X-Git-Url: https://git.decadent.org.uk/gitweb/?p=lca-dvswitch.git;a=blobdiff_plain;f=index.html;h=ae10127caf46ad364d531e5830ca65ddb4afafed;hp=1c087b3a6eb580a3e40c99302f05cb68cd86ba0e;hb=10c860eebb181fcef72f1b01c9ccf839c818487f;hpb=f0d3f2251bb6cbbf1c8461f980de0d244069fe02 diff --git a/index.html b/index.html index 1c087b3..ae10127 100644 --- a/index.html +++ b/index.html @@ -4,7 +4,7 @@ -DVswitch - Ben Hutchings - LCA2011 +Making great conference videos on a budget - Ben Hutchings - LCA2011 @@ -23,6 +23,9 @@ th { border-bottom: 2pt solid black } th, td { padding: 0 6pt } + @@ -36,7 +39,7 @@ @@ -45,7 +48,7 @@
-

DVswitch

+

Making great conference videos
on a budget

Ben Hutchings

@@ -96,8 +99,8 @@ Now used more widely, often without streaming
  • - Mixing is live - required for streaming, and avoids the - need for extensive editing after the event + Mixing is live - required for streaming, and avoids + extensive editing after the event
  • Mixing is interactive - required for good coverage of @@ -118,7 +121,8 @@ A general video editor
  • - An audio mixer (but it does implement audio dubbing and level monitoring) + An audio mixer - audio functionality is limited to dubbing and + level monitoring
  • A complete recording and publishing system @@ -133,7 +137,7 @@

    The 'DV' in DVswitch

    - The name refers to the DV formats used by many video cameras: + The name refers to the DV format used by many video cameras:

    @@ -179,10 +183,13 @@

    Overview of the system

    -

    - A simplified view of the typical components: -

    - + +
    +

    + This is a simplified view of the typical components. The system + is completely flexible as to which sinks and sources are used. +

    +
    @@ -218,6 +225,12 @@ +
    +

    + DIF is the DV Interchange Format, sometimes referred to as 'raw + DV' although it is a container format in its own right. +

    +
    @@ -246,13 +259,86 @@
    -

    Mixer

    - +

    Mixer UI

    + +
    + +
    +

    Mixer UI, annotated

    + +
    + +
    +

    Mixer internals

    + +
    +

    + To simplify the diagram, I omitted connection setup, tally light + and recording control, and the internal sinks that haven't been + implemented yet. +

    +

    + All these interfaces have limited-length queues. If a queue + fills up, frames have to be dropped - we must not block or use + unlimited memory! +

    +

    + The mixer clock thread maintains a frame clock at about 25 or + 30 Hz depending on the video system, constantly adjusted to + follow the audio source. +

    +
    +
    + +
    +

    Icecast streaming server

    +
      +
    • + Simple HTTP streaming server supporting MP3, Ogg Vorbis and + Ogg Theora streams +
      • +
    • + Each stream is provided by an authenticated source client or + relayed from another server +
      • +
    • + Relaying allows you to build a distribution network serving + viewers inside and outside the conference +
      • +
    +
    + +
    +

    Icecast distribution network

    + +
      +
    • + Internal master serves internal viewers and external master +
      • +
    • + Public servers serve viewers anywhere +
      • +
    • + Relaying restricted by password and/or firewall +
      • +
    -

    Mixer

    - +

    Further information

    +