/* * Copyright (c) by Jaroslav Kysela * * * This program 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. * * This program 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 this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include #include #include typedef signed short sint_16; typedef unsigned int uint_32; #include "output.h" static output_t out_config; static snd_pcm_t *pcm; /* * open the audio device for writing to */ int output_open(output_t *output) { const char *pcm_name = output->pcm_name; char devstr[128]; int card, dev; snd_pcm_hw_params_t *params; snd_pcm_sw_params_t *swparams; snd_pcm_sframes_t buffer_time; snd_pcm_sframes_t period_time, tmp; int err, step; snd_pcm_hw_params_alloca(¶ms); snd_pcm_sw_params_alloca(&swparams); out_config = *output; /* * Open the device driver */ if (pcm_name == NULL) { card = snd_defaults_pcm_card(); dev = snd_defaults_pcm_device(); if (card < 0 || dev < 0) { fprintf(stderr, "defaults are not set\n"); return -ENODEV; } switch (output->channels) { case 1: case 2: sprintf(devstr, "plug:%d,%d", card, dev); break; case 4: sprintf(devstr, "surround40:%d,%d", card, dev); break; case 6: sprintf(devstr, "surround51:%d,%d", card, dev); break; default: fprintf(stderr, "%d channels are not supported\n", output->channels); return -EINVAL; } pcm_name = devstr; } if ((err = snd_pcm_open(&pcm, pcm_name, SND_PCM_STREAM_PLAYBACK, 0)) < 0) { fprintf(stderr, "snd_pcm_open: %s\n", snd_strerror(err)); return err; } err = snd_pcm_hw_params_any(pcm, params); if (err < 0) { fprintf(stderr, "Broken configuration for this PCM: no configurations available"); goto __close; } /* set interleaved access */ err = snd_pcm_hw_params_set_access(pcm, params, SND_PCM_ACCESS_RW_INTERLEAVED); if (err < 0) { fprintf(stderr, "Access type not available"); goto __close; } err = snd_pcm_hw_params_set_format(pcm, params, output->bits == 16 ? SND_PCM_FORMAT_S16_LE : SND_PCM_FORMAT_U8); if (err < 0) { fprintf(stderr, "Sample format non available"); goto __close; } err = snd_pcm_hw_params_set_channels(pcm, params, output->channels); if (err < 0) { fprintf(stderr, "Channels count non available"); goto __close; } err = snd_pcm_hw_params_set_rate_near(pcm, params, output->rate, 0); if (err < 0) { fprintf(stderr, "Rate not available"); goto __close; } buffer_time = snd_pcm_hw_params_set_buffer_time_near(pcm, params, 500000, 0); if (buffer_time < 0) { fprintf(stderr, "Buffer time not available"); goto __close; } step = 2; period_time = 10000 * 2; do { period_time /= 2; tmp = snd_pcm_hw_params_set_period_time_near(pcm, params, period_time, 0); if (tmp == period_time) { period_time /= 3; tmp = snd_pcm_hw_params_set_period_time_near(pcm, params, period_time, 0); if (tmp == period_time) period_time = 10000 * 2; } if (period_time < 0) { fprintf(stderr, "Period time not available"); goto __close; } } while (buffer_time == period_time && period_time > 10000); if (buffer_time == period_time) { fprintf(stderr, "Buffer time and period time match, could not use\n"); goto __close; } if ((err = snd_pcm_hw_params(pcm, params)) < 0) { fprintf(stderr, "PCM hw_params failed: %s\n", snd_strerror(err)); goto __close; } if (output->spdif != SPDIF_NONE) { snd_pcm_info_t *info; snd_ctl_elem_value_t *ctl; snd_ctl_t *ctl_handle; char ctl_name[12]; int ctl_card; snd_aes_iec958_t spdif; memset(&spdif, 0, sizeof(spdif)); if (output->spdif == SPDIF_PRO) { spdif.status[0] = (IEC958_AES0_PROFESSIONAL | IEC958_AES0_NONAUDIO | IEC958_AES0_PRO_EMPHASIS_NONE | IEC958_AES0_PRO_FS_48000); spdif.status[1] = (IEC958_AES1_PRO_MODE_NOTID | IEC958_AES1_PRO_USERBITS_NOTID); spdif.status[2] = IEC958_AES2_PRO_WORDLEN_NOTID; spdif.status[3] = 0; } else { spdif.status[0] = (IEC958_AES0_NONAUDIO | IEC958_AES0_CON_EMPHASIS_NONE); spdif.status[1] = (IEC958_AES1_CON_ORIGINAL | IEC958_AES1_CON_PCM_CODER); spdif.status[2] = 0; spdif.status[3] = IEC958_AES3_CON_FS_48000; } snd_pcm_info_alloca(&info); if ((err = snd_pcm_info(pcm, info)) < 0) { fprintf(stderr, "pcm info error: %s", snd_strerror(err)); goto __close; } snd_ctl_elem_value_alloca(&ctl); snd_ctl_elem_value_set_interface(ctl, SND_CTL_ELEM_IFACE_PCM); snd_ctl_elem_value_set_device(ctl, snd_pcm_info_get_device(info)); snd_ctl_elem_value_set_subdevice(ctl, snd_pcm_info_get_subdevice(info)); snd_ctl_elem_value_set_name(ctl, SND_CTL_NAME_IEC958("",PLAYBACK,PCM_STREAM)); snd_ctl_elem_value_set_iec958(ctl, &spdif); ctl_card = snd_pcm_info_get_card(info); if (ctl_card < 0) { fprintf(stderr, "Unable to setup the IEC958 (S/PDIF) interface - PCM has no assigned card\n"); goto __diga_end; } sprintf(ctl_name, "hw:%d", ctl_card); if ((err = snd_ctl_open(&ctl_handle, ctl_name, 0)) < 0) { fprintf(stderr, "Unable to open the control interface '%s': %s\n", ctl_name, snd_strerror(err)); goto __diga_end; } if ((err = snd_ctl_elem_write(ctl_handle, ctl)) < 0) { fprintf(stderr, "Unable to update the IEC958 control: %s\n", snd_strerror(err)); goto __diga_end; } snd_ctl_close(ctl_handle); __diga_end: } return 0; __close: snd_pcm_close(pcm); pcm = NULL; return err; } /* * play the sample to the already opened file descriptor */ int output_play(sint_16* output_samples, uint_32 num_frames) { snd_pcm_sframes_t res = 0; do { if (res == -EPIPE) res = snd_pcm_prepare(pcm); res = res < 0 ? res : snd_pcm_writei(pcm, (void *)output_samples, num_frames); if (res > 0) { output_samples += out_config.channels * res; num_frames -= res; } } while (res == -EPIPE || num_frames > 0); if (res < 0) fprintf(stderr, "writei returned error: %s\n", snd_strerror(res)); return res < 0 ? (int)res : 0; } void output_close(void) { snd_pcm_close(pcm); }