Fixed use of itertools.count() to generate segment numbers (ref #32).

nigel.stanger / process_podcast

Browse code Fixed use of itertools.count() to generate segment numbers (ref #32). master
1 parent 59086ed commit 01eb528a9d74077d2499d38bb7a601f55237dc4f Nigel Stanger authored on 28 Aug 2018

Patch

Showing 1 changed file

Ignore Space Show notes View segment.py
#!/usr/bin/env python3 from collections import OrderedDict import errno import itertools import logging import os from pathlib import Path import globals from shell_command import (ConvertCommand, FFprobeCommand, FFmpegCommand) class SegmentException(Exception): pass class Segment(object): """A segment within the podcast. A segment has an input file, and a punch-in and punch-out point (both in seconds). """ # Automatic segment number generator. _new_segment_num = next(itertools.count()) # Keep track of input files in the order they're loaded, so that we # can easily reference them by index in the ffmpeg command (i.e., # first input file is, 0, etc.). _input_files = OrderedDict() # A string representing the type of the segment (e.g., "audio"). # This is handy for generating temporary files and means that we # can implement this as a single method in the root class. _TYPE = "" # Which trim and setpts filters to use in ffmpeg complex filters. # As above, this lets us implement a single method in the root class. _TRIM = "" _SETPTS = "" @staticmethod def input_files(): return Segment._input_files @staticmethod def _rename_input_file(old, new): tmp = OrderedDict() for f in Segment._input_files: if (f == old): tmp[new] = Segment._input_files[f] else: tmp[f] = Segment._input_files[f] Segment._input_files = tmp def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0): self.segment_number = self.__class__._new_segment_num() self.input_file = file self.punch_in = punch_in self.punch_out = punch_out self.input_stream = input_stream self._temp_file = "" self._temp_suffix = "mov" # List of temporary files to delete when cleaning up. self._temp_files_list = [] if (file not in self.__class__._input_files): self.__class__._input_files[file] = None self._input_options = ["-ss", str(self.punch_in.total_seconds()), "-t", str(self.get_duration()), "-i", self.input_file] self._output_options = [] def __repr__(self): return('<{c} {n}: file "{f}", in {i}, out ' '{o}>'.format(c=self.__class__.__name__, n=self.segment_number, t=self._TYPE, f=self.input_file, i=self.punch_in, o=self.punch_out)) def get_duration(self): """Return the duration of the segment in seconds.""" return (self.punch_out - self.punch_in).total_seconds() def generate_temp_filename(self, output, suffix=None): """Generate a temporary filename for the segment.""" if not suffix: suffix = self._temp_suffix return Path("temp_{t}_{o}_{n:03d}".format( t=self._TYPE, o=Path(output).stem, n=self.segment_number)).with_suffix(suffix) def generate_temp_file(self, output, width=0, height=0): """Compile the segment from the original source file(s).""" # Note: width and height are currently ignored for segments # in general. This may (or may not) need to change if there # are multiple inputs of different dimensions. fn = "generate_temp_file" self._temp_file = self.generate_temp_filename(output) command = FFmpegCommand( input_options=self._input_options + ["-codec", "copy"], output_options=self._output_options + [self._temp_file]) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) if (command.run() == 0): self._temp_files_list.append(self._temp_file) return self._temp_file else: raise SegmentException( "Failed to generate temporary file {f} for " "{s}".format(f=self._temp_file, s=self)) def temp_file(self): """Return the temporary file associated with the segment.""" return self._temp_file def delete_temp_files(self): """Delete the temporary file(s) associated with the segment.""" # Note: sometimes segments (especially frame segments) may # share the same temporary file. Just ignore the file not # found exception that occurs in these cases. for f in self._temp_files_list: try: os.remove(f) except OSError as e: if (e.errno != errno.ENOENT): raise e def input_stream_specifier(self): """Return the segment's ffmpeg stream input specifier.""" return "[{n}:{t}]".format( n=self.__class__._input_files.keys().index(self.input_file), t=self._TYPE[0] if self._TYPE else "") def output_stream_specifier(self): """Return the segment's ffmpeg audio stream output specifier.""" return "[{t}{n}]".format(t=self._TYPE[0] if self._TYPE else "", n=self.segment_number) def trim_filter(self): """Return an FFMPEG trim filter for this segment.""" return ("{inspec} " "{trim}=start={pi}:duration={po},{setpts}=PTS-STARTPTS " "{outspec}".format( inspec=self.input_stream_specifier(), trim=self._TRIM, setpts=self._SETPTS, pi=self.punch_in.total_seconds(), po=self.get_duration(), outspec=self.output_stream_specifier())) class AudioSegment(Segment): """A segment of an audio input stream.""" _TYPE = "audio" _TRIM = "atrim" _SETPTS = "asetpts" def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0): super(AudioSegment, self).