int main() { int st; int card = -1; const char iface[] = "pcm"; char** hints; fprintf(stderr, "Alsa API version is %s\n", snd_asoundlib_version()); st = snd_device_name_hint(card, iface, &hints); card = 0; while(hints[card] != NULL) { fprintf(stderr, "hints: %s\n", hints[card]); ++card; } return 0; }
int main() { printf("Found ALSA version %s, expected version %s\n", snd_asoundlib_version(), CMAKE_EXPECTED_ALSA_VERSION); return strcmp(snd_asoundlib_version(), CMAKE_EXPECTED_ALSA_VERSION); }
/* open & setup audio device return: 1=success 0=fail */ static int init(int rate_hz, int channels, int format, int flags) { unsigned int alsa_buffer_time = 500000; /* 0.5 s */ unsigned int alsa_fragcount = 16; int err; int block; strarg_t device; snd_pcm_uframes_t chunk_size; snd_pcm_uframes_t bufsize; snd_pcm_uframes_t boundary; const opt_t subopts[] = { {"block", OPT_ARG_BOOL, &block, NULL}, {"device", OPT_ARG_STR, &device, str_maxlen}, {NULL} }; char alsa_device[ALSA_DEVICE_SIZE + 1]; // make sure alsa_device is null-terminated even when using strncpy etc. memset(alsa_device, 0, ALSA_DEVICE_SIZE + 1); mp_msg(MSGT_AO,MSGL_V,"alsa-init: requested format: %d Hz, %d channels, %x\n", rate_hz, channels, format); alsa_handler = NULL; #if SND_LIB_VERSION >= 0x010005 mp_msg(MSGT_AO,MSGL_V,"alsa-init: using ALSA %s\n", snd_asoundlib_version()); #else mp_msg(MSGT_AO,MSGL_V,"alsa-init: compiled for ALSA-%s\n", SND_LIB_VERSION_STR); #endif snd_lib_error_set_handler(alsa_error_handler); ao_data.samplerate = rate_hz; ao_data.format = format; ao_data.channels = channels; switch (format) { case AF_FORMAT_S8: alsa_format = SND_PCM_FORMAT_S8; break; case AF_FORMAT_U8: alsa_format = SND_PCM_FORMAT_U8; break; case AF_FORMAT_U16_LE: alsa_format = SND_PCM_FORMAT_U16_LE; break; case AF_FORMAT_U16_BE: alsa_format = SND_PCM_FORMAT_U16_BE; break; case AF_FORMAT_AC3_LE: case AF_FORMAT_S16_LE: case AF_FORMAT_IEC61937_LE: alsa_format = SND_PCM_FORMAT_S16_LE; break; case AF_FORMAT_AC3_BE: case AF_FORMAT_S16_BE: case AF_FORMAT_IEC61937_BE: alsa_format = SND_PCM_FORMAT_S16_BE; break; case AF_FORMAT_U32_LE: alsa_format = SND_PCM_FORMAT_U32_LE; break; case AF_FORMAT_U32_BE: alsa_format = SND_PCM_FORMAT_U32_BE; break; case AF_FORMAT_S32_LE: alsa_format = SND_PCM_FORMAT_S32_LE; break; case AF_FORMAT_S32_BE: alsa_format = SND_PCM_FORMAT_S32_BE; break; case AF_FORMAT_U24_LE: alsa_format = SND_PCM_FORMAT_U24_3LE; break; case AF_FORMAT_U24_BE: alsa_format = SND_PCM_FORMAT_U24_3BE; break; case AF_FORMAT_S24_LE: alsa_format = SND_PCM_FORMAT_S24_3LE; break; case AF_FORMAT_S24_BE: alsa_format = SND_PCM_FORMAT_S24_3BE; break; case AF_FORMAT_FLOAT_LE: alsa_format = SND_PCM_FORMAT_FLOAT_LE; break; case AF_FORMAT_FLOAT_BE: alsa_format = SND_PCM_FORMAT_FLOAT_BE; break; case AF_FORMAT_MU_LAW: alsa_format = SND_PCM_FORMAT_MU_LAW; break; case AF_FORMAT_A_LAW: alsa_format = SND_PCM_FORMAT_A_LAW; break; default: alsa_format = SND_PCM_FORMAT_MPEG; //? default should be -1 break; } //subdevice parsing // set defaults block = 1; /* switch for spdif * sets opening sequence for SPDIF * sets also the playback and other switches 'on the fly' * while opening the abstract alias for the spdif subdevice * 'iec958' */ if (AF_FORMAT_IS_IEC61937(format)) { device.str = "iec958"; mp_msg(MSGT_AO,MSGL_V,"alsa-spdif-init: playing AC3/iec61937/iec958, %i channels\n", channels); } else /* in any case for multichannel playback we should select * appropriate device */ switch (channels) { case 1: case 2: device.str = "default"; mp_msg(MSGT_AO,MSGL_V,"alsa-init: setup for 1/2 channel(s)\n"); break; case 4: if (alsa_format == SND_PCM_FORMAT_FLOAT_LE) // hack - use the converter plugin device.str = "plug:surround40"; else device.str = "surround40"; mp_msg(MSGT_AO,MSGL_V,"alsa-init: device set to surround40\n"); break; case 6: if (alsa_format == SND_PCM_FORMAT_FLOAT_LE) device.str = "plug:surround51"; else device.str = "surround51"; mp_msg(MSGT_AO,MSGL_V,"alsa-init: device set to surround51\n"); break; case 8: if (alsa_format == SND_PCM_FORMAT_FLOAT_LE) device.str = "plug:surround71"; else device.str = "surround71"; mp_msg(MSGT_AO,MSGL_V,"alsa-init: device set to surround71\n"); break; default: device.str = "default"; mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_ChannelsNotSupported,channels); } device.len = strlen(device.str); if (subopt_parse(ao_subdevice, subopts) != 0) { print_help(); return 0; } parse_device(alsa_device, device.str, device.len); mp_msg(MSGT_AO,MSGL_V,"alsa-init: using device %s\n", alsa_device); if (!alsa_handler) { int open_mode = block ? 0 : SND_PCM_NONBLOCK; int isac3 = AF_FORMAT_IS_IEC61937(format); //modes = 0, SND_PCM_NONBLOCK, SND_PCM_ASYNC mp_msg(MSGT_AO,MSGL_V,"alsa-init: opening device in %sblocking mode\n", block ? "" : "non-"); if ((err = try_open_device(alsa_device, open_mode, isac3)) < 0) { if (err != -EBUSY && !block) { mp_msg(MSGT_AO,MSGL_INFO,MSGTR_AO_ALSA_OpenInNonblockModeFailed); if ((err = try_open_device(alsa_device, 0, isac3)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PlaybackOpenError, snd_strerror(err)); return 0; } } else { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PlaybackOpenError, snd_strerror(err)); return 0; } } if ((err = snd_pcm_nonblock(alsa_handler, 0)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_ErrorSetBlockMode, snd_strerror(err)); } else { mp_msg(MSGT_AO,MSGL_V,"alsa-init: device reopened in blocking mode\n"); } snd_pcm_hw_params_alloca(&alsa_hwparams); snd_pcm_sw_params_alloca(&alsa_swparams); // setting hw-parameters if ((err = snd_pcm_hw_params_any(alsa_handler, alsa_hwparams)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetInitialParameters, snd_strerror(err)); return 0; } err = snd_pcm_hw_params_set_access(alsa_handler, alsa_hwparams, SND_PCM_ACCESS_RW_INTERLEAVED); if (err < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetAccessType, snd_strerror(err)); return 0; } /* workaround for nonsupported formats sets default format to S16_LE if the given formats aren't supported */ if ((err = snd_pcm_hw_params_test_format(alsa_handler, alsa_hwparams, alsa_format)) < 0) { mp_msg(MSGT_AO,MSGL_INFO, MSGTR_AO_ALSA_FormatNotSupportedByHardware, af_fmt2str_short(format)); alsa_format = SND_PCM_FORMAT_S16_LE; if (AF_FORMAT_IS_AC3(ao_data.format)) ao_data.format = AF_FORMAT_AC3_LE; else if (AF_FORMAT_IS_IEC61937(ao_data.format)) ao_data.format = AF_FORMAT_IEC61937_LE; else ao_data.format = AF_FORMAT_S16_LE; } if ((err = snd_pcm_hw_params_set_format(alsa_handler, alsa_hwparams, alsa_format)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetFormat, snd_strerror(err)); return 0; } if ((err = snd_pcm_hw_params_set_channels_near(alsa_handler, alsa_hwparams, &ao_data.channels)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetChannels, snd_strerror(err)); return 0; } /* workaround for buggy rate plugin (should be fixed in ALSA 1.0.11) prefer our own resampler, since that allows users to choose the resampler, even per file if desired */ #if SND_LIB_VERSION >= 0x010009 if ((err = snd_pcm_hw_params_set_rate_resample(alsa_handler, alsa_hwparams, 0)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToDisableResampling, snd_strerror(err)); return 0; } #endif if ((err = snd_pcm_hw_params_set_rate_near(alsa_handler, alsa_hwparams, &ao_data.samplerate, NULL)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetSamplerate2, snd_strerror(err)); return 0; } bytes_per_sample = af_fmt2bits(ao_data.format) / 8; bytes_per_sample *= ao_data.channels; ao_data.bps = ao_data.samplerate * bytes_per_sample; if ((err = snd_pcm_hw_params_set_buffer_time_near(alsa_handler, alsa_hwparams, &alsa_buffer_time, NULL)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetBufferTimeNear, snd_strerror(err)); return 0; } if ((err = snd_pcm_hw_params_set_periods_near(alsa_handler, alsa_hwparams, &alsa_fragcount, NULL)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetPeriods, snd_strerror(err)); return 0; } /* finally install hardware parameters */ if ((err = snd_pcm_hw_params(alsa_handler, alsa_hwparams)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetHwParameters, snd_strerror(err)); return 0; } // end setting hw-params // gets buffersize for control if ((err = snd_pcm_hw_params_get_buffer_size(alsa_hwparams, &bufsize)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetBufferSize, snd_strerror(err)); return 0; } else { ao_data.buffersize = bufsize * bytes_per_sample; mp_msg(MSGT_AO,MSGL_V,"alsa-init: got buffersize=%i\n", ao_data.buffersize); } if ((err = snd_pcm_hw_params_get_period_size(alsa_hwparams, &chunk_size, NULL)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetPeriodSize, snd_strerror(err)); return 0; } else { mp_msg(MSGT_AO,MSGL_V,"alsa-init: got period size %li\n", chunk_size); } ao_data.outburst = chunk_size * bytes_per_sample; /* setting software parameters */ if ((err = snd_pcm_sw_params_current(alsa_handler, alsa_swparams)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetSwParameters, snd_strerror(err)); return 0; } #if SND_LIB_VERSION >= 0x000901 if ((err = snd_pcm_sw_params_get_boundary(alsa_swparams, &boundary)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetBoundary, snd_strerror(err)); return 0; } #else boundary = 0x7fffffff; #endif /* start playing when one period has been written */ if ((err = snd_pcm_sw_params_set_start_threshold(alsa_handler, alsa_swparams, chunk_size)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetStartThreshold, snd_strerror(err)); return 0; } /* disable underrun reporting */ if ((err = snd_pcm_sw_params_set_stop_threshold(alsa_handler, alsa_swparams, boundary)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetStopThreshold, snd_strerror(err)); return 0; } #if SND_LIB_VERSION >= 0x000901 /* play silence when there is an underrun */ if ((err = snd_pcm_sw_params_set_silence_size(alsa_handler, alsa_swparams, boundary)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetSilenceSize, snd_strerror(err)); return 0; } #endif if ((err = snd_pcm_sw_params(alsa_handler, alsa_swparams)) < 0) { mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetSwParameters, snd_strerror(err)); return 0; } /* end setting sw-params */ mp_msg(MSGT_AO,MSGL_V,"alsa: %d Hz/%d channels/%d bpf/%d bytes buffer/%s\n", ao_data.samplerate, ao_data.channels, (int)bytes_per_sample, ao_data.buffersize, snd_pcm_format_description(alsa_format)); } // end switch alsa_handler (spdif) alsa_can_pause = snd_pcm_hw_params_can_pause(alsa_hwparams); return 1; } // end init
