Files
jellytau/src-tauri/src/player/session.rs
T
dtourolle 109700b949 feat(playback): let Rust decide what stream to play, and say so
Playing a video meant asking the server to re-encode it, always. That
decision was made nowhere and written down nowhere, so whoever needed it
re-derived it downstream — the player worked out whether it had been handed
a playlist by looking for ".m3u8" in the URL, in two places. A viewer paid
for a transcode of a file their device could have played untouched, and the
app could not tell them which it was.

One negotiation now produces one self-describing StreamSelection — direct
play, remux or transcode; over a playlist, a plain HTTP file, or a local one
— and every renderer consumes that same answer.

Measured against the development server (Jellyfin 10.11.5), 400 items
sampled for codec mix and 40 put through a real PlaybackInfo negotiation
per profile:

  Linux / WebKitGTK (h264 only, 2ch)          3/40 —  7% direct play
  Android / ExoPlayer (hevc, ac3/eac3, 6ch)  34/40 — 85% direct play

The library is ~80% hevc, which is why the two diverge so hard. The payoff
is overwhelmingly Android, where 85% of plays were starting a transcode
nobody needed. Linux stays near 7% until libmpv decodes the picture — the
h264-only profile is a WebKitGTK constraint, not a JellyTau choice.

DR-219  StreamSelection: url + tagged Transport (hls/progressive/localFile)
        + PlaybackKind (directPlay/directStream/transcode) + the negotiated
        rendition + this source's ladder + a needs_transcoding flag derived
        in Rust so the rule is answered once. Both enums are serde-tagged
        so the frontend matches a discriminant, not a substring. The paths
        that never negotiate get the same shape from Rust rather than
        assembling one — media_local_selection for a downloaded file,
        LiveStreamInfo.transport for a live channel — so there is no second
        place where a transport is decided.

DR-220  The ceiling becomes two levels: a durable device default (Settings,
        persisted) and a per-playback override the in-player picker sets.
        The picker had called itself a "this film, this connection" control
        since it was written but wrote the process-wide default, so dropping
        one awkward film to 2 Mbps silently capped every video played
        afterwards for the rest of the process, with Settings still showing
        the old value. The override is cleared whenever playback moves to a
        new item, which stops it surviving into an autoplayed next episode.
        effective_streaming_quality() is the single resolution point.

DR-221  The quality picker is filled from what this media source can offer.
        Rust marks a rung exceeds_source when its ceiling is at or above the
        source's own bitrate — such a rung is another way to spell Original
        — and the frontend does not draw those. Original is never marked; a
        source whose bitrate the server does not report marks nothing, which
        keeps every rung offered.

DR-222  Direct play and direct stream are negotiated, with two client-side
        overrides on top because the server's answer is right about the file
        and wrong about what this app will do with it: undecodable audio
        (Jellyfin 10.11.5 honours a DirectPlayProfile's container and video
        codec but ignores its audio codec, so it offers direct play for an
        E-AC-3 track the webview renders in silence) and a viewer-pinned
        audio track the file does not default to. A direct stream is a remux
        and is deliberately not counted as transcoding.

DR-223  Dropped on measurement, not deferred. A master playlist from this
        server carries exactly one EXT-X-STREAM-INF: Jellyfin builds it from
        the single rendition the request asked for rather than publishing a
        ladder. So there is no adaptation for hls.js to be preserving and
        none mpv would lose — the claim that there was, in
        playback-backend-unification.md, does not hold. Recorded rather than
        deleted because it is a measurement: a server that does publish a
        ladder would change the answer.

DR-224  Every backend consumes the same selection. The queue item carries
        the transport, so player_seek_video picks its seek strategy from the
        backend's decision instead of the last stream_url.contains(".m3u8")
        in the codebase. Items queued by a path that never negotiated carry
        None and fall back to needs_transcoding, which is exact rather than
        a guess because every transcode this app requests is HLS (DR-140).

The frontend loader decision moves to streamTransport.ts so it can be
tested: the two cases that pin it are the ones that failed against the old
implementation — a progressive stream whose URL contains ".m3u8" must not
get an HLS loader, and an HLS stream whose URL contains none must.

Also verified the URL the direct-play branch builds actually serves playable
bytes: 206, video/mp4, valid ISO-BMFF, and a mid-file range works, so
seeking a direct play works.

The spec is folded into docs/architecture/{01,02,03} and deleted, per the
rule that docs/specs holds only work that has not shipped. DR-121 leaves
read-through-media-cache.md with a pointer; that spec keeps its capture half.