__init__(file, punch_in, punch_out, input_stream) self._temp_suffix = "wav" self._output_options = ["-ac", "1", "-map", "{n}:a".format(n=self.input_stream)] class VideoSegment(Segment): """A segment of a video input stream.""" _TYPE = "video" _TRIM = "trim" _SETPTS = "setpts" def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0): super(VideoSegment, self).__init__(file, punch_in, punch_out, input_stream) self._output_options = ["-map", "{n}:v".format(n=self.input_stream)] self._temp_frame_file = "" def get_last_frame_number(self): """Calculate frame number of segment's last frame using ffprobe.""" fn = "get_last_frame_number" if (self._temp_file): self._temp_frame_file = "__{f}".format(f=self._temp_file) # To speed things up, grab up to the last 5 seconds of the # segment's temporary file, as we otherwise have to scan the # entire temporary file to find the last frame, which can # take a while. command = FFmpegCommand( input_options=["-ss", str(max(self.get_duration() - 5, 0)), "-i", self._temp_file], output_options=["-codec:v", "copy", "-map", "0:v", self._temp_frame_file]) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) if (command.run() == 0): self._temp_files_list.append(self._temp_frame_file) command = FFprobeCommand([self._temp_frame_file]) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) return int(command.get_entries( section="stream", find_list=["nb_frames"])[0]) - 1 else: raise SegmentException( "Failed to generate temporary file to get last frame " "number for {s}".format(s=self)) else: raise SegmentException( "Can't get last frame of {s} because it has no temporary " "file".format(s=self)) def generate_frame(self, frame_number, output, width=2048, height=1536): """Create a JPEG file from the specified frame of the segment.""" # Note: width and height are currently ignored for video # segments. This will need to change if there are multiple # video inputs of different dimensions. fn = "generate_frame" temp_frame = self.generate_temp_filename(output, suffix="jpg") if (frame_number == -1): frame_number = self.get_last_frame_number() command = FFmpegCommand( input_options=["-i", self._temp_frame_file], output_options=["-filter:v", "select='eq(n, {n})'".format(n=frame_number), "-frames:v", "1", "-f", "image2", "-map", "0:v", temp_frame]) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) if (command.run() == 0): self._temp_files_list.append(temp_frame) return temp_frame else: raise SegmentException( "Failed to create JPEG for frame {n} of " "{s}".format(n=frame_number, s=self)) class FrameSegment(VideoSegment): """A video segment derived from a single still frame.""" _TYPE = "frame" def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0, frame_number=0): super(FrameSegment, self).__init__(file, punch_in, punch_out, input_stream) self.frame_number = frame_number self._input_options = ["-loop", "1", "-t", str(self.get_duration()), "-i", self.input_file] self.__class__._input_files[file] = self._input_options[:4] def __repr__(self): return('<{c} {n}: file "{f}", in {i}, out {o}, frame number ' '{fn}>'.format(c=self.__class__.__name__, n=self.segment_number, t=self._TYPE, f=self.input_file, i=self.punch_in, o=self.punch_out, fn=self.frame_number)) def generate_temp_file(self, output, width=2048, height=1536): """Compile the segment from the original source file(s).""" fn = "generate_temp_file" self._temp_file = self.generate_temp_filename(output, suffix="jpg") command = ConvertCommand( input_options=["{f}[{n}]".format( f=self.input_file, n=self.frame_number)], output_options=["{f}".format(f=self._temp_file)], width=width, height=height) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) if (command.run() == 0): self._temp_files_list.append(self._temp_file) return self._temp_file else: raise SegmentException( "Failed to generate temporary file {f} for " "{s}".format(f=self._temp_file, s=self)) def use_frame(self, frame): """Set the image to use for generating the frame video.""" self.__class__._rename_input_file(self.input_file, frame) self.input_file = frame self._input_options = ["-loop", "1", "-t", str(self.get_duration()), "-i", self.input_file] self.__class__._input_files[frame] = self._input_options[:4] def input_stream_specifier(self): """Return the segment's ffmpeg stream input specifier.""" return "[{n}:v]".format( n=self.