gstreamer/gst/audioconvert/audioconvert.h
Bernhard Miller b2db18cda2 audioconvert: avoid float calculations when mixing integer-formatted channels
The patch calculates a second channel mixing matrix from the current one. The
matrix contains the original values * (2^10) as integers. This matrix is used
when integer-formatted channels are mixed.

On a ARM Cortex-A8, single core, 800MHz this improves performance in a
testcase from 29s to 9s for downmixing 6 channels to stereo.

https://bugzilla.gnome.org/show_bug.cgi?id=747005
2015-04-01 07:31:37 -07:00

151 lines
4.1 KiB
C

/* GStreamer
* Copyright (C) 2004 Ronald Bultje <rbultje@ronald.bitfreak.net>
*
* audioconvert.h: audio format conversion library
*
* 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 __AUDIO_CONVERT_H__
#define __AUDIO_CONVERT_H__
#include <gst/gst.h>
#include <gst/audio/audio.h>
GST_DEBUG_CATEGORY_EXTERN (audio_convert_debug);
#define GST_CAT_DEFAULT (audio_convert_debug)
/**
* GstAudioConvertDithering:
* @DITHER_NONE: No dithering
* @DITHER_RPDF: Rectangular dithering
* @DITHER_TPDF: Triangular dithering (default)
* @DITHER_TPDF_HF: High frequency triangular dithering
*
* Set of available dithering methods when converting audio.
*/
typedef enum
{
DITHER_NONE = 0,
DITHER_RPDF,
DITHER_TPDF,
DITHER_TPDF_HF
} GstAudioConvertDithering;
/**
* GstAudioConvertNoiseShaping:
* @NOISE_SHAPING_NONE: No noise shaping (default)
* @NOISE_SHAPING_ERROR_FEEDBACK: Error feedback
* @NOISE_SHAPING_SIMPLE: Simple 2-pole noise shaping
* @NOISE_SHAPING_MEDIUM: Medium 5-pole noise shaping
* @NOISE_SHAPING_HIGH: High 8-pole noise shaping
*
* Set of available noise shaping methods
*/
typedef enum
{
NOISE_SHAPING_NONE = 0,
NOISE_SHAPING_ERROR_FEEDBACK,
NOISE_SHAPING_SIMPLE,
NOISE_SHAPING_MEDIUM,
NOISE_SHAPING_HIGH
} GstAudioConvertNoiseShaping;
typedef struct _AudioConvertCtx AudioConvertCtx;
#if 0
typedef struct _AudioConvertFmt AudioConvertFmt;
struct _AudioConvertFmt
{
/* general caps */
gboolean is_int;
gint endianness;
gint width;
gint rate;
gint channels;
GstAudioChannelPosition *pos;
gboolean unpositioned_layout;
/* int audio caps */
gboolean sign;
gint depth;
gint unit_size;
};
#endif
typedef void (*AudioConvertUnpack) (gpointer src, gpointer dst, gint scale,
gint count);
typedef void (*AudioConvertPack) (gpointer src, gpointer dst, gint scale,
gint count);
typedef void (*AudioConvertMix) (AudioConvertCtx *, gpointer, gpointer, gint);
typedef void (*AudioConvertQuantize) (AudioConvertCtx * ctx, gpointer src,
gpointer dst, gint count);
struct _AudioConvertCtx
{
GstAudioInfo in;
GstAudioInfo out;
AudioConvertUnpack unpack;
AudioConvertPack pack;
/* channel conversion matrix, m[in_channels][out_channels].
* If identity matrix, passthrough applies. */
gfloat **matrix;
/* channel conversion matrix with int values, m[in_channels][out_channels].
* this is matrix * (2^10) as integers */
gint **matrix_int;
/* temp storage for channelmix */
gpointer tmp;
gboolean in_default;
gboolean mix_passthrough;
gboolean out_default;
gpointer tmpbuf;
gint tmpbufsize;
gint in_scale;
gint out_scale;
AudioConvertMix channel_mix;
AudioConvertQuantize quantize;
GstAudioConvertDithering dither;
GstAudioConvertNoiseShaping ns;
/* last random number generated per channel for hifreq TPDF dither */
gpointer last_random;
/* contains the past quantization errors, error[out_channels][count] */
gdouble *error_buf;
};
gboolean audio_convert_prepare_context (AudioConvertCtx * ctx,
GstAudioInfo * in, GstAudioInfo * out,
GstAudioConvertDithering dither, GstAudioConvertNoiseShaping ns);
gboolean audio_convert_get_sizes (AudioConvertCtx * ctx, gint samples,
gint * srcsize, gint * dstsize);
gboolean audio_convert_clean_context (AudioConvertCtx * ctx);
gboolean audio_convert_convert (AudioConvertCtx * ctx, gpointer src,
gpointer dst, gint samples, gboolean src_writable);
#endif /* __AUDIO_CONVERT_H__ */