URL import fails with Failed ('total_bytes') when yt-dlp progress hook has no total_bytes

Description

Buzz 1.4.6 development build fails when importing a URL from SVT Play (Swedish public broadcaster).

The URL is successfully recognized by yt-dlp and the DASH stream starts downloading, but Buzz immediately changes the task status to:

Failed ('total_bytes')

The same URL downloads successfully with standalone yt-dlp 2026.08.19, and the resulting local .m4a file can then be transcribed successfully in Buzz.

Environment

• Buzz: 1.4.6 development build
• OS: Windows 11 x64, build 26200
• yt-dlp: 2026.08.19
• FFmpeg: N-125875-g5d4d3bdc61-20260731
• Model used in Buzz: OpenAI Whisper Large-v3

URL

https://www.svtplay.se/video/eJyyYk4/rapport/igar-19-30?video=visa&position=50

Steps to reproduce

1. Start Buzz 1.4.6.
2. Add a transcription using URL import.
3. Enter the SVT Play URL above.
4. Select Transcribe and start the task.

Actual result

Buzz successfully extracts the SVT metadata and selects the DASH stream, but fails as soon as downloading starts.

Buzz displays:

Failed ('total_bytes')

Relevant log output:

[svt:play] Extracting URL: https://www.svtplay.se/video/eJyyYk4/rapport/igar-19-30?video=visa&position=50
[svt:play] eJyyYk4: Downloading webpage
[svt:play] 82ddAPa: Downloading JSON metadata
[svt:play] 82ddAPa: Downloading MPD manifest
[svt:play] 82ddAPa: Downloading m3u8 information
[info] 82ddAPa: Downloading 1 format(s): dash-lb-full-2
[dashsegments] Total fragments: 236
[download] Destination: ...
[download] 0.4% ...