__class__._input_files.keys().index(self.input_file)) def output_stream_specifier(self): """Return the segment's ffmpeg audio stream output specifier.""" return self.input_stream_specifier() def trim_filter(self): """Return an FFMPEG trim filter for this segment.""" return "" if (__name__ == "__main__"): pass #!/usr/bin/env python3 from collections import OrderedDict import errno import itertools import logging import os from pathlib import Path import globals from shell_command import (ConvertCommand, FFprobeCommand, FFmpegCommand) class SegmentException(Exception): pass class Segment(object): """A segment within the podcast. A segment has an input file, and a punch-in and punch-out point (both in seconds). """ # Automatic segment number generator. _new_segment_num = itertools.count().next # Keep track of input files in the order they're loaded, so that we # can easily reference them by index in the ffmpeg command (i.e., # first input file is, 0, etc.). _input_files = OrderedDict() # A string representing the type of the segment (e.g., "audio"). # This is handy for generating temporary files and means that we # can implement this as a single method in the root class. _TYPE = "" # Which trim and setpts filters to use in ffmpeg complex filters. # As above, this lets us implement a single method in the root class. _TRIM = "" _SETPTS = "" @staticmethod def input_files(): return Segment._input_files @staticmethod def _rename_input_file(old, new): tmp = OrderedDict() for f in Segment._input_files: if (f == old): tmp[new] = Segment._input_files[f] else: tmp[f] = Segment._input_files[f] Segment._input_files = tmp def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0): self.segment_number = self.__class__._new_segment_num() self.input_file = file self.punch_in = punch_in self.punch_out = punch_out self.input_stream = input_stream self._temp_file = "" self._temp_suffix = "mov" # List of temporary files to delete when cleaning up. self._temp_files_list = [] if (file not in self.__class__._input_files): self.__class__._input_files[file] = None self._input_options = ["-ss", str(self.punch_in.total_seconds()), "-t", str(self.get_duration()), "-i", self.input_file] self._output_options = [] def __repr__(self): return('<{c} {n}: file "{f}", in {i}, out ' '{o}>'.format(c=self.__class__.__name__, n=self.segment_number, t=self._TYPE, f=self.input_file, i=self.punch_in, o=self.punch_out)) def get_duration(self): """Return the duration of the segment in seconds.""" return (self.punch_out - self.punch_in).total_seconds() def generate_temp_filename(self, output, suffix=None): """Generate a temporary filename for the segment.""" if not suffix: suffix = self._temp_suffix return Path("temp_{t}_{o}_{n:03d}".format( t=self._TYPE, o=Path(output).stem, n=self.segment_number)).with_suffix(suffix) def generate_temp_file(self, output, width=0, height=0): """Compile the segment from the original source file(s).""" # Note: width and height are currently ignored for segments # in general. This may (or may not) need to change if there # are multiple inputs of different dimensions. fn = "generate_temp_file" self._temp_file = self.generate_temp_filename(output) command = FFmpegCommand( input_options=self._input_options + ["-codec", "copy"], output_options=self._output_options + [self._temp_file]) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) if (command.run() == 0): self._temp_files_list.append(self._temp_file) return self._temp_file else: raise SegmentException( "Failed to generate temporary file {f} for " "{s}".format(f=self._temp_file, s=self)) def temp_file(self): """Return the temporary file associated with the segment.""" return self._temp_file def delete_temp_files(self): """Delete the temporary file(s) associated with the segment.""" # Note: sometimes segments (especially frame segments) may # share the same temporary file. Just ignore the file not # found exception that occurs in these cases. for f in self._temp_files_list: try: os.remove(f) except OSError as e: if (e.errno != errno.ENOENT): raise e def input_stream_specifier(self): """Return the segment's ffmpeg stream input specifier.""" return "[{n}:{t}]".format( n=self.__class__._input_files.keys().index(self.input_file), t=self._TYPE[0] if self._TYPE else "") def output_stream_specifier(self): """Return the segment's ffmpeg audio stream output specifier.""" return "[{t}{n}]".format(t=self._TYPE[0] if self._TYPE else "", n=self.segment_number) def trim_filter(self): """Return an FFMPEG trim filter for this segment.""" return ("{inspec} " "{trim}=start={pi}:duration={po},{setpts}=PTS-STARTPTS " "{outspec}".format( inspec=self.input_stream_specifier(), trim=self._TRIM, setpts=self._SETPTS, pi=self.punch_in.total_seconds(), po=self.get_duration(), outspec=self.output_stream_specifier())) class AudioSegment(Segment): """A segment of an audio input stream.""" _TYPE = "audio" _TRIM = "atrim" _SETPTS = "asetpts" def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0): super(AudioSegment, self).