doc/design/video_path.tex

   1 \documentclass{article}
   2 \usepackage[explicit]{titlesec}
   3 \usepackage{lipsum,framed,color,xcolor}
   4 \definecolor{shadecolor}{rgb}{1,0.8,0.3}
   5 \titleformat{name=\subsection,numberless}{\ttfamily}{}{0em}{\colorbox{shadecolor}{\parbox{\dimexpr\textwidth-2\fboxsep\relax}{{#1}}}}\title{Video paths}
   6 \author{}
   7 \date{}
   8 \begin{document}
   9 \maketitle
  10
  11 \emph{Encoder} calls \texttt{Player::pass()} repeatedly.
  12
  13 \subsection*{Player::pass()}
  14
  15 Look through all `pieces' (content, decoder, video/audio position) and
  16 find earliest last emission.  Call \texttt{pass()} on earliest
  17 decoder.
  18
  19 \subsection*{FFmpegDecoder::pass()}
  20
  21 Decoder may or may not generate a frame.  Adjust for gaps in PTS.
  22 (FFmpegDecoder does FFmpeg filtering here).
  23
  24 \subsection*{VideoDecoder::video(image, same, frame)}
  25
  26 The \emph{frame} parameter is the frame within the source.  This
  27 handles 3D and emits \texttt{Video}, which is caught by
  28 \texttt{Player::process\_video}.
  29
  30 \subsection*{Player::process\_video(piece, image, eyes, same, frame)}
  31
  32 \begin{itemize}
  33 \item Trim
  34 \item Crop
  35 \item Scale
  36 \item Superposition of burnt-in subtitles.
  37 \end{itemize}
  38
  39 Emits \texttt{Video} which is caught by \texttt{Encoder::process\_video}.
  40
  41 \end{document}