Statistics
| Branch: | Revision:

ffmpeg / doc / hooks.html @ 3df7be0f

History | View | Annotate | Download (2.29 KB)

1
<HTML>
2
<HEAD>
3
<!-- Created by texi2html 1.56k from hooks.texi on 28 December 2002 -->
4

    
5
<TITLE>Video Hook Documentation</TITLE>
6
</HEAD>
7
<BODY>
8
<H1>Video Hook Documentation</H1>
9
<P>
10
<P><HR><P>
11
<H1>Table of Contents</H1>
12
<UL>
13
<LI><A NAME="TOC1" HREF="hooks.html#SEC1">1. Introduction</A>
14
<UL>
15
<LI><A NAME="TOC2" HREF="hooks.html#SEC2">1.1 null.c</A>
16
<LI><A NAME="TOC3" HREF="hooks.html#SEC3">1.2 fish.c</A>
17
<LI><A NAME="TOC4" HREF="hooks.html#SEC4">1.3 imlib2.c</A>
18
</UL>
19
</UL>
20
<P><HR><P>
21

    
22
<P>
23
Video Hook Documentation
24

    
25

    
26

    
27

    
28
<H1><A NAME="SEC1" HREF="hooks.html#TOC1">1. Introduction</A></H1>
29

    
30
<P>
31
The video hook functionality is designed (mostly) for live video. It allows
32
the video to be modified or examined between the decoder and the encoder.
33

    
34

    
35
<P>
36
Any number of hook modules can be placed inline, and they are run in the
37
order that they were specified on the ffmpeg command line.
38

    
39

    
40
<P>
41
Three modules are provided and are described below. They are all intended to
42
be used as a base for your own modules. 
43

    
44

    
45
<P>
46
Modules are loaded using the -vhook option to ffmpeg. The value of this parameter
47
is a space seperated list of arguments. The first is the module name, and the rest
48
are passed as arguments to the Configure function of the module.
49

    
50

    
51

    
52

    
53
<H2><A NAME="SEC2" HREF="hooks.html#TOC2">1.1 null.c</A></H2>
54

    
55
<P>
56
This does nothing. Actually it converts the input image to RGB24 and then converts
57
it back again. This is meant as a sample that you can use to test your setup.
58

    
59

    
60

    
61

    
62
<H2><A NAME="SEC3" HREF="hooks.html#TOC3">1.2 fish.c</A></H2>
63

    
64
<P>
65
This implements a 'fish detector'. Essentially it converts the image into HSV
66
space and tests whether more than a certain percentage of the pixels fall into
67
a specific HSV cuboid. If so, then the image is saved into a file for processing
68
by other bits of code.
69

    
70

    
71
<P>
72
Why use HSV? It turns out that HSV cuboids represent a more compact range of
73
colors than would an RGB cuboid.
74

    
75

    
76

    
77

    
78
<H2><A NAME="SEC4" HREF="hooks.html#TOC4">1.3 imlib2.c</A></H2>
79

    
80
<P>
81
This allows a caption to be placed onto each frame. It supports inserting the
82
time and date. By using the imlib functions, it would be easy to add your own
83
graphical logo, add a frame/border, etc.
84

    
85

    
86
<P><HR><P>
87
This document was generated on 28 December 2002 using
88
<A HREF="http://wwwinfo.cern.ch/dis/texi2html/">texi2html</A>&nbsp;1.56k.
89
</BODY>
90
</HTML>