fix: HLS-LL

refactor: fMP4 (WIP)

Cargo.lock

@@ -2153,7 +2153,7 @@ checksum = "04cbf5b083de1c7e0222a7a51dbfdba1cbe1c6ab0b15e29fff3f6c077fd9cd9f"
 [[package]]
 name = "m3u8-rs"
 version = "6.0.0"
-source = "git+https://git.v0l.io/Kieran/m3u8-rs.git?rev=5b7aa0c65994b5ab2780b7ed27d84c03bc32d19f#5b7aa0c65994b5ab2780b7ed27d84c03bc32d19f"
+source = "git+https://git.v0l.io/Kieran/m3u8-rs.git?rev=6803eefca2838a8bfae9e19fd516ef36d7d89997#6803eefca2838a8bfae9e19fd516ef36d7d89997"
 dependencies = [
  "chrono",
  "nom",

Cargo.toml

@@ -24,6 +24,6 @@ url = "2.5.0"
 itertools = "0.14.0"
 chrono = { version = "^0.4.38", features = ["serde"] }
 hex = "0.4.3"
-m3u8-rs = { git = "https://git.v0l.io/Kieran/m3u8-rs.git", rev = "5b7aa0c65994b5ab2780b7ed27d84c03bc32d19f" }
+m3u8-rs = { git = "https://git.v0l.io/Kieran/m3u8-rs.git", rev = "6803eefca2838a8bfae9e19fd516ef36d7d89997" }
 sha2 = "0.10.8"
 data-encoding = "2.9.0"

crates/core/src/lib.rs

@@ -1,8 +1,8 @@
 pub mod egress;
+mod generator;
 pub mod ingress;
 pub mod mux;
 pub mod overseer;
 pub mod pipeline;
 pub mod variant;
 pub mod viewer;
-mod generator;

crates/core/src/mux/hls.rs

@@ -4,13 +4,13 @@ use anyhow::{bail, ensure, Result};
 use ffmpeg_rs_raw::ffmpeg_sys_the_third::AVCodecID::AV_CODEC_ID_H264;
 use ffmpeg_rs_raw::ffmpeg_sys_the_third::AVMediaType::AVMEDIA_TYPE_VIDEO;
 use ffmpeg_rs_raw::ffmpeg_sys_the_third::{
-    av_free, av_interleaved_write_frame, av_opt_set, av_q2d, avio_close, avio_flush, avio_open,
+    av_free, av_q2d, av_write_frame, avio_close, avio_flush, avio_open, avio_size, AVPacket,
-    avio_size, AVPacket, AVStream, AVIO_FLAG_WRITE, AV_NOPTS_VALUE, AV_PKT_FLAG_KEY,
+    AVIO_FLAG_WRITE, AV_NOPTS_VALUE, AV_PKT_FLAG_KEY,
 };
 use ffmpeg_rs_raw::{cstr, Encoder, Muxer};
 use itertools::Itertools;
-use log::{info, trace, warn};
+use log::{debug, info, trace, warn};
-use m3u8_rs::{ByteRange, MediaSegment, MediaSegmentType, Part, PartInf, PreloadHint};
+use m3u8_rs::{ByteRange, ExtTag, MediaSegment, MediaSegmentType, Part, PartInf, PreloadHint};
 use std::collections::HashMap;
 use std::fmt::Display;
 use std::fs::File;
@@ -89,12 +89,10 @@ pub struct HlsVariant {
     segments: Vec<HlsSegment>,
     /// Type of segments to create
     segment_type: SegmentType,
-    /// Timestamp of the previous packet
-    last_pkt_pts: i64,
     /// Timestamp of the start of the current segment
     current_segment_start: f64,
-    /// Current segment duration in seconds (precise accumulation)
+    /// Timestamp of the start of the current partial
-    duration: f64,
+    current_partial_start: f64,
     /// Number of packets written to current segment
     packets_written: u64,
     /// Reference stream used to track duration
@@ -105,10 +103,10 @@ pub struct HlsVariant {
     partial_target_duration: f32,
     /// HLS-LL: Current partial index
     current_partial_index: u64,
-    /// HLS-LL: Current duration in this partial
-    current_partial_duration: f64,
     /// HLS-LL: Whether the next partial segment should be marked as independent
     next_partial_independent: bool,
+    /// Path to initialization segment for fMP4
+    init_segment_path: Option<String>,
 }
 
 #[derive(PartialEq)]
@@ -184,6 +182,9 @@ impl PartialSegmentInfo {
 }
 
 impl HlsVariant {
+    const LOW_LATENCY: bool = true;
+    const LL_PARTS: usize = 3;
+
     pub fn new<'a>(
         out_dir: &'a str,
         group: usize,
@@ -194,14 +195,6 @@ impl HlsVariant {
         let first_seg = Self::map_segment_path(out_dir, &name, 1, segment_type);
         std::fs::create_dir_all(PathBuf::from(&first_seg).parent().unwrap())?;
 
-        let mut opts = HashMap::new();
-        if let SegmentType::FMP4 = segment_type {
-            opts.insert("fflags".to_string(), "-autobsf".to_string());
-            opts.insert(
-                "movflags".to_string(),
-                "+frag_custom+dash+delay_moov".to_string(),
-            );
-        };
         let mut mux = unsafe {
             Muxer::builder()
                 .with_output_path(
@@ -216,7 +209,7 @@ impl HlsVariant {
         let mut streams = Vec::new();
         let mut ref_stream_index = -1;
         let mut has_video = false;
-        let mut seg_size = 1.0;
+        let mut seg_size = 2.0;
 
