dec

The dec command is used to manage A/V decoder settings. The dec start and dec stop commands can be used to start and stop decoding video. ID can be all or id1[,id2,id3,id4] with values from 0 to 3. You can specify a comma-separated list of IDs for the operation, as shown in the examples that follow.

Synopsis

dec ID start
dec ID stop
dec ID set parameter=value [parameter=value]
dec ID get [config/stats/all] [video/buffer/metadata/audio/clockrecovery/all]
dec ID capture [filename=value] [resolution=WxH]
dec ID clear

Actions

Action	Description
start	Starts decoding the video input.
stop	Stops decoding the video input.
set	Configures A/V decoder settings. A series of one or more `parameter=value` pairs can be specified at once. See Parameters below.
get	Displays information on the decoder. You can choose to display the configuration (`config`), `stats`, or `all` [`config/stats/all`], and optionally specify a section of interest [`video/buffer/metadata/audio/clockrecovery/all`] Tip To display a summary of all the decoders in a table format, you can use `dec all get table:` # dec all get table ID STREAM ALT-STREAM STATE FORMAT BUFFERING OUTPUTS ---------------------------------------------------------------------------------------- 0 1 (None) ACTIVE NATIVE AUTOMATIC SDI-1 1 (None) (None) STOPPED NATIVE AUTOMATIC SDI-2 2 (None) (None) STOPPED NATIVE AUTOMATIC SDI-3 3 (None) (None) STOPPED NATIVE AUTOMATIC SDI-4
clear	Clears the decoder’s statistics.
help	Displays usage information for the `dec` command.

Parameters

Parameter	Default	Description/Values
streamId	n/a	Positive stream index. See Configuring Decoder Outputs.
stillImage	freeze	The type of static image to display when the decoder is not receiving a video stream. `freeze`: continues to display the last decoded video frame. `black`: displays a black screen. `blue`: displays a blue screen. `bars`: displays a series of vertical color bars across the width of the display. `mute`: disables the video output. `custom:` displays the custom still image specified for `stillFile`. Note When the still image is substituted on the display outputs, the video frame rate and resolution will be maintained. When the video decoder receives a new video stream, it waits until it receives a new IDR frame and re-starts the display with that IDR frame.
stillFile	n/a	Filename of the custom still image. Default images are provided, and your system administrator may have imported additional Still Images for your decoder. See mkstill.
stillDelay	3	The delay in seconds before the still image is displayed: 1...1000
format	auto	The output display format: `Auto:` The decoder will select an output resolution that attempts to closely match the coded picture resolution, taking into account the capabilities of any displays connected to the HDMI interface. `Native:` The output resolution will be exactly the same as the coded picture resolution. If the coded picture resolution is not compatible with the output interfaces, nothing will be displayed. See "Output Resolution" in Decoder Settings. Video scaling is not supported.
frameRate	auto	The output frame rate for the displays. `Auto, 23, 24, 25, 29, 30, 50, 59` or `60` If `Auto` is selected, the actual frame rate generated will be the next highest valid frame rate supported by the SDI interface, plus the one that gives the best decimation factor. For example, 30Hz could be chosen instead of 29.970 Hz. Values set which are impossible to implement will be treated as `Auto`. Reasons for not supporting the selection can range from “Display does not support the frame rate” or “Frame rate is undefined for the detected input resolution”.
buffering	automatic	The type of buffering to use. A jitter buffer temporarily stores arriving packets in order to remove the effects of jitter from the decoded stream. `automatic` - Set buffering automatically for good quality and proper sync `fixed` - Set buffering for fixed delay (use delay=X parameter) `multisync` - Set buffering for fixed delay from the encode time (use multiSyncDelay=X parameter, requires SYSTEM TC and NTP)
delay	n/a	The delay in ms when using `stc syncmode` with fixed buffering. Range: `0...3000`
multiSyncDelay	n/a	The delay in ms from encoder TC when using multisync buffering. Range: `0...10000`
hardwareDelayAdd	n/a	The number of ms to add to the delay for processing the output in the hardware. Range: `-60...200`
dropCorruptedFrames	no	Configures the decoder to drop corrupted frames before they reach the decoder. Options: `no, yes`
dynamicrange	automatic	Configures the decoder to detect the inbound High Dynamic Range (HDR) transfer function signaling and forward that information within the decoded stream. automatic: the decoder detects HDR transfer function from the source off (SDR/BT.709) HLG: HDR content is based on the Hybrid Log Gamma (HLG, BT.2100) transfer function PQ: HDR content is based on the Perceptual Quantizer (PQ, SMPTE ST 2084/BT.2100) transfer function Note HLG and PQ override the settings in the stream.
downmixAudio	no	Enable to automatically downmix surround sound audio to stereo. Options: `no, yes`
outputs	n/a	A list of physical SDI outputs the decoder core will feed: 1..4 none, all, default, quad2SI, or id1[,id2,id3,id4]

Examples

# dec 3,2,0 start

Starts decoders 3, 2 and 0 (in the order specified)

# dec 0 get stats

Returns (all) decoder statistics for decoder 0:

