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74 lines
1.5 KiB
Text
74 lines
1.5 KiB
Text
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A type properties system might look like following:
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1) Type definition includes the properties and their ranges:
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audio/mp3
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layer: 1 - 3
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bitrate: 8 - 320
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audio/raw
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format: bitfield (using asound.h definitions)
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depth: 8 - 32
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rate: 4000 - 96000
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channels: 1 - n
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interleave: boolean
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video/raw
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format: 32-bit FOURCC
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bpp: 1 - 32
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width: 1 - n
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height: 1 - n
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framerate: 32-bit float
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etc.
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2) An element can specify what subtypes it can deal with by creating a list of property tables:
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mpg123: audio/mp3
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layer: 1 - 3
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bitrate: 8 - 320
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osssink:
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format: S8, S16, etc.
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depth: 8 - 16
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rate: 8000 - 48000
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channels: 1 - 2
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interleave: true
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And you could list several of these, so for instance if the card only supports 8-bit at up to 22KHz in
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mono, you can remove S8 from the above list and add a second entry:
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osssink:
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format: S8
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depth: 8
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rate: 8000 - 22050
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channels: 1
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interleave: false (irrelevant)
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The obvious problem with these examples is that the rate isn't really 8000 - 48000, it's 8000, 11025,
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16000, 22050, 44100, and 48000. However, we may be able to leave these to pad connect time.
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struct _type_definition {
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char *mime_type;
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....
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GData *properties;
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}
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gst_type_add_property_int(_type *type,gchar *propname,int min,int max) {
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struct _type_prop_int prop_int;
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GQuark quark = g_quark_from_string(propname);
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prop_int->id = quark;
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prop_int->min = min;
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prop_int->max = max;
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g_datalist_id_set_data(type->properties,quark,&prop_int);
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}
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