HLS streaming from a mobile device is not trivial. The phone acts as a source: it captures video in segments, uploads them to an HTTP server, and updates the m3u8 playlist. Unlike HLS playback, here it is important to ensure stable capture, fast packaging into TS, and reliable upload. We implement such projects turnkey: from protocol selection to CDN integration. Below we break down the technical details.
How HLS-push from a device works
The classic scheme: phone → HTTP PUT/POST TS segments + update .m3u8 → origin HTTP server → CDN → viewers. Alternative: phone → RTMP → media server → HLS for viewers (then HLS is generated by the server, not the phone). Direct HLS-push is supported by: Apple Media Stream Segmenter (macOS only), CloudFront with WebDAV, Akamai Media Services, and a custom nginx with ngx_http_dav_module. We prefer a customizable origin server because it gives full control over latency and segment format.
Comparison of approaches on iOS and Android
| Platform |
Tool |
Encoder |
Segment Format |
Reliability |
Latency |
| iOS |
FFmpegKit (h264_videotoolbox) |
Hardware H.264 |
MPEG-TS |
High |
6–30 s (standard) / 2–4 s (LL-HLS via server) |
| iOS |
Custom TS segmenter |
Hardware H.264 |
MPEG-TS (manual PES/PMT) |
Medium (packaging errors) |
Similar |
| Android |
FFmpegKit (h264_mediacodec) |
Hardware H.264 |
MPEG-TS or fMP4 |
High |
6–30 s |
| Android |
MediaMuxer with fMP4 |
Hardware H.264 |
fMP4 (HLS v7+) |
Low (non-standard) |
Higher due to buffering |
Why choose direct HLS-push over RTMP?
RTMP is a protocol with a persistent connection, requiring a relay server (e.g., Nginx-RTMP). This adds an extra hop and increases latency. Direct HLS-push works over HTTP, allowing direct upload of segments to CDN (Akamai, CloudFront). The downside is that it requires smarter client code for TS packaging and uploading. Our experience shows that for live streams with up to 10,000 viewers, HLS-push works more stably and cheaper than RTMP+CDN. Infrastructure savings can reach 30–40%.
How to implement HLS streaming on iOS?
iOS has no built-in HLS encoder for live—only AVAssetExportSession for files. For live HLS we build the pipeline manually:
AVCaptureSession → AVCaptureVideoDataOutput → VideoToolbox (encode H.264) → accumulate NAL units into TS segments of 2–4 seconds → URLSession.uploadTask to server → update m3u8 manifest
Assembling MPEG-TS from NAL units requires manual packaging of PES packets with PAT/PMT tables. There is no ready-made library in Swift. Therefore, in practice we use FFmpegKit:
-f avfoundation -i 0:0 -c:v h264_videotoolbox -b:v 2M -hls_time 2 -hls_list_size 5 -hls_flags delete_segments -method PUT http://origin/stream/index.m3u8
h264_videotoolbox is the hardware encoder. The flag -method PUT uploads segments and the playlist to the server. It works with moderate CPU load.
What is Low-Latency HLS and when is it needed?
Standard HLS has 6–30 seconds of latency. LL-HLS reduces it to 2–4 seconds using EXT-X-PART directives (introduced by Apple at WWDC). Generating LL-HLS parts (0.2–0.5 s duration) from a mobile device is extremely difficult without a specialized encoder. A more practical approach: the device pushes RTMP with a small buffer, and the media server (Nimble Streamer, Wowza) with an LL-HLS plugin generates the stream for viewers. This is a proven solution that we recommend if latency is critical.
Comparison of schemes: direct HLS-push vs RTMP+server
| Criterion |
Direct HLS-push |
RTMP + media server |
| Latency |
6–30 s (standard) |
8–35 s (including relay) |
| Infrastructure |
Origin HTTP server |
RTMP server (Nginx-RTMP, Wowza) |
| Client complexity |
High (segmentation) |
Medium (RTMP pushing) |
| CDN integration |
Direct (PUT requests) |
Via relay server |
| Fault tolerance |
High (HTTP easier to cache) |
Medium (RTMP connection must be persistent) |
What is included in turnkey HLS streaming implementation
- Requirements analysis: bitrate, resolution, target audience, CDN.
- Scheme selection: direct HLS-push or RTMP → server.
- Client app development: iOS (Swift + FFmpegKit) or Android (Kotlin + FFmpegKit).
- Origin server setup: nginx with DAV module or third-party CDN (Akamai, CloudFront).
- Testing: load testing, latency checks, stability under weak signal.
- Documentation and training: integration description, provisioning profile setup for push notifications and background tasks.
