2 * Copyright (C) 2011 Michael Niedermayer (michaelni@gmx.at)
4 * This file is part of libswresample
6 * libswresample is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * libswresample is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with libswresample; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * libswresample public header
30 #include "libavutil/samplefmt.h"
32 #define LIBSWRESAMPLE_VERSION_MAJOR 0
33 #define LIBSWRESAMPLE_VERSION_MINOR 11
34 #define LIBSWRESAMPLE_VERSION_MICRO 100
36 #define LIBSWRESAMPLE_VERSION_INT AV_VERSION_INT(LIBSWRESAMPLE_VERSION_MAJOR, \
37 LIBSWRESAMPLE_VERSION_MINOR, \
38 LIBSWRESAMPLE_VERSION_MICRO)
40 #if LIBSWRESAMPLE_VERSION_MAJOR < 1
41 #define SWR_CH_MAX 32 ///< Maximum number of channels
44 #define SWR_FLAG_RESAMPLE 1 ///< Force resampling even if equal sample rate
45 //TODO use int resample ?
46 //long term TODO can we enable this dynamically?
50 SWR_DITHER_RECTANGULAR,
51 SWR_DITHER_TRIANGULAR,
52 SWR_DITHER_TRIANGULAR_HIGHPASS,
53 SWR_DITHER_NB, ///< not part of API/ABI
56 typedef struct SwrContext SwrContext;
59 * Get the AVClass for swrContext. It can be used in combination with
60 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
64 const AVClass *swr_get_class(void);
67 * Allocate SwrContext.
69 * If you use this function you will need to set the parameters (manually or
70 * with swr_alloc_set_opts()) before calling swr_init().
72 * @see swr_alloc_set_opts(), swr_init(), swr_free()
73 * @return NULL on error, allocated context otherwise
75 struct SwrContext *swr_alloc(void);
78 * Initialize context after user parameters have been set.
80 * @return AVERROR error code in case of failure.
82 int swr_init(struct SwrContext *s);
85 * Allocate SwrContext if needed and set/reset common parameters.
87 * This function does not require s to be allocated with swr_alloc(). On the
88 * other hand, swr_alloc() can use swr_alloc_set_opts() to set the parameters
89 * on the allocated context.
91 * @param s Swr context, can be NULL
92 * @param out_ch_layout output channel layout (AV_CH_LAYOUT_*)
93 * @param out_sample_fmt output sample format (AV_SAMPLE_FMT_*).
94 * @param out_sample_rate output sample rate (frequency in Hz)
95 * @param in_ch_layout input channel layout (AV_CH_LAYOUT_*)
96 * @param in_sample_fmt input sample format (AV_SAMPLE_FMT_*).
97 * @param in_sample_rate input sample rate (frequency in Hz)
98 * @param log_offset logging level offset
99 * @param log_ctx parent logging context, can be NULL
101 * @see swr_init(), swr_free()
102 * @return NULL on error, allocated context otherwise
104 struct SwrContext *swr_alloc_set_opts(struct SwrContext *s,
105 int64_t out_ch_layout, enum AVSampleFormat out_sample_fmt, int out_sample_rate,
106 int64_t in_ch_layout, enum AVSampleFormat in_sample_fmt, int in_sample_rate,
107 int log_offset, void *log_ctx);
110 * Free the given SwrContext and set the pointer to NULL.
112 void swr_free(struct SwrContext **s);
117 * in and in_count can be set to 0 to flush the last few samples out at the
120 * If more input is provided than output space then the input will be buffered.
121 * You can avoid this buffering by providing more output space than input.
122 * Convertion will run directly without copying whenever possible.
124 * @param s allocated Swr context, with parameters set
125 * @param out output buffers, only the first one need be set in case of packed audio
126 * @param out_count amount of space available for output in samples per channel
127 * @param in input buffers, only the first one need to be set in case of packed audio
128 * @param in_count number of input samples available in one channel
130 * @return number of samples output per channel, negative value on error
132 int swr_convert(struct SwrContext *s, uint8_t **out, int out_count,
133 const uint8_t **in , int in_count);
136 * Activate resampling compensation.
138 int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance);
141 * Set a customized input channel mapping.
143 * @param s allocated Swr context, not yet initialized
144 * @param channel_map customized input channel mapping (array of channel
145 * indexes, -1 for a muted channel)
146 * @return AVERROR error code in case of failure.
148 int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map);
151 * Set a customized remix matrix.
153 * @param s allocated Swr context, not yet initialized
154 * @param matrix remix coefficients; matrix[i + stride * o] is
155 * the weight of input channel i in output channel o
156 * @param stride offset between lines of the matrix
157 * @return AVERROR error code in case of failure.
159 int swr_set_matrix(struct SwrContext *s, const double *matrix, int stride);
162 * Return the LIBSWRESAMPLE_VERSION_INT constant.
164 unsigned swresample_version(void);
167 * Return the swr build-time configuration.
169 const char *swresample_configuration(void);
172 * Return the swr license.
174 const char *swresample_license(void);