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 10
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?
49 typedef struct SwrContext SwrContext;
52 * Allocate SwrContext.
54 * If you use this function you will need to set the parameters (manually or
55 * with swr_alloc_set_opts()) before calling swr_init().
57 * @see swr_alloc_set_opts(), swr_init(), swr_free()
58 * @return NULL on error, allocated context otherwise
60 struct SwrContext *swr_alloc(void);
63 * Initialize context after user parameters have been set.
65 * @return AVERROR error code in case of failure.
67 int swr_init(struct SwrContext *s);
70 * Allocate SwrContext if needed and set/reset common parameters.
72 * This function does not require s to be allocated with swr_alloc(). On the
73 * other hand, swr_alloc() can use swr_alloc_set_opts() to set the parameters
74 * on the allocated context.
76 * @param s Swr context, can be NULL
77 * @param out_ch_layout output channel layout (AV_CH_LAYOUT_*)
78 * @param out_sample_fmt output sample format (AV_SAMPLE_FMT_*).
79 * @param out_sample_rate output sample rate (frequency in Hz)
80 * @param in_ch_layout input channel layout (AV_CH_LAYOUT_*)
81 * @param in_sample_fmt input sample format (AV_SAMPLE_FMT_*).
82 * @param in_sample_rate input sample rate (frequency in Hz)
83 * @param log_offset logging level offset
84 * @param log_ctx parent logging context, can be NULL
86 * @see swr_init(), swr_free()
87 * @return NULL on error, allocated context otherwise
89 struct SwrContext *swr_alloc_set_opts(struct SwrContext *s,
90 int64_t out_ch_layout, enum AVSampleFormat out_sample_fmt, int out_sample_rate,
91 int64_t in_ch_layout, enum AVSampleFormat in_sample_fmt, int in_sample_rate,
92 int log_offset, void *log_ctx);
95 * Free the given SwrContext and set the pointer to NULL.
97 void swr_free(struct SwrContext **s);
102 * in and in_count can be set to 0 to flush the last few samples out at the
105 * If more input is provided than output space then the input will be buffered.
106 * You can avoid this buffering by providing more output space than input.
107 * Convertion will run directly without copying whenever possible.
109 * @param s allocated Swr context, with parameters set
110 * @param out output buffers, only the first one need be set in case of packed audio
111 * @param out_count amount of space available for output in samples per channel
112 * @param in input buffers, only the first one need to be set in case of packed audio
113 * @param in_count number of input samples available in one channel
115 * @return number of samples output per channel, negative value on error
117 int swr_convert(struct SwrContext *s, uint8_t **out, int out_count,
118 const uint8_t **in , int in_count);
121 * Activate resampling compensation.
123 int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance);
126 * Set a customized input channel mapping.
128 * @param s allocated Swr context, not yet initialized
129 * @param channel_map customized input channel mapping (array of channel
130 * indexes, -1 for a muted channel)
131 * @return AVERROR error code in case of failure.
133 int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map);
136 * Set a customized remix matrix.
138 * @param s allocated Swr context, not yet initialized
139 * @param matrix remix coefficients; matrix[i + stride * o] is
140 * the weight of input channel i in output channel o
141 * @param stride offset between lines of the matrix
142 * @return AVERROR error code in case of failure.
144 int swr_set_matrix(struct SwrContext *s, const double *matrix, int stride);
147 * Return the LIBSWRESAMPLE_VERSION_INT constant.
149 unsigned swresample_version(void);
152 * Return the swr build-time configuration.
154 const char *swresample_configuration(void);
157 * Return the swr license.
159 const char *swresample_license(void);