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SDI output

media.push.sdi

Purpose

The media.push.sdi feature sends stream video and embedded audio to a physical SDI card output. It is configured separately from SDI ingest and requires an output port.

Stream requirements

Output requires an uncompressed v210 or uyvy422 video track. SDI push packages prepared frames: decoding and resizing belong to the transcoder. For a stream containing only encoded video, add a raw video track using !set v210 or !set uyvy422. An SDI input with a suitable format can feed another SDI port without transcoding.

The video track standard must match the output port mode. For a new card, verify video and audio output under the intended workload.

Configuration

Submit configuration through the central API. Example stream using different ports for ingest and output:

streams:
  - name: tv1
    inputs:
      - sdi:
          device: /dev/v4l/by-path/pci-0000:5e:00.0-video-index0
          pixel_format: v210
    pushes:
      sdi-out:
        sdi:
          device: /dev/v4l/by-path/pci-0000:5e:00.0-video-index1
          queue: 4
          audio:
            - track: 1
              channels: [1, 2]

Replace the example device paths with your card input and output paths. standard is optional: otherwise, it is derived from the video track. If set, a mismatch with the track causes a push error. The ntsc output standard is unsupported.

Set pixel_format on the input; output format comes from the video track. queue sets the output device queue to 2–8 frames, with a default of 4. In audio, track is the stream audio track number starting at 1, and channels is the destination SDI audio channel pair. Without an explicit mapping, tracks occupy pairs in order, up to eight pairs.

Source loss

Once the line is open, push sends black frames with silence when source frames are temporarily absent. Filler frames are counted separately from stream frames. Initial opening requires a stream description with an uncompressed video track. A busy device or standard mismatch puts push in Error; last_error contains the cause.

12G-SDI ingest is a separate ingest extension; its availability does not verify 12G output on the selected card. ASI carries MPEG-TS and has separate documentation; ASI output belongs to media.push.asi.

Transport

A physical SDI card output carries video and embedded audio on one link.

Supported codecs

  • v210
  • uyvy422
  • PCM (16-bit)
  • S32P
  • FLTP

Video must arrive uncompressed as v210 or uyvy422. Embedded audio supports 16-bit PCM, S32P, and FLTP; compressed H.264/HEVC/AAC tracks are not automatically decoded for SDI — prepare the required raw tracks beforehand.