gstreamer/gst-libs/gst/video/video-resampler.h
Wim Taymans 7b7270ecff video-resampler: add option to limits taps
Add an option to limit the number of taps to use in automatic mode. The
problem is that for lanczos, we might use more taps than what we can
handle with the current precision.
Rework the other options a little to make it nicer to set defaults.
2014-11-21 11:12:50 +01:00

170 lines
5.2 KiB
C

/* 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>
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"
/**
* GST_VIDEO_RESAMPLER_OPT_ENVELOPE:
*
* G_TYPE_DOUBLE, specifies the size of filter envelope for
* @GST_VIDEO_RESAMPLER_METHOD_LANCZOS. values are clamped between
* 1.0 and 5.0. 2.0 is the default.
*/
#define GST_VIDEO_RESAMPLER_OPT_ENVELOPE "GstVideoResampler.envelope"
/**
* GST_VIDEO_RESAMPLER_OPT_SHARPNESS:
*
* G_TYPE_DOUBLE, specifies sharpness of the filter for
* @GST_VIDEO_RESAMPLER_METHOD_LANCZOS. values are clamped between
* 0.5 and 1.5. 1.0 is the default.
*/
#define GST_VIDEO_RESAMPLER_OPT_SHARPNESS "GstVideoResampler.sharpness"
/**
* GST_VIDEO_RESAMPLER_OPT_SHARPEN:
*
* G_TYPE_DOUBLE, specifies sharpening of the filter for
* @GST_VIDEO_RESAMPLER_METHOD_LANCZOS. values are clamped between
* 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"
/**
* GstVideoResamplerFlags:
* @GST_VIDEO_RESAMPLER_FLAG_NONE: no flags
*
* Different resampler flags.
*
* Since: 1.6
*/
typedef enum {
GST_VIDEO_RESAMPLER_FLAG_NONE = (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;
gpointer _gst_reserved[GST_PADDING];
};
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);
void gst_video_resampler_clear (GstVideoResampler *resampler);
G_END_DECLS
#endif /* __GST_VIDEO_RESAMPLER_H__ */