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* morituri/common/crc.py (added):

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Copy from task.py before splitting.
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Thomas Vander Stichele
2009-04-11 15:36:02 +00:00
parent 1a02c32fc1
commit 2e93bfb988
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@@ -1,3 +1,8 @@
2009-04-11 Thomas Vander Stichele <thomas at apestaart dot org>
* morituri/common/crc.py (added):
Copy from task.py before splitting.
2009-04-11 Thomas Vander Stichele <thomas at apestaart dot org>
* examples/gtkcrc.py:

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morituri/common/crc.py Normal file
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# -*- Mode: Python; test-case-name: morituri.test.test_common_task -*-
# vi:si:et:sw=4:sts=4:ts=4
# Morituri - for those about to RIP
# Copyright (C) 2009 Thomas Vander Stichele
# This file is part of morituri.
#
# morituri is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# morituri 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with morituri. If not, see <http://www.gnu.org/licenses/>.
import os
import sys
import struct
import zlib
import gobject
import gst
FRAMES_PER_DISC_FRAME = 588
SAMPLES_PER_DISC_FRAME = FRAMES_PER_DISC_FRAME * 4
class Task(object):
"""
I wrap a task in an asynchronous interface.
I can be listened to for starting, stopping, and progress updates.
@ivar description: what am I doing
"""
description = 'I am doing something.'
progress = 0.0
increment = 0.01
running = False
_listeners = None
def debug(self, *args, **kwargs):
return
print args, kwargs
sys.stdout.flush()
def start(self):
self.running = True
self._notifyListeners('started')
def stop(self):
self.debug('stopping')
self.running = False
self._notifyListeners('stopped')
def setProgress(self, value):
if value - self.progress > self.increment or value >= 1.0:
self.progress = value
self._notifyListeners('progressed', value)
self.debug('notifying progress', value)
def addListener(self, listener):
if not self._listeners:
self._listeners = []
self._listeners.append(listener)
def _notifyListeners(self, methodName, *args, **kwargs):
if self._listeners:
for l in self._listeners:
getattr(l, methodName)(*args, **kwargs)
class CRCTask(Task):
# this object needs a main loop to stop
description = 'Calculating CRC checksum...'
def __init__(self, path, frameStart=0, frameLength=-1):
"""
A frame is considered a set of samples for each channel;
ie 16 bit stereo is 4 bytes per frame.
If frameLength < 0 it is treated as 'unknown' and calculated.
@type frameStart: int
@param frameStart: the frame to start at
"""
if not os.path.exists(path):
raise IndexError, '%s does not exist' % path
self._path = path
self._frameStart = frameStart
self._frameLength = frameLength
self._frameEnd = None
self._crc = 0
self._bytes = 0
self._first = None
self._last = None
self._adapter = gst.Adapter()
self.crc = None # result
def start(self):
Task.start(self)
self._pipeline = gst.parse_launch('''
filesrc location="%s" !
decodebin ! audio/x-raw-int !
appsink name=sink sync=False emit-signals=True''' % self._path)
self.debug('pausing')
self._pipeline.set_state(gst.STATE_PAUSED)
self._pipeline.get_state()
self.debug('paused')
self.debug('query duration')
sink = self._pipeline.get_by_name('sink')
if self._frameLength < 0:
length, format = sink.query_duration(gst.FORMAT_DEFAULT)
# wavparse 0.10.14 returns in bytes
if format == gst.FORMAT_BYTES:
self.debug('query returned in BYTES format')
length /= 4
self.debug('total length', length)
self._frameLength = length - self._frameStart
self.debug('audio frame length is', self._frameLength)
self._frameEnd = self._frameStart + self._frameLength - 1
self.debug('event')
# the segment end only is respected since -good 0.10.14.1
event = gst.event_new_seek(1.0, gst.FORMAT_DEFAULT,
gst.SEEK_FLAG_FLUSH,
gst.SEEK_TYPE_SET, self._frameStart,
gst.SEEK_TYPE_SET, self._frameEnd + 1) # half-inclusive interval
# FIXME: sending it with frameEnd set screws up the seek, we don't get
# everything for flac; fixed in recent -good
result = sink.send_event(event)
#self.debug('event sent')
#self.debug(result)
sink.connect('new-buffer', self._new_buffer_cb)
sink.connect('eos', self._eos_cb)
self.debug('scheduling setting to play')
