fix: Windows环境下进度条因stdout阻塞迟迟未能显示

顺便重构一下`hevc_encode`，这样就“轻”多了。

.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Python Debugger: Current File with Arguments",
+            "type": "debugpy",
+            "request": "launch",
+            "program": "${file}",
+            "console": "integratedTerminal",
+            "args": "${command:pickArgs}"
+        }
+    ]
+}

cmps_hevc_crf18.py

@@ -46,70 +46,79 @@ def get_duration(file_path: Path):
         raise
 
 
-def read_progress(ostream_line, dur, pbar):
+def set_progress(line: str, dur, pbar):
-    if not ostream_line.startswith("out_time_ms="):
+    if not line.startswith("out_time_ms="):
         return
     try:
-        us = int(ostream_line.split('=')[1])
+        us = int(line.split('=')[1])
         if us < 0:
             return
-        secs = us / 1_000_000
+        current_sec = us / 1_000_000
-        if secs > dur * 1.1:  # Allow 10% overshoot
+        pbar.n = min(current_sec, dur)
-            pbar.n = dur
-        else:
-            pbar.n = secs
         pbar.refresh()
-    except (ValueError, OverflowError):
+    except (ValueError, IndexError, OverflowError):
-        pass
+        return
 
 
-def hevc_encode(infile: Path, outfile: Path, progress: bool = True):
+def start_ffmpeg(infile: Path, outfile: Path):
-    # too heavy bro.
-    dur = get_duration(infile)
     cmd = [
         "ffmpeg", "-y", "-i", str(infile),
-        "-progress", "pipe:1", "-nostats",
+        "-progress", "pipe:1", "-nostats", "-loglevel", "error",
         *COMPRESS_OPTIONS, str(outfile)
     ]
-    logger.debug(f"Duration: {dur:.2f} seconds")
+    return subprocess.Popen(
-    logger.debug(f"Command: {' '.join(cmd)}")
+        cmd,
-    proc = subprocess.Popen(
+        stdout=subprocess.PIPE,
-        cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
-        text=True, encoding='utf-8', bufsize=1)
+        bufsize=1,
-    progress = progress and is_tty()
+        text=True,
-    pbar = None if not progress else get_progress_bar(
+        encoding='utf-8')
-        total=dur, unit='s',
+
-        bar_format='{l_bar}{bar}| {n:.2f}/{total:.2f}({unit})')
+
-    try:
+def clean_on_failure(proc: subprocess.Popen, outfile: Path):
-        while True:
-            line = proc.stdout.readline()
-            if not line and proc.poll() is not None:
-                break
-            if not pbar:
-                continue
-            read_progress(line.strip(), dur, pbar)
-        proc.wait()
-        if proc.returncode != 0:
-            raise subprocess.CalledProcessError(proc.returncode, cmd)
-    except (
-        KeyboardInterrupt,
-        subprocess.CalledProcessError
-    ) as e:
     if proc.poll() is None:
         proc.kill()
         proc.wait()
-        logger.error(
-            f"Encoding failed with code {proc.returncode}:"
-            f" {e.__class__.__name__}")
     if outfile.exists():
         try:
             outfile.unlink()
         except OSError:
             pass
+
+
+def hevc_encode(infile: Path, outfile: Path, progress: bool = True):
+    dur = get_duration(infile)
+    logger.debug(f"Duration: {dur:.2f} seconds")
+    proc = start_ffmpeg(infile, outfile)
+    logger.debug(f"Command: {proc.args}")
+
+    pbar = get_progress_bar(
+        total=dur, unit='s',
+        bar_format='{l_bar}{bar}| {n:.2f}/{total:.2f}({unit})'
+    ) if progress and is_tty() else None
+
+    try:
+        for line in iter(proc.stdout.readline, ''):
+            set_progress(line.strip(), dur, pbar)
+            if proc.poll() is not None:
+                break
+
+        proc.wait()
+        if proc.returncode != 0:
+            raise subprocess.CalledProcessError(proc.returncode, "ffmpeg")
+    except (
+        KeyboardInterrupt,
+        subprocess.CalledProcessError
+    ) as e:
+        logger.error(
+            f"Encoding failed with code {proc.returncode}:"
+            f" {e.__class__.__name__}")
+        clean_on_failure(proc, outfile)
         raise
     finally:
         if pbar:
             pbar.close()
+        proc.stdout.close()
 
 
 def build_file_list(srcdir, extensions):