321 lines
10 KiB
Python
321 lines
10 KiB
Python
|
# This file is part of audioread.
|
||
|
|
# Copyright 2014, Adrian Sampson.
|
||
|
|
#
|
||
|
|
# Permission is hereby granted, free of charge, to any person obtaining
|
||
|
|
# a copy of this software and associated documentation files (the
|
||
|
|
# "Software"), to deal in the Software without restriction, including
|
||
|
|
# without limitation the rights to use, copy, modify, merge, publish,
|
||
|
|
# distribute, sublicense, and/or sell copies of the Software, and to
|
||
|
|
# permit persons to whom the Software is furnished to do so, subject to
|
||
|
|
# the following conditions:
|
||
|
|
#
|
||
|
|
# The above copyright notice and this permission notice shall be
|
||
|
|
# included in all copies or substantial portions of the Software.
|
||
|
|
|
||
|
|
"""Read audio data using the ffmpeg command line tool via its standard
|
||
|
|
output.
|
||
|
|
"""
|
||
|
|
|
||
|
|
import queue
|
||
|
|
import re
|
||
|
|
import subprocess
|
||
|
|
import sys
|
||
|
|
import threading
|
||
|
|
import time
|
||
|
|
from io import DEFAULT_BUFFER_SIZE
|
||
|
|
|
||
|
|
from .exceptions import DecodeError
|
||
|
|
from .base import AudioFile
|
||
|
|
|
||
|
|
COMMANDS = ('ffmpeg', 'avconv')
|
||
|
|
|
||
|
|
if sys.platform == "win32":
|
||
|
|
PROC_FLAGS = 0x08000000
|
||
|
|
else:
|
||
|
|
PROC_FLAGS = 0
|
||
|
|
|
||
|
|
|
||
|
|
class FFmpegError(DecodeError):
|
||
|
|
pass
|
||
|
|
|
||
|
|
|
||
|
|
class CommunicationError(FFmpegError):
|
||
|
|
"""Raised when the output of FFmpeg is not parseable."""
|
||
|
|
|
||
|
|
|
||
|
|
class UnsupportedError(FFmpegError):
|
||
|
|
"""The file could not be decoded by FFmpeg."""
|
||
|
|
|
||
|
|
|
||
|
|
class NotInstalledError(FFmpegError):
|
||
|
|
"""Could not find the ffmpeg binary."""
|
||
|
|
|
||
|
|
|
||
|
|
class ReadTimeoutError(FFmpegError):
|
||
|
|
"""Reading from the ffmpeg command-line tool timed out."""
|
||
|
|
|
||
|
|
|
||
|
|
class QueueReaderThread(threading.Thread):
|
||
|
|
"""A thread that consumes data from a filehandle and sends the data
|
||
|
|
over a Queue.
|
||
|
|
"""
|
||
|
|
def __init__(self, fh, blocksize=1024, discard=False):
|
||
|
|
super().__init__()
|
||
|
|
self.fh = fh
|
||
|
|
self.blocksize = blocksize
|
||
|
|
self.daemon = True
|
||
|
|
self.discard = discard
|
||
|
|
self.queue = None if discard else queue.Queue()
|
||
|
|
|
||
|
|
def run(self):
|
||
|
|
while True:
|
||
|
|
data = self.fh.read(self.blocksize)
|
||
|
|
if not self.discard:
|
||
|
|
self.queue.put(data)
|
||
|
|
if not data:
|
||
|
|
# Stream closed (EOF).
|
||
|
|
break
|
||
|
|
|
||
|
|
|
||
|
|
def popen_multiple(commands, command_args, *args, **kwargs):
|
||
|
|
"""Like `subprocess.Popen`, but can try multiple commands in case
|
||
|
|
some are not available.
|
||
|
|
|
||
|
|
`commands` is an iterable of command names and `command_args` are
|
||
|
|
the rest of the arguments that, when appended to the command name,
|
||
|
|
make up the full first argument to `subprocess.Popen`. The
|
||
|
|
other positional and keyword arguments are passed through.
|
||
|
|
"""
|
||
|
|
for i, command in enumerate(commands):
|
||
|
|
cmd = [command] + command_args
|
||
|
|
try:
|
||
|
|
return subprocess.Popen(cmd, *args, **kwargs)
|
||
|
|
except OSError:
|
||
|
|
if i == len(commands) - 1:
|
||
|
|
# No more commands to try.
|
||
|
|
raise
|
||
|
|
|
||
|
|
|
||
|
|
def available():
|
||
|
|
"""Detect whether the FFmpeg backend can be used on this system.
