content for %s' % format.get('id')  except AssertionError, e:    log.error('A format did not pass all assertions: %s' % e)    continue

media = SlideVideoMedia()media.format = format_lookup[output]media.converted_file.save('blah.%s' % file_ext, ContentFile(content))media.save()

? bower install video.jsbower caching git://github.com/videojs/video.js-component.gitbower cloning git://github.com/videojs/video.js-component.gitbower fetching video.jsbower checking out video.js#v4.0.3bower copying /home/mark/.bower/cache/video.js/5ab058cd60c5615aa38e8e706cd0f307bower installing video.js#4.0.3

!!! 5html(lang="en", class="no-js") head  meta(http-equiv='Content-Type', content='text/html; charset=UTF-8')  ...  link(rel='stylesheet', type='text/css', href='/components/video-js-4.1.0/video-js.css')  script(type='text/javascript', src='/components/video-js-4.1.0/video.js')

#main.span12  video#example_video_1.video-js.vjs-default-skin(controls, preload="auto", width="640", height="264", poster="{{video_thumbnail}}", data-setup='{"example_option":true}', ng-show="videos")    source(ng-repeat="video in videos", src="{{video.src}}", type="{{video.type}}")