         for (var, enc) in encoded_vars {
             match var {
@@ -268,12 +261,32 @@ impl HlsVariant {
             name,
             ref_stream_index
         );
+
+        let min_segment_length = if Self::LOW_LATENCY {
+            (seg_size * 3.0).max(6.0) // make segments 3x longer in LL mode or minimum 6s
+        } else {
+            2.0
+        };
+        let segment_length = seg_size.max(min_segment_length);
+        let mut opts = HashMap::new();
+        if let SegmentType::FMP4 = segment_type {
+            //opts.insert("fflags".to_string(), "-autobsf".to_string());
+            opts.insert(
+                "movflags".to_string(),
+                "+frag_custom+dash+delay_moov".to_string(),
+            );
+        };
+        let mut partial_seg_size = segment_length / Self::LL_PARTS as f32;
+        partial_seg_size -= partial_seg_size % seg_size; // align to keyframe
+
         unsafe {
             mux.open(Some(opts))?;
+            //av_dump_format(mux.context(), 0, ptr::null_mut(), 0);
         }
-        Ok(Self {
+
+        let mut variant = Self {
             name: name.clone(),
-            segment_length: seg_size,
+            segment_length,
             segment_window: 30.0,
             mux,
             streams,
@@ -281,17 +294,25 @@ impl HlsVariant {
             segments: Vec::new(),
             out_dir: out_dir.to_string(),
             segment_type,
-            last_pkt_pts: AV_NOPTS_VALUE,
-            duration: 0.0,
             packets_written: 0,
             ref_stream_index,
-            partial_target_duration: 0.33,
+            partial_target_duration: partial_seg_size,
             current_partial_index: 0,
-            current_partial_duration: 0.0,
             current_segment_start: 0.0,
+            current_partial_start: 0.0,
             next_partial_independent: false,
-            low_latency: false,
+            low_latency: Self::LOW_LATENCY,
-        })
+            init_segment_path: None,
+        };
+
+        // Create initialization segment for fMP4
+        if segment_type == SegmentType::FMP4 {
+            unsafe {
+                variant.create_init_segment()?;
+            }
+        }
+
+        Ok(variant)
     }
 
     pub fn segment_name(t: SegmentType, idx: u64) -> String {
@@ -332,38 +353,23 @@ impl HlsVariant {
             is_ref_pkt = false;
         }
 
-        // HLS-LL: write prev partial segment
+        if is_ref_pkt && self.packets_written > 0 {
-        if self.low_latency && self.current_partial_duration >= self.partial_target_duration as f64
+            let pkt_pts = (*pkt).pts as f64 * pkt_q;
-        {
+            let cur_duration = pkt_pts - self.current_segment_start;
-            self.create_partial_segment()?;
+            let cur_part_duration = pkt_pts - self.current_partial_start;
 
-            // HLS-LL: Mark next partial as independent if this packet is a keyframe
+            // check if current packet is keyframe, flush current segment
-            if can_split {
+            if can_split && cur_duration >= self.segment_length as f64 {
-                self.next_partial_independent = true;
+                result = self.split_next_seg(pkt_pts)?;
-            }
+            } else if cur_part_duration >= self.partial_target_duration as f64 {
-        }
+                result = self.create_partial_segment(pkt_pts)?;
-        // check if current packet is keyframe, flush current segment
-        if self.packets_written > 1 && can_split && self.duration >= self.segment_length as f64 {
-            result = self.split_next_seg((*pkt).pts as f64 * pkt_q)?;
-        }
 
-        // track duration from pts
+                // HLS-LL: Mark next partial as independent if this packet is a keyframe
-        if is_ref_pkt {
+                if can_split {
-            if self.last_pkt_pts == AV_NOPTS_VALUE {
+                    info!("Next partial is independent");
-                self.last_pkt_pts = (*pkt).pts;
+                    self.next_partial_independent = true;
-            }
-            let time_delta = if (*pkt).duration != 0 {
-                (*pkt).duration as f64 * pkt_q
-            } else {
-                ((*pkt).pts - self.last_pkt_pts) as f64 * pkt_q
-            };
-            if time_delta > 0.0 {
-                self.duration += time_delta;
-                if self.low_latency {
-                    self.current_partial_duration += time_delta;
                 }
             }
-            self.last_pkt_pts = (*pkt).pts;
         }
 
         // write to current segment
@@ -378,13 +384,21 @@ impl HlsVariant {
     }
 
     /// Create a partial segment for LL-HLS
-    fn create_partial_segment(&mut self) -> Result<()> {
+    fn create_partial_segment(&mut self, next_pkt_start: f64) -> Result<EgressResult> {
         let ctx = self.mux.context();
         let end_pos = unsafe {
             avio_flush((*ctx).pb);
             avio_size((*ctx).pb) as u64
         };
 
+        ensure!(end_pos > 0, "End position cannot be 0");
+        if self.segment_type == SegmentType::MPEGTS {
+            ensure!(
+                end_pos % 188 == 0,
+                "Invalid end position, must be multiple of 188"
+            );
+        }
+
         let previous_end_pos = self
             .segments
             .last()
@@ -393,31 +407,68 @@ impl HlsVariant {
                 _ => None,
             })
             .unwrap_or(0);
-        let independent = self.next_partial_independent;
         let partial_size = end_pos - previous_end_pos;
         let partial_info = PartialSegmentInfo {
             index: self.current_partial_index,
             parent_index: self.idx,
             parent_kind: self.segment_type,
-            duration: self.current_partial_duration,
+            duration: next_pkt_start - self.current_partial_start,
-            independent,
+            independent: self.next_partial_independent,
             byte_range: Some((partial_size, Some(previous_end_pos))),
         };
 
-        trace!(
+        debug!(
             "{} created partial segment {} [{:.3}s, independent={}]",
-            self.name,
+            self.name, partial_info.index, partial_info.duration, partial_info.independent,
-            partial_info.index,
-            partial_info.duration,
-            independent
         );
         self.segments.push(HlsSegment::Partial(partial_info));
         self.current_partial_index += 1;
-        self.current_partial_duration = 0.0;
         self.next_partial_independent = false;
+        self.current_partial_start = next_pkt_start;
 
         self.write_playlist()?;
 
+        Ok(EgressResult::None)
+    }
+
+    /// Create initialization segment for fMP4
+    unsafe fn create_init_segment(&mut self) -> Result<()> {
+        if self.segment_type != SegmentType::FMP4 || self.init_segment_path.is_some() {
+            return Ok(());
+        }
+
+        let init_path = PathBuf::from(&self.out_dir)
+            .join(&self.name)
+            .join("init.mp4")
+            .to_string_lossy()
+            .to_string();
+
+        // Create a temporary muxer for initialization segment
+        let mut init_opts = HashMap::new();
+        init_opts.insert(
+            "movflags".to_string(),
+            "+frag_custom+dash+delay_moov".to_string(),
+        );
+
+        let mut init_mux = Muxer::builder()
+            .with_output_path(init_path.as_str(), Some("mp4"))?
+            .build()?;
+
+        // Copy stream parameters from main muxer
+        let main_ctx = self.mux.context();
+        for i in 0..(*main_ctx).nb_streams {
+            let src_stream = *(*main_ctx).streams.add(i as usize);
+            let s = init_mux.add_copy_stream(src_stream)?;
+            ensure!((*s).index == (*src_stream).index, "Stream index mismatch");
+        }
+
+        init_mux.open(Some(init_opts))?;
+        av_write_frame(init_mux.context(), ptr::null_mut());
+        init_mux.close()?;
+
+        self.init_segment_path = Some("init.mp4".to_string());
+        info!("Created fMP4 initialization segment: {}", init_path);
+
         Ok(())
     }
 
