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131 lines
4.4 KiB
Python
131 lines
4.4 KiB
Python
from flask import (Flask, render_template, flash, redirect,
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url_for, request, send_file, abort)
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from flask_bootstrap import Bootstrap
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from flask_wtf import FlaskForm
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from wtforms import DateTimeField, IntegerField, SubmitField
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from wtforms.validators import InputRequired, NumberRange
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from datetime import datetime, timedelta
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from tempfile import mkstemp
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import os
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import random
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import re
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import subprocess
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from config import Config
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app = Flask(__name__)
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app.config.from_object(Config)
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Bootstrap(app)
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attachment_filenames = {}
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class DownloadForm(FlaskForm):
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start_time = DateTimeField('Start time',
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validators=[InputRequired()],
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format='%Y-%m-%d %H:%M')
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length = IntegerField('Length',
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validators=[
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InputRequired(),
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NumberRange(min=1, max=app.config['MAX_LENGTH'])])
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submit = SubmitField('Download')
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@app.route('/', methods=['GET', 'POST'])
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def download():
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form = DownloadForm()
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if request.method == 'GET':
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form.start_time.data = datetime.now().replace(minute=0, second=0) - timedelta(hours=1)
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form.length.data = 60
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elif form.validate_on_submit():
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try:
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output_filename, attachment_filename = prepare_download(form)
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attachment_filenames[output_filename] = attachment_filename
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flash('The download should start immediately.', 'success')
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return render_template('download.html', form=form, filename=output_filename)
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except ValueError as e:
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flash('Error preparing download: {}'.format(e), 'warning')
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else:
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flash('Error in form!', 'warning')
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return render_template('download.html', form=form)
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@app.route('/download_file/<filename>')
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def download_file(filename):
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"""Download an output file"""
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# Get attachment filename. This also makes sure that the user only downloads
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# (and removes) a file generated by us.
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try:
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attachment_filename = attachment_filenames.pop(filename)
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except KeyError:
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abort(404)
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fh = open(os.path.join(app.config['TMP_DIR'], filename), 'rb')
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os.remove(os.path.join(app.config['TMP_DIR'], filename))
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# XXX How to close fh?
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return send_file(fh, as_attachment=True,
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attachment_filename=attachment_filename)
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def prepare_download(form):
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"""Prepare a download given the user's request form"""
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def start_time_for_source_fn(fn):
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return datetime.strptime(fn, 'qfhi-%Y%m%d-%H%M.mp3')
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def length_for_source_fn(fn):
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size = os.stat(os.path.join(app.config['DATA_DIR'], fn)).st_size
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length = timedelta(minutes=size / (1000*app.config['KBITS']/8) / 60)
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return length
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# Get a sorted list of all source files with start time and length
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sources = []
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for fn in os.listdir(app.config['DATA_DIR']):
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try:
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start_time = start_time_for_source_fn(fn)
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length = length_for_source_fn(fn)
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sources.append({'fn': fn, 'start_time': start_time, 'length': length})
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except ValueError:
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pass
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sources = sorted(sources, key=lambda s: s['start_time'])
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# Only interested in the source files from the start file
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start_index = None
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for i, source in enumerate(sources):
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if source['start_time'] <= form.start_time.data < source['start_time'] + source['length']:
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start_index = i
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if start_index is None:
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raise ValueError('Could not find start file')
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sources = sources[start_index:]
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# Super lazy: Limit to 5 source files input
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sources = sources[:5]
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# Seek into the first file
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ss = (form.start_time.data - sources[0]['start_time']).total_seconds()
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# Let ffmpeg do the rest of the job
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_, output_filename = mkstemp(suffix='.mp3', dir=app.config['TMP_DIR'])
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output_filename = os.path.basename(output_filename)
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attachment_filename = '{}_{}.mp3'.format(form.start_time.data, form.length.data)
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c = ['ffmpeg', '-y']
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c += ['-ss', str(ss)]
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c += ['-i', 'concat:' + '|'.join([os.path.join(app.config['DATA_DIR'],
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source['fn']) for source in sources])]
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c += ['-codec', 'copy']
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c += ['-t', str(form.length.data * 60)]
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c += [os.path.join(app.config['TMP_DIR'], output_filename)]
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app.logger.debug(' '.join(c))
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subprocess.call(c)
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return output_filename, attachment_filename
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if __name__ == '__main__':
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app.run(debug=True)
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