__init__(file, punch_in, punch_out, input_stream) self._temp_suffix = "wav" self._output_options = ["-ac", "1", "-map", "{n}:a".format(n=self.input_stream)] class VideoSegment(Segment): """A segment of a video input stream.""" _TYPE = "video" _TRIM = "trim" _SETPTS = "setpts" def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0): super(VideoSegment, self).__init__(file, punch_in, punch_out, input_stream) self._output_options = ["-map", "{n}:v".format(n=self.input_stream)] self._temp_frame_file = "" def get_last_frame_number(self): """Calculate frame number of segment's last frame using ffprobe.""" fn = "get_last_frame_number" if (self._temp_file): self._temp_frame_file = "__{f}".format(f=self._temp_file) # To speed things up, grab up to the last 5 seconds of the # segment's temporary file, as we otherwise have to scan the # entire temporary file to find the last frame, which can # take a while. command = FFmpegCommand( input_options=["-ss", str(max(self.get_duration() - 5, 0)), "-i", self._temp_file], output_options=["-codec:v", "copy", "-map", "0:v", self._temp_frame_file]) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) if (command.run() == 0): self._temp_files_list.append(self._temp_frame_file) command = FFprobeCommand([self._temp_frame_file]) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) return int(command.get_entries( section="stream", find_list=["nb_frames"])[0]) - 1 else: raise SegmentException( "Failed to generate temporary file to get last frame " "number for {s}".format(s=self)) else: raise SegmentException( "Can't get last frame of {s} because it has no temporary " "file".format(s=self)) def generate_frame(self, frame_number, output, width=2048, height=1536): """Create a JPEG file from the specified frame of the segment.""" # Note: width and height are currently ignored for video # segments. This will need to change if there are multiple # video inputs of different dimensions. fn = "generate_frame" temp_frame = self.generate_temp_filename(output, suffix="jpg") if (frame_number == -1): frame_number = self.get_last_frame_number() command = FFmpegCommand( input_options=["-i", self._temp_frame_file], output_options=["-filter:v", "select='eq(n, {n})'".format(n=frame_number), "-frames:v", "1", "-f", "image2", "-map", "0:v", temp_frame]) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) if (command.run() == 0): self._temp_files_list.append(temp_frame) return temp_frame else: raise SegmentException( "Failed to create JPEG for frame {n} of " "{s}".format(n=frame_number, s=self)) class FrameSegment(VideoSegment): """A video segment derived from a single still frame.""" _TYPE = "frame" def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0, frame_number=0): super(FrameSegment, self).__init__(file, punch_in, punch_out, input_stream) self.frame_number = frame_number self._input_options = ["-loop", "1", "-t", str(self.get_duration()), "-i", self.input_file] self.__class__._input_files[file] = self._input_options[:4] def __repr__(self): return('<{c} {n}: file "{f}", in {i}, out {o}, frame number ' '{fn}>'.format(c=self.__class__.__name__, n=self.segment_number, t=self._TYPE, f=self.input_file, i=self.punch_in, o=self.punch_out, fn=self.frame_number)) def generate_temp_file(self, output, width=2048, height=1536): """Compile the segment from the original source file(s).""" fn = "generate_temp_file" self._temp_file = self.generate_temp_filename(output, suffix="jpg") command = ConvertCommand( input_options=["{f}[{n}]".format( f=self.input_file, n=self.frame_number)], output_options=["{f}".format(f=self._temp_file)], width=width, height=height) globals.log.debug("{cls}.{fn}(): {cmd}".format( cls=self.__class__.__name__, fn=fn, cmd=command)) if (command.run() == 0): self._temp_files_list.append(self._temp_file) return self._temp_file else: raise SegmentException( "Failed to generate temporary file {f} for " "{s}".format(f=self._temp_file, s=self)) def use_frame(self, frame): """Set the image to use for generating the frame video.""" self.__class__._rename_input_file(self.input_file, frame) self.input_file = frame self._input_options = ["-loop", "1", "-t", str(self.get_duration()), "-i", self.input_file] self.__class__._input_files[frame] = self._input_options[:4] def input_stream_specifier(self): """Return the segment's ffmpeg stream input specifier.""" return "[{n}:v]".format( n=self.__class__._input_files.keys().index(self.input_file)) def output_stream_specifier(self): """Return the segment's ffmpeg audio stream output specifier.""" return self.input_stream_specifier() def trim_filter(self): """Return an FFMPEG trim filter for this segment.""" return "" if (__name__ == "__main__"): pass

