Gotcha — you want to grab a stream file with yt-dlp. Here’s the clean, practical cheat-sheet, from basic to more advanced cases.

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1️⃣ Download a normal stream (HLS / DASH)

Most “streams” (Twitch, YouTube live replays, m3u8 URLs, etc.):

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yt-dlp "STREAM_URL"

yt-dlp will automatically:

• Detect HLS/DASH

• Download segments

• Merge them into a single file

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2️⃣ Download from an .m3u8 stream URL directly

If you already have the playlist URL:

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yt-dlp "https://example.com/stream.m3u8"

Optional: force output format

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yt-dlp -o "video.%(ext)s" "STREAM_URL"

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3️⃣ Best quality (recommended)

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yt-dlp -f "bv*+ba/best" "STREAM_URL"

This:

• Downloads best video + audio

• Falls back cleanly if separate streams don’t exist

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4️⃣ Save stream without re-encoding (fast + lossless)

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yt-dlp --merge-output-format mp4 "STREAM_URL"

Or MKV (best for weird streams):

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yt-dlp --merge-output-format mkv "STREAM_URL"

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5️⃣ Download a live stream while it’s live

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yt-dlp --live-from-start "STREAM_URL"

If you join late and want only what’s available:

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yt-dlp "STREAM_URL"

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6️⃣ Resume interrupted stream downloads

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yt-dlp -c "STREAM_URL"

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7️⃣ Debug / inspect stream formats

If something fails, check what yt-dlp sees:

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yt-dlp -F "STREAM_URL"

Then download a specific format:

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yt-dlp -f 137+140 "STREAM_URL"

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8️⃣ Common fixes for stubborn streams

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yt-dlp \
  --no-check-certificates \
  --user-agent "Mozilla/5.0" \
  "STREAM_URL"

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⚠️ Notes

• DRM-protected streams cannot be downloaded (yt-dlp will fail — that’s expected)

• For Twitch, YouTube, Kick, etc., use the page URL, not the raw m3u8 when possible

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If you want, tell me:

• 🔗 the site (YouTube, Twitch, custom site, camera feed, etc.)

• 📡 live or VOD

• 📁 desired format (mp4, mkv, audio-only)

…and I’ll give you the exact command that just works.

Totally fair question — the confusion is exactly where streaming tech is weird. Let’s demystify it step by step.

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Short answer

There is no single file that “describes” the resulting .mp4.

The .mp4 is constructed by yt-dlp from many small pieces, based on a playlist/manifest file.

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What actually happens under the hood

1️⃣ The manifest / playlist (the “description”)

For streams, yt-dlp first downloads a text file that describes the stream.

Common types:

• .m3u8 → HLS (most common)

• .mpd → DASH

Example (HLS .m3u8, simplified):

text
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#EXTM3U
#EXT-X-STREAM-INF:BANDWIDTH=3000000,RESOLUTION=1920x1080
video_1080p.m3u8

That file:

• Lists available qualities

• Points to segment files

• Contains timing info

👉 This is the “file describing the stream”, but it is not an MP4.

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2️⃣ The media segments

The playlist points to hundreds/thousands of tiny files:

• .ts

• .m4s

• .aac

Example:

text
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segment0001.ts
segment0002.ts
segment0003.ts

Each one is:

• ~2–6 seconds of audio or video

• Encoded already (H.264, AAC, etc.)

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3️⃣ yt-dlp downloads all segments

yt-dlp:

• Fetches the playlist

• Downloads every segment in order

• Keeps them in a temp folder

At this stage you do not have an .mp4.

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4️⃣ Muxing (building the .mp4)

Now the magic part.

yt-dlp calls ffmpeg to:

• Concatenate the segments

• Copy streams without re-encoding

• Wrap them into an .mp4 container

Conceptually:

text
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[H.264 video] + [AAC audio]
        ↓
      MP4

💡 MP4 is just a container, not the video itself.

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So what is the MP4 file?

An .mp4 contains:

• Encoded video stream (H.264 / HEVC / AV1)

• Encoded audio stream (AAC / Opus)

• Metadata (timestamps, indexes, etc.)

It does not remember:

• The .m3u8

• The segment URLs

• The website

Once built, it’s just a normal video file.

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Mental model (very important)

Think of it like this:

📜 Playlist (.m3u8) = recipe
🧩 Segments (.ts, .m4s) = ingredients
🍱 .mp4 = cooked meal

The recipe is used, then thrown away.

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Can I see these files myself?

Yes 🙂

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yt-dlp --keep-fragments "URL"

This will leave the segment files behind so you can inspect them.

To see the playlist:

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yt-dlp -v "URL"

Look for:

• .m3u8

• .mpd

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Why streaming works this way

• Fast seeking

• Adaptive quality

• Easy CDN caching

• Works live

MP4 alone can’t do that efficiently.

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If you want, I can:

• Walk through a real m3u8 line by line

• Show how ffmpeg merges segments

• Explain why some sites use .ts vs .m4s

• Explain DRM vs non-DRM streams

Just tell me where you want to go next 👀

Yes — yt-dlp does download the manifest, but it does not keep it by default. It’s treated as a temporary control file, not an output.

Here’s exactly how it works and how you can get it.

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Does yt-dlp download the manifest?

Yes. Always.

