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IRIX Base Documentation 2001 May
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SGI IRIX Base Documentation 2001 May.iso
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relnotes
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dmedia_eoe
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2001-04-17
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- 1 -
15. _D_i_g_i_t_a_l__M_e_d_i_a__D_S_O_'_s
A number of shared execution libraries (DSO's) are included
in the _d_m_e_d_i_a__e_o_e images. The directory /usr/lib contains
versions of these DSO's for use by o32 applications, and the
directory /usr/lib32 contains versions for use by n32
applications. The subsystems _d_m_e_d_i_a__e_o_e._s_w._l_i_b and
_d_m_e_d_i_a__e_o_e._s_w_3_2._l_i_b install the o32 and n32 versions of the
base DSO's respectively. The subsystems
_d_m_e_d_i_a__e_o_e._s_w._p_l_u_g_i_n_s and _d_m_e_d_i_a__e_o_e._s_w_3_2._p_l_u_g_i_n_s install
the o32 and n32 versions of special-effects plug-in modules.
This section briefly describes the functions of the
different digital media DSO's.
15.1 _A_u_d_i_o__L_i_b_r_a_r_y
The Audio Library provides an application software interface
to the audio I/O device capabilities of the system.
15.1.1 _C_h_a_n_g_e_s__a_n_d__A_d_d_i_t_i_o_n_s
+o In IRIX 6.4, and starting with IRIX 6.3, the Audio
Library is now a DSO rather than a static library. It
is installed as /usr/{lib,lib32,lib64}/libaudio.so.1.
Applications which were linked with libaudio.a in
previous releases will continue to operate properly in
IRIX 6.4.
15.2 _V_i_d_e_o__L_i_b_r_a_r_y
The Video Library provides an application software interface
to the video I/O device capabilities of the system, as well
as access to special video hardware paths such as video to
screen or screen capture to memory on some systems which
have these features. The Video Library DSO is installed as
/_u_s_r/{_l_i_b,_l_i_b_3_2}/_l_i_b_v_l._s_o.
- 2 -
15.3 _D_i_g_i_t_a_l__M_e_d_i_a__L_i_b_r_a_r_y__a_n_d__I_m_a_g_e_/_A_u_d_i_o__C_o_n_v_e_r_t_e_r_s
The Digital Media Library provides core functionality for
digital media applications. Functionality in IRIX 6.4
includes:
+o IIIImmmmaaaaggggeeee ccccoooonnnnvvvveeeerrrrssssiiiioooonnnn mmmmaaaannnnaaaaggggeeeemmmmeeeennnntttt: a software framework for
managing software image codecs and realtime memory-to-
memory image codecs which rely on hardware
acceleration.
+o AAAAuuuuddddiiiioooo ccccoooonnnnvvvveeeerrrrssssiiiioooonnnn mmmmaaaannnnaaaaggggeeeemmmmeeeennnntttt: a software framework for
managing audio data conversion including
compression/decompression, sampling rate conversion,
sample data format conversion, and channel matrix
conversion.
+o DDDDiiiiggggiiiittttaaaallll mmmmeeeeddddiiiiaaaa bbbbuuuuffffffffeeeerrrr ssssyyyysssstttteeeemmmm: a software framework which
allows memory buffers containing compressed or
uncompressed image data to be moved with copying
between various subsystems including video I/O ports,
software or realtime memory-to-memory image
compressors, and OpenGL.
+o SSSSooooffffttttwwwwaaaarrrreeee ccccoooolllloooorrrr ssssppppaaaacccceeee ccccoooonnnnvvvveeeerrrrssssiiiioooonnnn: the Digital Media
Library includes optimized code for performing high
quality color space conversion in software.
+o DDDDiiiiggggiiiittttaaaallll mmmmeeeeddddiiiiaaaa nnnneeeettttwwwwoooorrrrkkkkiiiinnnngggg: a network-independent
framework which allows the interchange of _D_M_b_u_f_f_e_r_s
between processes, whether on the same machine or on
machines connected by a network.
15.3.1 _D_i_g_i_t_a_l__M_e_d_i_a__L_i_b_r_a_r_y__D_S_O_'_s The Digital Media
Library is composed of the following DSO's:
+o /_u_s_r/{_l_i_b,_l_i_b_3_2}/_l_i_b_d_m_e_d_i_a._s_o: The Digital Media
Library.