Ignore Space Show notes View

segment.py

#!/usr/bin/env python3

from collections import OrderedDict
import errno
import itertools
import logging
import os
from pathlib import Path

import globals
from shell_command import (ConvertCommand, FFprobeCommand, FFmpegCommand)

class SegmentException(Exception):
    pass

class Segment(object):
    """A segment within the podcast.
    
    A segment has an input file, and a punch-in and punch-out
    point (both in seconds).
    """
    # Automatic segment number generator.
    _new_segment_num = next(itertools.count())
    
    # Keep track of input files in the order they're loaded, so that we
    # can easily reference them by index in the ffmpeg command (i.e.,
    # first input file is, 0, etc.).
    _input_files = OrderedDict()
    
    # A string representing the type of the segment (e.g., "audio").
    # This is handy for generating temporary files and means that we
    # can implement this as a single method in the root class.
    _TYPE = ""
    
    # Which trim and setpts filters to use in ffmpeg complex filters.
    # As above, this lets us implement a single method in the root class.
    _TRIM = ""
    _SETPTS = ""
    
    @staticmethod
    def input_files():
        return Segment._input_files
    
    @staticmethod
    def _rename_input_file(old, new):
        tmp = OrderedDict()
        for f in Segment._input_files:
            if (f == old):
                tmp[new] = Segment._input_files[f]
            else:
                tmp[f] = Segment._input_files[f]
        Segment._input_files = tmp
    
    def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0):
        self.segment_number = self.__class__._new_segment_num()
        self.input_file = file
        self.punch_in = punch_in
        self.punch_out = punch_out
        self.input_stream = input_stream
        self._temp_file = ""
        self._temp_suffix = "mov"
        # List of temporary files to delete when cleaning up.
        self._temp_files_list = []
        
        if (file not in self.__class__._input_files):
            self.__class__._input_files[file] = None
        
        self._input_options = ["-ss", str(self.punch_in.total_seconds()),
                               "-t", str(self.get_duration()),
                               "-i", self.input_file]
        self._output_options = []
            
    def __repr__(self):
        return('<{c} {n}: file "{f}", in {i}, out '
               '{o}>'.format(c=self.__class__.__name__,
                             n=self.segment_number,
                             t=self._TYPE,
                             f=self.input_file,
                             i=self.punch_in,
                             o=self.punch_out))
    
    def get_duration(self):
        """Return the duration of the segment in seconds."""
        return (self.punch_out - self.punch_in).total_seconds()
    
    def generate_temp_filename(self, output, suffix=None):
        """Generate a temporary filename for the segment."""
        if not suffix:
            suffix = self._temp_suffix
        return Path("temp_{t}_{o}_{n:03d}".format(
            t=self._TYPE, o=Path(output).stem,
            n=self.segment_number)).with_suffix(suffix)
    
    def generate_temp_file(self, output, width=0, height=0):
        """Compile the segment from the original source file(s)."""
        # Note: width and height are currently ignored for segments
        # in general. This may (or may not) need to change if there
        # are multiple inputs of different dimensions.
        fn = "generate_temp_file"
        self._temp_file = self.generate_temp_filename(output)
        command = FFmpegCommand(
            input_options=self._input_options + ["-codec", "copy"],
            output_options=self._output_options + [self._temp_file])
        globals.log.debug("{cls}.{fn}(): {cmd}".format(
            cls=self.__class__.__name__, fn=fn, cmd=command))
        if (command.run() == 0):
            self._temp_files_list.append(self._temp_file)
            return self._temp_file
        else:
            raise SegmentException(
                "Failed to generate temporary file {f} for "
                "{s}".format(f=self._temp_file, s=self))
    
