gstreamer/gst/extend/discoverer.py
Michael Smith 66f9b9f28e gst/extend/discoverer.py: Better support for demuxers that don't create all pads at startup.
Original commit message from CVS:
Patch by : Michael Smith  <msmith@fluendo.com>
* gst/extend/discoverer.py:
Better support for demuxers that don't create all pads at startup.
Fixes #380966
2007-06-08 16:16:34 +00:00

339 lines
12 KiB
Python

# -*- Mode: Python -*-
# vi:si:et:sw=4:sts=4:ts=4
# discoverer.py
# (c) 2005 Edward Hervey <edward at fluendo dot com>
# Discovers multimedia information on files
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
"""
Class and functions for getting multimedia information about files
"""
import os.path
import gobject
import gst
from gst.extend.pygobject import gsignal
class Discoverer(gst.Pipeline):
"""
Discovers information about files.
This class is event-based and needs a mainloop to work properly.
Emits the 'discovered' signal when discovery is finished.
The 'discovered' callback has one boolean argument, which is True if the
file contains decodable multimedia streams.
"""
__gsignals__ = {
'discovered' : (gobject.SIGNAL_RUN_FIRST,
None,
(gobject.TYPE_BOOLEAN, ))
}
mimetype = None
audiocaps = {}
videocaps = {}
videowidth = 0
videoheight = 0
videorate = 0
audiofloat = False
audiorate = 0
audiodepth = 0
audiowidth = 0
audiochannels = 0
audiolength = 0L
videolength = 0L
is_video = False
is_audio = False
otherstreams = []
finished = False
sinknumber = 0
tags = {}
def __init__(self, filename):
gobject.GObject.__init__(self)
self.mimetype = None
self.audiocaps = {}
self.videocaps = {}
self.videowidth = 0
self.videoheight = 0
self.videorate = gst.Fraction(0,1)
self.audiofloat = False
self.audiorate = 0
self.audiodepth = 0
self.audiowidth = 0
self.audiochannels = 0
self.audiolength = 0L
self.videolength = 0L
self.is_video = False
self.is_audio = False
self.otherstreams = []
self.finished = False
self.tags = {}
self._success = False
self._nomorepads = False
self._timeoutid = 0
if not os.path.isfile(filename):
self.debug("File '%s' does not exist, finished" % filename)
self.finished = True
return
# the initial elements of the pipeline
self.src = gst.element_factory_make("filesrc")
self.src.set_property("location", filename)
self.src.set_property("blocksize", 1000000)
self.dbin = gst.element_factory_make("decodebin")
self.add(self.src, self.dbin)
self.src.link(self.dbin)
self.typefind = self.dbin.get_by_name("typefind")
# callbacks
self.typefind.connect("have-type", self._have_type_cb)
self.dbin.connect("new-decoded-pad", self._new_decoded_pad_cb)
self.dbin.connect("no-more-pads", self._no_more_pads_cb)
self.dbin.connect("unknown-type", self._unknown_type_cb)
def _timed_out_or_eos(self):
if (not self.is_audio and not self.is_video) or \
(self.is_audio and not self.audiocaps) or \
(self.is_video and not self.videocaps):
self._finished(False)
else:
self._finished(True)
def _finished(self, success=False):
self.debug("success:%d" % success)
self._success = success
self.bus.remove_signal_watch()
if self._timeoutid:
gobject.source_remove(self._timeoutid)
self._timeoutid = 0
gobject.idle_add(self._stop)
return False
def _stop(self):
self.debug("success:%d" % self._success)
self.finished = True
self.set_state(gst.STATE_READY)
self.debug("about to emit signal")
self.emit('discovered', self._success)
def _bus_message_cb(self, bus, message):
if message.type == gst.MESSAGE_EOS:
self.debug("Got EOS")
self._timed_out_or_eos()
elif message.type == gst.MESSAGE_TAG:
for key in message.parse_tag().keys():
self.tags[key] = message.structure[key]
elif message.type == gst.MESSAGE_ERROR:
self.debug("Got error")
self._finished()
def discover(self):
"""Find the information on the given file asynchronously"""
self.debug("starting discovery")
if self.finished:
self.emit('discovered', False)
return
self.bus = self.get_bus()
self.bus.add_signal_watch()
self.bus.connect("message", self._bus_message_cb)
# 3s timeout
self._timeoutid = gobject.timeout_add(3000, self._timed_out_or_eos)
self.info("setting to PLAY")
if not self.set_state(gst.STATE_PLAYING):
self._finished()
def _time_to_string(self, value):
"""
transform a value in nanoseconds into a human-readable string
"""
ms = value / gst.MSECOND
sec = ms / 1000
ms = ms % 1000
min = sec / 60
sec = sec % 60
return "%2dm %2ds %3d" % (min, sec, ms)
def print_info(self):
"""prints out the information on the given file"""
if not self.finished:
return
if not self.mimetype:
print "Unknown media type"
return
print "Mime Type :\t", self.mimetype
if not self.is_video and not self.is_audio:
return
print "Length :\t", self._time_to_string(max(self.audiolength, self.videolength))
print "\tAudio:", self._time_to_string(self.audiolength), "\tVideo:", self._time_to_string(self.videolength)
if self.is_video and self.videorate:
print "Video :"
print "\t%d x %d @ %d/%d fps" % (self.videowidth,
self.videoheight,
self.videorate.num, self.videorate.denom)
if self.tags.has_key("video-codec"):
print "\tCodec :", self.tags.pop("video-codec")
if self.is_audio:
print "Audio :"
if self.audiofloat:
print "\t%d channels(s) : %dHz @ %dbits (float)" % (self.audiochannels,
self.audiorate,
self.audiowidth)
else:
print "\t%d channels(s) : %dHz @ %dbits (int)" % (self.audiochannels,
self.audiorate,
self.audiodepth)
if self.tags.has_key("audio-codec"):
print "\tCodec :", self.tags.pop("audio-codec")
for stream in self.otherstreams:
if not stream == self.mimetype:
print "Other unsuported Multimedia stream :", stream
if self.tags:
print "Additional information :"
for tag in self.tags.keys():
print "%20s :\t" % tag, self.tags[tag]
def _no_more_pads_cb(self, dbin):
self.info("no more pads")
self._nomorepads = True
def _unknown_type_cb(self, dbin, pad, caps):
self.debug("unknown type : %s" % caps.to_string())
