gstreamer/gst/extend/discoverer.py
Michael Smith 26f5653a79 gst/extend/discoverer.py: Avoid buffering infinite amounts of decoded data if a decoder is feeding us data without a ...
Original commit message from CVS:
* gst/extend/discoverer.py:
Avoid buffering infinite amounts of decoded data if a decoder is
feeding us data without a duration (or with bad duration values).
2006-11-15 14:36:39 +00:00

324 lines
11 KiB
Python

#!/usr/bin/env 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 pygtk
pygtk.require('2.0')
import gobject
import pygst
pygst.require('0.10')
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
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._timeoutid = 0
if not os.path.isfile(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("unknown-type", self._unknown_type_cb)
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._finished()
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._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._finished)
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 _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 (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 (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._finished(False)
return
# we connect a fakesink to the new pad...
pad.info("adding queue->fakesink")
fakesink = gst.element_factory_make("fakesink")
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')