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<span style="font-family: monospace;">int lqt_colormodel_has_alpha(int
colormodel);</span><br style="font-family: monospace;">
<span style="font-family: monospace;">int lqt_colormodel_is_rgb(int
colormodel);</span><br style="font-family: monospace;">
<span style="font-family: monospace;">int lqt_colormodel_is_yuv(int
colormodel);</span><br style="font-family: monospace;">
<span style="font-family: monospace;"><br>
int lqt_num_colormodels();</span><br style="font-family: monospace;">
<span style="font-family: monospace;">const char *
lqt_get_colormodel_string(int index);</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">int lqt_get_colormodel(int index);</span><br
 style="font-family: monospace;">
<br>
The best idea is to decide, which colormodels you want to support in
your application. <span style="font-family: monospace;">BC_RGB888</span>
and <span style="font-family: monospace;">BC_YUV420P</span> should
always be supported. Please note, that libquicktimes internal
colorspace converter is not the fastest out there. The more colorspaces
you can handle yourself, the fewer time consuming internal conversions
will be used. A nice library, which converts many
libquicktime colormodels, is <a
 href="http://gmerlin.soutceforge.net/gavl.html">gavl</a>. Then call
for each video track:<br>
<br>
<span style="font-family: monospace;">int
lqt_get_best_colormodel(quicktime_t * file, int track, int * supported);</span><br>
<br>
<span style="font-family: monospace;">supported</span> is an array of
the colorspaces, you can handle terminated with <span
 style="font-family: monospace;">LQT_COLORMODEL_NONE</span>. The
function works for both en- and decoding and tries to minimize
conversion overhead and information loss.<br>
<h3><a name="6._Codec_registry_interface"></a>6. Codec registry
interface</h3>
This allows you to access the codecs, which are installed on the system
along with information about them. To query the registry about the
installed codecs, use:<br>
<br>
<span style="font-family: monospace;">lqt_codec_info_t **
lqt_query_registry(int audio, int video,</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
int encode, int decode);</span><br style="font-family: monospace;">
<br>
The return value is a NULL terminated array of <span
 style="font-family: monospace;">lqt_codec_info_t</span> pointers. The
codec info is defined in lqt_codecinfo.h:<br>
<br>
<span style="font-family: monospace;">typedef struct lqt_codec_info_s
lqt_codec_info_t;<br>
<br style="font-family: monospace;">
</span><span style="font-family: monospace;">struct lqt_codec_info_s</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; {</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; int compatibility_flags;
/* Compatibility flags (See defines above) */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; </span><span
 style="font-family: monospace;">char *
name;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
/* Name of the
codec&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
*/</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; char *
long_name;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /*
Long name of the codec&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
*/</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; char *
description;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /*
Description&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
*/</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;</span><span
 style="font-family: monospace;"> lqt_codec_type type;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; lqt_codec_direction
direction;</span><br style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; int
num_fourccs;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
/* Fourccs, this codec can handle */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; char ** fourccs;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; int num_wav_ids;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; int * wav_ids;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; int num_encoding_parameters;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; lqt_parameter_info_t *
encoding_parameters;</span><br style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; int num_decoding_parameters;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; lqt_parameter_info_t *
decoding_parameters;</span><br style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; /* Colormodels this codec can
handle */</span><br style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; int num_encoding_colormodels;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; int * encoding_colormodels;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;"></span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; int decoding_colormodel;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; /* The following members are
set by libquicktime&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; char *
module_filename;&nbsp;&nbsp;&nbsp; /* Filename of the module&nbsp; */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; int
module_index;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /*
Index inside the module */</span><br style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; uint32_t
file_time;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* File
modification time&nbsp; */</span><br style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; struct lqt_codec_info_s *
next;&nbsp;&nbsp; /* For chaining */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; };</span><br
 style="font-family: monospace;">
<br style="font-family: monospace;">
Most interesting are the name, long name and description. The <span
 style="font-family: monospace;">encoding_parameters</span> and <span
 style="font-family: monospace;">decoding_parameters</span> arrays
contain informations about the parameters you can pass to
lqt_set_[audio|video]_parameter. The parameter infos are defined like
this:<br>
<br>
<span style="font-family: monospace;">typedef enum</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; {</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;
LQT_PARAMETER_INT,</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;
LQT_PARAMETER_STRING,</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;
LQT_PARAMETER_STRINGLIST, /* String with options */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp;&nbsp; /* This dummy
type is used to separate sections (real_name will be on tab-label) */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;
LQT_PARAMETER_SECTION</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; } lqt_parameter_type_t;</span><br
 style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">typedef union</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; {</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; int val_int;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; char * val_string;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; } lqt_parameter_value_t;</span><br
 style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">typedef struct</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; {</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; /* Parameter name (to be
passed to quicktime_set_parameter() ) */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; char * name;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; char * real_name; /* Other
name (for making dialogs) */</span><br style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; lqt_parameter_type_t type;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; lqt_parameter_value_t
val_default;</span><br style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; /*</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp; *&nbsp;&nbsp;
Minimum and maximum values:</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp; *&nbsp;&nbsp; These
are only valid for numeric types and if val_min &lt; val_max</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp; */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; int val_min;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; int val_max;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; /*</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp; *&nbsp; Possible
options (only valid for LQT_STRINGLIST)</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;&nbsp; */</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; int num_stringlist_options;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp; char ** stringlist_options;</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp; } lqt_parameter_info_t;</span><br
 style="font-family: monospace;">
<br>
You can also get the codec infos, when you read a file:<br>
<br>
<span style="font-family: monospace;">lqt_codec_info_t **
lqt_audio_codec_from_file(quicktime_t *, int track);</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">lqt_codec_info_t **
lqt_video_codec_from_file(quicktime_t *, int track);</span><br>
<br>
Codec infos are returned as a local copy, so you must free them. This
is done with:<br>
<br>
<span style="font-family: monospace;">void
lqt_destroy_codec_info(lqt_codec_info_t ** info);</span><br>
<br>
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