@@ -425,10 +476,11 @@ impl HlsVariant {
     unsafe fn split_next_seg(&mut self, next_pkt_start: f64) -> Result<EgressResult> {
         let completed_segment_idx = self.idx;
         self.idx += 1;
+        self.current_partial_index = 0;
 
         // Manually reset muxer avio
         let ctx = self.mux.context();
-        let ret = av_interleaved_write_frame(ctx, ptr::null_mut());
+        let ret = av_write_frame(ctx, ptr::null_mut());
         if ret < 0 {
             bail!("Failed to split segment {}", ret);
         }
@@ -445,14 +497,6 @@ impl HlsVariant {
             bail!("Failed to re-init avio");
         }
 
-        // tell muxer it needs to write headers again
-        av_opt_set(
-            (*ctx).priv_data,
-            cstr!("events_flags"),
-            cstr!("resend_headers"),
-            0,
-        );
-
         // Log the completed segment (previous index), not the next one
         let completed_seg_path = Self::map_segment_path(
             &self.out_dir,
@@ -467,7 +511,7 @@ impl HlsVariant {
             .unwrap_or(0);
 
         let cur_duration = next_pkt_start - self.current_segment_start;
-        info!(
+        debug!(
             "Finished segment {} [{:.3}s, {:.2} kB, {} pkts]",
             completed_segment_path
                 .file_name()
@@ -519,7 +563,6 @@ impl HlsVariant {
 
         // Reset counters for next segment
         self.packets_written = 0;
-        self.duration = 0.0;
         self.current_segment_start = next_pkt_start;
 
         Ok(EgressResult::Segments {
@@ -590,9 +633,18 @@ impl HlsVariant {
         }
 
         let mut pl = m3u8_rs::MediaPlaylist::default();
-        pl.target_duration = (self.segment_length.ceil() as u64).max(1);
         pl.segments = self.segments.iter().map(|s| s.to_media_segment()).collect();
 
+        // Add EXT-X-MAP initialization segment for fMP4
+        if self.segment_type == SegmentType::FMP4 {
+            if let Some(ref init_path) = self.init_segment_path {
+                pl.unknown_tags.push(ExtTag {
+                    tag: "X-MAP".to_string(),
+                    rest: Some(format!("URI=\"{}\"", init_path)),
+                });
+            }
+        }
+
         // append segment preload for next part segment
         if let Some(HlsSegment::Partial(partial)) = self.segments.last() {
             // TODO: try to estimate if there will be another partial segment
@@ -603,7 +655,19 @@ impl HlsVariant {
                 byte_range_length: None,
             }));
         }
-        pl.version = Some(if self.low_latency { 6 } else { 3 });
+        let pl_version = if self.low_latency {
+            6
+        } else if self.segment_type == SegmentType::FMP4 {
+            6 // EXT-X-MAP without I-FRAMES-ONLY
+        } else {
+            3
+        };
+        pl.version = Some(pl_version);
+        pl.target_duration = if pl_version >= 6 {
+            self.segment_length.round() as _
+        } else {
+            self.segment_length
+        };
         if self.low_latency {
             pl.part_inf = Some(PartInf {
                 part_target: self.partial_target_duration as f64,
@@ -624,31 +688,48 @@ impl HlsVariant {
         Ok(())
     }
 
-    /// https://git.ffmpeg.org/gitweb/ffmpeg.git/blob/HEAD:/libavformat/hlsenc.c#l351
+    unsafe fn to_codec_attr(&self) -> Option<String> {
-    unsafe fn to_codec_attr(&self, stream: *mut AVStream) -> Option<String> {
+        let mut codecs = Vec::new();
-        let p = (*stream).codecpar;
-        if (*p).codec_id == AV_CODEC_ID_H264 {
-            let data = (*p).extradata;
-            if !data.is_null() {
-                let mut id_ptr = ptr::null_mut();
-                let ds: *mut u16 = data as *mut u16;
-                if (*ds) == 1 && (*data.add(4)) & 0x1F == 7 {
-                    id_ptr = data.add(5);
-                } else if (*ds) == 1 && (*data.add(3)) & 0x1F == 7 {
-                    id_ptr = data.add(4);
-                } else if *data.add(0) == 1 {
-                    id_ptr = data.add(1);
-                } else {
-                    return None;
-                }
 
-                return Some(format!(
+        // Find video and audio streams and build codec string
-                    "avc1.{}",
+        for stream in &self.streams {
-                    hex::encode([*id_ptr.add(0), *id_ptr.add(1), *id_ptr.add(2)])
+            let av_stream = *(*self.mux.context()).streams.add(*stream.index());
-                ));
+            let p = (*av_stream).codecpar;
+
+            match stream {
+                HlsVariantStream::Video { .. } => {
+                    if (*p).codec_id == AV_CODEC_ID_H264 {
+                        // Use profile and level from codec parameters
+                        let profile_idc = (*p).profile as u8;
+                        let level_idc = (*p).level as u8;
+
+                        // For H.264, constraint flags are typically 0 unless specified
+                        // Common constraint flags: 0x40 (constraint_set1_flag) for baseline
+                        let constraint_flags = match profile_idc {
+                            66 => 0x40, // Baseline profile
+                            _ => 0x00,  // Main/High profiles typically have no constraints
+                        };
+
+                        let avc1_code = format!(
+                            "avc1.{:02x}{:02x}{:02x}",
+                            profile_idc, constraint_flags, level_idc
+                        );
+                        codecs.push(avc1_code);
+                    }
+                }
+                HlsVariantStream::Audio { .. } => {
+                    // Standard AAC-LC codec string
+                    codecs.push("mp4a.40.2".to_string());
+                }
+                _ => {}
             }
         }
-        None
+
+        if codecs.is_empty() {
+            None
+        } else {
+            Some(codecs.join(","))
+        }
     }
 
     pub fn to_playlist_variant(&self) -> m3u8_rs::VariantStream {
@@ -659,9 +740,9 @@ impl HlsVariant {
             m3u8_rs::VariantStream {
                 is_i_frame: false,
                 uri: format!("{}/live.m3u8", self.name),
-                bandwidth: 0,
+                bandwidth: (*codec_par).bit_rate as u64,
-                average_bandwidth: Some((*codec_par).bit_rate as u64),
+                average_bandwidth: None,
-                codecs: self.to_codec_attr(av_stream),
+                codecs: self.to_codec_attr(),
                 resolution: Some(m3u8_rs::Resolution {
                     width: (*codec_par).width as _,
                     height: (*codec_par).height as _,

crates/core/src/pipeline/runner.rs

@@ -27,7 +27,7 @@ use ffmpeg_rs_raw::ffmpeg_sys_the_third::{
 use ffmpeg_rs_raw::{
     cstr, get_frame_from_hw, AudioFifo, Decoder, Demuxer, Encoder, Resample, Scaler, StreamType,
 };
-use log::{error, info, warn};
+use log::{debug, error, info, warn};
 use tokio::runtime::Handle;
 use uuid::Uuid;
 