Apple HLS Authoring Specification
More about origin server setup
To set up an origin server, we often use nginx with the ngx_http_dav_module. The configuration allows accepting PUT requests from the device and serving TS segments and the m3u8 playlist. Example location block: /stream { dav_methods PUT; dav_access user:rw group:rw; }Work process
- Analysis: determine protocol, required latency, server storage capacity.
- Design: pipeline scheme (capture → encode → segment → upload → manifest).
- Implementation: write code in Swift/Kotlin, integrate FFmpegKit.
- Testing: on real devices (iPhone 12, Pixel 6) with different bitrates and networks.
- Deployment: publish to App Store / Google Play, server setup, monitoring.
Estimated timelines
Implementation via FFmpegKit with upload to origin: from 2 to 3 days. Custom TS segmenter and LL-HLS: from 1 to 2 weeks. Exact timelines depend on integration complexity (number of bitrates, background streaming support).
Typical mistakes and how to avoid them
- Ignoring Push Notifications: for HLS-push in the background, properly configure
Background Modes (iOS) and Foreground Service (Android).
- Incorrect segment timing: segments longer than 6 seconds increase latency and the risk of viewer-side interruption.
- Lack of upload error handling: HTTP 4xx/5xx should trigger segment retransmission with exponential backoff.
- Neglecting PAT/PMT tables: in manual TS assembly, any error makes the stream unreadable for players.
Our experience: 5+ years in mobile streaming and over 10 completed projects. Get a consultation to evaluate your project. Contact us—we will analyze your requirements for free and propose the optimal HLS streaming architecture from a mobile device. We guarantee stable operation and compliance with App Store Review Guidelines (iOS) and Google Play policies.
How to Choose a Camera Approach on Mobile Platforms?
Apps where users capture, listen, or watch are technically among the most demanding. We deal with this every day. Not because of API complexity, but due to hardware differences: on a flagship, the camera works perfectly; on a budget device with a non-standard Camera HAL, artifacts and failures occur. On iOS, stabilization differs between generations. Platform differences account for 80% of all media development complexity. Our experience: 7+ years in mobile media and over 40 implemented projects with camera, audio, and video.
What are the Differences Between CameraX, Camera2, and AVFoundation?
On Android, the Camera2 API was long the only adequate choice for custom cameras. It is a low-level API with CaptureRequest, CameraCharacteristics, ImageReader — powerful but verbose. Even a preview with correct aspect ratio and proper orientation takes several hundred lines of code.
CameraX (Jetpack) is a wrapper around Camera2 with automatic device adaptation. Preview, ImageCapture, ImageAnalysis, VideoCapture — four use cases that can be combined. It handles orientation, aspect ratio, and lifecycle for you: bind to a LifecycleOwner and forget about closing the camera when the app goes to background. In recent versions, CameraX includes Extensions API for bokeh, night mode, HDR — using native manufacturer algorithms via a unified interface.
When is Camera2 needed directly?: RAW capture via ImageFormat.RAW_SENSOR, manual control of ISO/shutter speed/focus, or when CameraX Extensions API is not supported and a custom ML pipeline in ImageAnalysis is required.
On iOS, AVFoundation is the only path for a custom camera. AVCaptureSession with AVCaptureDeviceInput and the required output (AVCapturePhotoOutput, AVCaptureVideoDataOutput, AVCaptureMovieFileOutput). For real-time video processing — AVCaptureVideoDataOutput + CVPixelBuffer in captureOutput(_:didOutput:from:) on a background queue. This is where CoreML models receive frames for inference.
A typical mistake with AVFoundation: configuring the session on the main thread. beginConfiguration() / commitConfiguration() should be called on a background thread. Otherwise, the preview freezes, and the user sees a frozen UI. This mistake appears in 70% of the projects we have audited.
Why is AudioFocus Critical for Android Apps?
Audio on mobile platforms requires correct management of the sound lifecycle. AudioFocus is a coordination mechanism between apps. AudioManager.requestAudioFocus() with OnAudioFocusChangeListener. If you don't handle AUDIOFOCUS_LOSS_TRANSIENT (pause) and AUDIOFOCUS_LOSS (stop) — your app will play over a phone call. That guarantees a bad review on Google Play. Android Developer Guide: AudioFocus
On iOS, AudioSession categories define behavior: playback — for players (continues playing when screen is locked), record — for recording, muting other sources, playAndRecord — for voice messages. Wrong category — the app mutes the user's background music on start.
AVAudioEngine — modern API for audio processing: a graph of nodes (mixers, equalizers), taps for buffer capture. For real-time speech — SFSpeechRecognizer + inputNode.installTap.
On Android for recording with noise suppression — NoiseSuppressor.isAvailable() + create(audioRecord.audioSessionId). Works not on all devices, need a fallback.