# if we get an unknown type and we don't already have an
# audio or video pad, we are finished !
self.otherstreams.append(caps.to_string())
if not self.is_video and not self.is_audio:
self.finished = True
self._finished()
def _have_type_cb(self, typefind, prob, caps):
self.mimetype = caps.to_string()
def _notify_caps_cb(self, pad, args):
caps = pad.get_negotiated_caps()
if not caps:
pad.info("no negotiated caps available")
return
pad.info("caps:%s" % caps.to_string())
# the caps are fixed
# We now get the total length of that stream
q = gst.query_new_duration(gst.FORMAT_TIME)
pad.info("sending position query")
if pad.get_peer().query(q):
format, length = q.parse_duration()
pad.info("got position query answer : %d:%d" % (length, format))
else:
length = -1
gst.warning("position query didn't work")
# We store the caps and length in the proper location
if "audio" in caps.to_string():
self.audiocaps = caps
self.audiolength = length
self.audiorate = caps[0]["rate"]
self.audiowidth = caps[0]["width"]
self.audiochannels = caps[0]["channels"]
if "x-raw-float" in caps.to_string():
self.audiofloat = True
else:
self.audiodepth = caps[0]["depth"]
if self._nomorepads and ((not self.is_video) or self.videocaps):
self._finished(True)
elif "video" in caps.to_string():
self.videocaps = caps
self.videolength = length
self.videowidth = caps[0]["width"]
self.videoheight = caps[0]["height"]
self.videorate = caps[0]["framerate"]
if self._nomorepads and ((not self.is_audio) or self.audiocaps):
self._finished(True)
def _new_decoded_pad_cb(self, dbin, pad, is_last):
# Does the file contain got audio or video ?
caps = pad.get_caps()
gst.info("caps:%s" % caps.to_string())
if "audio" in caps.to_string():
self.is_audio = True
elif "video" in caps.to_string():
self.is_video = True
else:
self.warning("got a different caps.. %s" % caps.to_string())
return
if is_last and not self.is_video and not self.is_audio:
self.debug("is last, not video or audio")
self._finished(False)
return
# we connect a fakesink to the new pad...
pad.info("adding queue->fakesink")
fakesink = gst.element_factory_make("fakesink", "fakesink%d-%s" %
(self.sinknumber, "audio" in caps.to_string() and "audio" or "video"))
self.sinknumber += 1
queue = gst.element_factory_make("queue")
# we want the queue to buffer up to 2 seconds of data before outputting
# This enables us to cope with formats that don't create their source
# pads straight away, but instead wait for the first buffer of that
# stream.
queue.props.min_threshold_time = 1 * gst.SECOND
queue.props.max_size_time = 2 * gst.SECOND
queue.props.max_size_bytes = 0
# If durations are bad on the buffers (common for video decoders), we'll
# never reach the min_threshold_time or max_size_time. So, set a large
# max size in buffers, and if reached, disable the min_threshold_time.
# This ensures we don't fail to discover with various ffmpeg
# demuxers/decoders that provide bogus (or no) duration.
queue.props.max_size_buffers = 100
def _disable_min_threshold_cb(queue):
queue.props.min_threshold_time = 0
queue.disconnect(signal_id)
signal_id = queue.connect('overrun', _disable_min_threshold_cb)
self.add(fakesink, queue)
queue.link(fakesink)
sinkpad = fakesink.get_pad("sink")
queuepad = queue.get_pad("sink")
# ... and connect a callback for when the caps are fixed
sinkpad.connect("notify::caps", self._notify_caps_cb)
if pad.link(queuepad):
pad.warning("##### Couldn't link pad to queue")
queue.set_state(gst.STATE_PLAYING)
fakesink.set_state(gst.STATE_PLAYING)
gst.info('finished here')