+o /_u_s_r/{_l_i_b,_l_i_b_3_2}/_d_m_e_d_i_a/_i_m_a_g_e_c_o_n_v_e_r_t_e_r_s/*._s_o: Image
converter modules for software image codecs and
realtime memory-to-memory hardware-accelerated codecs.
These modules are loaded at runtime by the Digital
Media Library when required by an application. They are
not loaded directly by applications.
+o /_u_s_r/{_l_i_b,_l_i_b_3_2}/_d_m_e_d_i_a/_a_u_d_i_o_c_o_n_v_e_r_t_e_r_s/*._s_o: Audio
converter modules for audio compression/decompression,
audio sampling rate conversion, and audio data format
and channel matrix conversion. These modules are loaded
- 3 -
at runtime by the Digital Media Library when required
by an application. They are not loaded directly by
applications.
+o /_u_s_r/{_l_i_b,_l_i_b_3_2}/_l_i_b_c_l._s_o: The "old" Compression
Library. This library provides the developer interface
and software framework for several image codecs and a
few audio codecs in IRIX 6.2 and earlier releases. The
full IRIX 6.2 functionality is supported in IRIX 6.4
and future releases for backward compatibility with
existing applications. Low level image codec modules in
the "imageconverters" directory are now shared by
libdmedia.so and libcl.so.
+o /_u_s_r/{_l_i_b, _l_i_b_3_2}/_l_i_b_a_w_a_r_e_a_u_d_i_o._s_o: Aware,Inc audio
compression framework DSO. There are no routines in
this DSO that are visible to developers. This DSO is
used internally by libcl.so for interfacing to the MPEG
and Aware, Inc MultiRate codecs only.
+o /_u_s_r/{_l_i_b, _l_i_b_3_2}/_l_i_b_a_u_d_i_o_u_t_i_l._s_o: In earlier releases,
this library included audio conversion and compression
operations. In IRIX 6.3 and IRIX 6.4, audio conversion
operations have all been centralized in the Digital
Media Library, libdmedia.so. As a result,
libaudioutil.so is now a symlink to libdmedia.so.
+o /usr/{lib,lib32}/libdmnet.so: _T_h_i_s _l_i_b_r_a_r_y _p_r_o_v_i_d_e_s _a
_s_t_a_n_d_a_r_d _A_P_I _f_o_r _m_o_v_i_n_g _D_i_g_i_t_a_l _M_e_d_i_a _b_u_f_f_e_r_s _b_e_t_w_e_e_n
_a_p_p_l_i_c_a_t_i_o_n_s _o_n _t_h_e _s_a_m_e _m_a_c_h_i_n_e _o_r _a_p_p_l_i_c_a_t_i_o_n_s
_s_e_p_a_r_a_t_e_d _b_y _a _n_e_t_w_o_r_k.
_1_5._3._2 _C_h_a_n_g_e_s__a_n_d__A_d_d_i_t_i_o_n_s
+o IRIX 6.5.12 added support for decompressing Microsoft
RLE. This will only work with data which was previously
generated using Quicktime(*).
+o The DMNet API for Digital Media Networking is an
addition to IRIX 6.5. It provides a standard API on
all IRIX platforms for interchanging Digital Media
buffers between processes, whether they are on the same
machine or separated by a network.
- 4 -
15.4 _M_o_v_i_e__L_i_b_r_a_r_y
The Movie Library provides core library software for
reading, writing, editing, and playing back standard movie
file formats (QuickTime(*), AVI, MPEG-1 video/systems
bitstreams, SGI Movie).
Starting with IRIX 6.3, the Movie Library is now composed of
a set of DSO's rather than a single static library.
Applications which were linked with libmovie.a in previous
releases will continue to operate properly in IRIX 6.4.
15.4.1 _M_o_v_i_e__L_i_b_r_a_r_y__D_S_O_'_s The Movie Library is composed
of the following DSO's:
+o /_u_s_r/{_l_i_b,_l_i_b_3_2}/_l_i_b_m_o_v_i_e_f_i_l_e._s_o: The Movie File
Library. This DSO implements file read, write, edit
support. It is a high-level library which builds on top
of the image compression/conversion and audio
compression/conversion functions in the core Digital
Media Library.