Not verified: real playback on a device. Direct play changes what actually
gets played, and neither fixtures nor curl prove the WebKitGTK and ExoPlayer
paths render it.
2026-08-22 13:45:03 +02:00

385 lines
12 KiB
Rust

use super::media::MediaItem;
/**
* Media Session Management
*
* Tracks high-level playback context (Audio/Movie/TvShow/Idle) that persists
* beyond individual playback states. Enables persistent UI (miniplayer) and
* proper transitions between content types.
*
* See docs/architecture/01-rust-backend.md for the state machine diagram.
*/
use log::info;
use serde::{Deserialize, Serialize};
/// Media session type tracking the high-level playback context
#[derive(specta::Type, Debug, Clone, Serialize, Deserialize, PartialEq)]
#[serde(tag = "type", rename_all = "snake_case")]
pub enum MediaSessionType {
/// No active session - browsing library
Idle,
/// Audio playback session (music, audiobooks, podcasts)
/// Persists until explicitly dismissed
Audio {
/// Last/current track being played
last_item: Option<MediaItem>,
/// True = playing/paused, False = stopped/ended
is_active: bool,
},
/// Movie playback (single video, auto-dismiss on end)
Movie {
/// Currently loaded movie
item: MediaItem,
/// True = playing/paused, False = ended
is_active: bool,
},
/// TV show playback (supports next episode auto-advance)
TvShow {
/// Currently loaded episode
item: MediaItem,
/// Series ID for fetching next episodes
series_id: String,
/// True = playing/paused, False = ended
is_active: bool,
},
}
impl MediaSessionType {
/// Check if this is an active session (any type except Idle)
#[allow(dead_code)]
pub fn is_active_session(&self) -> bool {
!matches!(self, MediaSessionType::Idle)
}
/// Check if playback is currently active within the session
#[allow(dead_code)]
pub fn is_playing_or_paused(&self) -> bool {
match self {
MediaSessionType::Audio { is_active, .. } => *is_active,
MediaSessionType::Movie { is_active, .. } => *is_active,
MediaSessionType::TvShow { is_active, .. } => *is_active,
MediaSessionType::Idle => false,
}
}
/// Get the current media item if any
#[allow(dead_code)]
pub fn current_item(&self) -> Option<&MediaItem> {
match self {
MediaSessionType::Audio { last_item, .. } => last_item.as_ref(),
MediaSessionType::Movie { item, .. } => Some(item),
MediaSessionType::TvShow { item, .. } => Some(item),
MediaSessionType::Idle => None,
}
}
}
/// Manages media session state transitions
pub struct MediaSessionManager {
current: MediaSessionType,
}
#[allow(dead_code)]
impl MediaSessionManager {
pub fn new() -> Self {
Self {
current: MediaSessionType::Idle,
}
}
/// Get the current session state
pub fn current(&self) -> &MediaSessionType {
&self.current
}
/// Start an audio session with a queue
/// Transitions: Idle → Audio(active), Any → Audio(active)
pub fn start_audio_session(&mut self, first_item: MediaItem) {
info!(
"[MediaSession] Starting audio session: {}",
first_item.title
);
self.current = MediaSessionType::Audio {
last_item: Some(first_item),
is_active: true,
};
}
/// Update audio session with new track (during playback)
pub fn update_audio_track(&mut self, item: MediaItem) {
if let MediaSessionType::Audio {
last_item,
is_active,
} = &mut self.current
{
info!("[MediaSession] Updating audio track: {}", item.title);
*last_item = Some(item);
*is_active = true;
}
}
/// Mark audio session as inactive (playback ended, queue finished)
/// Session persists for resume
pub fn audio_session_inactive(&mut self) {
if let MediaSessionType::Audio { is_active, .. } = &mut self.current {
info!("[MediaSession] Audio session now inactive (queue ended)");
*is_active = false;
}
}
/// Resume audio session
pub fn resume_audio_session(&mut self) {
if let MediaSessionType::Audio { is_active, .. } = &mut self.current {
info!("[MediaSession] Resuming audio session");
*is_active = true;
}
}
/// Start a movie session
/// Transitions: Any → Movie(active)
pub fn start_movie_session(&mut self, item: MediaItem) {
info!("[MediaSession] Starting movie session: {}", item.title);
self.current = MediaSessionType::Movie {
item,
is_active: true,
};
}
/// Mark movie session as inactive (playback ended)
/// Movie sessions auto-dismiss to Idle
pub fn movie_session_ended(&mut self) {
if matches!(self.current, MediaSessionType::Movie { .. }) {
info!("[MediaSession] Movie ended, transitioning to Idle");
self.current = MediaSessionType::Idle;
}
}
/// Start a TV show session
/// Transitions: Any → TvShow(active)
pub fn start_tv_session(&mut self, item: MediaItem, series_id: String) {
info!("[MediaSession] Starting TV show session: {}", item.title);
self.current = MediaSessionType::TvShow {
item,
series_id,
is_active: true,
};
}
/// Mark TV show session as inactive (episode ended, awaiting next)
pub fn tv_session_episode_ended(&mut self) {
if let MediaSessionType::TvShow { is_active, .. } = &mut self.current {
