ref: c61a5fec6258b484fc7e5fbd2a088eff1c4571be
dir: /src/alsa.c/
#if defined(ALSA_PLAYER) /* * Copyright 1997 Jimen Ching And Sundry Contributors * This source code is freely redistributable and may be used for * any purpose. This copyright notice must be maintained. * Jimen Ching And Sundry Contributors are not * responsible for the consequences of using this software. */ /* Direct to ALSA sound driver * * added by Jimen Ching (jching@flex.com) 19990207 * based on info grabed from aplay.c in alsa-utils package. */ #include <malloc.h> #include <unistd.h> #include <stdlib.h> #include <stdio.h> #include <fcntl.h> #include <linux/asound.h> #include <sys/ioctl.h> #include "st.h" #include "libst.h" char *get_style(style) int style; { switch(style) { case UNSIGNED: return "UNSIGNED"; case SIGN2: return "SIGNED LINEAR 2's Comp"; case ULAW: return "uLaw"; case ALAW: return "aLaw"; case ADPCM: return "ADPCM"; default: return "unknown"; } } /* * Do anything required before you start reading samples. * Read file header. * Find out sampling rate, * size and style of samples, * mono/stereo/quad. */ void alsastartread(ft) ft_t ft; { int bps, fmt, size; snd_pcm_record_info_t r_info; snd_pcm_format_t format; snd_pcm_record_params_t r_params; memset(&r_info, 0, sizeof(r_info)); ioctl(fileno(ft->fp), SND_PCM_IOCTL_RECORD_INFO, &r_info); ft->file.count = 0; ft->file.pos = 0; ft->file.eof = 0; ft->file.size = r_info.buffer_size; if ((ft->file.buf = malloc (ft->file.size)) == NULL) { fail("unable to allocate output buffer of size %d", ft->file.size); } if (ft->info.rate < r_info.min_rate) ft->info.rate = 2 * r_info.min_rate; else if (ft->info.rate > r_info.max_rate) ft->info.rate = r_info.max_rate; if (ft->info.channels == -1) ft->info.channels = r_info.min_channels; else if (ft->info.channels > r_info.max_channels) ft->info.channels = r_info.max_channels; if (ft->info.size == -1) { if ((r_info.hw_formats & SND_PCM_FMT_U8) || (r_info.hw_formats & SND_PCM_FMT_S8)) ft->info.size = BYTE; else ft->info.size = WORD; } if (ft->info.style == -1) { if ((r_info.hw_formats & SND_PCM_FMT_S16_LE) || (r_info.hw_formats & SND_PCM_FMT_S8)) ft->info.style = SIGN2; else ft->info.style = UNSIGNED; } if (ft->info.size == BYTE) { switch (ft->info.style) { case SIGN2: if (!(r_info.hw_formats & SND_PCM_FMT_S8)) fail("ALSA driver does not support signed byte samples"); fmt = SND_PCM_SFMT_S8; break; case UNSIGNED: if (!(r_info.hw_formats & SND_PCM_FMT_U8)) fail("ALSA driver does not support unsigned byte samples"); fmt = SND_PCM_SFMT_U8; break; default: fail("Hardware does not support %s output", get_style(ft->info.style)); break; } } else { switch (ft->info.style) { case SIGN2: if (!(r_info.hw_formats & SND_PCM_FMT_S16_LE)) fail("ALSA driver does not support signed word samples"); fmt = SND_PCM_SFMT_S16_LE; break; case UNSIGNED: if (!(r_info.hw_formats & SND_PCM_FMT_U16_LE)) fail("ALSA driver does not support unsigned word samples"); fmt = SND_PCM_SFMT_U16_LE; break; default: fail("Hardware does not support %s output", get_style(ft->info.style)); break; } } memset(&format, 0, sizeof(format)); format.format = fmt; format.rate = ft->info.rate; format.channels = ft->info.channels; ioctl(fileno(ft->fp), SND_PCM_IOCTL_RECORD_FORMAT, &format); size = ft->file.size; bps = format.rate * format.channels; if (ft->info.size == WORD) bps <<= 1; bps >>= 2; while (size > bps) size >>= 1; if (size < 16) size = 16; memset(&r_params, 0, sizeof(r_params)); r_params.fragment_size = size; r_params.fragments_min = 1; ioctl(fileno(ft->fp), SND_PCM_IOCTL_RECORD_PARAMS, &r_params); sigintreg(ft); /* Prepare to catch SIGINT */ } void alsastartwrite(ft) ft_t ft; { int bps, fmt, size; snd_pcm_playback_info_t p_info; snd_pcm_format_t format; snd_pcm_playback_params_t p_params; memset(&p_info, 0, sizeof(p_info)); ioctl(fileno(ft->fp), SND_PCM_IOCTL_PLAYBACK_INFO, &p_info); ft->file.pos = 0; ft->file.eof = 0; ft->file.size = p_info.buffer_size; if ((ft->file.buf = malloc (ft->file.size)) == NULL) { fail("unable to allocate output buffer of size %d", ft->file.size); } if (ft->info.rate < p_info.min_rate) ft->info.rate = 2 * p_info.min_rate; else if (ft->info.rate > p_info.max_rate) ft->info.rate = p_info.max_rate; if (ft->info.channels == -1) ft->info.channels = p_info.min_channels; else if (ft->info.channels > p_info.max_channels) ft->info.channels = p_info.max_channels; if (ft->info.size == -1) { if ((p_info.hw_formats & SND_PCM_FMT_U8) || (p_info.hw_formats & SND_PCM_FMT_S8)) ft->info.size = BYTE; else ft->info.size = WORD; } if (ft->info.style == -1) { if ((p_info.hw_formats & SND_PCM_FMT_S16_LE) || (p_info.hw_formats & SND_PCM_FMT_S8)) ft->info.style = SIGN2; else ft->info.style = UNSIGNED; } if (ft->info.size == BYTE) { switch (ft->info.style) { case SIGN2: if (!(p_info.hw_formats & SND_PCM_FMT_S8)) fail("ALSA driver does not support signed byte samples"); fmt = SND_PCM_SFMT_S8; break; case UNSIGNED: if (!(p_info.hw_formats & SND_PCM_FMT_U8)) fail("ALSA driver does not support unsigned byte samples"); fmt = SND_PCM_SFMT_U8; break; default: fail("Hardware does not support %s output", get_style(ft->info.style)); break; } } else { switch (ft->info.style) { case SIGN2: if (!(p_info.hw_formats & SND_PCM_FMT_S16_LE)) fail("ALSA driver does not support signed word samples"); fmt = SND_PCM_SFMT_S16_LE; break; case UNSIGNED: if (!(p_info.hw_formats & SND_PCM_FMT_U16_LE)) fail("ALSA driver does not support unsigned word samples"); fmt = SND_PCM_SFMT_U16_LE; break; default: fail("Hardware does not support %s output", get_style(ft->info.style)); break; } } memset(&format, 0, sizeof(format)); format.format = fmt; format.rate = ft->info.rate; format.channels = ft->info.channels; ioctl(fileno(ft->fp), SND_PCM_IOCTL_PLAYBACK_FORMAT, &format); size = ft->file.size; bps = format.rate * format.channels; if (ft->info.size == WORD) bps <<= 1; bps >>= 2; while (size > bps) size >>= 1; if (size < 16) size = 16; memset(&p_params, 0, sizeof(p_params)); p_params.fragment_size = size; p_params.fragments_max = -1; p_params.fragments_room = 1; ioctl(fileno(ft->fp), SND_PCM_IOCTL_PLAYBACK_PARAMS, &p_params); sigintreg(ft); } #endif