For streaming sites:

• HLS → .m3u8

• DASH → .mpd

yt-dlp must download it first to know:

• what streams exist

• where the segments are

• how to stitch them together

But…

👉 By default it is deleted after use.

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Where is the manifest stored?

Temporarily, in yt-dlp’s working directory / temp directory.

Typical locations:

• Linux / macOS:
  /tmp/yt-dlp-*

• Windows:
  %TEMP%\yt-dlp-*

It lives only while yt-dlp is running.

Once the download finishes (or fails), it’s gone.

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How to keep the manifest (this is the key part)

✅ Save the manifest to disk

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yt-dlp --write-info-json --write-playlist-metafiles "URL"

This will save:

• .m3u8 or .mpd (the manifest)

• .info.json (metadata)

📁 Stored in the output directory, next to the .mp4.

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✅ Keep everything (manifest + segments)

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yt-dlp --keep-fragments --write-playlist-metafiles "URL"

You’ll get:

• the manifest file

• all .ts / .m4s fragments

• final merged .mp4

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✅ Only download the manifest (no video)

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yt-dlp --skip-download --write-playlist-metafiles "URL"

Useful for:

• debugging

• archiving streams

• feeding the manifest into ffmpeg manually

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Can I choose where it’s saved?

Yes:

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yt-dlp -P "manifests:./manifests" --write-playlist-metafiles "URL"

Or everything:

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yt-dlp -P "./output" --write-playlist-metafiles "URL"

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What will the manifest file be named?

Usually something like:

text
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Video Title [id].m3u8

or

text
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Video Title [id].mpd

Exact naming depends on site + protocol.

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Bonus: View manifest without downloading anything

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yt-dlp -v --skip-download "URL"

Look for lines like:

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[download] Downloading m3u8 manifest

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Important notes

• DRM manifests will still download, but the segments will be encrypted

• The manifest alone is harmless; it’s just text

• yt-dlp does not modify the manifest (it reads it)

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TL;DR

• ✅ yt-dlp downloads the manifest

• ❌ it’s deleted by default

• ✅ use --write-playlist-metafiles to keep it

• 📁 temp dir while running, output dir if saved

If you want, tell me your OS + site and I’ll give you the exact command and where to look 👌

Yep — HLS (.m3u8) and DASH (.mpd) are just the big two, but they’re not the whole universe. Streaming has gone through multiple generations, and a few niche / legacy / internal formats still exist.

Here’s the clean map, from most common → rare / legacy.

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🌍 Modern adaptive streaming standards (dominant today)

1️⃣ HLS (HTTP Live Streaming) — Apple

Manifest

• .m3u8 (UTF-8 M3U)

Segments

• .ts (classic)

• .m4s (modern CMAF)

• sometimes .aac

Notes:

• Most widely supported format

• Used by YouTube, Twitch, Apple, many CDNs

• yt-dlp handles it extremely well

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2️⃣ MPEG-DASH

Manifest

• .mpd (XML)

Segments

• .m4s

• .webm chunks (rare)

Notes:

• More flexible than HLS

• Common on YouTube, Netflix (internally), many sites

• Designed for multi-codec streaming

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3️⃣ CMAF (Common Media Application Format)

Not a protocol — a shared segment format

Used by:

• HLS

• DASH

Files:

• .m4s

• .cmfv / .cmfa (rarely visible)

Why it matters:

• Same segments can serve HLS and DASH

• Industry standard going forward

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🧓 Legacy / declining formats

4️⃣ Progressive MP4

File

• .mp4

No manifest, no segments.

Notes:

• Old-school “download the whole file”

• Still used for small videos

• Not adaptive, not live

yt-dlp just downloads it directly.

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5️⃣ Adobe HDS (dead but sometimes seen)

Manifest

• .f4m

Segments

• .f4f

Notes:

• Flash-era

• yt-dlp has limited support

• Mostly extinct

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6️⃣ Microsoft Smooth Streaming

Manifest

• .ism / .ismc

Segments

• .ismv / .isma

Notes:

• Used by Silverlight

• Mostly gone

• Sometimes still appears on old enterprise sites

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🧪 Niche / weird / internal systems

7️⃣ WebRTC (not downloadable like files)

• No manifest

• No segments

• Real-time packets

Notes:

• Used for video calls, low-latency streams

• yt-dlp cannot download this

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8️⃣ RTMP / RTSP

• Persistent socket stream

• No playlist

Files:

• None (live stream only)

yt-dlp:

• Can sometimes record via ffmpeg

• Not “downloadable” in the HTTP sense

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9️⃣ Proprietary JSON manifests

Some sites use:

• .json manifests

• Signed URLs

• API-generated playlists

But under the hood they still resolve to:

• HLS or DASH

yt-dlp:

• Handles these via extractors

• You rarely see them unless debugging

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🧠 Big picture (mental model)

Everything modern converges toward:

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Manifest (text)  →  Small encoded segments  →  Muxed into MP4/MKV

Different standards just change:

• manifest syntax

• segment container

• encryption method

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🔒 DRM is orthogonal

DRM can exist on any of these:

• HLS + AES / FairPlay

• DASH + Widevine / PlayReady

File extensions look normal — content is encrypted.

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📊 Quick comparison table

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If you want, next we can:

• dissect a real .mpd or .m3u8

• compare HLS vs DASH in practice

• explain why .ts still exists

• dive into DRM signaling in manifests

Just point 👇