info!("[MediaSession] Episode ended, awaiting next episode");
*is_active = false;
}
}
/// Advance to next episode in TV session
pub fn tv_session_next_episode(&mut self, next_item: MediaItem) {
if let MediaSessionType::TvShow {
item, is_active, ..
} = &mut self.current
{
info!(
"[MediaSession] Advancing to next episode: {}",
next_item.title
);
*item = next_item;
*is_active = true;
}
}
/// End TV show session (series complete or user dismissed)
pub fn tv_session_ended(&mut self) {
if matches!(self.current, MediaSessionType::TvShow { .. }) {
info!("[MediaSession] TV show session ended, transitioning to Idle");
self.current = MediaSessionType::Idle;
}
}
/// Dismiss/clear current session (user action)
/// Transitions: Any → Idle
pub fn dismiss(&mut self) {
info!("[MediaSession] Dismissing session: {:?}", self.current);
self.current = MediaSessionType::Idle;
}
/// Check if we should show miniplayer
pub fn should_show_miniplayer(&self) -> bool {
matches!(self.current, MediaSessionType::Audio { .. })
}
/// Check if we should show video player
pub fn should_show_video_player(&self) -> bool {
matches!(
self.current,
MediaSessionType::Movie { .. } | MediaSessionType::TvShow { .. }
)
}
}
impl Default for MediaSessionManager {
fn default() -> Self {
Self::new()
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::player::media::MediaSource;
fn create_test_audio_item(title: &str) -> MediaItem {
MediaItem {
// Audio and direct-URL items never negotiate a transport.
transport: None,
id: title.to_string(),
title: title.to_string(),
name: Some(title.to_string()),
artist: Some("Test Artist".to_string()),
album: Some("Test Album".to_string()),
album_name: Some("Test Album".to_string()),
album_id: None,
artist_items: None,
artists: Some(vec!["Test Artist".to_string()]),
primary_image_tag: None,
image_id: None,
item_type: Some("Audio".to_string()),
playlist_id: None,
duration: Some(180.0),
artwork_url: None,
media_type: crate::player::media::MediaType::Audio,
source: MediaSource::DirectUrl {
url: "http://example.com/audio.mp3".to_string(),
},
video_codec: None,
needs_transcoding: false,
video_width: None,
video_height: None,
subtitles: vec![],
series_id: None,
server_id: None,
}
}
fn create_test_movie_item(title: &str) -> MediaItem {
MediaItem {
// Audio and direct-URL items never negotiate a transport.
transport: None,
id: title.to_string(),
title: title.to_string(),
name: Some(title.to_string()),
artist: None,
album: None,
album_name: None,
album_id: None,
artist_items: None,
artists: None,
primary_image_tag: None,
image_id: None,
item_type: Some("Movie".to_string()),
playlist_id: None,
duration: Some(7200.0),
artwork_url: None,
media_type: crate::player::media::MediaType::Video,
source: MediaSource::DirectUrl {
url: "http://example.com/movie.mp4".to_string(),
},
video_codec: None,
needs_transcoding: false,
video_width: None,
video_height: None,
subtitles: vec![],
series_id: None,
server_id: None,
}
}
#[test]
fn test_initial_state_is_idle() {
let manager = MediaSessionManager::new();
assert_eq!(manager.current(), &MediaSessionType::Idle);
}
#[test]
fn test_audio_session_lifecycle() {
let mut manager = MediaSessionManager::new();
// Start audio session
let track = create_test_audio_item("Track 1");
manager.start_audio_session(track.clone());
assert!(matches!(
manager.current(),
MediaSessionType::Audio {
is_active: true,
..
}
));
assert!(manager.should_show_miniplayer());
// Update to next track
let track2 = create_test_audio_item("Track 2");
manager.update_audio_track(track2);
assert!(manager.current().is_playing_or_paused());
// Queue ends, session goes inactive
manager.audio_session_inactive();
assert!(matches!(
manager.current(),
MediaSessionType::Audio {
is_active: false,
..
}
));
assert!(manager.should_show_miniplayer()); // Still shows!
// Resume
manager.resume_audio_session();
assert!(manager.current().is_playing_or_paused());
// Dismiss
manager.dismiss();
assert_eq!(manager.current(), &MediaSessionType::Idle);
assert!(!manager.should_show_miniplayer());
}
#[test]
fn test_movie_session_auto_dismiss() {
let mut manager = MediaSessionManager::new();
let movie = create_test_movie_item("Test Movie");
manager.start_movie_session(movie);
assert!(matches!(
manager.current(),
MediaSessionType::Movie {
is_active: true,
..
}
));
assert!(manager.should_show_video_player());
// Movie ends, auto-dismiss to Idle
manager.movie_session_ended();
assert_eq!(manager.current(), &MediaSessionType::Idle);
}
#[test]
fn test_session_replacement() {
let mut manager = MediaSessionManager::new();
// Start with audio
let track = create_test_audio_item("Track 1");
manager.start_audio_session(track);
assert!(manager.should_show_miniplayer());
// Switch to movie (replaces audio session)
let movie = create_test_movie_item("Test Movie");
manager.start_movie_session(movie);
assert!(!manager.should_show_miniplayer());
assert!(manager.should_show_video_player());
}
}