Av1an/VMAF/vmaf.py
2020-09-27 03:55:29 +03:00

151 lines
5 KiB
Python
Executable file

#! /bin/env python
import json
import shlex
import subprocess
import sys
from pathlib import Path
from subprocess import PIPE, STDOUT
import numpy as np
from math import log10
from matplotlib import pyplot as plt
from Av1an.bar import process_pipe
from Chunks.chunk import Chunk
import matplotlib
matplotlib.use('Agg')
def read_vmaf_json(file, percentile):
"""Reads vmaf file with vmaf scores in it and return N percentile score from it.
:return: N percentile score
:rtype: float
"""
with open(file, 'r') as f:
file = json.load(f)
vmafs = [x['metrics']['vmaf'] for x in file['frames']]
perc = round(np.percentile(vmafs, percentile), 2)
return perc
def call_vmaf(chunk: Chunk, encoded: Path, n_threads, model, res,
fl_path: Path = None, vmaf_filter=None, vmaf_rate=0):
cmd = ''
# settings model path
mod = f":model_path={model}" if model else ''
# limiting amount of threads for calculation
n_threads = f':n_threads={n_threads}' if n_threads else ''
if fl_path is None:
fl_path = chunk.fake_input_path.with_name(encoded.stem).with_suffix('.json')
fl = fl_path.as_posix()
filter = vmaf_filter + ',' if vmaf_filter else ''
# For vmaf calculation both source and encoded segment scaled to 1080
# Also it's required to use -r before both files of vmaf calculation to avoid errors
cmd_in = ('ffmpeg', '-loglevel', 'info', '-y', '-thread_queue_size', '1024', '-hide_banner',
'-r', '60', '-i', encoded.as_posix(), '-r', '60', '-i', '-')
filter_complex = ('-filter_complex',)
# Change framerate of comparison to framerate of probe
select_frames = f"select=not(mod(n\\,{vmaf_rate}))," if vmaf_rate != 0 else ''
distorted = f'[0:v]{select_frames}scale={res}:flags=bicubic:\
force_original_aspect_ratio=decrease,setpts=PTS-STARTPTS[distorted];'
ref = fr'[1:v]{select_frames}{filter}scale={res}:flags=bicubic:'\
'force_original_aspect_ratio=decrease,setpts=PTS-STARTPTS[ref];'
vmaf_filter = f"[distorted][ref]libvmaf=log_fmt='json':eof_action=endall:\
log_path={shlex.quote(fl)}{mod}{n_threads}"
cmd_out = ('-f', 'null', '-')
cmd = (*cmd_in, *filter_complex, distorted + ref + vmaf_filter, *cmd_out)
ffmpeg_gen_pipe = subprocess.Popen(chunk.ffmpeg_gen_cmd, stdout=PIPE, stderr=STDOUT)
pipe = subprocess.Popen(cmd, stdin=ffmpeg_gen_pipe.stdout,
stdout=PIPE, stderr=STDOUT, universal_newlines=True)
process_pipe(pipe)
return fl_path
def plot_vmaf(source: Path, encoded: Path, args, model, vmaf_res):
"""
Making VMAF plot after encode is done
"""
print('Calculating Vmaf...\r', end='')
fl_path = encoded.with_name(f'{encoded.stem}_vmaflog').with_suffix(".json")
# call_vmaf takes a chunk, so make a chunk of the entire source
ffmpeg_gen_cmd = ['ffmpeg', '-y', '-hide_banner', '-loglevel', 'error', '-i',
source.as_posix(), *args.pix_format, '-f', 'yuv4mpegpipe', '-']
input_chunk = Chunk(args.temp, 0, ffmpeg_gen_cmd, '', 0, 0)
scores = call_vmaf(input_chunk, encoded, 0, model, vmaf_res, fl_path=fl_path)
if not scores.exists():
print(f'Vmaf calculation failed for chunks:\n {source.name} {encoded.stem}')
sys.exit()
file_path = encoded.with_name(f'{encoded.stem}_plot').with_suffix('.png')
plot_vmaf_score_file(scores, file_path)
def plot_vmaf_score_file(scores: Path, plot_path: Path):
"""
Read vmaf json and plot VMAF values for each frame
"""
perc_1 = read_vmaf_json(scores, 1)
perc_25 = read_vmaf_json(scores, 25)
perc_75 = read_vmaf_json(scores, 75)
mean = read_vmaf_json(scores, 50)
with open(scores) as f:
file = json.load(f)
vmafs = [x['metrics']['vmaf'] for x in file['frames']]
plot_size = len(vmafs)
figure_width = 3 + round((4 * log10(plot_size)))
plt.figure(figsize=(figure_width, 5))
plt.plot([1, plot_size], [perc_1, perc_1], '-', color='red')
plt.annotate(f'1%: {perc_1}', xy=(0, perc_1), color='red')
plt.plot([1, plot_size], [perc_25, perc_25], ':', color='orange')
plt.annotate(f'25%: {perc_25}', xy=(0, perc_25), color='orange')
plt.plot([1, plot_size], [perc_75, perc_75], ':', color='green')
plt.annotate(f'75%: {perc_75}', xy=(0, perc_75), color='green')
plt.plot([1, plot_size], [mean, mean], ':', color='black')
plt.annotate(f'Mean: {mean}', xy=(0, mean), color='black')
for i in range(0, 100):
plt.axhline(i, color='grey', linewidth=0.4)
if i % 5 == 0:
plt.axhline(i, color='black', linewidth=0.6)
plt.plot(range(plot_size), vmafs,
label=f'Frames: {plot_size}\nMean:{mean}\n'
f'1%: {perc_1} \n25%: {perc_25} \n75%: {perc_75}', linewidth=0.7)
plt.ylabel('VMAF')
plt.legend(loc="lower right", markerscale=0, handlelength=0, fancybox=True, )
plt.ylim(int(perc_1), 100)
plt.tight_layout()
plt.margins(0)
# Save
plt.savefig(plot_path, dpi=250)