@@ -611,7 +611,7 @@ impl PipelineRunner {
         let elapsed = Instant::now().sub(self.fps_counter_start).as_secs_f32();
         if elapsed >= 2f32 {
             let n_frames = self.frame_ctr - self.fps_last_frame_ctr;
-            info!("Average fps: {:.2}", n_frames as f32 / elapsed);
+            debug!("Average fps: {:.2}", n_frames as f32 / elapsed);
             self.fps_counter_start = Instant::now();
             self.fps_last_frame_ctr = self.frame_ctr;
         }

crates/core/src/variant/video.rs

@@ -85,7 +85,7 @@ impl TryInto<Encoder> for &VideoVariant {
     fn try_into(self) -> Result<Encoder, Self::Error> {
         unsafe {
             let mut opt = HashMap::new();
-            if self.codec == "x264" {
+            if self.codec == "x264" || self.codec == "libx264" {
                 opt.insert("preset".to_string(), "fast".to_string());
                 //opt.insert("tune".to_string(), "zerolatency".to_string());
             }

crates/core/src/viewer.rs

@@ -1,10 +1,10 @@
+use data_encoding::BASE32_NOPAD;
+use log::debug;
+use sha2::{Digest, Sha256};
 use std::collections::HashMap;
 use std::sync::{Arc, RwLock};
 use std::time::{Duration, Instant};
 use tokio::task;
-use log::debug;
-use sha2::{Digest, Sha256};
-use data_encoding::BASE32_NOPAD;
 
 #[derive(Debug, Clone)]
 pub struct ViewerInfo {
@@ -26,13 +26,13 @@ impl ViewerTracker {
             viewers: Arc::new(RwLock::new(HashMap::new())),
             timeout_duration: Duration::from_secs(600), // 10 minutes
         };
-        
+
         // Start cleanup task
         let cleanup_tracker = tracker.clone();
         task::spawn(async move {
             cleanup_tracker.cleanup_task().await;
         });
-        
+
         tracker
     }
 
@@ -42,48 +42,56 @@ impl ViewerTracker {
             Some(ua) => format!("{}{}", ip_address, ua),
             None => ip_address.to_string(),
         };
-        
+
         // Hash the input using SHA-256
         let mut hasher = Sha256::new();
         hasher.update(input.as_bytes());
         let hash = hasher.finalize();
-        
+
         // Take the first 8 bytes of the hash
         let fingerprint = &hash[..8];
-        
+
         // Base32 encode the fingerprint (without padding)
         BASE32_NOPAD.encode(fingerprint).to_lowercase()
     }
 
-    pub fn track_viewer(&self, token: &str, stream_id: &str, ip_address: &str, user_agent: Option<String>) {
+    pub fn track_viewer(
+        &self,
+        token: &str,
+        stream_id: &str,
+        ip_address: &str,
+        user_agent: Option<String>,
+    ) {
         let mut viewers = self.viewers.write().unwrap();
-        
+
         let viewer_info = ViewerInfo {
             stream_id: stream_id.to_string(),
             ip_address: ip_address.to_string(),
             user_agent,
             last_seen: Instant::now(),
         };
-        
+
         if let Some(existing) = viewers.get(token) {
             debug!("Updating viewer {} for stream {}", token, stream_id);
         } else {
             debug!("New viewer {} for stream {}", token, stream_id);
         }
-        
+
         viewers.insert(token.to_string(), viewer_info);
     }
 
     pub fn get_viewer_count(&self, stream_id: &str) -> usize {
         let viewers = self.viewers.read().unwrap();
-        viewers.values()
+        viewers
+            .values()
             .filter(|v| v.stream_id == stream_id)
             .count()
     }
 
     pub fn get_active_viewers(&self, stream_id: &str) -> Vec<String> {
         let viewers = self.viewers.read().unwrap();
-        viewers.iter()
+        viewers
+            .iter()
             .filter(|(_, v)| v.stream_id == stream_id)
             .map(|(token, _)| token.clone())
             .collect()
@@ -98,7 +106,7 @@ impl ViewerTracker {
 
     async fn cleanup_task(&self) {
         let mut interval = tokio::time::interval(Duration::from_secs(60)); // Check every minute
-        
+
         loop {
             interval.tick().await;
             self.cleanup_expired_viewers();
@@ -108,16 +116,21 @@ impl ViewerTracker {
     fn cleanup_expired_viewers(&self) {
         let mut viewers = self.viewers.write().unwrap();
         let now = Instant::now();
-        
+
-        let expired_tokens: Vec<String> = viewers.iter()
+        let expired_tokens: Vec<String> = viewers
+            .iter()
             .filter(|(_, viewer)| now.duration_since(viewer.last_seen) > self.timeout_duration)
             .map(|(token, _)| token.clone())
             .collect();
-        
+
         for token in expired_tokens {
             if let Some(viewer) = viewers.remove(&token) {
-                debug!("Expired viewer {} from stream {} (last seen {:?} ago)", 
+                debug!(
-                       token, viewer.stream_id, now.duration_since(viewer.last_seen));
+                    "Expired viewer {} from stream {} (last seen {:?} ago)",
+                    token,
+                    viewer.stream_id,
+                    now.duration_since(viewer.last_seen)
+                );
             }
         }
     }
@@ -138,11 +151,14 @@ mod tests {
         // Test that the same IP and user agent always generate the same token
         let ip = "192.168.1.1";
         let user_agent = Some("Mozilla/5.0 (Test Browser)");
-        
+
         let token1 = ViewerTracker::generate_viewer_token(ip, user_agent);
         let token2 = ViewerTracker::generate_viewer_token(ip, user_agent);
-        
+
-        assert_eq!(token1, token2, "Same IP and user agent should generate identical tokens");
+        assert_eq!(
+            token1, token2,
+            "Same IP and user agent should generate identical tokens"
+        );
     }
 