|
||
|
|
"""
|
||
|
|
try:
|
||
|
|
proc = popen_multiple(
|
||
|
|
COMMANDS,
|
||
|
|
['-version'],
|
||
|
|
stdout=subprocess.PIPE,
|
||
|
|
stderr=subprocess.PIPE,
|
||
|
|
creationflags=PROC_FLAGS,
|
||
|
|
)
|
||
|
|
except OSError:
|
||
|
|
return False
|
||
|
|
else:
|
||
|
|
proc.communicate()
|
||
|
|
return proc.returncode == 0
|
||
|
|
|
||
|
|
|
||
|
|
# For Windows error switch management, we need a lock to keep the mode
|
||
|
|
# adjustment atomic.
|
||
|
|
windows_error_mode_lock = threading.Lock()
|
||
|
|
|
||
|
|
|
||
|
|
class FFmpegAudioFile(AudioFile):
|
||
|
|
"""An audio file decoded by the ffmpeg command-line utility."""
|
||
|
|
def __init__(self, filename, block_size=DEFAULT_BUFFER_SIZE):
|
||
|
|
# On Windows, we need to disable the subprocess's crash dialog
|
||
|
|
# in case it dies. Passing SEM_NOGPFAULTERRORBOX to SetErrorMode
|
||
|
|
# disables this behavior.
|
||
|
|
windows = sys.platform.startswith("win")
|
||
|
|
if windows:
|
||
|
|
windows_error_mode_lock.acquire()
|
||
|
|
SEM_NOGPFAULTERRORBOX = 0x0002
|
||
|
|
import ctypes
|
||
|
|
# We call SetErrorMode in two steps to avoid overriding
|
||
|
|
# existing error mode.
|
||
|
|
previous_error_mode = \
|
||
|
|
ctypes.windll.kernel32.SetErrorMode(SEM_NOGPFAULTERRORBOX)
|
||
|
|
ctypes.windll.kernel32.SetErrorMode(
|
||
|
|
previous_error_mode | SEM_NOGPFAULTERRORBOX
|
||
|
|
)
|
||
|
|
|
||
|
|
try:
|
||
|
|
self.proc = popen_multiple(
|
||
|
|
COMMANDS,
|
||
|
|
['-i', filename, '-f', 's16le', '-'],
|
||
|
|
stdout=subprocess.PIPE,
|
||
|
|
stderr=subprocess.PIPE,
|
||
|
|
stdin=subprocess.DEVNULL,
|
||
|
|
creationflags=PROC_FLAGS,
|
||
|
|
)
|
||
|
|
|
||
|
|
except OSError:
|
||
|
|
raise NotInstalledError()
|
||
|
|
|
||
|
|
finally:
|
||
|
|
# Reset previous error mode on Windows. (We can change this
|
||
|
|
# back now because the flag was inherited by the subprocess;
|
||
|
|
# we don't need to keep it set in the parent process.)
|
||
|
|
if windows:
|
||
|
|
try:
|
||
|
|
import ctypes
|
||
|
|
ctypes.windll.kernel32.SetErrorMode(previous_error_mode)
|
||
|
|
finally:
|
||
|
|
windows_error_mode_lock.release()
|
||
|
|
|
||
|
|
# Start another thread to consume the standard output of the
|
||
|
|
# process, which contains raw audio data.
|
||
|
|
self.stdout_reader = QueueReaderThread(self.proc.stdout, block_size)
|
||
|
|
self.stdout_reader.start()
|
||
|
|
|
||
|
|
# Read relevant information from stderr.
|
||
|
|
self._get_info()
|
||
|
|
|
||
|
|
# Start a separate thread to read the rest of the data from
|
||
|
|
# stderr. This (a) avoids filling up the OS buffer and (b)
|
||
|
|
# collects the error output for diagnosis.
|
||
|
|
self.stderr_reader = QueueReaderThread(self.proc.stderr)
|
||
|
|
self.stderr_reader.start()
|
||
|
|
|
||
|
|
def read_data(self, timeout=10.0):
|
||
|
|
"""Read blocks of raw PCM data from the file."""
|
||
|
|
# Read from stdout in a separate thread and consume data from
|
||
|
|
# the queue.
|
||
|
|
start_time = time.time()
|
||
|
|
while True:
|
||
|
|
# Wait for data to be available or a timeout.
|
||
|
|
data = None
|
||
|
|
try:
|
||
|
|
data = self.stdout_reader.queue.get(timeout=timeout)
|
||
|
|
if data:
|
||
|
|
yield data
|
||
|
|
else:
|
||
|
|
# End of file.
|
||
|
|
break
|
||
|
|
except queue.Empty:
|
||
|
|
# Queue read timed out.
|
||
|
|
end_time = time.time()
|
||
|
|
if not data:
|
||
|
|
if end_time - start_time >= timeout:
|
||
|
|
# Nothing interesting has happened for a while --
|
||
|
|
# FFmpeg is probably hanging.
|
||
|
|
raise ReadTimeoutError('ffmpeg output: {}'.format(
|
||
|
|
b''.join(self.stderr_reader.queue.queue)
|
||
|
|
))
|
||
|
|
else:
|
||
|
|
start_time = end_time
|
||
|
|
# Keep waiting.
|
||
|
|
continue
|
||
|
|
|
||
|
|
def _get_info(self):
|
||
|
|
"""Reads the tool's output from its stderr stream, extracts the
|
||
|
|
relevant information, and parses it.
