How do I find the play开发者_运维技巧back time of media with gstreamer?

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Here's a simple Python script to get the duration of anything gstreamer can decode. Note that all times in gstreamer are in nanoseconds.

duration.py:

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import division

import sys
import gobject
gobject.threads_init()
import pygst
pygst.require("0.10")
import gst
d = gst.parse_launch("filesrc name=source ! decodebin2 ! fakesink")
source = d.get_by_name("source")
source.set_property("location", sys.argv[1])
d.set_state(gst.STATE_PLAYING)
d.get_state()
format = gst.Format(gst.FORMAT_TIME)
duration = d.query_duration(format)[0]
d.set_state(gst.STATE_NULL)

import datetime
delta = datetime.timedelta(seconds=(duration / gst.SECOND))
print delta

Examples:

$ python duration.py VIDEO_TS/VTS_03_1.VOB
0:20:10.528000
$ python duration.py ~/Movies/BigBuckBunny_640x360.m4v
0:09:56.461667

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See Section 6.5.

http://majorsilence.com/pygtk_audio_and_video_playback_gstreamer

It avoids need to create a pipeline and run it manually.

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Why re-invent the wheel?
Use:
gst-discoverer-1.0 filename
or
gst-discoverer-0.10 filename

Depending on the file type you may want to add " | grep Duration" to avoid the tags which can be lengthy.
For the ridding of extraneous tags for video,flac and mp3 files this should do the trick by using grep to exclude them.
gst-discoverer-1.0 filename | grep -v Tags | grep -v ID3v2 | grep -v image | grep -v attachment