| 1 | #!/usr/bin/env python3 |
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| 2 | # |
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| 3 | import sys, os |
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| 4 | import shutil |
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| 5 | import argparse |
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| 6 | import subprocess |
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| 7 | |
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| 8 | # prefer C-based ElementTree |
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| 9 | try: |
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| 10 | import xml.etree.cElementTree as etree |
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| 11 | except ImportError: |
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| 12 | import xml.etree.ElementTree as etree |
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| 13 | |
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| 14 | # check for matplot lib |
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| 15 | try: |
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| 16 | import numpy |
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| 17 | import matplotlib.pyplot as matplot |
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| 18 | except ImportError: |
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| 19 | sys.stderr.write("Error: Missing package 'python3-matplotlib'\n") |
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| 20 | sys.exit(1) |
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| 21 | |
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| 22 | # check for ffprobe in path |
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| 23 | if not shutil.which("mythffprobe"): |
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| 24 | sys.stderr.write("Error: Missing mythffprobe\n") |
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| 25 | sys.exit(1) |
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| 26 | |
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| 27 | # get list of supported matplotlib formats |
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| 28 | format_list = list( |
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| 29 | matplot.figure().canvas.get_supported_filetypes().keys()) |
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| 30 | matplot.close() # destroy test figure |
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| 31 | |
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| 32 | # parse command line arguments |
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| 33 | parser = argparse.ArgumentParser( |
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| 34 | description="Graph bitrate for audio/video stream") |
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| 35 | parser.add_argument('input', nargs='*', help="input file", metavar="INPUT") |
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| 36 | parser.add_argument('-o', '--output', help="output file") |
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| 37 | parser.add_argument('-f', '--format', help="output file format", |
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| 38 | choices=format_list) |
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| 39 | args = parser.parse_args() |
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| 40 | |
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| 41 | # select input file if no arg |
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| 42 | if not args.input: |
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| 43 | from tkinter.filedialog import askopenfilenames |
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| 44 | args.input = askopenfilenames() |
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| 45 | |
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| 46 | # check if format given w/o output file |
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| 47 | if args.format and not args.output: |
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| 48 | sys.stderr.write("Error: Output format requires output file\n") |
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| 49 | sys.exit(1) |
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| 50 | |
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| 51 | for filename in args.input: |
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| 52 | |
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| 53 | pkt_data = {} |
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| 54 | discontinuity = [] |
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| 55 | peak_discontinuity = 0 |
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| 56 | pkt_count = 0 |
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| 57 | prev_pts = 0 |
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| 58 | |
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| 59 | # get packet data for the selected stream |
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| 60 | with subprocess.Popen( |
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| 61 | ["mythffprobe", |
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| 62 | "-show_packets", |
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| 63 | "-print_format", "xml", |
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| 64 | filename |
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| 65 | ], |
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| 66 | stdout=subprocess.PIPE, |
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| 67 | stderr=subprocess.DEVNULL) as proc: |
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| 68 | |
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| 69 | # process xml elements as they close |
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| 70 | for event in etree.iterparse(proc.stdout): |
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| 71 | |
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| 72 | # skip non-packet elements |
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| 73 | node = event[1] |
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| 74 | if node.tag != 'packet': |
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| 75 | continue |
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| 76 | |
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| 77 | # count number of packets |
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| 78 | pkt_count += 1 |
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| 79 | |
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| 80 | # collect packet data |
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| 81 | pkt_type = node.get('codec_type') |
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| 82 | pkt_start = float(node.get('pts_time')) |
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| 83 | pkt_end = pkt_start + float(node.get('duration_time')) |
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| 84 | packet = (pkt_count, pkt_start, pkt_end) |
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| 85 | |
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| 86 | # create new packet list if new type |
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| 87 | if pkt_type not in pkt_data: |
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| 88 | pkt_data[pkt_type] = [] |
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| 89 | |
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| 90 | # append packet to list by type |
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| 91 | pkt_data[pkt_type].append(packet) |
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| 92 | |
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| 93 | # calculate pts jump |
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| 94 | pkt_discontinuity = pkt_start - prev_pts |
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| 95 | if abs(pkt_discontinuity) > abs(peak_discontinuity): |
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| 96 | peak_discontinuity = pkt_discontinuity |
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| 97 | prev_pts = pkt_start |
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| 98 | |
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| 99 | discontinuity.append((pkt_count, pkt_discontinuity)) |
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| 100 | |
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| 101 | # check if ffprobe was successful |
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| 102 | if pkt_count == 0: |
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| 103 | sys.stderr.write("Error: No packet data, failed to execute mythffprobe\n") |
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| 104 | sys.exit(1) |
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| 105 | |
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| 106 | # end packet subprocess |
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| 107 | |
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| 108 | # setup new figure |
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| 109 | matplot.figure() |
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| 110 | matplot.title("Packet Distribution of " + os.path.basename(filename)) |
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| 111 | matplot.xlabel("Packet Count") |
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| 112 | matplot.ylabel("PTS Time (sec)") |
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| 113 | matplot.grid(True) |
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| 114 | |
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| 115 | # map packet type to color |
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| 116 | pkt_type_color = { |
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| 117 | 'audio': 'red', |
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| 118 | 'video': 'blue' |
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| 119 | } |
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| 120 | |
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| 121 | for pkt_type in ['audio', 'video']: |
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| 122 | |
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| 123 | # skip packet type if missing |
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| 124 | if pkt_type not in pkt_data: |
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| 125 | continue |
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| 126 | |
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| 127 | # convert list of tuples to numpy 2d array |
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| 128 | pkt_list = pkt_data[pkt_type] |
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| 129 | pkt_array = numpy.array(pkt_list) |
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| 130 | |
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| 131 | # plot chart using gnuplot-like impulses |
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| 132 | matplot.vlines( |
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| 133 | pkt_array[:,0], pkt_array[:,1], pkt_array[:,2], |
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| 134 | color=pkt_type_color[pkt_type], |
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| 135 | label=pkt_type) |
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| 136 | |
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| 137 | # plot discontinuities |
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| 138 | array = numpy.array(discontinuity) |
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| 139 | matplot.plot( |
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| 140 | array[:,0], array[:,1], |
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| 141 | color='cyan', |
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| 142 | label='Discontinuity (Peak {:.2f}s)'.format(peak_discontinuity)) |
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| 143 | |
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| 144 | matplot.legend(loc='upper left') |
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| 145 | |
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| 146 | # render graph to file (if requested) or screen |
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| 147 | if args.output: |
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| 148 | matplot.savefig(args.output, format=args.format) |
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| 149 | else: |
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| 150 | matplot.show(block=False) |
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| 151 | |
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| 152 | matplot.show() |
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