Base classes for the external programs API.
"""
+import os
+import re
+import random
+
import cis_exceptions
+import cis_util
class BaseTranscoder:
"""
- Abstractization of the API class for the transcoder program.
+ Abstraction of the API class for the transcoder program.
"""
prog_bin = None
input_file = None
+ output_file = None
+ dest_path = ''
+ name = None
# Recommended formats.
containers = {
"webm": None,
"mpegts": None
}
+ # File extensions by container. First value is for audio files and the
+ # second one is for (audio-)video files.
+ extensions = {
+ "avi": ["avi", "avi"],
+ "flv": ["flv", "flv"],
+ "mp4": ["mp4", "mp4"],
+ "ogg": ["oga", "ogv"],
+ "webm": ["webm", "webm"],
+ "mpegts": ["mts", "mts"]
+ }
a_codecs = {
"mp3": None,
"vorbis": None
"vp8": None
}
- def __init__(self, input_file, prog_bin=None):
+ def __init__(self, input_file, name=None, prog_bin=None):
self.input_file = input_file
- self.prog_bin = prog_bin
+ if prog_bin is not None:
+ self.prog_bin = prog_bin
+
+ if name is None:
+ name = cis_util.get_name(input_file)
+
+ self.name = name
- def transcode(self, container, a_codec, v_codec,
+ def transcode(self, container, a_codec=None, v_codec=None,
a_bitrate=None, a_samplingrate=None, a_channels=None,
- v_bitrate=None, v_fraterate=None, v_resolution=None, v_dar=None):
+ v_bitrate=None, v_framerate=None, v_resolution=None, v_dar=None):
"""
Transcodes the input file to an audio-video file.
- container: possible values are listed in containers member as keys
- a_codec: possible values are listed in a_codecs member as keys
- v_codec: possible values are listed in v_codecs member as keys
+ @param container: possible values are listed in containers member
+ as keys
+ @param a_codec possible values are listed in a_codecs member as keys
+ @param v_codec possible values are listed in v_codecs member as keys
+ @param a_bitrate (numeric) audio bit rate
+ @param a_samplingrate (numeric) audio sampling rate in Hz
+ @param a_channels (numeric) number of audio channels
+ @param v_bitrate (numeric) video bit rate
+ @param v_framerate (numeric) number of frames per second for a video
+ @param v_resolution (string) video image size as <width>x<height>
+ @param v_dar video display aspect ratio as <den>x<num> or float
+ @return output file name
"""
- pass
+ # Check parameters.
+ if a_codec is None and v_codec is None:
+ raise ValueError('No audio or video codec specified.')
- def transcode_audio(self, container, a_codec,
- a_bitrate=None, a_samplingrate=None, a_channels=None):
- pass
+ if a_codec is not None and type(a_codec) not in [str, unicode]:
+ raise TypeError('Audio codec must be string.')
+
+ if v_codec is not None and type(v_codec) not in [str, unicode]:
+ raise TypeError('Video codec must be string.')
+
+ if a_samplingrate is not None and type(a_samplingrate) is not int:
+ raise TypeError('Audio sampling rate must be an integer.')
+
+ if a_channels is not None and type(a_channels) is not int:
+ raise TypeError('Audio channels parameter must be an integer.')
+
+ if v_framerate is not None and type(v_framerate) is not int:
+ raise TypeError('Video frate rate must be an integer.')
+
+ if v_resolution is not None \
+ and re.match('[\d]+x[\d]+', v_resolution) is None:
+ raise ValueError('Video resolution must be a string like <width>x<height>.')
- def transcode_video(self, container, v_codec,
- v_bitrate=None, v_fraterate=None, v_resolution=None, v_dar=None):
+ if v_dar is not None and (type(v_dar) is not float \
+ and re.match('[\d]+:[\d]+', v_dar) is None):
+ raise ValueError('Video display aspect ratio must be a float or a string like <den>:<num>.')
+
+ self.output_file = os.path.join(self.dest_path, self.name)
+ if os.path.exists(self.output_file):
+ raise cis_exceptions.FileAlreadyExistsException( \
+ 'file "%s" already exists' % self.output_file)
+
+ if v_resolution is not None:
+ self.output_file += '_'
+ self.output_file += v_resolution[(v_resolution.rindex('x')+1):]
+ self.output_file += 'p'
+ ext = self.tr_extension(container, (v_codec is not None))
+ if ext is not None:
+ self.output_file += '.' + ext
+
+ return self._transcode(self.tr_container(container),
+ self.tr_a_codec(a_codec), self.tr_v_codec(v_codec),
+ a_bitrate, a_samplingrate, a_channels,
+ v_bitrate, v_framerate, v_resolution, v_dar)
+
+ def _transcode(self, container, a_codec=None, v_codec=None,
+ a_bitrate=None, a_samplingrate=None, a_channels=None,
+ v_bitrate=None, v_framerate=None, v_resolution=None, v_dar=None):
+ """
+ Called by transcode; must be overridden by a child class which
+ effectively transcodes the input file.
