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Diffstat (limited to 'src/audioin.h')
| -rw-r--r-- | src/audioin.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/src/audioin.h b/src/audioin.h new file mode 100644 index 0000000..fe12fa4 --- /dev/null +++ b/src/audioin.h @@ -0,0 +1,130 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/*************************************************************************** + * audioin.h + * + * Wed Sep 30 11:36:18 CEST 2009 + * Copyright 2011 Bent Bisballe Nyeng + * deva@aasimon.org + ****************************************************************************/ + +/* + * This file is part of libaudioin. + * + * libaudioin is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * libaudioin 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with libaudioin; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ +#ifndef __LIBAUDIOIN_AUDIOIN_H__ +#define __LIBAUDIOIN_AUDIOIN_H__ + +#ifdef __cplusplus +extern "C" { +#endif + +#define NO_ERROR 0 + +#define OUT_OF_MEMORY 101 +#define MISSING_HANDLE 102 + +#define COULD_NOT_OPEN_DEVICE 203 +#define COULD_NOT_SET_HW_PARAMS 204 +#define COULD_NOT_INIT_PARAMS 205 +#define COULD_NOT_SET_ACCESS_MODE 206 +#define COULD_NOT_SET_FORMAT 207 +#define COULD_NOT_SET_CHANNELS 208 +#define COULD_NOT_SET_SAMPLE_RATE 209 +#define COULD_NOT_SET_PERIOD_SIZE 210 + +#define BUFFER_TOO_SMALL 305 +#define BUFFER_OVERRUN 306 +#define READ_ERROR 307 +#define SHORT_READ 308 + +#define MIXER_INIT_FAILED 400 + +#define MIXER_NOT_INITIALISED 401 +#define INVALID_MIXER_LEVEL 402 +#define INVALID_CHANNEL_NUMBER 403 +#define COULD_NOT_SET_MIXER_LEVEL 404 + +struct ai_t; + +/** + * Initalise the AudioIn library and connect to a soundcard and a mixer. + * @param err An int pointer containing error value if function is unsuccessful. + * @param device A string containing the device name to connect to. A list + * possible devices can be seen with the 'aplay -L' command. The device + * "default" are usually the one needed. + * @param mixer A string containing the mixer interface to connect to. A list + * of possible interfaces can be seen with the 'amixer scontrols' command. + * Usually the interface "Capture" is the one needed. + * @param samplerate An unsigned integer containing the desired samplerate in + * Hertz. + * @param channels An unsigned integer containing the desired number of + * channels. The channel samples will be interleaved in the data stream whe + * ai_read is called. + * @return A pointer to the newly created handle or NULL on failure. + */ +struct ai_t *ai_init(int *err, const char *device, const char *mixer, + unsigned int samplerate, unsigned int channels); + +/** + * Read samples from the soundcard. + * @param err An int pointer containing error value if function is unsuccessful. + * @param handle A pointer to the handle to be used. + * @param maxsize The maximum number of bytes (not samples) to read. + * @return Returns the number of bytes (not samples) read or -1 on error. + * NOTE: to get the number of samples read, devide the return value with the + * sample width (2 bytes / 16 bits) and the number of interleaved channels + * (usually 1 or 2). + */ +int ai_read(int *err, struct ai_t *handle, void *pcm, unsigned int maxsize); + +/** + * Adjust channel mixer levels. + * @param err An int pointer containing error value if function is unsuccessful. + * @param handle A pointer to the handle to be used. + * @param channel The channel number to set mixer level of. 0 or 1 should be + * used for the two channels of a stereo interface. + * @param level The mixer level to set, ranging from 0.0 to 1.0 where 0.0 is + * mute and 1.0 is maximum gain. + * @return Returns -1 on error 0 otherwise. + */ +int ai_set_mixer_level(int *err, struct ai_t *handle, unsigned int channel, + float level); + +/** + * Get actual samplerate. + * The samplerate set in ai_init may or may not match a possible samplerate for + * the audio hardware and therefore the ALSA library might decide to use another + * samplerate than the one specified. + * This function can be called to obtain the actual samplerate that the hardware + * has been configured to use. + * @param err An int pointer containing error value if function is unsuccessful. + * @param handle A pointer to the handle to be used. + * @return The samplerate as an integer or -1 on error. + */ +int ai_get_samplerate(int *err, struct ai_t *handle); + +/** + * Close and free the handle. + * @param err An int pointer containing error value if function is unsuccessful. + * @param handle A pointer to the handle to be closed. + */ +void ai_close(int *err, struct ai_t *handle); + +#ifdef __cplusplus +} +#endif + +#endif/*__LIBAUDIOIN_AUDIOIN_H__*/ |