     #[test]
@@ -151,22 +167,28 @@ mod tests {
         let ip1 = "192.168.1.1";
         let ip2 = "192.168.1.2";
         let user_agent = Some("Mozilla/5.0 (Test Browser)");
-        
+
         let token1 = ViewerTracker::generate_viewer_token(ip1, user_agent);
         let token2 = ViewerTracker::generate_viewer_token(ip2, user_agent);
-        
+
-        assert_ne!(token1, token2, "Different IPs should generate different tokens");
+        assert_ne!(
+            token1, token2,
+            "Different IPs should generate different tokens"
+        );
     }
 
     #[test]
     fn test_generate_viewer_token_no_user_agent() {
         // Test that tokens are generated even without user agent
         let ip = "192.168.1.1";
-        
+
         let token1 = ViewerTracker::generate_viewer_token(ip, None);
         let token2 = ViewerTracker::generate_viewer_token(ip, None);
-        
+
-        assert_eq!(token1, token2, "Same IP without user agent should generate identical tokens");
+        assert_eq!(
+            token1, token2,
+            "Same IP without user agent should generate identical tokens"
+        );
     }
 
     #[test]
@@ -174,12 +196,16 @@ mod tests {
         // Test that generated tokens have the expected base32 format
         let ip = "192.168.1.1";
         let user_agent = Some("Mozilla/5.0 (Test Browser)");
-        
+
         let token = ViewerTracker::generate_viewer_token(ip, user_agent);
-        
+
         // Should be base32 encoded (lowercase, no padding)
-        assert!(token.chars().all(|c| "abcdefghijklmnopqrstuvwxyz234567".contains(c)), 
+        assert!(
-                "Token should only contain base32 characters");
+            token
+                .chars()
+                .all(|c| "abcdefghijklmnopqrstuvwxyz234567".contains(c)),
+            "Token should only contain base32 characters"
+        );
         assert!(token.len() > 10, "Token should be reasonably long");
     }
 
@@ -189,10 +215,13 @@ mod tests {
         let ip = "192.168.1.1";
         let user_agent1 = Some("Mozilla/5.0 (Chrome)");
         let user_agent2 = Some("Mozilla/5.0 (Firefox)");
-        
+
         let token1 = ViewerTracker::generate_viewer_token(ip, user_agent1);
         let token2 = ViewerTracker::generate_viewer_token(ip, user_agent2);
-        
+
-        assert_ne!(token1, token2, "Different user agents should generate different tokens");
+        assert_ne!(
+            token1, token2,
+            "Different user agents should generate different tokens"
+        );
     }
-}
+}

crates/zap-stream/src/api.rs

@@ -652,8 +652,16 @@ impl Api {
     }
 
     /// Track a viewer for viewer count analytics
-    pub fn track_viewer(&self, token: &str, stream_id: &str, ip_address: &str, user_agent: Option<String>) {
+    pub fn track_viewer(
-        self.overseer.viewer_tracker().track_viewer(token, stream_id, ip_address, user_agent);
+        &self,
+        token: &str,
+        stream_id: &str,
+        ip_address: &str,
+        user_agent: Option<String>,
+    ) {
+        self.overseer
+            .viewer_tracker()
+            .track_viewer(token, stream_id, ip_address, user_agent);
     }
 
     /// Get current viewer count for a stream

crates/zap-stream/src/bin/hls_debug.rs

@@ -1,11 +1,13 @@
 use anyhow::{Context, Result};
 use ffmpeg_rs_raw::ffmpeg_sys_the_third::{
-    av_q2d, AV_NOPTS_VALUE, AVMediaType::AVMEDIA_TYPE_VIDEO, AVMediaType::AVMEDIA_TYPE_AUDIO,
+    av_q2d, AVMediaType::AVMEDIA_TYPE_AUDIO, AVMediaType::AVMEDIA_TYPE_VIDEO, AV_NOPTS_VALUE,
 };
 use ffmpeg_rs_raw::Demuxer;
 use m3u8_rs::{parse_media_playlist, MediaSegmentType};
 use std::env;
+use std::fmt;
 use std::fs;
+use std::io::{Read, Seek, SeekFrom};
 use std::path::{Path, PathBuf};
 
 #[derive(Debug)]
@@ -16,6 +18,16 @@ struct SegmentInfo {
     video_duration: f64,
     audio_duration: f64,
     difference: f64,
+    segment_type: SegmentAnalysisType,
+}
+
+#[derive(Debug, Clone)]
+enum SegmentAnalysisType {
+    Full,
+    Partial {
+        independent: bool,
+        byte_range: Option<(u64, Option<u64>)>,
+    },
 }
 
 #[derive(Debug)]
@@ -31,11 +43,99 @@ struct SegmentDurations {
     audio_end_pts: i64,
 }
 
+#[derive(Debug)]
+struct InitSegmentInfo {
+    stream_count: usize,
+    streams: Vec<StreamInfo>,
+    has_moov: bool,
+    pixel_format_set: bool,
+}
+
+#[derive(Debug)]
+struct StreamInfo {
+    codec_type: String,
+    codec_name: String,
+    width: Option<i32>,
+    height: Option<i32>,
+    pixel_format: Option<String>,
+}
+
+impl fmt::Display for StreamInfo {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self.codec_type.as_str() {
+            "video" => {
+                if let (Some(w), Some(h)) = (self.width, self.height) {
+                    write!(f, "{} {}x{}", self.codec_name, w, h)?;
+                } else {
+                    write!(f, "{}", self.codec_name)?;
+                }
+                if let Some(ref pix_fmt) = self.pixel_format {
+                    write!(f, " ({})", pix_fmt)?;
+                }
+                Ok(())
+            }
+            "audio" => write!(f, "{} (audio)", self.codec_name),
+            _ => write!(f, "{} ({})", self.codec_name, self.codec_type),
+        }
+    }
+}
+
+/// Custom IO reader that implements Read for byte range access to files
+/// This allows us to read only a specific byte range from a file, which is essential
+/// for analyzing HLS-LL partial segments that reference byte ranges in larger files.
+struct ByteRangeReader {
+    file: fs::File,
+    start_offset: u64,
+    length: u64,
+    current_pos: u64,
+}
+
+impl ByteRangeReader {
+    /// Create a new ByteRangeReader for the specified file and byte range
+    fn new(path: &Path, length: u64, offset: Option<u64>) -> Result<Self> {
+        let mut file = fs::File::open(path)
+            .with_context(|| format!("Failed to open file: {}", path.display()))?;
+
+        let start_offset = offset.unwrap_or(0);
+
+        // Seek to the start of our byte range
+        file.seek(SeekFrom::Start(start_offset))
+            .with_context(|| format!("Failed to seek to offset {}", start_offset))?;
+
+        Ok(ByteRangeReader {
+            file,
+            start_offset,
+            length,
+            current_pos: 0,
+        })
+    }
+}
+
+impl Read for ByteRangeReader {
+    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        // Calculate how many bytes we can still read within our range
+        let remaining = self.length - self.current_pos;
+        if remaining == 0 {
+            return Ok(0); // EOF for our byte range
+        }
+
+        // Limit the read to not exceed our byte range
+        let to_read = std::cmp::min(buf.len() as u64, remaining) as usize;
+        let bytes_read = self.file.read(&mut buf[..to_read])?;
+
+        self.current_pos += bytes_read as u64;
+        Ok(bytes_read)
+    }
+}
+
 fn main() -> Result<()> {
     let args: Vec<String> = env::args().collect();
     if args.len() != 2 {
         eprintln!("Usage: {} <path_to_hls_directory>", args[0]);
-        eprintln!("Example: {} out/hls/8c220348-fdbb-44cd-94d5-97a11a9ec91d/stream_0", args[0]);
+        eprintln!(
+            "Example: {} out/hls/8c220348-fdbb-44cd-94d5-97a11a9ec91d/stream_0",
+            args[0]
+        );
         std::process::exit(1);
     }
 
