src/pcm_convert.h

   1 /*
   2  * Copyright (C) 2003-2010 The Music Player Daemon Project
   3  * http://www.musicpd.org
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #ifndef PCM_CONVERT_H
  21 #define PCM_CONVERT_H
  22
  23 #include "pcm_resample.h"
  24 #include "pcm_dither.h"
  25 #include "pcm_buffer.h"
  26
  27 struct audio_format;
  28
  29 /**
  30  * This object is statically allocated (within another struct), and
  31  * holds buffer allocations and the state for all kinds of PCM
  32  * conversions.
  33  */
  34 struct pcm_convert_state {
  35         struct pcm_resample_state resample;
  36
  37         struct pcm_dither dither;
  38
  39         /** the buffer for converting the sample format */
  40         struct pcm_buffer format_buffer;
  41
  42         /** the buffer for converting to/from packed samples */
  43         struct pcm_buffer pack_buffer;
  44
  45         /** the buffer for converting the channel count */
  46         struct pcm_buffer channels_buffer;
  47
  48         /** the buffer for swapping the byte order */
  49         struct pcm_buffer byteswap_buffer;
  50 };
  51
  52 static inline GQuark
  53 pcm_convert_quark(void)
  54 {
  55         return g_quark_from_static_string("pcm_convert");
  56 }
  57
  58 /**
  59  * Initializes a pcm_convert_state object.
  60  */
  61 void pcm_convert_init(struct pcm_convert_state *state);
  62
  63 /**
  64  * Deinitializes a pcm_convert_state object and frees allocated
  65  * memory.
  66  */
  67 void pcm_convert_deinit(struct pcm_convert_state *state);
  68
  69 /**
  70  * Converts PCM data between two audio formats.
  71  *
  72  * @param state an initialized pcm_convert_state object
  73  * @param src_format the source audio format
  74  * @param src the source PCM buffer
  75  * @param src_size the size of #src in bytes
  76  * @param dest_format the requested destination audio format
  77  * @param dest_size_r returns the number of bytes of the destination buffer
  78  * @param error_r location to store the error occuring, or NULL to
  79  * ignore errors
  80  * @return the destination buffer, or NULL on error
  81  */
  82 const void *
  83 pcm_convert(struct pcm_convert_state *state,
  84             const struct audio_format *src_format,
  85             const void *src, size_t src_size,
  86             const struct audio_format *dest_format,
  87             size_t *dest_size_r,
  88             GError **error_r);
  89
  90 #endif