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Wiki Video: Streaming Protocols, Video Chunk, Format/Codec, Playback

Overview​

This document provides a quick reference to modern video streaming technologies, covering key differences between streaming protocols, video chunking strategies, and how video playback works in browsers and players. It focuses especially on the difference between progressive MP4 streaming and chunk-based playback via HLS/DASH.

Video Format/Codec​

Common Video Streaming Protocols​

ProtocolFull NameUse CaseLive/VODLatencyStatusNotes
HLSHTTP Live StreamingApple TV, SafariBoth10–30 secActivemodern, scalable, used for both live and VOD.
DASHMPEG-DASHYouTube, NetflixBoth5–15 secActiveOpen standard, alternative to HLS
RTMPReal-Time Messaging ProtocolOBS to YouTube/TwitchLive Only~2–5 secDeprecated (playback)used for sending live video to servers, not for playback
RTSPReal-Time Streaming ProtocolCCTV, IP camerasLive Only~1 secActive (niche)Not browser-compatible; mostly in special app(surveillance systems, etc.)
WebRTCWeb Real-Time CommunicationLive chat, callsLive Only~0.5 secGrowingLow latency; peer-to-peer(video calls, etc.)

Video Chunking(HLS/DASH)​

In real world applications, like youtube, they will divide a video into many chunks for HLS or DASH for better performance.

ProtocolChunk File FormatNotes
HLS.ts (MPEG-2 Transport Stream) or .mp4 (fMP4).ts is traditional, .mp4 (fMP4) is newer and supports low-latency
DASH.mp4 (fMP4)DASH usually uses fragmented MP4
  • fMP4 = fragmented MP4 — this allows streaming before the full file is complete, perfect for chunked delivery.
  • Each chunk might be ~2–10 seconds long depending on settings.

How Does Client Handle Chunks?​

The client (player) must understand how to:

  • Parse the manifest file (.m3u8 for HLS, .mpd for DASH)
  • Download the chunks in order
  • Buffer a few chunks ahead
  • Handle adaptive bitrate switching

Usually, this is done by a video player library like:

  • HLS.js (for browsers)
  • Shaka Player (for DASH)
  • AVPlayer (on iOS/tvOS)
  • ExoPlayer (on Android)

Playback​

A. Chunk-Based Playback (HLS/DASH)​

  1. The player loads the manifest file.
  2. It picks the best quality (bitrate) based on bandwidth.
  3. It downloads chunk 1 and starts playing it while downloading chunk 2.
  4. It continues in parallel: downloading one or more chunks ahead, playing current one.
  5. If network speed drops, it switches bitrate (adaptive bitrate streaming).

So, no, the player doesn’t download the whole chunked video first. It streams it in real time by pulling chunks one by one.

Bonus: Manifest Files​

HLS .m3u8 Example:

#EXTM3U
#EXT-X-VERSION:3
#EXTINF:10.0,
chunk1.ts
#EXTINF:10.0,
chunk2.ts
...

DASH .mpd Manifest:

An XML file describing all chunks, qualities, and durations.

Bonus: How to Create HLS from MP4 (ffmpeg Example)​

ffmpeg -i input.mp4 \
  -codec: copy -start_number 0 \
  -hls_time 6 -hls_list_size 0 \
  -f hls output.m3u8

This will create .ts chunks and an .m3u8 playlist ready for HLS playback.

B. Progressive MP4 Download (Direct in Browser, via a streaming api supported by server)​

  • A single .mp4 file is streamed via HTTP.
  • Browsers like Chrome or Safari can start playback once enough is buffered.
  • Doesn’t require special manifests.
  • Supports basic seeking (if moov atom is early).
  • No adaptive bitrate or chunk control.

Bonus: Streaming API In Python to Support Progressive MP4 Playback​

fastapi_streaming.py
loading...

Playback Comparison​

FeatureMP4 ProgressiveHLS/DASH Chunk Streaming
File FormatSingle .mp4Multiple .ts or .mp4 chunks
Requires Manifest❌ No✅ Yes (.m3u8 / .mpd)
Native Browser Support✅ Yes (Chrome, etc.)❌ (except Safari for HLS)
Adaptive Bitrate❌ No✅ Yes
Low-Latency Live Support❌ Limited✅ Yes
JS Player Required❌ No✅ Usually
Suitable for Long VOD⚠️ Not ideal✅ Excellent

When to Use Which,

  • MP4 Progressive:

    • Small or simple videos
    • Static content without network adaptation needs

  • HLS/DASH:

    • Live streaming
    • VOD with varying network conditions
    • Need for adaptive bitrate
    • Complex playback control (seeking, DVR, etc.)

References​