kopia lustrzana https://github.com/xdsopl/robot36
135 wiersze
3.2 KiB
C
135 wiersze
3.2 KiB
C
/*
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robot36 - encode and decode images using SSTV in Robot 36 mode
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Written in 2011 by <Ahmet Inan> <xdsopl@googlemail.com>
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To the extent possible under law, the author(s) have dedicated all copyright and related and neighboring rights to this software to the public domain worldwide. This software is distributed without any warranty.
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You should have received a copy of the CC0 Public Domain Dedication along with this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <alsa/asoundlib.h>
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#include "alsa.h"
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typedef struct {
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void (*close)(pcm_t *);
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void (*info)(pcm_t *);
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int (*rate)(pcm_t *);
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int (*channels)(pcm_t *);
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int (*read)(struct pcm *, short *, int);
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snd_pcm_t *pcm;
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int r;
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int c;
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} alsa_t;
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void close_alsa(pcm_t *pcm)
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{
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alsa_t *alsa = (alsa_t *)pcm;
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snd_pcm_close(alsa->pcm);
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}
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void info_alsa(pcm_t *pcm)
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{
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alsa_t *alsa = (alsa_t *)pcm;
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fprintf(stderr, "%d channel(s), %d rate\n", alsa->c, alsa->r);
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}
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int rate_alsa(pcm_t *pcm)
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{
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alsa_t *alsa = (alsa_t *)pcm;
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return alsa->r;
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}
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int channels_alsa(pcm_t *pcm)
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{
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alsa_t *alsa = (alsa_t *)pcm;
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return alsa->c;
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}
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int read_alsa(pcm_t *pcm, short *buff, int frames)
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{
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alsa_t *alsa = (alsa_t *)pcm;
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int got = 0;
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while (0 < frames) {
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while ((got = snd_pcm_readi(alsa->pcm, buff, frames)) < 0) {
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snd_pcm_prepare(alsa->pcm);
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fprintf(stderr, "<<<<<<<<<<<<<<< Buffer Overrun >>>>>>>>>>>>>>>\n");
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}
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buff += got * alsa->c;
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frames -= got;
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}
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return 1;
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}
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int open_alsa(pcm_t **p, char *name)
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{
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alsa_t *alsa = (alsa_t *)malloc(sizeof(alsa_t));
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alsa->close = close_alsa;
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alsa->info = info_alsa;
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alsa->rate = rate_alsa;
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alsa->channels = channels_alsa;
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alsa->read = read_alsa;
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snd_pcm_t *pcm;
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snd_pcm_hw_params_t *params;
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snd_pcm_hw_params_alloca(¶ms);
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if (snd_pcm_open(&pcm, name, SND_PCM_STREAM_CAPTURE, 0) < 0) {
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fprintf(stderr, "Error opening PCM device %s\n", name);
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free(alsa);
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return 0;
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}
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if (snd_pcm_hw_params_any(pcm, params) < 0) {
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fprintf(stderr, "Can not configure this PCM device.\n");
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snd_pcm_close(alsa->pcm);
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free(alsa);
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return 0;
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}
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if (snd_pcm_hw_params_set_access(pcm, params, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) {
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fprintf(stderr, "Error setting access.\n");
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snd_pcm_close(alsa->pcm);
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free(alsa);
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return 0;
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}
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if (snd_pcm_hw_params_set_format(pcm, params, SND_PCM_FORMAT_S16_LE) < 0) {
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fprintf(stderr, "Error setting S16_LE format.\n");
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snd_pcm_close(alsa->pcm);
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free(alsa);
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return 0;
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}
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if (snd_pcm_hw_params_set_rate_resample(pcm, params, 0) < 0) {
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fprintf(stderr, "Error disabling resampling.\n");
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snd_pcm_close(alsa->pcm);
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free(alsa);
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return 0;
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}
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if (snd_pcm_hw_params(pcm, params) < 0) {
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fprintf(stderr, "Error setting HW params.\n");
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snd_pcm_close(alsa->pcm);
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free(alsa);
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return 0;
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}
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unsigned int rate = 0;
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if (snd_pcm_hw_params_get_rate(params, &rate, 0) < 0) {
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fprintf(stderr, "Error getting rate.\n");
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snd_pcm_close(alsa->pcm);
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free(alsa);
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return 0;
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}
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unsigned int channels = 0;
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if (snd_pcm_hw_params_get_channels(params, &channels) < 0) {
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fprintf(stderr, "Error getting channels.\n");
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snd_pcm_close(alsa->pcm);
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free(alsa);
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return 0;
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}
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alsa->pcm = pcm;
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alsa->r = rate;
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alsa->c = channels;
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*p = (pcm_t *)alsa;
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return 1;
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}
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