broken pipe from ffmpeg when transcoding

[jcaesar]

broken pipe from ffmpeg when transcoding

[anacrolix]

This error should occur when the device you're streaming abruptly rejects the stream. Most likely the format that ffmpeg is sending is not what the TV is expecting, or is not supported by the TV. Perhaps web is the wrong transcode target for your TV.

[jcaesar]

That was my first hypothesis, but I finally got some time to look around:

1. The error is output once per second many times over, seemingly indefinitely, while the TV displays a spinner.
2. This behavior only happens with webb and chromecast. With vp8, the TV immediately displays a "Unplayable file" message
3. I confirmed that I can stream files with dms (without -forceTranscode) that can also be streamed from other servers (minidlna/rygel)
4. I created a foo.dms.json containing {"Title":"Foo","Resources":[{"MimeType":"video/x-matroska","Command":"cat file-that-plays-without-transcoding.mkv"}]} and confirmed that it doesn't play (I get the same failed: signal: broken pipe but no spinner from the TV, just an immediate exit from the playback menu.
5. Looking at -logHeaders, it seems there are two subsequent requests, the second containing Range: bytes=7075-.

Could the range request pose a problem? [Edit:] Looking at the response, there's no Content-Range, so I'll make that my prime suspect.

[anacrolix]

Hm yes, I don't remember the specifics (I started this project nearly 12 years ago), but I doubt range requests are supported for on-the-fly transcodes if that is what it is doing. Range requests should work fine for static files.