Mapping Syntax

Use explicit maps only when automatic track selection is insufficient. Input and track indexes are zero-based; MPEG-TS PID selectors use decimal values.

Video and Audio Maps

Video: [INPUT:]v[:INDEX|best|HEIGHTp|WIDTHxHEIGHT][:CODEC][@FPS][FLAG][>FALLBACK]
Audio: [INPUT:]a[:INDEX|best][:CODEC][FLAG][>FALLBACK]

Selector	Result
`v` / `a`	All video or audio tracks
`v:0` / `a:0`	First track of that type
`1:v:0` / `1:a:0`	First matching track from input 1
`v:best` / `a:best`	Highest-quality matching track
`p:100:v:0` / `p:100:a:0`	First matching track in program 100
`i:256` / `#256`	PID 256, restricted by the Video or Audio Map field

Video filters:

Selector	Result
`v:1080p`	Highest-bitrate video with height 1080
`v:1920x1080`	Highest-bitrate video with exact dimensions
`v:1080p@25`	1080-height video at 25 fps
`v:h264`	H.264 video; also supports `hevc`, `vp8`, `vp9`, and `av1`
`v:1920x1080:h264@25`	Exact size, codec, and frame rate

Audio codec selectors are aac, eac3, ac3, mp3, and mp2, for example a:0:aac.

Fallback and Multiple Matches

Syntax	Result
`v:720p>v:1080p>v:0`	First selector that matches
`a:0>a:1`	Use track 1 only when track 0 does not match
`v:0,v:1` / `a:0,a:1`	Multiple independent tracks
`a:0?`	No match is allowed
`v:1080p+`	Every matching 1080p track
`v:1080p*`	Optional plus all matches

Compatibility forms include bare 0, v:, a:, :v:0, and :a:0. In matching fields, p:100 and p:100:0 abbreviate program selectors. Prefer explicit forms in new configurations.

Tip

Map Restrictions: PID Map selectors such as i:256 accept decimal only. Multiple selected video tracks are valid only when every Video Encoder uses Copy. For yt-dlp sources, use one Video Map and one Audio Map selector rather than comma-separated lists.

Subtitle Map

Use [INPUT:]s[:INDEX|best][:CODEC][FLAG][>FALLBACK].

Selector	Result
`s` / `s:0` / `1:s:0`	All subtitles, first subtitle, or first from input 1
`s:best`	Highest-quality matching subtitle
`s:dvb_subtitle` / `s:dvb_teletext`	DVB bitmap subtitle or teletext
`s:webvtt` / `s:ttml` / `s:text`	Named text subtitle codec
`p:100:s:0`	First subtitle in program 100
`i:258` / `#258`	Decimal MPEG-TS PID 258
`s:0>s:1` / `s:0,s:1` / `s:0?`	Fallback, multiple tracks, or optional match

Add -cc as a separate comma item, for example s:0?,-cc, to remove supported H.264/H.265 closed-caption SEI units. It does not select a subtitle track.

PID Map

PID Map uses comma-separated OUTPUT_STREAM_INDEX:PID pairs. The index is zero-based decimal; PID may be decimal or hexadecimal and must be 0–8191.

0:0x101,1:0x102

Each output index may appear once. Avoid reserved or conflicting PIDs and verify PAT/PMT with an MPEG-TS analyzer.

Metadata

Metadata uses comma-separated SCOPE:key=value entries. Scopes are g for global, s for stream, p for zero-based program, and c for zero-based chapter.

g:title=Channel,s:a:0:language=eng,p:0:service_name=News,c:1:title=Introduction

Stream scope accepts an output index, media type, or TYPE:INDEX. It does not accept map-only fallback, codec, resolution, best, ?, +, or * syntax. Values may contain = but not commas. A later duplicate scope and key replaces the earlier value.

Verify a Map

Probe the source and identify its input, program, track, or PID.
Start with v:0, a:0, or s:0.
Add only the required constraint or fallback.
Save and confirm the selected tracks in the generated process log.