Encoder - AV

Encoder - AV - MistProcAV

This encoder is made by the MistServer team to handle a selection of known/good settings for various codecs to be used for encoding. By only allowing a small selection within the supported Codecs quality and performance can be assured. The main focus of this encoder is adding audio and video tracks as well as providing a JPG track for thumbnails.

This encoder directly integrates with the ffmpeg library allowing a much more efficient and faster pipeline rather than transmuxing twice.

This encoder requires ffmpeg to be installed in order to use and the following compile flag must be set while building Mistserver:

-DWITH_AV=true

codec support

Type	Codecs
Audio	Opus, AAC, PCM
Video	H264, AV1, JPG, UYVY, YUYV, NV12

Default settings that always apply

Bframes will always be removed from outputs
Framerate will always be copied from the source
MistProcAV creates an audio or video pipeline per process
Sync is guaranteed between source and added tracks

Configuration

MistProcAV is best configured through the interface, it can be started manually by passing JSON to MistProcAV or it can be saved directly into the configuration. When not using the interface we recommend running MistProcAV -j to see all the available options and how to set them.

Interface

MistProcAV has different settings for audio and video. The interface makes the selection easier.

video

audio

Configuration file / API

The following would be setting up an H264/Opus encode using the defaults.

      "processes": [
        {
          "bitrate": 8000000,
          "codec": "H264",
          "exit_unmask": false,
          "gopsize": 120,
          "inconsequential": false,
          "process": "AV",
          "tags_inhibit": [],
          "tune": "zerolatency-lq",
          "x-LSP-kind": "video"
        },
        {
          "bitrate": 192000,
          "codec": "opus",
          "exit_unmask": false,
          "inconsequential": false,
          "process": "AV",
          "tags_inhibit": [],
          "x-LSP-kind": "audio"
        }
      ]

Command line

In order for MistProcAV to run command line you need to make sure you're also setting a source.

Example: Setting an opus encode for the stream example.

MistProcAV '{"bitrate":110000,"codec":"opus","exit_unmask":0,"inconsequential":false,"process":"AV","source":"example","x-LSP-kind": "audio"}'

Required options

You need to set the codec wanted for the end result. This is done through "codec":"SELECT_OPTION". The codec determines whether audio or video is used.

Anything between () should not get passed, it is a comment for readability

Key	Name	Type	Help / Description	Select Options	Default / Value
process	process selector	select	Selects the specific process	AV
x-LSP-kind	Input type	select	Type of input to use	Video, Audio	video
codec (video)	Target codec	select	Which codec to encode to	AV1, H264, JPEG, UYVY	H264
codec (audio)	Target codec	select	Which codec to encode to	AAC, Opus, PCM	opus

Optional options

Anything between () should not get passed, it is a comment for readability

Key	Name	Type	Default / Value	Unit	Help / Description	Options (if applicable)
accel	Hardware acceleration	select	Automatic: attempt acceleration, fallback to software	—	Control whether hardware acceleration is used or not	`hw` (Force enabled), `sw` (Software-only)
bitrate (video)	Bitrate	uint	8,000,000 (8 mbps)	bit/s, kbit/s, Mbit/s, Gbit/s	Target bitrate for video; not used with JPEG or UYVY	—
bitrate (audio)	Bitrate	uint	192,000 (192 kbps)	bit/s, kbit/s	Target bitrate for audio; not used with PCM	—
crf	Constant Rate Factor (software only)	int	23	—	Software encoding quality (1–51, lower = better). Used for H264 only.	—
gopsize (video)	GOP Size	uint	120	—	Frames before new keyframe (except JPEG/UYVY)	—
gopsize (JPEG)	GOP Size	uint	120	—	Minimum frames between images (JPEG)	—
preset	Encode preset	select	faster	—	Encoding speed vs compression ratio (H264 only)	ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow
profile (H264)	Encode profile	select	high	—	Select encoding profile	main, baseline, high
profile (AAC)	Encode profile	select	low	—	Select encoding profile	low, main, he
quality	Quality	int	20	—	JPEG-only compression quality (1–31, lower = better)	—
resolution	Resolution	str	keep source resolution	—	Output stream resolution (e.g., 1920x1080)	—
sample_rate (AAC)	Sample rate	uint	—	Hz, kHz	Output sample rate; copies input if possible	—
sample_rate (PCM)	Sample rate	uint	48000	Hz, kHz	Output sample rate for PCM audio	—
tune	Encode tuning	select	zerolatency-lq	—	H264 tuning for performance/quality	zerolatency, zerolatency-lq, zerolatency-hq, animation, film

General process options

Key	Name	Type	Default / Value	Unit	Help / Description	Options (if applicable)
debug	Debug level	debug	—	—	Debug message level for process	—
exit_unmask	Undo masks on process exit/fail	boolean	false	—	Resets input track masks to defaults on exit/fail	—
sink	Target stream	string	—	—	Which stream the encoded track should be added to	—
source	Source stream	string	—	—	Which stream the encoded track should pull from, defaults to the stream the process is added towards	—
source_mask	Source track mask	select	Keep original value	—	Access permissions for source tracks	Everything, Processing, Processing+Pushing, Processing+Viewing
target_mask	Output track mask	select	Keep original value	—	Access permissions for output tracks	Viewer, Pushing, Processing, combinations thereof
track_select	Source selector(s)	string	audio=all&video=all	—	Which tracks to select for input	—
start_control	Process start behaviour	group	—	—	Controls when and how process starts	see below

start control options

Subkey	Name	Type	Default	Unit	Help / Description	Options (if applicable)
inconsequential	Inconsequential process	bool	false	—	Process not required for stream to be considered active	—
restart_delay	Restart delay	uint	0	ms	Delay between restarts	—
restart_type	Restart behaviour	select	fixed	—	What to do when the process exits/fails	fixed, backoff, disabled
tags_inhibit	Tag inhibitor(s)	inputlist	""	—	List of tags preventing process start	—
track_inhibit	Track inhibitor(s)	string	audio=none&video=none&subtitle=none	—	Which tracks inhibit process start	—

Encoder - AV - MistProcAV​

codec support​

Default settings that always apply​

Configuration​

Interface​

video​

audio​

Configuration file / API​

Command line​

Required options​

Optional options​

General process options​

start control options​