+
+ @return output file name
+ """
pass
def tr_container(self, name):
""" Translates container API name into external program identifier."""
- if not self.containers.has_key(name) or self.containers[name] == None:
- raise cis_exceptions.NotImplementedException("Container " + name)
+ if not self.containers.has_key(name) or self.containers[name] is None:
+ raise cis_exceptions.NotImplementedException("Container " + name \
+ + "not implemented")
return self.containers[name]
+
+ def tr_extension(self, name, video=True):
+ """ Translates container API name into file extension."""
+
+ if video is True:
+ i = 1
+ else:
+ i = 0
+
+ if not self.extensions.has_key(name) or self.extensions[name] is None:
+ return None
+
+ return self.extensions[name][i]
+
+ def tr_a_codec(self, name):
+ """ Translates audio codec API name into external program identifier."""
+
+ if not self.a_codecs.has_key(name) or self.a_codecs[name] is None:
+ raise cis_exceptions.NotImplementedException("Audio Codec " + name \
+ + "not implemented")
+
+ return self.a_codecs[name]
+
+ def tr_v_codec(self, name):
+ """ Translates video codec API name into external program identifier."""
+
+ if not self.v_codecs.has_key(name) or self.v_codecs[name] is None:
+ raise cis_exceptions.NotImplementedException("Video Codec " + name \
+ + "not implemented")
+
+ return self.v_codecs[name]
+
+
+class BaseThumbExtractor:
+ """
+ Abstraction of the API class for the thumbnail extraction program.
+
+ Thumbnail extracted are in JPEG format.
+ """
+
+ prog_bin = None
+ input_file = None
+ dest_path = ''
+ name = None
+
+ def __init__(self, input_file, name=None, prog_bin=None):
+ self.input_file = input_file
+ if prog_bin is not None:
+ self.prog_bin = prog_bin
+
+ if name is None:
+ name = cis_util.get_name(input_file)
+
+ self.name = name
+
+ def extract_thumb(self, seek_pos, resolution="120x90", index=0):
+ """
+ Extracts a thumbnail from the video from a specified position
+ expressed in seconds (int/float).
+
+ index: an index appended to the image name in order to avoid
+ overwriting.
+ """
+ pass
+
+ def extract_random_thumb(self, resolution="120x90", index=0):
+ """
+ Extracts a thumbnail from the video from a random position.
+ """
+ duration = self.get_video_duration()
+ seek_pos = random.random() * duration
+ self.extract_thumb(seek_pos, resolution, index)
+
+ def extract_summary_thumbs(self, count, resolution="120x90"):
+ """
+ Extracts a series of thumbnails from a video by taking several
+ snapshots.
+
+ The snapshots are taken from equally spaced positions such that
+ `count` thumbs are extracted.
+ """
+ duration = self.get_video_duration()
+ interval = duration / (count + 1)
+
+ n_thumbs_extracted = 0
+ seek_pos = interval
+ for index in range (0, count):
+ thumb_extracted = True
+ try:
+ self.extract_thumb(seek_pos, resolution, n_thumbs_extracted)
+ except cis_exceptions.ThumbExtractionException as e:
+ thumb_extracted = False
+
+ if thumb_extracted:
+ n_thumbs_extracted += 1
+
+ seek_pos += interval
+
+ return n_thumbs_extracted
+
+ def get_output_file_name(self, index):
+ """ Returns the name required as output file name based on index. """
+ output_file_name = os.path.join(self.dest_path, self.name) \
+ + '_t' + ("%02d" % index) + '.jpg'
+
+ if os.path.exists(output_file_name):
+ raise cis_exceptions.FileAlreadyExistsException( \
+ 'file "%s" already exists' % output_file_name)
+
+ return output_file_name
+
+ def get_video_duration(self):
+ pass
+
+
+class BaseFileTransferer:
+ """
+ Ensures file transfer from the Web Server to the CIS (here).
+
+ Several implementations can be done by extending this class for
+ file transfer protocol such as FTP, SCP, RSYNC, HTTP etc.
+ """
+
+ local_path = ''
+ remote_path = ''
+
+ def __init__(self, local_path='', remote_path=''):
+ """ Initialize by setting local and remote paths for file transfer. """
+ self.local_path = local_path
+ self.remote_path = remote_path
+
+ def __del__(self):
+ self.close()
+
+ def get(self, files):
+ """
+ Transfers files locally from the Web Server.
+
+ files: a list of file name strings
+ """
+ pass
+
+ def put(self, files):
+ """
+ Transfers files from the Web Server locally.
+
+ files: a list of file name strings
+ """
+ pass
+
+ def close(self):
+ """
+ This method should be called when the instance is no longer required.
+
+ Class's destructor calls this method.
+ """
+ pass
+
+
+class BaseAVInfo:
+ @staticmethod
+ def get_video_duration(input_file, formated=False):
+ """
+ Returns the number of seconds of a video (int/float) if formated is
+ False and a string for duration formated as [HH:]:mm:ss otherwise.
+ """
+ pass
projects / living-lab-site.git / blobdiff