From 1caef9097bc25f0fa33416e17c75ffab32323ba3 Mon Sep 17 00:00:00 2001
From: blank X <theblankx@protonmail.com>
Date: Mon, 2 Nov 2020 13:12:11 +0700
Subject: [PATCH] Use ffprobe to try to get file extension

---
 redditbot.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/redditbot.py b/redditbot.py
index 126ea88..b3484df 100644
--- a/redditbot.py
+++ b/redditbot.py
@@ -230,6 +230,22 @@ async def main():
         proc = await asyncio.create_subprocess_exec('file', '--brief', '--extension', filename, stdout=asyncio.subprocess.PIPE)
         stdout, _ = await proc.communicate()
         ext = stdout.decode().strip().split('/', maxsplit=1)[0]
+        if not ext or ext == '???':
+            ffprobe_exists = any(True for i in os.environ.get('PATH', '').split(':') if os.path.exists(os.path.join(i, 'ffprobe')))
+            if ffprobe_exists:
+                proc = await asyncio.create_subprocess_exec('ffprobe', '-print_format', 'json', '-show_format', filename, stdout=asyncio.subprocess.PIPE)
+                stdout, _ = await proc.communicate()
+                format = json.loads(stdout).get('format')
+                if format:
+                    format_name = format.get('format_name')
+                    if format_name:
+                        proc = await asyncio.create_subprocess_exec('ffprobe', '-h', f'demuxer={format_name}', stdout=asyncio.subprocess.PIPE)
+                        stdout, _ = await proc.communicate()
+                        text = stdout.decode().split('\n', 2)
+                        if len(text) > 1:
+                            text = text[1].strip().rstrip('.')
+                            if text.startswith('Common extensions: '):
+                                ext = text[19:].split(',', 1)[0]
         if not ext or ext == '???':
             mimetype = await _get_file_mimetype(filename)
             ext = mimetypes.guess_extension(mimetype) or '.bin'