gstreamer/gst-libs/gst/video/video-resampler.h

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/* GStreamer
* Copyright (C) <2014> Wim Taymans <wim.taymans@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_VIDEO_RESAMPLER_H__
#define __GST_VIDEO_RESAMPLER_H__
#include <gst/gst.h>
#include <gst/video/video-prelude.h>
G_BEGIN_DECLS
typedef struct _GstVideoResampler GstVideoResampler;
/**
* GstVideoResamplerMethod:
* @GST_VIDEO_RESAMPLER_METHOD_NEAREST: Duplicates the samples when
* upsampling and drops when downsampling
* @GST_VIDEO_RESAMPLER_METHOD_LINEAR: Uses linear interpolation to reconstruct
* missing samples and averaging to downsample
* @GST_VIDEO_RESAMPLER_METHOD_CUBIC: Uses cubic interpolation
* @GST_VIDEO_RESAMPLER_METHOD_SINC: Uses sinc interpolation
* @GST_VIDEO_RESAMPLER_METHOD_LANCZOS: Uses lanczos interpolation
*
* Different subsampling and upsampling methods
*
* Since: 1.6
*/
typedef enum {
GST_VIDEO_RESAMPLER_METHOD_NEAREST,
GST_VIDEO_RESAMPLER_METHOD_LINEAR,
GST_VIDEO_RESAMPLER_METHOD_CUBIC,
GST_VIDEO_RESAMPLER_METHOD_SINC,
GST_VIDEO_RESAMPLER_METHOD_LANCZOS
} GstVideoResamplerMethod;
/**
* GST_VIDEO_RESAMPLER_OPT_CUBIC_B:
*
* G_TYPE_DOUBLE, B parameter of the cubic filter. The B
* parameter controls the bluriness. Values between 0.0 and
* 2.0 are accepted. 1/3 is the default.
*
* Below are some values of popular filters:
* B C
* Hermite 0.0 0.0
* Spline 1.0 0.0
* Catmull-Rom 0.0 1/2
* Mitchell 1/3 1/3
* Robidoux 0.3782 0.3109
* Robidoux
* Sharp 0.2620 0.3690
* Robidoux
* Soft 0.6796 0.1602
*/
#define GST_VIDEO_RESAMPLER_OPT_CUBIC_B "GstVideoResampler.cubic-b"
/**
* GST_VIDEO_RESAMPLER_OPT_CUBIC_C:
*
* G_TYPE_DOUBLE, C parameter of the cubic filter. The C
* parameter controls the Keys alpha value. Values between 0.0 and
* 2.0 are accepted. 1/3 is the default.
*
* See #GST_VIDEO_RESAMPLER_OPT_CUBIC_B for some more common values
*/
#define GST_VIDEO_RESAMPLER_OPT_CUBIC_C "GstVideoResampler.cubic-c"
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/**
* GST_VIDEO_RESAMPLER_OPT_ENVELOPE:
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*
* G_TYPE_DOUBLE, specifies the size of filter envelope for
* @GST_VIDEO_RESAMPLER_METHOD_LANCZOS. values are clamped between
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* 1.0 and 5.0. 2.0 is the default.
*/
#define GST_VIDEO_RESAMPLER_OPT_ENVELOPE "GstVideoResampler.envelope"
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/**
* GST_VIDEO_RESAMPLER_OPT_SHARPNESS:
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*
* G_TYPE_DOUBLE, specifies sharpness of the filter for
* @GST_VIDEO_RESAMPLER_METHOD_LANCZOS. values are clamped between
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* 0.5 and 1.5. 1.0 is the default.
*/
#define GST_VIDEO_RESAMPLER_OPT_SHARPNESS "GstVideoResampler.sharpness"
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/**
* GST_VIDEO_RESAMPLER_OPT_SHARPEN:
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*
* G_TYPE_DOUBLE, specifies sharpening of the filter for
* @GST_VIDEO_RESAMPLER_METHOD_LANCZOS. values are clamped between
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* 0.0 and 1.0. 0.0 is the default.
*/
#define GST_VIDEO_RESAMPLER_OPT_SHARPEN "GstVideoResampler.sharpen"
/**
* GST_VIDEO_RESAMPLER_OPT_MAX_TAPS:
*
* G_TYPE_INT, limits the maximum number of taps to use.
* 16 is the default.
*/
#define GST_VIDEO_RESAMPLER_OPT_MAX_TAPS "GstVideoResampler.max-taps"
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/**
* GstVideoResamplerFlags:
* @GST_VIDEO_RESAMPLER_FLAG_NONE: no flags
* @GST_VIDEO_RESAMPLER_FLAG_HALF_TAPS: when no taps are given, half the
* number of calculated taps. This can be used when making scalers
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* for the different fields of an interlaced picture. Since: 1.10
*
* Different resampler flags.
*
* Since: 1.6
*/
typedef enum {
GST_VIDEO_RESAMPLER_FLAG_NONE = (0),
GST_VIDEO_RESAMPLER_FLAG_HALF_TAPS = (1 << 0),
} GstVideoResamplerFlags;
/**
* GstVideoResampler:
* @in_size: the input size
* @out_size: the output size
* @max_taps: the maximum number of taps
* @n_phases: the number of phases
* @offset: array with the source offset for each output element
* @phase: array with the phase to use for each output element
* @n_taps: array with new number of taps for each phase
* @taps: the taps for all phases
*
* A structure holding resampler information.
*
* Since: 1.6
*/
struct _GstVideoResampler
{
gint in_size;
gint out_size;
guint max_taps;
guint n_phases;
guint32 *offset;
guint32 *phase;
guint32 *n_taps;
gdouble *taps;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GST_VIDEO_API
gboolean gst_video_resampler_init (GstVideoResampler *resampler,
GstVideoResamplerMethod method,
GstVideoResamplerFlags flags,
guint n_phases, guint n_taps,
gdouble shift,
guint in_size, guint out_size,
GstStructure *options);
GST_VIDEO_API
void gst_video_resampler_clear (GstVideoResampler *resampler);
G_END_DECLS
#endif /* __GST_VIDEO_RESAMPLER_H__ */