|
||
|
|
"""
|
||
|
|
out_parts = []
|
||
|
|
while True:
|
||
|
|
line = self.proc.stderr.readline()
|
||
|
|
if not line:
|
||
|
|
# EOF and data not found.
|
||
|
|
raise CommunicationError("stream info not found")
|
||
|
|
|
||
|
|
# In Python 3, result of reading from stderr is bytes.
|
||
|
|
if isinstance(line, bytes):
|
||
|
|
line = line.decode('utf8', 'ignore')
|
||
|
|
|
||
|
|
line = line.strip().lower()
|
||
|
|
|
||
|
|
if 'no such file' in line:
|
||
|
|
raise OSError('file not found')
|
||
|
|
elif 'invalid data found' in line:
|
||
|
|
raise UnsupportedError()
|
||
|
|
elif 'duration:' in line:
|
||
|
|
out_parts.append(line)
|
||
|
|
elif 'audio:' in line:
|
||
|
|
out_parts.append(line)
|
||
|
|
self._parse_info(''.join(out_parts))
|
||
|
|
break
|
||
|
|
|
||
|
|
def _parse_info(self, s):
|
||
|
|
"""Given relevant data from the ffmpeg output, set audio
|
||
|
|
parameter fields on this object.
|
||
|
|
"""
|
||
|
|
# Sample rate.
|
||
|
|
match = re.search(r'(\d+) hz', s)
|
||
|
|
if match:
|
||
|
|
self.samplerate = int(match.group(1))
|
||
|
|
else:
|
||
|
|
self.samplerate = 0
|
||
|
|
|
||
|
|
# Channel count.
|
||
|
|
match = re.search(r'hz, ([^,]+),', s)
|
||
|
|
if match:
|
||
|
|
mode = match.group(1)
|
||
|
|
if mode == 'stereo':
|
||
|
|
self.channels = 2
|
||
|
|
else:
|
||
|
|
cmatch = re.match(r'(\d+)\.?(\d)?', mode)
|
||
|
|
if cmatch:
|
||
|
|
self.channels = sum(map(int, cmatch.group().split('.')))
|
||
|
|
else:
|
||
|
|
self.channels = 1
|
||
|
|
else:
|
||
|
|
self.channels = 0
|
||
|
|
|
||
|
|
# Duration.
|
||
|
|
match = re.search(
|
||
|
|
r'duration: (\d+):(\d+):(\d+).(\d)', s
|
||
|
|
)
|
||
|
|
if match:
|
||
|
|
durparts = list(map(int, match.groups()))
|
||
|
|
duration = (
|
||
|
|
durparts[0] * 60 * 60 +
|
||
|
|
durparts[1] * 60 +
|
||
|
|
durparts[2] +
|
||
|
|
float(durparts[3]) / 10
|
||
|
|
)
|
||
|
|
self.duration = duration
|
||
|
|
else:
|
||
|
|
# No duration found.
|
||
|
|
self.duration = 0
|
||
|
|
|
||
|
|
def close(self):
|
||
|
|
"""Close the ffmpeg process used to perform the decoding."""
|
||
|
|
if hasattr(self, 'proc'):
|
||
|
|
# First check the process's execution status before attempting to
|
||
|
|
# kill it. This fixes an issue on Windows Subsystem for Linux where
|
||
|
|
# ffmpeg closes normally on its own, but never updates
|
||
|
|
# `returncode`.
|
||
|
|
self.proc.poll()
|
||
|
|
|
||
|
|
# Kill the process if it is still running.
|
||
|
|
if self.proc.returncode is None:
|
||
|
|
self.proc.kill()
|
||
|
|
self.proc.wait()
|
||
|
|
|
||
|
|
# Wait for the stream-reading threads to exit. (They need to
|
||
|
|
# stop reading before we can close the streams.)
|
||
|
|
if hasattr(self, 'stderr_reader'):
|
||
|
|
self.stderr_reader.join()
|
||
|
|
if hasattr(self, 'stdout_reader'):
|
||
|
|
self.stdout_reader.join()
|
||
|
|
|
||
|
|
# Close the stdout and stderr streams that were opened by Popen,
|
||
|
|
# which should occur regardless of if the process terminated
|
||
|
|
# cleanly.
|
||
|
|
self.proc.stdout.close()
|
||
|
|
self.proc.stderr.close()
|
||
|
|
|
||
|
|
def __del__(self):
|
||
|
|
self.close()
|
||
|
|
|
||
|
|
# Iteration.
|
||
|
|
def __iter__(self):
|
||
|
|
return self.read_data()
|
||
|
|
|
||
|
|
# Context manager.
|
||
|
|
def __enter__(self):
|
||
|
|
return self
|
||
|
|
|
||
|
|
def __exit__(self, exc_type, exc_val, exc_tb):
|
||
|
|
self.close()
|
||
|
|
return False
|