我想为x265.exe编写一个GUI，它提供了更好(更人性化(的实时进度。
以下是我用来捕获子流程输出的代码：
import subprocess
cmd = r'ping www.baidu.com -n 4'
popen = subprocess.Popen(cmd, stdout = subprocess.PIPE ,stderr=subprocess.STDOUT ,shell=True)
while True:
next_line = popen.stdout.readline()
if next_line == b'' and popen.poll() != None:
break
else:
print(next_line.decode('ascii').replace('rn','n') , end='')
它与"ping"完美结合。
然而，当我切换到"x265"命令时，事情就变为有线了。
例如，如果我在前面的代码中将字符串变量'cmd'替换为"x265 --y4m --crf 21 --output output.hevc input.y4m"。理论上，它应该在按时间顺序排列的行中给出以下输出：
y4m [info]: 1920x1080 fps 24000/1001 i420p10 frames 0 - 100 of 101
x265 [info]: Using preset ultrafast & tune none
raw [info]: output file: C:tempoutput.hevc
x265 [info]: Main 10 profile, Level-4 (Main tier)
x265 [info]: Thread pool created using 16 threads
x265 [info]: Slices : 1
x265 [info]: frame threads / pool features : 4 / wpp(34 rows)
x265 [info]: Coding QT: max CU size, min CU size : 32 / 16
x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra
x265 [info]: ME / range / subpel / merge : dia / 57 / 0 / 2
x265 [info]: Keyframe min / max / scenecut / bias: 23 / 250 / 0 / 5.00
x265 [info]: Lookahead / bframes / badapt : 5 / 3 / 0
x265 [info]: AQ: mode / str / qg-size / cu-tree : 1 / 0.0 / 32 / 1
x265 [info]: Rate Control / qCompress : CRF-21.0 / 0.60
x265 [info]: tools: strong-intra-smoothing lslices=6 deblock
[1.0%] 1/101 frames, 6.289 fps, 7217.8 kb/s
[25.7%] 26/101 frames, 59.23 fps, 299.23 kb/s
[45.5%] 46/101 frames, 66.76 fps, 322.81 kb/s
[69.3%] 70/101 frames, 73.30 fps, 224.53 kb/s
[93.1%] 94/101 frames, 77.05 fps, 173.67 kb/s
x265 [info]: frame I: 1, Avg QP:23.45 kb/s: 7098.44
x265 [info]: frame P: 25, Avg QP:25.71 kb/s: 311.24
x265 [info]: frame B: 75, Avg QP:28.33 kb/s: 23.89
x265 [info]: consecutive B-frames: 3.8% 0.0% 0.0% 96.2%
encoded 101 frames in 1.22s (82.58 fps), 165.06 kb/s, Avg QP:27.64
但事实是，中间部分的那些指示实时进度的输出块不会在每次更新时都被捕获。popen.stdout.readline()命令将被阻止，直到进度达到100%，然后全部输出。显然那不是我想要的。
(↓我指的是这个部分(
[1.0%] 1/101 frames, 6.289 fps, 7217.8 kb/s
[25.7%] 26/101 frames, 59.23 fps, 299.23 kb/s
[45.5%] 46/101 frames, 66.76 fps, 322.81 kb/s
[69.3%] 70/101 frames, 73.30 fps, 224.53 kb/s
[93.1%] 94/101 frames, 77.05 fps, 173.67 kb/s
有人能帮我弄清楚发生了什么，以及如何解决它以实现我的目标吗？
非常感谢。
我的猜测是，由于命令输出正在原地更新文本，因此末尾没有换行符，相反，输出只有一个回车符，用于将光标返回到同一行的开头并覆盖前一行。所以使用readline不会达到你想要的效果。您必须编写自己的自定义逻辑来读取输出并将输出拆分为行。
以下是我的实现
import re
import subprocess
cmd = r'ping www.baidu.com -n 4'
popen = subprocess.Popen(cmd, stdout = subprocess.PIPE ,stderr=subprocess.STDOUT ,shell=True)
read_chunk_size = 20
next_lines = ['']
while True:
# read the stdout upto read_chunk_size bytes
chunk = popen.stdout.read(read_chunk_size)
# checking if process has finished
if not chunk and popen.poll() != None:
break
# splitting the read string of charachters by either n, r or nr
split_chunk = re.split('n|r|nr', chunk.decode('utf-8'))
# combining the first of the split strings to the last of the strings
# which were read in the last iteration. since we are reading upto only
# a fixed length, we may get incomplete lines
next_lines = [next_lines[-1] + split_chunk[0]] + split_chunk[1:]
# iterate upto the second last item in next_lines, since the last item may
# still be incomplete which will be read in the next iteration
for line in next_lines[:-1]:
# read your lines here
print(line)