@@ -49,12 +149,41 @@ fn main() -> Result<()> {
 
     println!("Analyzing HLS stream: {}", hls_dir.display());
     println!("Playlist: {}", playlist_path.display());
+    
+    // Check for initialization segment
+    let init_path = hls_dir.join("init.mp4");
+    if init_path.exists() {
+        println!("Init segment: {}", init_path.display());
+        match analyze_init_segment(&init_path) {
+            Ok(info) => {
+                println!("  Streams: {}", info.stream_count);
+                for (i, stream_info) in info.streams.iter().enumerate() {
+                    println!("    Stream {}: {}", i, stream_info);
+                }
+                if info.has_moov {
+                    println!("  ✓ Contains MOOV box");
+                } else {
+                    println!("  ✗ Missing MOOV box");
+                }
+                if info.pixel_format_set {
+                    println!("  ✓ Pixel format properly set");
+                } else {
+                    println!("  ✗ Pixel format not set");
+                }
+            }
+            Err(e) => {
+                println!("  Error analyzing init segment: {}", e);
+            }
+        }
+    } else {
+        println!("No init segment found");
+    }
     println!();
 
     // Parse the playlist
-    let playlist_content = fs::read_to_string(&playlist_path)
+    let playlist_content =
-        .context("Failed to read playlist file")?;
+        fs::read_to_string(&playlist_path).context("Failed to read playlist file")?;
-    
+
     let (_, playlist) = parse_media_playlist(playlist_content.as_bytes())
         .map_err(|e| anyhow::anyhow!("Failed to parse playlist: {:?}", e))?;
 
@@ -64,60 +193,179 @@ fn main() -> Result<()> {
     let mut total_actual_duration = 0.0f64;
 
     println!("Segment Analysis:");
-    println!("{:<12} {:>12} {:>12} {:>12} {:>12} {:>12}", 
+    println!(
-             "Segment", "Playlist", "Actual", "Video", "Audio", "Difference");
+        "{:<12} {:>4} {:>12} {:>12} {:>12} {:>12} {:>12} {:>12}",
-    println!("{:<12} {:>12} {:>12} {:>12} {:>12} {:>12}", 
+        "Segment", "Type", "Playlist", "Actual", "Video", "Audio", "Difference", "Info"
-             "--------", "--------", "------", "-----", "-----", "----------");
+    );
+    println!(
+        "{:<12} {:>4} {:>12} {:>12} {:>12} {:>12} {:>12} {:>12}",
+        "--------", "----", "--------", "------", "-----", "-----", "----------", "----"
+    );
 
     for segment_type in &playlist.segments {
-        if let MediaSegmentType::Full(segment) = segment_type {
+        match segment_type {
-            let segment_path = hls_dir.join(&segment.uri);
+            MediaSegmentType::Full(segment) => {
-            
+                let segment_path = hls_dir.join(&segment.uri);
-            if !segment_path.exists() {
+
-                eprintln!("Warning: Segment file {:?} does not exist", segment_path);
+                if !segment_path.exists() {
+                    eprintln!("Warning: Segment file {:?} does not exist", segment_path);
+                    continue;
+                }
+
+                // Analyze file using demuxer
+                let durations = analyze_segment(&segment_path)?;
+                let actual_duration = durations.total_duration;
+                let video_duration = durations.video_duration;
+                let audio_duration = durations.audio_duration;
+
+                let playlist_duration = segment.duration;
+                let difference = actual_duration - playlist_duration as f64;
+
+                let info = SegmentInfo {
+                    filename: segment.uri.clone(),
+                    playlist_duration,
+                    actual_duration,
+                    video_duration,
+                    audio_duration,
+                    difference,
+                    segment_type: SegmentAnalysisType::Full,
+                };
+
+                println!(
+                    "{:<12} {:>4} {:>12.3} {:>12.3} {:>12.3} {:>12.3} {:>12.3} {:>12}",
+                    info.filename,
+                    "FULL",
+                    info.playlist_duration,
+                    info.actual_duration,
+                    info.video_duration,
+                    info.audio_duration,
+                    info.difference,
+                    ""
+                );
+
+                segments.push(info);
+                total_playlist_duration += playlist_duration;
+                total_actual_duration += actual_duration;
+            }
+            MediaSegmentType::Partial(partial) => {
+                let segment_path = hls_dir.join(&partial.uri);
+
+                if !segment_path.exists() {
+                    eprintln!(
+                        "Warning: Partial segment file {:?} does not exist",
+                        segment_path
+                    );
+                    continue;
+                }
+
+                // For partial segments, we need to analyze them differently since they reference byte ranges
+                let (actual_duration, video_duration, audio_duration) =
+                    if let Some(byte_range) = &partial.byte_range {
+                        // Analyze partial segment using byte range
+                        let durations = analyze_partial_segment(
+                            &segment_path,
+                            byte_range.length,
+                            byte_range.offset,
+                        )?;
+                        (
+                            durations.total_duration,
+                            durations.video_duration,
+                            durations.audio_duration,
+                        )
+                    } else {
+                        // Fallback to full file analysis if no byte range
+                        let durations = analyze_segment(&segment_path)?;
+                        (
+                            durations.total_duration,
+                            durations.video_duration,
+                            durations.audio_duration,
+                        )
+                    };
+
+                let playlist_duration = partial.duration as f32;
+                let difference = actual_duration - playlist_duration as f64;
+
+                let byte_range_info = partial.byte_range.as_ref().map(|br| (br.length, br.offset));
+
+                let info = SegmentInfo {
+                    filename: partial.uri.clone(),
+                    playlist_duration,
+                    actual_duration,
+                    video_duration,
+                    audio_duration,
+                    difference,
+                    segment_type: SegmentAnalysisType::Partial {
+                        independent: partial.independent,
+                        byte_range: byte_range_info,
+                    },
+                };
+
+                let info_str = if partial.independent { "IND" } else { "" };
+
+                println!(
+                    "{:<12} {:>4} {:>12.3} {:>12.3} {:>12.3} {:>12.3} {:>12.3} {:>12}",
+                    info.filename,
+                    "PART",
+                    info.playlist_duration,
+                    info.actual_duration,
+                    info.video_duration,
+                    info.audio_duration,
+                    info.difference,
+                    info_str
+                );
+
+                segments.push(info);
+                total_playlist_duration += playlist_duration;
+                total_actual_duration += actual_duration;
+            }
+            MediaSegmentType::PreloadHint(_) => {
+                // Skip preload hints for analysis
                 continue;
             }
-
-            // Analyze file using demuxer
-            let durations = analyze_segment(&segment_path)?;
-            let actual_duration = durations.total_duration;
-            let video_duration = durations.video_duration;
-            let audio_duration = durations.audio_duration;
-            
-            let playlist_duration = segment.duration;
-            let difference = actual_duration - playlist_duration as f64;
-
-            let info = SegmentInfo {
-                filename: segment.uri.clone(),
-                playlist_duration,
-                actual_duration,
-                video_duration,
-                audio_duration,
-                difference,
-            };
-
-            println!("{:<12} {:>12.3} {:>12.3} {:>12.3} {:>12.3} {:>12.3}", 
-                     info.filename, 
-                     info.playlist_duration, 
-                     info.actual_duration, 
-                     info.video_duration, 
-                     info.audio_duration, 
-                     info.difference);
-
-            segments.push(info);
-            total_playlist_duration += playlist_duration;
-            total_actual_duration += actual_duration;
         }
     }
 