+o /_u_s_r/{_l_i_b,_l_i_b_3_2}/_l_i_b_m_o_v_i_e_p_l_a_y._s_o: The Movie Playback
Library. This DSO provides high level playback and
transport control functions to applications. It is
built on top of the "lower level" functions provided by
the Movie File Library, and uses OpenGL and the Audio
Library for rendering synchronized audio/image output.
+o /_u_s_r/{_l_i_b,_l_i_b_3_2}/_d_m_e_d_i_a/_m_o_v_i_e/*._s_o: Movie display ports
and rendering modules loaded internally by the playback
engine, libmovieplay.so, as required at runtime.
Applications do not load these modules directly.
+o /_u_s_r/{_l_i_b, _l_i_b_3_2}/{_l_i_b_m_o_v_i_e._s_o,_l_i_b_m_o_v_i_e_G_L._s_o}: These
are now "stub" DSO's which simply make available all
the public symbols from libmovieplay.so and
libmoviefile.so. They exist only to provide backward
compatibility with link lines for applications that
were previously built using "-lmovie" or "-lmovieGL".
In IRIX 6.4, it is strongly recommended that developers
explicitly link with "-lmovieplay -lmoviefile" or just
"-lmoviefile" as appropriate.
15.4.2 _C_h_a_n_g_e_s__a_n_d__A_d_d_i_t_i_o_n_s
+o IRIX 6.5.12 adds support for reading of 1, 2, 4, 8, 16
and 24 bit uncompressed AVI files. Originally only 32
bit uncompressed AVI files were supported.
- 5 -
+o IRIX 6.5.12 adds support for reading of Microsoft RLE
compressed AVI files.
+o IRIX 6.5.12 adds support to allow reading of compressed
header Quicktime(*) movie files.
+o As of IRIX 6.3 the Movie Library is no longer
statically linked into applications. It is now composed
of two high-level DSO's, libmoviefile.so and
libmovieplay.so, which contain the public movie file
and playback API's, as well as several of rendering and
playback modules loaded internally by libmovieplay.so.
15.4.3 _B_u_g__F_i_x_e_s
Bug 610006: An internal Movie Library data structure
and the algorithm that managed its growth could
fragment the application memory heap and cause poor
performance during movie capture. The data structure
and algorithm have been corrected in Irix 6.5.1m.
+o
15.5 _A_u_d_i_o__F_i_l_e__L_i_b_r_a_r_y
The Audio File Library, /_u_s_r/{_l_i_b,_l_i_b_3_2}/_l_i_b_a_u_d_i_o_f_i_l_e._s_o,
provides core library software for reading and writing a
variety of sound file formats (see the "Supported Media File
Formats" chapter of these release notes).
The Audio File Library is a high-level library that makes
use of the lower-level audio compression and conversion
functions offered by the core Digital Media Library.
15.5.1 _C_h_a_n_g_e_s__a_n_d__A_d_d_i_t_i_o_n_s
+o Addition of support for 32- and 64-bit floating point
AIFF-C files.
+o Addition of support for AIFF-C files which use IMA4:1
compression, and full compliance with Apple, Inc.
AIFF-C compression specifications.
- 6 -
15.6 _M_I_D_I__L_i_b_r_a_r_y
The MIDI Library, /_u_s_r/{_l_i_b, _l_i_b_3_2}/_l_i_b_m_d._s_o, provides an
application interface to the IRIX MIDI I/O system built.
This system offers support for timestamped MIDI I/O through
serial ports, and for delivery of interprocess MIDI events
(eg, play back a MIDI sound file using _I_S_o_u_n_d_P_l_a_y_e_r(_1) and
trigger music synthesis on a second process, the software
MIDI synthesizer).
15.6.1 _C_h_a_n_g_e_s__a_n_d__A_d_d_i_t_i_o_n_s
+o The MIDI Library has not changed since IRIX 6.2.
15.6.2 _K_n_o_w_n__P_r_o_b_l_e_m_s__a_n_d__W_o_r_k_a_r_o_u_n_d_s
+o In IRIX 6.4, MIDI I/O through the serial ports is fully
functional for the Onyx2 workstation and also for
Origin2000 with the optional base audio option. In
IRIX 6.3, MIDI I/O through the serial ports is not
functional on the O2 workstation. It is our hope that
we will be able to provide this functionality for IRIX
6.3 in the form of a patch.
(*) QuickTime is a registered trademark of Apple Computer,
Inc.