feat: Expose live stream media info for the Stream Monitor UI#54
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Captures live ffmpeg progress (bitrate, fps, frame, speed) from each SharedTranscodingProcess's stderr by extending the line-buffer to split on \r as well as \n (ffmpeg writes its periodic stats line with a trailing \r so it overwrites in-place in a terminal — without the \r split they got buffered until the next newline arrived and we missed every update). On stream start we additionally fire-and-forget an ffprobe against the source URL so codec/container/resolution/audio get populated without delaying the start. The merged media_info dict is exposed in GET /streams alongside existing per-stream stats so the m3u-editor UI can render Dispatcharr-style badges. media_info is empty for plain HTTP-proxy streams since there's no live ffmpeg producer.
Running ffprobe against the source URL alongside ffmpeg doubled the upstream
connection count, which trips per-user concurrent-connection limits at IPTV
providers — the provider rejects the second connection (or both, looking like
a duplicate session) and ffmpeg dies seconds after starting. That broke
failover end-to-end: the old process was force-stopped on failover, the new
one would also die almost immediately, and the client connection timed out
before recovery.
ffmpeg already prints all the codec/container/resolution/audio info we need
in its own stderr at startup ("Input #0, FORMAT, from URL:" and "Stream #N:N:
Video|Audio: ..." lines). Parse those instead — zero extra connections, and
the data reflects what ffmpeg actually negotiated rather than what a separate
probe might see. Live progress (bitrate/fps/frame/speed) was already coming
from the periodic stats line, that path is unchanged.
…arted Two concurrent issues caused the freshly-started failover ffmpeg to die two seconds after it started, leaving the stream alive in name only (is_active true, no data flowing, media_info empty). 1. _try_update_failover_url awaited force_stop_stream before clearing stream_info.transcode_stream_key. While that await was in flight the client's streaming generator woke from failover_event, read the still-set key, and called get_or_create_shared_stream(reuse_stream_key=OLD_KEY, url=NEW_URL) — which detected url_changed, cleaned up the old process, and stood up a new SharedTranscodingProcess at the same key with the new URL. Clear the key first so concurrent readers see None and generate a fresh key from the new URL. 2. force_stop_stream took a reference to the old process, awaited per-client removal, then called _cleanup_local_process(stream_key) at the end. By the time that ran the dict could already hold the brand-new process the reconnecting client just installed at the same key, and we'd tear it down instead. Pop and capture up front; clean up the captured reference.
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This was referenced May 2, 2026
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Summary
Surfaces live ffmpeg metadata (resolution, codec, fps, audio, container, bitrate, speed) on the
/streams/activeresponse so the m3u-editor Stream Monitor can overlay live values on top of its stored ffprobe-derived badges.Implements the proxy half of m3ue/m3u-editor#1085. Editor companion: m3ue/m3u-editor#1089.
What changed
SharedTranscodingProcessnow carries amedia_infodict that's populated from ffmpeg's own stderr — no extra ffprobe pass against the upstream URL, so we don't double the connection count and trip per-user limits at IPTV providers.Input #0, FORMAT, from URL:→containerStream #0:N: Video|Audio: codec, ..., 1920x1080, 50 fps, ...→video_codec,resolution,audio_codec,audio_channelsframe= ... fps= ... bitrate=...kbits/s speed=...x→ liveframe,fps,bitrate_kbps,speedStreamManager.get_stats()looks up the linked process and includesmedia_infoin each stream entry. Plain HTTP-proxy streams (no transcoding) return{}so the editor falls back to its stored probe data for those.Bonus: failover race fix
While testing this end-to-end I caught a latent race in the failover path that was killing the freshly-started transcoder ~2-3s after a successful failover swap.
_try_update_failover_urlwas clearingtranscode_stream_keyafter awaitingforce_stop_stream. During that await, a client coroutine could wake, read the still-set old key, and re-insert a brand-newSharedTranscodingProcessat that same key. Thenforce_stop_stream's tail-end cleanup popped and killed the new process by key — taking down the failover stream the user was trying to recover.Fix is two parts:
stream_info.transcode_stream_key = Nonebefore awaiting cleanup, so concurrent reconnects can't latch onto the doomed key.force_stop_streamnow pops + captures the process reference at the top and tears down that captured reference, regardless of what's at the key when the await chain unwinds.Test plan
/streams/activeshows populatedmedia_info(resolution, codec, fps, bitrate)media_info: {}media_inforepopulates from the failover streamtranscode_stream_keymismatches