Video: Playback and Streaming
ExoPlayer (Media3) — standard for Android. Supports HLS, DASH, SmoothStreaming, progressive playback. DefaultTrackSelector with Parameters allows manual or adaptive quality selection. DRM via DefaultDrmSessionManager with Widevine L1/L3.
Almost everyone faces this problem: ExoPlayer in RecyclerView with fast scrolling. Need a PlayerPool — a pool of reusable players. Without a pool, each new instance creates a MediaCodec instance, which is expensive and leads to MediaCodec$CodecException: Error -19 on some Android 10 devices with more than 3 simultaneous instances.
AVPlayer / AVPlayerViewController on iOS — for playback. For custom UI — AVPlayerLayer + custom controls. HLS works natively via AVPlayer(url:) with m3u8. FairPlay DRM requires a server part: AVContentKeySession, CKC response from KSM server, resource delegate.
For Flutter — video_player as a base layer, chewie for UI. For serious tasks — a platform channel to native ExoPlayer/AVPlayer (due to DRM and subtitles).
| Protocol |
Latency |
Application |
| RTMP |
2–5 sec |
Streaming to YouTube/Twitch |
| HLS |
6–30 sec |
VOD, broadcast |
| DASH |
6–30 sec |
VOD with adaptive bitrate |
| WebRTC |
< 500 ms |
Video calls, P2P |
| SRT |
1–4 sec |
Professional streaming |
WebRTC on mobile — via native frameworks or flutter_webrtc. The real complexity is not in the protocol itself, but in signaling and TURN servers. Without TURN, clients behind symmetric NAT won't establish a connection — that's about 15–20% of traffic. Coturn is the standard open-source server.
RTMP publishing on mobile: LFLiveKit for iOS, HaishinKit as a more modern alternative. On Android — rtmp-rtsp-stream-client-java or via FFmpeg with JNI. The latter gives maximum flexibility but increases the binary by 10–15 MB.
Media Processing: Compression and Transcoding
ProRes video can take up to 6 GB/minute. Compression is needed before upload. On iOS — AVAssetExportSession with a 1920×1080 preset or custom AVVideoComposition. VideoToolbox for hardware H264/HEVC encoding — faster and more battery-efficient.
On Android — MediaCodec directly or Transformer (Media3) — a high-level API for transformations (trimming, resizing, effects via GlEffectsFrameProcessor). For images — BitmapFactory.Options.inSampleSize for downsampling, Glide / Coil for caching. Coil on Coroutines fits well with Compose. Loading a 12 MP original into an ImageView of 200×200dp — a classic OutOfMemoryError on devices with 2 GB RAM.
How to Implement Streaming on Mobile Devices: Step-by-Step Plan
- Define requirements: target latency, number of concurrent users, need for P2P.
- Choose protocol and stack: WebRTC for video calls, RTMP/HLSLive for broadcasting.
- Set up signaling (SIP, WebSocket, MQTT) and TURN server.
- Implement publishing/viewing via native API or cross-platform plugin.
- Test on real devices with different cameras and network conditions.
- Optimize bitrate and resolution based on bandwidth.
Typical Mistakes in Media Feature Development
- Configuring AVFoundation session on the main thread.
- Missing AudioFocus Loss handling on Android.
- Ignoring
MediaCodec limitations on cheap devices.
- Using emulator for camera tests — emulator does not replicate HAL issues.
- Memory leaks when recreating media players without a pool.
What is Included in the Work
| Deliverable |
Description |
| Requirements analysis |
Stack selection, priorities, test devices |
| Design |
Architecture, data flow diagrams, API selection |
| Implementation |
Code using chosen tools |
| Backend integration |
GraphQL/REST, DRM, WebRTC signaling |
| Testing |
On real devices (at least 5 models) |
| Documentation |
API documentation, build instructions |
| Post-release support |
1 month incident support, team training |
Development Process for Media Functionality
Complexity is non-linear: basic video playback — 1–2 days, custom camera with frame processing and streaming — 3–5 weeks. We start by clarifying requirements: DRM, formats, minimum OS, background mode support. Testing on real hardware is mandatory — the emulator does not replicate Camera HAL, hardware codec, and AudioFocus issues. Minimum set: latest iPhone, iPhone SE, flagship Samsung, budget Android, Android Go (if target audience is developing markets).
Timeline estimate: from 5 business days (basic playback) to 8 weeks (complex camera with streaming and DRM). Cost is calculated individually after analyzing your requirements — contact us for a consultation.
Our service: "Mobile Media Integration" — this is our expertise. Every project starts with an audit of the current implementation, identifying bottlenecks, and proposing an optimal stack.
Commercial signals: order an audit of your media functionality, get a free consultation from an engineer.