    def temp_file(self):
        """Return the temporary file associated with the segment."""
        return self._temp_file
    
    def delete_temp_files(self):
        """Delete the temporary file(s) associated with the segment."""
        # Note: sometimes segments (especially frame segments) may
        # share the same temporary file. Just ignore the file not
        # found exception that occurs in these cases.
        for f in self._temp_files_list:
            try:
                os.remove(f)
            except OSError as e:
                if (e.errno != errno.ENOENT):
                    raise e
    
    def input_stream_specifier(self):
        """Return the segment's ffmpeg stream input specifier."""
        return "[{n}:{t}]".format(
            n=self.__class__._input_files.keys().index(self.input_file),
            t=self._TYPE[0] if self._TYPE else "")
        
    def output_stream_specifier(self):
        """Return the segment's ffmpeg audio stream output specifier."""
        return "[{t}{n}]".format(t=self._TYPE[0] if self._TYPE else "",
                                 n=self.segment_number)
    
    def trim_filter(self):
        """Return an FFMPEG trim filter for this segment."""
        return ("{inspec} "
                "{trim}=start={pi}:duration={po},{setpts}=PTS-STARTPTS "
                "{outspec}".format(
                    inspec=self.input_stream_specifier(),
                    trim=self._TRIM, setpts=self._SETPTS,
                    pi=self.punch_in.total_seconds(),
                    po=self.get_duration(),
                    outspec=self.output_stream_specifier()))

class AudioSegment(Segment):
    """A segment of an audio input stream."""
    _TYPE = "audio"
    _TRIM = "atrim"
    _SETPTS = "asetpts"

def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0):
        super(AudioSegment, self).__init__(file, punch_in, punch_out,
                                           input_stream)
        self._temp_suffix = "wav"
        self._output_options = ["-ac", "1",
                                "-map", "{n}:a".format(n=self.input_stream)]

class VideoSegment(Segment):
    """A segment of a video input stream."""
    _TYPE = "video"
    _TRIM = "trim"
    _SETPTS = "setpts"

def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0):
        super(VideoSegment, self).__init__(file, punch_in, punch_out,
                                           input_stream)
        self._output_options = ["-map", "{n}:v".format(n=self.input_stream)]
        self._temp_frame_file = ""
    
    def get_last_frame_number(self):
        """Calculate frame number of segment's last frame using ffprobe."""
        fn = "get_last_frame_number"
        if (self._temp_file):
            self._temp_frame_file = "__{f}".format(f=self._temp_file)
        
            # To speed things up, grab up to the last 5 seconds of the
            # segment's temporary file, as we otherwise have to scan the
            # entire temporary file to find the last frame, which can
            # take a while.
            command = FFmpegCommand(
                input_options=["-ss", str(max(self.get_duration() - 5, 0)),
                               "-i", self._temp_file],
                output_options=["-codec:v", "copy",
                                "-map", "0:v",
                                self._temp_frame_file])
            globals.log.debug("{cls}.{fn}(): {cmd}".format(
                cls=self.__class__.__name__, fn=fn, cmd=command))
            if (command.run() == 0):
                self._temp_files_list.append(self._temp_frame_file)
                command = FFprobeCommand([self._temp_frame_file])
                globals.log.debug("{cls}.{fn}(): {cmd}".format(
                    cls=self.__class__.__name__, fn=fn, cmd=command))
                return int(command.get_entries(
                    section="stream", find_list=["nb_frames"])[0]) - 1
            else:
                raise SegmentException(
                    "Failed to generate temporary file to get last frame "
                    "number for {s}".format(s=self))
        else:
            raise SegmentException(
                "Can't get last frame of {s} because it has no temporary "
                "file".format(s=self))
    
