126 lines
4.5 KiB
Python
126 lines
4.5 KiB
Python
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#!/usr/bin/env python
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# Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
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#
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# Use of this source code is governed by a BSD-style license
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# that can be found in the LICENSE file in the root of the source
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# tree. An additional intellectual property rights grant can be found
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# in the file PATENTS. All contributing project authors may
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# be found in the AUTHORS file in the root of the source tree.
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import optparse
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import os
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import sys
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def _crop_one_frame(yuv_file, output_file, component_sizes):
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"""Crops one frame.
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This function crops one frame going through all the YUV planes and cropping
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respective amount of rows.
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Args:
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yuv_file(file): The opened (for binary reading) YUV file.
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output_file(file): The opened (for binary writing) file.
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component_sizes(list of 3 3-ples): The list contains the sizes for all the
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planes (Y, U, V) of the YUV file plus the crop_height scaled for every
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plane. The sizes equal width, height and crop_height for the Y plane,
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and are equal to width/2, height/2 and crop_height/2 for the U and V
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planes.
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Return:
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(bool): True if there are more frames to crop, False otherwise.
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"""
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for comp_width, comp_height, comp_crop_height in component_sizes:
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for row in range(comp_height):
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# Read the plane data for this row.
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yuv_plane = yuv_file.read(comp_width)
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# If the plane is empty, we have reached the end of the file.
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if yuv_plane == "":
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return False
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# Only write the plane data for the rows bigger than crop_height.
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if row >= comp_crop_height:
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output_file.write(yuv_plane)
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return True
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def crop_frames(yuv_file_name, output_file_name, width, height, crop_height):
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"""Crops rows of pixels from the top of the YUV frames.
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This function goes through all the frames in a video and crops the crop_height
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top pixel rows of every frame.
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Args:
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yuv_file_name(string): The name of the YUV file to be cropped.
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output_file_name(string): The name of the output file where the result will
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be written.
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width(int): The width of the original YUV file.
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height(int): The height of the original YUV file.
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crop_height(int): The height (the number of pixel rows) to be cropped from
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the frames.
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"""
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# Component sizes = [Y_sizes, U_sizes, V_sizes].
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component_sizes = [(width, height, crop_height),
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(width/2, height/2, crop_height/2),
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(width/2, height/2, crop_height/2)]
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yuv_file = open(yuv_file_name, 'rb')
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output_file = open(output_file_name, 'wb')
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data_left = True
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while data_left:
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data_left = _crop_one_frame(yuv_file, output_file, component_sizes)
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yuv_file.close()
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output_file.close()
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def _parse_args():
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"""Registers the command-line options."""
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usage = "usage: %prog [options]"
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parser = optparse.OptionParser(usage=usage)
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parser.add_option('--width', type='int',
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default=352,
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help=('Width of the YUV file\'s frames. '
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'Default: %default'))
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parser.add_option('--height', type='int', default=288,
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help=('Height of the YUV file\'s frames. '
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'Default: %default'))
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parser.add_option('--crop_height', type='int', default=32,
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help=('How much of the top of the YUV file to crop. '
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'Has to be module of 2. Default: %default'))
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parser.add_option('--yuv_file', type='string',
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help=('The YUV file to be cropped.'))
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parser.add_option('--output_file', type='string', default='output.yuv',
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help=('The output YUV file containing the cropped YUV. '
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'Default: %default'))
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options = parser.parse_args()[0]
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if not options.yuv_file:
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parser.error('yuv_file argument missing. Please specify input YUV file!')
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return options
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def _main():
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"""A tool to crop rows of pixels from the top part of a YUV file.
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A simple invocation will be:
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./yuv_cropper.py --width=640 --height=480 --crop_height=32
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--yuv_file=<path_and_name_of_yuv_file>
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--output_yuv=<path and name_of_output_file>
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"""
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options = _parse_args()
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if os.path.getsize(options.yuv_file) == 0:
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sys.stderr.write('Error: The YUV file you have passed has size 0. The '
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'produced output will also have size 0.\n')
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return -1
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crop_frames(options.yuv_file, options.output_file, options.width,
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options.height, options.crop_height)
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return 0
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if __name__ == '__main__':
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sys.exit(_main())
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