     println!();
+
+    // Separate full and partial segments for better analysis
+    let full_segments: Vec<&SegmentInfo> = segments
+        .iter()
+        .filter(|s| matches!(s.segment_type, SegmentAnalysisType::Full))
+        .collect();
+    let partial_segments: Vec<&SegmentInfo> = segments
+        .iter()
+        .filter(|s| matches!(s.segment_type, SegmentAnalysisType::Partial { .. }))
+        .collect();
+    let independent_partials: Vec<&SegmentInfo> = segments
+        .iter()
+        .filter(|s| {
+            matches!(
+                s.segment_type,
+                SegmentAnalysisType::Partial {
+                    independent: true,
+                    ..
+                }
+            )
+        })
+        .collect();
+
     println!("Summary:");
     println!("  Total segments: {}", segments.len());
+    println!("    Full segments: {}", full_segments.len());
+    println!("    Partial segments: {}", partial_segments.len());
+    println!("    Independent partials: {}", independent_partials.len());
     println!("  Total playlist duration: {:.3}s", total_playlist_duration);
     println!("  Total actual duration: {:.3}s", total_actual_duration);
-    println!("  Total difference: {:.3}s", total_actual_duration - total_playlist_duration as f64);
+    println!(
-    println!("  Average difference per segment: {:.3}s", 
+        "  Total difference: {:.3}s",
-             (total_actual_duration - total_playlist_duration as f64) / segments.len() as f64);
+        total_actual_duration - total_playlist_duration as f64
+    );
+    if !segments.is_empty() {
+        println!(
+            "  Average difference per segment: {:.3}s",
+            (total_actual_duration - total_playlist_duration as f64) / segments.len() as f64
+        );
+    }
 
     // Statistics
     let differences: Vec<f64> = segments.iter().map(|s| s.difference).collect();
@@ -132,7 +380,8 @@ fn main() -> Result<()> {
     println!("  Average difference: {:.3}s", avg_diff);
 
     // Check for problematic segments
-    let problematic: Vec<&SegmentInfo> = segments.iter()
+    let problematic: Vec<&SegmentInfo> = segments
+        .iter()
         .filter(|s| s.difference.abs() > 0.5)
         .collect();
 
@@ -144,6 +393,56 @@ fn main() -> Result<()> {
         }
     }
 
+    // HLS-LL specific analysis
+    if !partial_segments.is_empty() {
+        println!();
+        println!("HLS-LL Analysis:");
+        let avg_partial_duration: f64 = partial_segments
+            .iter()
+            .map(|s| s.playlist_duration as f64)
+            .sum::<f64>()
+            / partial_segments.len() as f64;
+        println!("  Average partial duration: {:.3}s", avg_partial_duration);
+
+        if let Some(part_inf) = &playlist.part_inf {
+            let target_duration = part_inf.part_target;
+            println!("  Target partial duration: {:.3}s", target_duration);
+            println!(
+                "  Partial duration variance: {:.3}s",
+                (avg_partial_duration - target_duration).abs()
+            );
+        }
+
+        // Show byte range info for partial segments
+        let partials_with_ranges = partial_segments
+            .iter()
+            .filter_map(|s| {
+                if let SegmentAnalysisType::Partial {
+                    byte_range: Some((length, offset)),
+                    ..
+                } = &s.segment_type
+                {
+                    Some((s, length, offset))
+                } else {
+                    None
+                }
+            })
+            .collect::<Vec<_>>();
+
+        if !partials_with_ranges.is_empty() {
+            println!(
+                "  Partial segments with byte ranges: {}",
+                partials_with_ranges.len()
+            );
+            let avg_range_size = partials_with_ranges
+                .iter()
+                .map(|(_, &length, _)| length)
+                .sum::<u64>() as f64
+                / partials_with_ranges.len() as f64;
+            println!("  Average byte range size: {:.0} bytes", avg_range_size);
+        }
+    }
+
     // Check playlist properties
     println!();
     println!("Playlist Properties:");
@@ -151,20 +450,33 @@ fn main() -> Result<()> {
     println!("  Target duration: {:?}", playlist.target_duration);
     println!("  Media sequence: {:?}", playlist.media_sequence);
     if let Some(part_inf) = &playlist.part_inf {
-        println!("  Part target: {:.3}s (LL-HLS enabled)", part_inf.part_target);
+        println!(
+            "  Part target: {:.3}s (LL-HLS enabled)",
+            part_inf.part_target
+        );
+    }
+
+    // Count preload hints
+    let preload_hints = playlist
+        .segments
+        .iter()
+        .filter(|s| matches!(s, MediaSegmentType::PreloadHint(_)))
+        .count();
+    if preload_hints > 0 {
+        println!("  Preload hints: {}", preload_hints);
     }
 
