Tell user to install ffmpeg if missing (#117)

Tell user to install ffmpeg if missing

corrscope.spec

@@ -8,11 +8,13 @@ from PyInstaller.building.datastruct import TOC
 block_cipher = None
 
 
-dir = "corrscope/gui"
-includes = glob.glob("corrscope/gui/*.ui")
-assert includes
+def keep(dir, wildcard):
+    includes = glob.glob(f"{dir}/{wildcard}")
+    assert includes
+    return [(include, dir) for include in includes]
 
-datas = [(include, dir) for include in includes]
+
+datas = keep("corrscope/gui", "*.ui") + keep("corrscope/path", "*")
 
 a = Analysis(
     ["corrscope\\__main__.py"],

corrscope/cli.py

@@ -1,4 +1,5 @@
 import datetime
+import sys
 from itertools import count
 from pathlib import Path
 from typing import Optional, List, Tuple, Union, Iterator
@@ -8,6 +9,7 @@ import click
 from corrscope import __version__
 from corrscope.channel import ChannelConfig
 from corrscope.config import yaml
+from corrscope.ffmpeg_path import MissingFFmpegError
 from corrscope.outputs import IOutputConfig, FFplayOutputConfig, FFmpegOutputConfig
 from corrscope.corrscope import default_config, CorrScope, Config, Arguments
 
@@ -211,7 +213,11 @@ def main(
                 profile_dump_name = get_profile_dump_name(first_song_name)
                 cProfile.runctx('command()', globals(), locals(), profile_dump_name)
             else:
-                command()
+                try:
+                    command()
+                except MissingFFmpegError as e:
+                    # Tell user how to install ffmpeg (__str__).
+                    print(e, file=sys.stderr)
 
 
 def get_profile_dump_name(prefix: str) -> str:

corrscope/ffmpeg_path.py

@@ -0,0 +1,50 @@
+import os
+import platform
+import sys
+from pathlib import Path
+
+from corrscope.config import CorrError
+
+# Add app-specific ffmpeg path.
+
+path_dir = str(Path(__file__).parent / "path")
+os.environ["PATH"] += os.pathsep + path_dir
+# Editing sys.path doesn't work.
+# https://bugs.python.org/issue8557 is relevant but may be outdated.
+
+
+# Unused
+# def ffmpeg_exists():
+#     return shutil.which("ffmpeg") is not None
+
+
+def get_ffmpeg_url() -> str:
+    # is_python_64 = sys.maxsize > 2 ** 32
+    is_os_64 = platform.machine().endswith("64")
+
+    def url(os_ver):
+        return f"https://ffmpeg.zeranoe.com/builds/{os_ver}/shared/ffmpeg-latest-{os_ver}-shared.zip"
+
+    if sys.platform == "win32" and is_os_64:
+        return url("win64")
+    elif sys.platform == "win32" and not is_os_64:
+        return url("win32")
+    elif sys.platform == "darwin" and is_os_64:
+        return url("macos64")
+    else:
+        return ""
+
+
+class MissingFFmpegError(CorrError):
+    ffmpeg_url = get_ffmpeg_url()
+    can_download = bool(ffmpeg_url)
+
+    message = f'FFmpeg must be in PATH or "{path_dir}" in order to use corrscope.\n'
+
+    if can_download:
+        message += f"Download ffmpeg from {ffmpeg_url}."
+    else:
+        message += "Cannot download FFmpeg for your platform."
+
+    def __str__(self):
+        return self.message

corrscope/gui/__init__.py

@@ -15,8 +15,10 @@ from PyQt5.QtWidgets import QShortcut
 
 from corrscope import __version__  # variable
 from corrscope import cli  # module wtf?
+from corrscope import ffmpeg_path
 from corrscope.channel import ChannelConfig
 from corrscope.config import CorrError, copy_config, yaml
+from corrscope.corrscope import CorrScope, Config, Arguments, default_config
 from corrscope.gui.data_bind import (
     PresentationModel,
     map_gui,
@@ -32,7 +34,6 @@ from corrscope.gui.util import (
     TracebackDialog,
 )
 from corrscope.outputs import IOutputConfig, FFplayOutputConfig, FFmpegOutputConfig
-from corrscope.corrscope import CorrScope, Config, Arguments, default_config
 from corrscope.triggers import CorrelationTriggerConfig, ITriggerConfig
 from corrscope.util import obj_name
 
@@ -336,15 +337,19 @@ class MainWindow(qw.QMainWindow):
 
         cfg = copy_config(self.model.cfg)
         t = self.corr_thread.obj = CorrThread(cfg, arg)
-        t.error.connect(self.on_play_thread_error)
         t.finished.connect(self.on_play_thread_finished)
+        t.error.connect(self.on_play_thread_error)
+        t.ffmpeg_missing.connect(self.on_play_thread_ffmpeg_missing)
         t.start()
 