    def generate_frame(self, frame_number, output, width=2048, height=1536):
        """Create a JPEG file from the specified frame of the segment."""
        # Note: width and height are currently ignored for video
        # segments. This will need to change if there are multiple
        # video inputs of different dimensions.
        fn = "generate_frame"
        temp_frame = self.generate_temp_filename(output, suffix="jpg")
        if (frame_number == -1):
            frame_number = self.get_last_frame_number()
        command = FFmpegCommand(
            input_options=["-i", self._temp_frame_file],
            output_options=["-filter:v",
                            "select='eq(n, {n})'".format(n=frame_number),
                            "-frames:v", "1",
                            "-f", "image2",
                            "-map", "0:v",
                            temp_frame])
        globals.log.debug("{cls}.{fn}(): {cmd}".format(
            cls=self.__class__.__name__, fn=fn, cmd=command))
        if (command.run() == 0):
            self._temp_files_list.append(temp_frame)
            return temp_frame
        else:
            raise SegmentException(
                "Failed to create JPEG for frame {n} of "
                "{s}".format(n=frame_number, s=self))

class FrameSegment(VideoSegment):
    """A video segment derived from a single still frame."""
    _TYPE = "frame"
    
    def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0,
                 frame_number=0):
        super(FrameSegment, self).__init__(file, punch_in, punch_out,
                                           input_stream)
        self.frame_number = frame_number
        self._input_options = ["-loop", "1",
                               "-t", str(self.get_duration()),
                               "-i", self.input_file]
        self.__class__._input_files[file] = self._input_options[:4]
    
    def __repr__(self):
        return('<{c} {n}: file "{f}", in {i}, out {o}, frame number '
               '{fn}>'.format(c=self.__class__.__name__,
                             n=self.segment_number,
                             t=self._TYPE,
                             f=self.input_file,
                             i=self.punch_in,
                             o=self.punch_out,
                             fn=self.frame_number))
    
    def generate_temp_file(self, output, width=2048, height=1536):
        """Compile the segment from the original source file(s)."""
        fn = "generate_temp_file"
        self._temp_file = self.generate_temp_filename(output, suffix="jpg")
        command = ConvertCommand(
            input_options=["{f}[{n}]".format(
                f=self.input_file, n=self.frame_number)],
            output_options=["{f}".format(f=self._temp_file)],
            width=width, height=height)
        globals.log.debug("{cls}.{fn}(): {cmd}".format(
            cls=self.__class__.__name__, fn=fn, cmd=command))
        if (command.run() == 0):
            self._temp_files_list.append(self._temp_file)
            return self._temp_file
        else:
            raise SegmentException(
                "Failed to generate temporary file {f} for "
                "{s}".format(f=self._temp_file, s=self))
    
    def use_frame(self, frame):
        """Set the image to use for generating the frame video."""
        self.__class__._rename_input_file(self.input_file, frame)
        self.input_file = frame
        self._input_options = ["-loop", "1",
                               "-t", str(self.get_duration()),
                               "-i", self.input_file]
        self.__class__._input_files[frame] = self._input_options[:4]
        
    def input_stream_specifier(self):
        """Return the segment's ffmpeg stream input specifier."""
        return "[{n}:v]".format(
            n=self.__class__._input_files.keys().index(self.input_file))
        
    def output_stream_specifier(self):
        """Return the segment's ffmpeg audio stream output specifier."""
        return self.input_stream_specifier()
    
    def trim_filter(self):
        """Return an FFMPEG trim filter for this segment."""
        return ""

if (__name__ == "__main__"):
    pass

#!/usr/bin/env python3

from collections import OrderedDict
import errno
import itertools
import logging
import os
from pathlib import Path

import globals
from shell_command import (ConvertCommand, FFprobeCommand, FFmpegCommand)

class SegmentException(Exception):
    pass

class Segment(object):
    """A segment within the podcast.
    
    A segment has an input file, and a punch-in and punch-out
    point (both in seconds).
    """
    # Automatic segment number generator.
    _new_segment_num = itertools.count().next
    
    # Keep track of input files in the order they're loaded, so that we
    # can easily reference them by index in the ffmpeg command (i.e.,
    # first input file is, 0, etc.).
    _input_files = OrderedDict()
    
    # A string representing the type of the segment (e.g., "audio").
    # This is handy for generating temporary files and means that we
    # can implement this as a single method in the root class.
    _TYPE = ""
    
    # Which trim and setpts filters to use in ffmpeg complex filters.
    # As above, this lets us implement a single method in the root class.
    _TRIM = ""
    _SETPTS = ""
    
