Repository: yt-dlp/yt-dlp
File: yt_dlp/extractor/mixlr.py (Python)

Code before:
        for item in included:
            if item.get('type') == 'broadcast':
                broadcast_data = item.get('attributes', {})
            elif item.get('type') == 'event' and item.get('id') == event_id:
                event_data = item.get('attributes', {})

            if broadcast_data and event_data:
                break

        if not broadcast_data or not broadcast_data.get('live', False):
            self.raise_no_formats('No active broadcast found', expected=True)
        if not event_data:
            self.raise_no_formats('No event data found', expected=True)

        streaming_url = broadcast_data.get('progressive_stream_url')
        title = event_data.get('title') or f'Mixlr broadcast by {username}'
        description = event_data.get('description') or broadcast_data.get('description') or ''

        formats = []
        if streaming_url:
            formats.append({
                'url': streaming_url,
                'format_id': 'http',
                'ext': 'mp3',
                'vcodec': 'none',
            })

        if not formats:
            self.raise_no_formats('No formats found', expected=True)

        return {
            'id': event_id,
            'title': title,
            'description': description,
            'uploader': username,
            'uploader_id': user_data.get('id'),
            'uploader_url': f'https://{username}.mixlr.com',
            'thumbnail': user_data.get('avatar_full_url') or user_data.get('avatar_url'),
            'is_live': broadcast_data.get('live', True),
            'formats': formats,
        }


Review comment (suggestion):
Sadly the stream is not always mp3, but for some streams also aac and we need make a HEADRequest. The server sometimes randomly also returns `octet-stream` as the content type so I added some logic to deal with that
```suggestion
        formats = []
        format_url = traverse_obj(
            broadcast_info, ('included', 0, 'attributes', 'progressive_stream_url', {url_or_none}))
        if format_url:
            urlh = self._request_webpage(
                HEADRequest(format_url), event_id, fatal=False, note='Checking stream')
            ext = urlhandle_detect_ext(urlh)
            if ext == 'octet-stream':
                self.report_warning(
                    'The server did not return a valid file extension for the stream URL, '
                    'defaulting to "mp3". Please ensure that the downloaded audio is actually mp3.')
                ext = 'mp3'
            if urlh and urlh.status == 200:
                formats.append({
                    'url': format_url,
                    'ext': urlhandle_detect_ext(urlh),
                    'vcodec': 'none',
                })
```

Code after:
            'thumbnail': r're:https://imagecdn\.mixlr\.com/cdn-cgi/image/[^/?#]+/c48727a59f690b87a55d47d123ba0d6d.jpg',
            'timestamp': 1752354007,
            'upload_date': '20250712',
            'release_timestamp': 1752354000,
            'release_date': '20250712',
            'live_status': 'is_live',
        },
    }, {
        'url': 'https://www.brcountdown.mixlr.com/events/4395480',
        'only_matching': True,
    }]

    def _real_extract(self, url):
        username, event_id = self._match_valid_url(url).group('username', 'id')

        broadcast_info = self._download_json(
            f'https://api.mixlr.com/v3/channels/{username}/events/{event_id}', event_id)

        formats = []
        format_url = traverse_obj(
            broadcast_info, ('included', 0, 'attributes', 'progressive_stream_url', {url_or_none}))
        if format_url:
            urlh = self._request_webpage(
                HEADRequest(format_url), event_id, fatal=False, note='Checking stream')
            if urlh and urlh.status == 200:
                ext = urlhandle_detect_ext(urlh)
                if ext == 'octet-stream':
                    self.report_warning(
                        'The server did not return a valid file extension for the stream URL. '
                        'Assuming an mp3 stream; postprocessing may fail if this is incorrect')
                    ext = 'mp3'
                formats.append({
                    'url': format_url,
                    'ext': ext,
                    'vcodec': 'none',
                })

        release_timestamp = traverse_obj(
            broadcast_info, ('data', 'attributes', 'starts_at', {str}))
        if not formats and release_timestamp:
            self.raise_no_formats(f'This event will start at {release_timestamp}', expected=True)

        return {
            'id': event_id,
            'uploader': username,
            'formats': formats,
            'release_timestamp': parse_iso8601(release_timestamp),
            **traverse_obj(broadcast_info, ('included', 0, 'attributes', {
                'title': ('title', {str}),
                'timestamp': ('started_at', {parse_iso8601}),
                'concurrent_view_count': ('concurrent_view_count', {int_or_none}),