【所感】
(*1)MPEG-4 Systems standard (ISO/IEC 14496-1)に基づくマルチメディア・フレームワークです。
これがGPACの本分。フレームワークと言うのは良く解らないが、なんでもイチからCでゴリゴリ書くより、必要に応じて呼び出せるもん作っておい たほうがいいでしょというようなもんらしい。ライブラリとどう違うのか良く解らないが「集合」かな？KTC眼鏡レンチセット、みてーな。プログラマではな いので深入りしない。
MPEG-4 Systemsとはなんぞやということになると、鬼のように幅広く、イメージしにくい。
放送・通信のみならず、インタラクティビティという点ではゲーム（的なもの）も包含しうる。
ってもオイラにイメージが湧くのはそのくらいで、ぜってーその先がある。
その他GPACプロジェクトのドキュメントを読んでも読んでも「なんだかスゴそうだ」という印象以上のもんが持てないのは、ベースがQuickTime（時 間軸を基軸にデジタルデータを管理する考え方、テクノロジーというよりプリンシパル）である事と無縁ではないだろう。
MPEG-4規格自体が、純粋に「デジタルで動画を扱う事」を目指したMPEG-1/2とは根本的に性質が異 なる。
(*2)他にもGPACはMPEG-4 Systemの encoder/multiplexerの機能を持っています。
【ソースコード内のmanがD&Dで開けた】
$ man /Users/USERNAME/gpac/doc/man/gpac.1
NAME
GPAC - MPEG-4 Systems Framework and Software Development Kit
DESCRIPTION
GPAC stands (does it ?) for GPAC Project on Advanced Content. It is an
implementation of the MPEG-4 Systems standard written in ANSI C. GPAC
provides tools for media playback, vector graphics and 3D rendering,
MPEG-4 authoring and distribution. This man page is about configura-
tion of the GPAC framework version 0.4.3.
INTRODUCTION
Some applications in the GPAC framework use a configuration file shared
among modules and reloadable at run time. This file is located in the
user home directory and called ".gpacrc".
The configuration file is based on the win32 .ini file model, ordered
by sections and keys.
A section is declared as [SectionName] , a key is declared as key-
Name=value , the key value is not interpreted and always handled as
ASCII text. Plugins may use the configuration file as well (to avoid
multiple files).
Note on plugin names: Plugin names as given in the configuration file
are names exported by each interface and not name of the physical
library file (.dll/.so ...). The physical file name can however be
used to identify a plugin, it will be replaced by the interface name if
the plugin was successfully loaded.
【~/gpac/applicationsの内容】
そうすっとgpacアプリケーションの一覧がそれなりに埋まる。
| 名前 | 種類 | メモ |
| CVS | folder | |
| GPAX | folder | GPAC ActiveX control, IE only |
| Makefile | file | |
| generators | folder | |
| mp42avi | folder | NAME MP42AVI - MPEG-4 BIFS to Video converter SYNOPSIS MP42AVI [options] file DESCRIPTION MP42AVI is a tool to convert a pure MPEG-4 BIFS presentation (no audio, no image, no video) to an uncompressed sequence of images or an uncom- pressed RGB avi file. Pages du manuel Linux |
| mp4box | folder | MPEG-4, 3GP, 3GP2コンテントの作成と配布に必要な機能を一つにまとめたツール。 NAME MP4Box - MPEG-4 Systems Toolbox SYNOPSIS MP4Box [options] file [options] DESCRIPTION MP4Box is a multi-purpose command line tool to create and edit MPEG-4 Systems presentations and manipulate ISO-media files (MP4, 3GP, MOV). MP4Box supports file conversion from various raw formats and IsoMe- dia/AVI/MPEG-PS/OGG containers, file hinting for RTP streaming for QuickTime compatible streaming servers, file interleaving, file frag- mentation and track extraction. MP4Box also provides dump tools used to inspect file layout, RTP hint tracks, SDP information, scene composition. It may also be used to con- vert to and from BT/XMT-A/VRML/X3D. MP4Box also features MPEG-4 Systems encoders and decoders for BIFS and OD tools. MP4Box doesn't expect any particular order in options at prompt. |
| mp4client | folder | NAME MP4Client - GPAC MPEG-4 command-line Player SYNOPSIS MP4Client [options] [file] DESCRIPTION MP4Client is GPAC command-line player. It supports all GPAC playback features (2D and 3D support, local playback, RTP streaming, HTTP fast- start, many audio and video codecs ...). MP4Client also supports visual extraction to BMP, RAW or AVI (no compression, no audio). |
| osmo4_sym | folder | GPAC Players |
| osmo4_w32 | folder | GPAC Players |
| osmo4_wce | folder | GPAC Players |
| osmo4_wx | folder | GPAC Players |
| osmophone | folder | GPAC Players |
| osmozilla | folder | GPAC plugin for mozilla-based browsers |
| standalone2drender | folder | |
| testapps | folder | |
| v4studio | folder |