+    def on_play_thread_finished(self):
+        self.corr_thread.set(None)
+
     def on_play_thread_error(self, stack_trace: str):
         TracebackDialog(self).showMessage(stack_trace)
 
-    def on_play_thread_finished(self):
-        self.corr_thread.set(None)
+    def on_play_thread_ffmpeg_missing(self):
+        DownloadFFmpegActivity(self)
 
     def _get_args(self, outputs: List[IOutputConfig]):
         arg = Arguments(cfg_dir=self.cfg_dir, outputs=outputs)
@@ -401,14 +406,24 @@ class CorrThread(qc.QThread):
         arg = self.arg
         try:
             CorrScope(cfg, arg).play()
-        except Exception:
+
+        except ffmpeg_path.MissingFFmpegError:
             arg.on_end()
-            stack_trace = traceback.format_exc()
+            self.ffmpeg_missing.emit()
+
+        except Exception as e:
+            arg.on_end()
+            if isinstance(e, CorrError):
+                stack_trace = traceback.format_exc(limit=0)
+            else:
+                stack_trace = traceback.format_exc()
             self.error.emit(stack_trace)
+
         else:
             arg.on_end()
 
     error = qc.pyqtSignal(str)
+    ffmpeg_missing = qc.pyqtSignal()
 
 
 class CorrProgressDialog(qw.QProgressDialog):
@@ -626,7 +641,6 @@ class ChannelModel(qc.QAbstractTableModel):
         Column("trigger_width", int, None, "Trigger Width ×"),
         Column("render_width", int, None, "Render Width ×"),
         Column("line_color", str, None, "Line Color"),
-        # TODO move from table view to sidebar QDataWidgetMapper?
         Column("trigger__edge_strength", float, None),
         Column("trigger__responsiveness", float, None),
         Column("trigger__buffer_falloff", float, None),
@@ -799,3 +813,32 @@ class ChannelModel(qc.QAbstractTableModel):
 
 
 nope = qc.QVariant()
+
+
+class DownloadFFmpegActivity:
+    title = "Missing FFmpeg"
+
+    ffmpeg_url = ffmpeg_path.get_ffmpeg_url()
+    can_download = bool(ffmpeg_url)
+
+    path_uri = qc.QUrl.fromLocalFile(ffmpeg_path.path_dir).toString()
+
+    required = (
+        f"FFmpeg must be in PATH or "
+        f'<a href="{path_uri}">corrscope folder</a> in order to use corrscope.<br>'
+    )
+
+    ffmpeg_template = required + (
+        f'Download ffmpeg from <a href="{ffmpeg_url}">{ffmpeg_url}</a>.'
+    )
+    fail_template = required + "Cannot download FFmpeg for your platform."
+
+    def __init__(self, window: qw.QWidget):
+        """Prompt the user to download and install ffmpeg."""
+        Msg = qw.QMessageBox
+
+        if not self.can_download:
+            Msg.information(window, self.title, self.fail_template, Msg.Ok)
+            return
+
+        Msg.information(window, self.title, self.ffmpeg_template, Msg.Ok)

corrscope/outputs.py

@@ -1,12 +1,13 @@
-# https://ffmpeg.org/ffplay.html
-import numpy as np
 import shlex
 import subprocess
 from abc import ABC, abstractmethod
 from os.path import abspath
 from typing import TYPE_CHECKING, Type, List, Union, Optional
 
+import numpy as np
+
 from corrscope.config import register_config
+from corrscope.ffmpeg_path import MissingFFmpegError
 
 if TYPE_CHECKING:
     from corrscope.corrscope import Config
@@ -95,12 +96,16 @@ class _FFmpegProcess:
             self.templates.append(cfg.audio_template)  # audio
 
     def popen(self, extra_args, bufsize, **kwargs) -> subprocess.Popen:
-        return subprocess.Popen(
-            self._generate_args() + extra_args,
-            stdin=subprocess.PIPE,
-            bufsize=bufsize,
-            **kwargs,
-        )
+        """Raises FileNotFoundError if FFmpeg missing"""
+        try:
+            args = self._generate_args() + extra_args
+            return subprocess.Popen(
+                args, stdin=subprocess.PIPE, bufsize=bufsize, **kwargs
+            )
+        except FileNotFoundError as e:
+            raise MissingFFmpegError(
+                # FIXME REMOVE f'Class {obj_name(self)}: program {args[0]} is missing'
+            )
 
     def _generate_args(self) -> List[str]:
         return [arg for template in self.templates for arg in shlex.split(template)]

corrscope/path/.gitignore

@@ -0,0 +1,3 @@
+*
+!*.txt
+!.gitignore