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Diffstat (limited to 'src/audioin.cc')
| -rw-r--r-- | src/audioin.cc | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/audioin.cc b/src/audioin.cc new file mode 100644 index 0000000..3792ae2 --- /dev/null +++ b/src/audioin.cc @@ -0,0 +1,189 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/*************************************************************************** + * audioin.cc + * + * 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. + */ +#include "audioin.h" + +AudioIn::AudioIn(std::string device, std::string mixer_interface, + unsigned int srate, int ch) +{ + frames = 940; + + elem = NULL; + mixhnd = NULL; + + int rc; + + // Open PCM device for recording (capture). + rc = snd_pcm_open(&handle, device.c_str(), SND_PCM_STREAM_CAPTURE, 0); + if (rc < 0) throw CouldNotOpenPCMDevice(); + + // Allocate a hardware parameters object. + snd_pcm_hw_params_alloca(¶ms); + + // Fill it in with default values. + rc = snd_pcm_hw_params_any(handle, params); + if (rc < 0) throw CouldNotInitialiseParams(); + + // Set the desired hardware parameters. + + // Interleaved mode + rc = snd_pcm_hw_params_set_access(handle, params, + SND_PCM_ACCESS_RW_INTERLEAVED); + if (rc < 0) throw CouldNotSetAccessMode(); + + // Signed 16-bit little-endian format + rc = snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_FLOAT); + if (rc < 0) throw CouldNotSetFormat(); + + // Set channels (stereo/mono) + rc = snd_pcm_hw_params_set_channels(handle, params, ch); + channels = ch; + if (rc < 0) throw CouldNotSetChannelNumber(); + + // Set sampling rate + unsigned int val = srate; + snd_pcm_hw_params_set_rate_near(handle, params, &val, &dir); + printf("srate: %d\n", val); + // if(val != srate) throw UnableToSetSampleRate(); + + // NOTE: Setting period size to 32 frames will force use of lowest possible value. + rc = snd_pcm_hw_params_set_period_size_near(handle, params, &frames, &dir); + if(rc < 0) throw UnableToSetPeriodSize(); + + // Write the parameters to the driver + rc = snd_pcm_hw_params(handle, params); + if (rc < 0) throw UnableToSetHWParams(); + + mixhnd = NULL; + /* + // + // Set up mixer + // + snd_mixer_selem_id_t *mixer; + + // Open mixer device + if(snd_mixer_open(&mixhnd, 0) != 0) throw MixerInitilisationFailed(); + + if(snd_mixer_attach(mixhnd, device.c_str()) != 0) + throw MixerInitilisationFailed(); + + if(snd_mixer_selem_register(mixhnd, NULL, NULL) < 0) + throw MixerInitilisationFailed(); + + if(snd_mixer_load(mixhnd) < 0) + throw MixerInitilisationFailed(); + + // Obtain mixer element + snd_mixer_selem_id_alloca(&mixer); + if(mixer == NULL) throw MixerInitilisationFailed(); + snd_mixer_selem_id_set_name(mixer, mixer_interface.c_str()); + + elem = snd_mixer_find_selem(mixhnd, mixer); + if(elem == NULL) throw MixerInitilisationFailed(); + + if(snd_mixer_selem_get_capture_volume_range(elem, &lvl_min, &lvl_max) != 0) + throw MixerInitilisationFailed(); + + if(snd_mixer_selem_set_capture_switch(elem, + SND_MIXER_SCHN_FRONT_LEFT, 1) != 0) + throw MixerInitilisationFailed(); + + if(snd_mixer_selem_set_capture_switch(elem, + SND_MIXER_SCHN_FRONT_RIGHT, 1) != 0) + throw MixerInitilisationFailed(); + + + // Obtain mixer enumeration element "Input Source" and set it to 2 (line). + snd_mixer_selem_id_set_name(mixer, "Input Source"); + + snd_mixer_elem_t *iselem = snd_mixer_find_selem(mixhnd, mixer); + if(iselem == NULL) return; + + if(snd_mixer_selem_is_enumerated(iselem)) { + // Set to line-in + snd_mixer_selem_set_enum_item(iselem, SND_MIXER_SCHN_MONO, 2); + } + */ +} + +AudioIn::~AudioIn() +{ + if(handle) { + snd_pcm_drain(handle); + snd_pcm_close(handle); + } + if(mixhnd) snd_mixer_close(mixhnd); +} + +size_t AudioIn::read(sample_t *buf, size_t size) +{ + int rc; + + if(size < frames * channels) { + throw PcmBufferTooSmall(); + } + + rc = snd_pcm_readi(handle, buf, frames); + if (rc == -EPIPE) { + // EPIPE means overrun + snd_pcm_prepare(handle); + throw OverRun(); + return 0; + } else if (rc < 0) { + throw ReadError(); + } else if (rc != (int)frames) { + throw ShortRead(); + } + + return rc * channels; +} + +int AudioIn::set_level(unsigned int channel, float level) +{ + + if(!elem) throw MixerNotInitialised(); + + if(level > 1.0 || level < 0.0) throw InvalidMixerLevel(); + + long lvl = ((lvl_max - lvl_min) * level) + lvl_min; + + snd_mixer_selem_channel_id_t ch; + switch(channel) { + case 0: + ch = SND_MIXER_SCHN_FRONT_LEFT; + break; + case 1: + ch = SND_MIXER_SCHN_FRONT_RIGHT; + break; + default: + throw IllegalChannelNumber(); + break; + } + if(snd_mixer_selem_set_capture_volume(elem, ch, lvl) != 0) { + throw CouldNotSetMixerLevel(); + } + return 0; +} |