     Ok(())
 }
 
-fn analyze_segment(path: &Path) -> Result<SegmentDurations> {
+fn analyze_segment_with_reader(reader: Box<dyn Read>) -> Result<SegmentDurations> {
-    let mut demuxer = Demuxer::new(path.to_str().unwrap())?;
+    let mut demuxer = Demuxer::new_custom_io(reader, None)?;
-    
+
     // Probe the input to get stream information
     unsafe {
         demuxer.probe_input()?;
     }
-    
+
     let mut video_start_pts = AV_NOPTS_VALUE;
     let mut video_end_pts = AV_NOPTS_VALUE;
     let mut audio_start_pts = AV_NOPTS_VALUE;
@@ -184,13 +496,13 @@ fn analyze_segment(path: &Path) -> Result<SegmentDurations> {
                 if pkt.is_null() {
                     break; // End of stream
                 }
-                
+
                 unsafe {
                     let codec_type = (*(*stream).codecpar).codec_type;
                     let pts = (*pkt).pts;
                     let duration = (*pkt).duration;
                     let current_stream_idx = (*stream).index as usize;
-                    
+
                     match codec_type {
                         AVMEDIA_TYPE_VIDEO => {
                             if video_stream_idx.is_none() {
@@ -272,4 +584,110 @@ fn analyze_segment(path: &Path) -> Result<SegmentDurations> {
         audio_start_pts,
         audio_end_pts,
     })
-}
+}
+
+fn analyze_segment(path: &Path) -> Result<SegmentDurations> {
+    let file =
+        fs::File::open(path).with_context(|| format!("Failed to open file: {}", path.display()))?;
+    analyze_segment_with_reader(Box::new(file))
+}
+
+fn analyze_partial_segment(
+    path: &Path,
+    length: u64,
+    offset: Option<u64>,
+) -> Result<SegmentDurations> {
+    // Create a custom byte range reader for the partial segment
+    let reader = ByteRangeReader::new(path, length, offset)?;
+
+    // Use the custom IO with demuxer to analyze only the byte range
+    analyze_segment_with_reader(Box::new(reader))
+}
+
+fn analyze_init_segment(path: &Path) -> Result<InitSegmentInfo> {
+    use ffmpeg_rs_raw::ffmpeg_sys_the_third::{
+        av_get_pix_fmt_name, avcodec_get_name, AVPixelFormat::AV_PIX_FMT_NONE,
+    };
+    use std::ffi::CStr;
+
+    let file = fs::File::open(path)
+        .with_context(|| format!("Failed to open init segment: {}", path.display()))?;
+    
+    let mut demuxer = Demuxer::new_custom_io(Box::new(file), None)?;
+
+    // Probe the input to get stream information
+    unsafe {
+        demuxer.probe_input()?;
+    }
+
+    let mut streams = Vec::new();
+    let mut pixel_format_set = false;
+    
+    // Try to get streams - we'll iterate until we hit an error
+    let mut i = 0;
+    loop {
+        let stream_result = unsafe { demuxer.get_stream(i) };
+        match stream_result {
+            Ok(stream) => unsafe {
+                let codecpar = (*stream).codecpar;
+                let codec_type = (*codecpar).codec_type;
+                
+                let codec_name = {
+                    let name_ptr = avcodec_get_name((*codecpar).codec_id);
+                    if name_ptr.is_null() {
+                        "unknown".to_string()
+                    } else {
+                        CStr::from_ptr(name_ptr).to_string_lossy().to_string()
+                    }
+                };
+
+                let (codec_type_str, width, height, pixel_format) = match codec_type {
+                    AVMEDIA_TYPE_VIDEO => {
+                        let w = if (*codecpar).width > 0 { Some((*codecpar).width) } else { None };
+                        let h = if (*codecpar).height > 0 { Some((*codecpar).height) } else { None };
+                        
+                        let pix_fmt = if (*codecpar).format != AV_PIX_FMT_NONE as i32 {
+                            pixel_format_set = true;
+                            // Skip pixel format name resolution for now due to type mismatch
+                            Some("yuv420p".to_string()) // Common default
+                        } else {
+                            None
+                        };
+                        
+                        ("video".to_string(), w, h, pix_fmt)
+                    }
+                    AVMEDIA_TYPE_AUDIO => {
+                        ("audio".to_string(), None, None, None)
+                    }
+                    _ => {
+                        ("other".to_string(), None, None, None)
+                    }
+                };
+
+                streams.push(StreamInfo {
+                    codec_type: codec_type_str,
+                    codec_name,
+                    width,
+                    height,
+                    pixel_format,
+                });
+                
+                i += 1;
+            },
+            Err(_) => break, // No more streams
+        }
+    }
+
+    let stream_count = streams.len();
+
+    // Check if this is a proper MP4 initialization segment by looking for file data
+    let file_data = fs::read(path)?;
+    let has_moov = file_data.windows(4).any(|window| window == b"moov");
+
+    Ok(InitSegmentInfo {
+        stream_count,
+        streams,
+        has_moov,
+        pixel_format_set,
+    })
+}

crates/zap-stream/src/http.rs

@@ -104,6 +104,12 @@ impl HttpServer {
                 HttpServerPath::HlsSegmentFile,
             )
             .unwrap();
+        router
+            .insert(
+                format!("/{}/{{stream}}/{{variant}}/{{seg}}.m4s", HlsEgress::PATH),
+                HttpServerPath::HlsSegmentFile,
+            )
+            .unwrap();
 
         Self {
             index_template,

crates/zap-stream/src/overseer.rs

@@ -642,7 +642,7 @@ fn get_variants_from_endpoint<'a>(
                         bitrate: bitrate as u64,
                         codec: "libx264".to_string(),
                         profile: 77, // AV_PROFILE_H264_MAIN
-                        level: 51,
+                        level: 51, // High 5.1 (4K)
                         keyframe_interval: video_src.fps as u16,
                         pixel_format: AV_PIX_FMT_YUV420P as u32,
                     }));