# since set_state returns non-False, adding it as timeout_add
# will repeatedly call it, and block the main loop; so
# gobject.timeout_add(0L, self._pipeline.set_state, gst.STATE_PLAYING)
# would not work.
def play():
self._pipeline.set_state(gst.STATE_PLAYING)
return False
gobject.timeout_add(0L, play)
#self._pipeline.set_state(gst.STATE_PLAYING)
self.debug('scheduled setting to play')
def _new_buffer_cb(self, sink):
buffer = sink.emit('pull-buffer')
gst.debug('received new buffer at offset %r with length %r' % (
buffer.offset, buffer.size))
if self._first is None:
self._first = buffer.offset
self.debug('first sample is', self._first)
self._last = buffer
assert len(buffer) % 4 == 0, "buffer is not a multiple of 4 bytes"
# FIXME: gst-python 0.10.14.1 doesn't have adapter_peek/_take wrapped
# see http://bugzilla.gnome.org/show_bug.cgi?id=576505
self._adapter.push(buffer)
while self._adapter.available() >= SAMPLES_PER_DISC_FRAME:
# FIXME: in 0.10.14.1, take_buffer leaks a ref
buffer = self._adapter.take_buffer(SAMPLES_PER_DISC_FRAME)
self._crc = self.do_crc_buffer(buffer, self._crc)
self._bytes += len(buffer)
# update progress
frame = self._first + self._bytes / 4
framesDone = frame - self._frameStart
progress = float(framesDone) / float((self._frameLength))
# marshall to the main thread
gobject.timeout_add(0L, self.setProgress, progress)
def do_crc_buffer(self, buffer, crc):
"""
Subclasses should implement this.
"""
raise NotImplementedError
def _eos_cb(self, sink):
# get the last one; FIXME: why does this not get to us before ?
#self._new_buffer_cb(sink)
self.debug('eos, scheduling stop')
gobject.timeout_add(0L, self.stop)
def stop(self):
self.debug('stopping')
self.debug('setting state to NULL')
self._pipeline.set_state(gst.STATE_NULL)
if not self._last:
# see http://bugzilla.gnome.org/show_bug.cgi?id=578612
print 'ERROR: not a single buffer gotten'
raise
else:
self._crc = self._crc % 2 ** 32
last = self._last.offset + len(self._last) / 4 - 1
self.debug("last sample:", last)
self.debug("frame length:", self._frameLength)
self.debug("CRC: %08X" % self._crc)
self.debug("bytes: %d" % self._bytes)
if self._frameEnd != last:
print 'ERROR: did not get all frames, %d missing' % (
self._frameEnd - last)
# publicize and stop
self.crc = self._crc
Task.stop(self)
class CRC32Task(CRCTask):
"""
I do a simple CRC32 check.
"""
def do_crc_buffer(self, buffer, crc):
return zlib.crc32(buffer, crc)
class CRCAudioRipTask(CRCTask):
def __init__(self, path, trackNumber, trackCount, frameStart=0, frameLength=-1):
CRCTask.__init__(self, path, frameStart, frameLength)
self._trackNumber = trackNumber
self._trackCount = trackCount
self._discFrameCounter = 0
def do_crc_buffer(self, buffer, crc):
self._discFrameCounter += 1
# on first track ...
if self._trackNumber == 1:
# ... skip first 4 CD frames
if self._discFrameCounter <= 4:
self.debug('skipping frame %d' % self._discFrameCounter)
return crc
# ... on 5th frame, only use last value
elif self._discFrameCounter == 5:
values = struct.unpack("<I", buffer[-4:])
crc += FRAMES_PER_DISC_FRAME * 5 * values[0]
crc &= 0xFFFFFFFF
# on last track, skip last 5 CD frames
if self._trackNumber == self._trackCount:
discFrameLength = self._frameLength / FRAMES_PER_DISC_FRAME
if self._discFrameCounter > discFrameLength - 5:
self.debug('skipping frame %d' % self._discFrameCounter)
return crc
values = struct.unpack("<%dI" % (len(buffer) / 4), buffer)
for i, value in enumerate(values):
crc += (self._bytes / 4 + i + 1) * value
crc &= 0xFFFFFFFF
offset = self._bytes / 4 + i + 1
# if offset % FRAMES_PER_DISC_FRAME == 0:
# print 'THOMAS: frame %d, offset %d, value %d, CRC %d' % (
# offset / FRAMES_PER_DISC_FRAME, offset, value, crc)
return crc
class TaskRunner:
"""
I am a base class for task runners.
Task runners should be reusable.
"""
def run(self, task):
"""
Run the given task.
@type task: Task
"""
raise NotImplementedError
# listener callbacks
def progressed(self, value):
"""
Implement me to be informed about progress.
@type value: float
@param value: progress, from 0.0 to 1.0
"""
def started(self):
"""
Implement me to be informed about the task starting.
"""
def stopped(self):
"""
Implement me to be informed about the task starting.
"""
class SyncRunner(TaskRunner):
def run(self, task):
self._task = task
self._loop = gobject.MainLoop()
self._task.addListener(self)
self._task.start()
self._loop.run()
def progressed(self, value):
sys.stdout.write('%s %3d %%\r' % (
self._task.description, value * 100.0))
sys.stdout.flush()
if value >= 1.0:
sys.stdout.write('%s %3d %%\n' % (
self._task.description, 100.0))
def stopped(self):
self._loop.quit()