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 5
34 #define LIBSWRESAMPLE_VERSION_MICRO 0
36 #define SWR_CH_MAX 16 ///< Maximum number of channels
38 #define SWR_FLAG_RESAMPLE 1 ///< Force resampling even if equal sample rate
39 //TODO use int resample ?
40 //long term TODO can we enable this dynamically?
46 * Allocate SwrContext.
48 * If you use this function you will need to set the parameters (manually or
49 * with swr_alloc_set_opts()) before calling swr_init().
51 * @see swr_alloc_set_opts(), swr_init(), swr_free()
52 * @return NULL on error, allocated context otherwise
54 struct SwrContext *swr_alloc(void);
57 * Initialize context after user parameters have been set.
59 * @return AVERROR error code in case of failure.
61 int swr_init(struct SwrContext *s);
64 * Allocate SwrContext if needed and set/reset common parameters.
66 * This function does not require s to be allocated with swr_alloc(). On the
67 * other hand, swr_alloc() can use swr_alloc_set_opts() to set the parameters
68 * on the allocated context.
70 * @param s Swr context, can be NULL
71 * @param out_ch_layout output channel layout (AV_CH_LAYOUT_*)
72 * @param out_sample_fmt output sample format (AV_SAMPLE_FMT_*).
73 * @param out_sample_rate output sample rate (frequency in Hz)
74 * @param in_ch_layout input channel layout (AV_CH_LAYOUT_*)
75 * @param in_sample_fmt input sample format (AV_SAMPLE_FMT_*).
76 * @param in_sample_rate input sample rate (frequency in Hz)
77 * @param log_offset logging level offset
78 * @param log_ctx parent logging context, can be NULL
80 * @see swr_init(), swr_free()
81 * @return NULL on error, allocated context otherwise
83 struct SwrContext *swr_alloc_set_opts(struct SwrContext *s,
84 int64_t out_ch_layout, enum AVSampleFormat out_sample_fmt, int out_sample_rate,
85 int64_t in_ch_layout, enum AVSampleFormat in_sample_fmt, int in_sample_rate,
86 int log_offset, void *log_ctx);
89 * Free the given SwrContext and set the pointer to NULL.
91 void swr_free(struct SwrContext **s);
96 * in and in_count can be set to 0 to flush the last few samples out at the
99 * @param s allocated Swr context, with parameters set
100 * @param out output buffers, only the first one need be set in case of packed audio
101 * @param out_count amount of space available for output in samples per channel
102 * @param in input buffers, only the first one need to be set in case of packed audio
103 * @param in_count number of input samples available in one channel
105 * @return number of samples output per channel
107 int swr_convert(struct SwrContext *s, uint8_t *out[SWR_CH_MAX], int out_count,
108 const uint8_t *in [SWR_CH_MAX], int in_count);
111 * Activate resampling compensation.
113 void swr_compensate(struct SwrContext *s, int sample_delta, int compensation_distance);
116 * Set a customized input channel mapping.
118 * @param s allocated Swr context, not yet initialized
119 * @param channel_map customized input channel mapping (array of channel
120 * indexes, -1 for a muted channel)
121 * @return AVERROR error code in case of failure.
123 int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map);