    @staticmethod
    def input_files():
        return Segment._input_files
    
    @staticmethod
    def _rename_input_file(old, new):
        tmp = OrderedDict()
        for f in Segment._input_files:
            if (f == old):
                tmp[new] = Segment._input_files[f]
            else:
                tmp[f] = Segment._input_files[f]
        Segment._input_files = tmp
    
    def __init__(self, file="", punch_in=0, punch_out=0, input_stream=0):
        self.segment_number = self.__class__._new_segment_num()
        self.input_file = file
        self.punch_in = punch_in
        self.punch_out = punch_out
        self.input_stream = input_stream
        self._temp_file = ""
        self._temp_suffix = "mov"
        # List of temporary files to delete when cleaning up.
        self._temp_files_list = []
        
        if (file not in self.__class__._input_files):
            self.__class__._input_files[file] = None
        
        self._input_options = ["-ss", str(self.punch_in.total_seconds()),
                               "-t", str(self.get_duration()),
                               "-i", self.input_file]
        self._output_options = []
            
    def __repr__(self):
        return('<{c} {n}: file "{f}", in {i}, out '
               '{o}>'.format(c=self.__class__.__name__,
                             n=self.segment_number,
                             t=self._TYPE,
                             f=self.input_file,
                             i=self.punch_in,
                             o=self.punch_out))
    
    def get_duration(self):
        """Return the duration of the segment in seconds."""
        return (self.punch_out - self.punch_in).total_seconds()
    
    def generate_temp_filename(self, output, suffix=None):
        """Generate a temporary filename for the segment."""
        if not suffix:
            suffix = self._temp_suffix
        return Path("temp_{t}_{o}_{n:03d}".format(
            t=self._TYPE, o=Path(output).stem,
            n=self.segment_number)).with_suffix(suffix)
    
    def generate_temp_file(self, output, width=0, height=0):
        """Compile the segment from the original source file(s)."""
        # Note: width and height are currently ignored for segments
        # in general. This may (or may not) need to change if there
        # are multiple inputs of different dimensions.
        fn = "generate_temp_file"
        self._temp_file = self.generate_temp_filename(output)
        command = FFmpegCommand(
            input_options=self._input_options + ["-codec", "copy"],
            output_options=self._output_options + [self._temp_file])
        globals.log.debug("{cls}.{fn}(): {cmd}".format(
            cls=self.__class__.__name__, fn=fn, cmd=command))
        if (command.run() == 0):
            self._temp_files_list.append(self._temp_file)
            return self._temp_file
        else:
            raise SegmentException(
                "Failed to generate temporary file {f} for "
                "{s}".format(f=self._temp_file, s=self))
    
    def temp_file(self):
        """Return the temporary file associated with the segment."""
        return self._temp_file
    
    def delete_temp_files(self):
        """Delete the temporary file(s) associated with the segment."""
        # Note: sometimes segments (especially frame segments) may
        # share the same temporary file. Just ignore the file not
        # found exception that occurs in these cases.
        for f in self._temp_files_list:
            try:
                os.remove(f)
            except OSError as e:
                if (e.errno != errno.ENOENT):
                    raise e
    
    def input_stream_specifier(self):
        """Return the segment's ffmpeg stream input specifier."""
        return "[{n}:{t}]".format(
            n=self.__class__._input_files.keys().index(self.input_file),
            t=self._TYPE[0] if self._TYPE else "")
        
    def output_stream_specifier(self):
        """Return the segment's ffmpeg audio stream output specifier."""
        return "[{t}{n}]".format(t=self._TYPE[0] if self._TYPE else "",
                                 n=self.segment_number)
    
    def trim_filter(self):
        """Return an FFMPEG trim filter for this segment."""
        return ("{inspec} "
                "{trim}=start={pi}:duration={po},{setpts}=PTS-STARTPTS "
                "{outspec}".format(
                    inspec=self.input_stream_specifier(),
                    trim=self._TRIM, setpts=self._SETPTS,
                    pi=self.punch_in.total_seconds(),
                    po=self.get_duration(),
                    outspec=self.output_stream_specifier()))

class AudioSegment(Segment):
    """A segment of an audio input stream."""
    _TYPE = "audio"
    _TRIM = "atrim"
    _SETPTS = "asetpts"

class VideoSegment(Segment):
    """A segment of a video input stream."""
    _TYPE = "video"
    _TRIM = "trim"
    _SETPTS = "setpts"

if (__name__ == "__main__"):
    pass

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