Decoder ID              : 0
Statistics
  State                 : ACTIVE
  Up Time               : 2d11h42m30s
Buffering
  Buffering Mode        : AUTOMATIC
  Buffering State       : ACTIVE
  Video Latency         : 363ms
  PCR Updates           : 4 (Last One: 1d18h59m4s ago)
  STC Updates           : 13 (Last One: 1d11h14m44s ago)
  Buffering Adjustments : 6 (Last One: 1d11h14m44s ago)
  STC Lead Time Adjusts : 8 (Last One: 1d11h14m44s ago)
  STC to PCR Lead Time  : -201ms (STC is behind PCR by 201ms)
  Packets Sent Late     : 21 (Last One: 8h44m12s ago, Max Late=95443694ms, Max Burst=11)
  Max Input Jitter      : 100ms (last changed 1d18h58m57s ago)
  Non-Video Late        : 0ms (max=0ms occurred Never)
  Video Decoder Latency : 42ms (max=57ms occurred 1d10h42m54s ago)
  Video Decoder Jitter  : 33ms (max=153ms occurred 8h44m4s ago)
  Hardware Delay        : 50ms
  Video STC Lead Time   : 168ms (Min=166ms, Max=199ms, Range=33ms)
  Last Video Skip/Replay: 8h44m11s ago
  Audio STC Lead Time   : 446ms (Min=426ms, Max=463ms, Range=37ms)
  Last Audio Skip       : 1d18h59m11s ago
Video
  Preprocessor State    : ACTIVE
  Stream Properties
    Compression         : H.265
    Color               : 4:2:0 8-bit
    Profile             : Main
    Level               : 5.1
    Format              : 1920x1080p59.94
    Bit Rate            : 10.18 Mbps
    Framing             : IP
    GOP Interval        : 60
    Slices per Frame    : 1
    Dynamic Range Stream : SDR
    Dynamic Range Output : SDR
    Metadata Present    : None
  Format Changes        : 1 (Last One: 2m29s ago)
  Input Frame Rate      : 59.94 [100.0%] (measured)
  Video Decoder State   : ACTIVE
  Display Format        : 1920x1080p59.94
  Video Decoder Load    : 24%
  Still Image           : FREEZE (INACTIVE) [Count=0, Max=0s, Last On=Never, Last Off=Never]
  Decoder Counters
    VCU Frm not Release    : 3 (Last One: 0s ago)
    VCU IN Discontinuity   : 1 (Last One: 2m29s ago)
  HW Counters
    Displayed Output Frms  : 8,750 [98.1162%] (Last One: 1s ago)
    Skipped Output Frames  : 8 [0.0897%] (Last One: 1m47s ago)
    Replayed Output Frames : 160 [1.7941%] (Last One: 31s ago)
Audio
  Audio Decoder State   : ACTIVE
  Number of Pairs       : 1
  Downmix to Stereo     : NO
  Played Output Frames  : 6,939 [99.0578%] (Last One: 0s ago)
  Skipped Output Frames : 66 [0.9422%] (Last One: 1m48s ago)
  TS Discontinuities    : 1
  AUDIO PAIR #1
    Audio pair state    : ACTIVE
    Compression         : AAC-ADTS
    Bit Rate            : 80.32 kbps
    Language            : None
    Decoder Index       : 0
    Surround Sound Pair : 1 of 1
    Left Level          : -6.7dB (max=4.5dB occurred 8h38m ago)
    Right Level         : -5.3dB (max=4.1dB occurred 10h30m ago)
    A/V Sync            : -2ms (Video TS 2830607135, Audio TS 2830607316)
    TS Discontinuities  : 3
    Input Layout        : 2.0 (FrontL FrontR)
    Sample Rate In      : 48 kHz
    Output Layout       : 2.0 (FrontL FrontR)
    Sample Rate Out     : 48 kHz
    Decoded Frames      : 15, 382, 521 (Last One: 0s ago)
    Played Output Frms  : 15, 461, 244 (Last One: 0s ago)
    Skipped Output Frms : 67 (Last One: 3d19h32m37s ago)
    STC Lead Time       : 274ms (Min=lms occurred 3d19h32m51s ago, Max=544ms occurred 3d19h32m51s ago, Range=543ms)
Metadata
  Metadata State        : IDLE
Clock Recovery
  Tracking Mode         : ENABLE
  Status                : UNLOCKED (more then +-5PPM)
  ReSync Count          : 2
  PCR Updates           : 2 (Last One: 2m19s ago)
  Current STC           : 27,000,723Hz (26PPM from Nominal)
  STC Avg (last 2 min)  : 27,000,495Hz (Deviation 14.0PPM)

# dec 0 get stats video

Returns (video) decoder statistics for decoder 0:

Decoder ID              : 0
Statistics
  State                 : ACTIVE
  Up Time               : 4m15s
Video
  Preprocessor State    : ACTIVE
  Stream Properties
    Compression         : H.265
    Color               : 4:2:0 8-bit
    Profile             : Main
    Level               : 5.1
    Format              : 1920x1080p29.97
    Bit Rate            : 10.03 Mbps
    Framing             : IP
    GOP Interval        : 60
    Slices per Frame    : 1
    Dynamic Range Stream: SDR
    Dynamic Range Output: HLG
    Metadata Present    : None
  Stream ID Changes     : 1 (Last One: 4m14s ago)
  Format Changes        : 1 (Last One: 4m14s ago)
  Input Frame Rate      : 29.96 [100.0%] (measured)
  Still Image           : FREEZE (INACTIVE) [Count=0, Max=18857d13h38m27s, Last On=Never, Last Off=4m10s ago]
  Video Decoder State   : ACTIVE
  Display Format        : 1920x1080p29.97
  Video Decoder Load    : 12%
  Decoder Counters
    VCU Frm not Release : 2 (Last One: 8s ago)
    VCU IN Discontinuity: 0
  HW Counters
    Displayed Output Frms: 7,473 [92.9131%] (Last One: 0s ago)
    Skipped Output Frames: 178 [2.2131%] (Last One: 3m50s ago)
    Replayed Output Frames: 392 [4.8738%] (Last One: 4m ago)

# dec 1 set stillimage=blue

Sets the static image to blue. You will receive the following confirmation:

Decoder configured successfully.

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