int main() { int result; snd_pcm_t *handle = NULL; snd_pcm_hw_params_t *params = NULL; snd_pcm_uframes_t frames; snd_pcm_access_t access; snd_pcm_format_t format; unsigned int rate = 44100; unsigned int val, val2; int dir = 0; const char *device = getenv ("ALSA_DEFAULT"); if (device == NULL) { device = "default"; } result = snd_pcm_open(&handle, device, SND_PCM_STREAM_PLAYBACK, 0); if (result < 0) showErrorAndExit(result, "Error: Unable to open PCM device: %s\n"); result = snd_pcm_hw_params_malloc(¶ms); if (result < 0) showErrorAndExit(result, "Error: No memory for hardware parameters: %s\n"); result = snd_pcm_hw_params_any(handle, params); if (result < 0) showErrorAndExit(result, "Error: Cannot read HW params: %s\n"); result = snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED); if (result < 0) showErrorAndExit(result, "Could not set access method: %s\n"); result = snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE); if (result < 0) showErrorAndExit(result, "Error: Could not set output format: %s\n"); result = snd_pcm_hw_params_set_channels(handle, params, 1); if (result < 0) showErrorAndExit(result, "Error: Cannot set to 1 channel: %s\n"); result = snd_pcm_hw_params_set_rate_near(handle, params, &rate, &dir); if (result < 0) showErrorAndExit(result, "Error: Could not set rate: %s\n"); result = snd_pcm_hw_params(handle, params); if (result < 0) showErrorAndExit(result, "Error: Could not write HW params: %s\n"); printf("Card Parameters\n"); printf("%30s: %s\n", "Alsa Library Version", snd_asoundlib_version()); result = snd_pcm_hw_params_get_access(params, &access); if (result < 0) { showErrorAndExit(result, "Error: Could not retrieve access mode: %s\n"); } else { printf("%30s: %s\n", "Access Method", snd_pcm_access_name(access)); } result = snd_pcm_hw_params_get_format(params, &format); if (result < 0) { showErrorAndExit(result, "Error: Unable to retrieve format type: %d\n"); } else { printf("%30s: %s\n", "Format", snd_pcm_format_name(format)); } result = snd_pcm_hw_params_get_channels(params, &val); if (result < 0) { showErrorAndExit(result, "Error: Unable to retrieve channel count: %s\n"); } else { printf("%30s: %d\n", "Channels", val); } result = snd_pcm_hw_params_get_rate(params, &val, &dir); if (result < 0) { showErrorAndExit(result, "Error: Unable to retrieve rate: %s\n"); } else { printf("%30s: %d bps\n", "Rate", val); } result = snd_pcm_hw_params_get_period_time(params, &val, &dir); if (result < 0) { showErrorAndExit(result, "Error: Unable to retrieve period time: %s\n"); } else { printf("%30s: %d us\n", "Period Time", val); } result = snd_pcm_hw_params_get_period_size(params, &frames, &dir); if (result < 0) { showErrorAndExit(result, "Error: Unable to retrieve period size: %s\n"); } else { printf("%30s: %d frames\n", "Period Size", (int) frames); } result = snd_pcm_hw_params_get_buffer_time(params, &val, &dir); if (result < 0) { showErrorAndExit(result, "Error: Unable to retrieve buffer time: %s\n"); } else { printf("%30s: %d us\n", "Buffer Time", val); } result = snd_pcm_hw_params_get_buffer_size(params, &frames); if (result < 0) { showErrorAndExit(result, "Error: Unable to retrieve buffer size: %s\n"); } else { printf("%30s: %d frames\n", "Buffer Size", (int) frames); } result = snd_pcm_hw_params_get_periods(params, &val, &dir); if (result < 0) { showErrorAndExit(result, "Error: Unable to get buffer periods: %s\n"); } else { printf("%30s: %d frames\n", "Periods per Buffer", val); } result = snd_pcm_hw_params_get_rate_numden(params, &val, &val2); if (result < 0) { showErrorAndExit(result, "Error: Unable to get rate numerator/denominator: %s\n"); } else { printf("%30s: %d/%d bps\n", "Exact Rate", val, val2); } val = snd_pcm_hw_params_get_sbits(params); printf("%30s: %d\n", "Significant Bits", val); result = snd_pcm_hw_params_get_tick_time(params, &val, &dir); if (result < 0) { showErrorAndExit(result, "Error: Could not retrieve tick time: %s\n"); } else { printf("%30s: %d\n", "Tick Time", val); } printf("Card Capabilities\n"); val = snd_pcm_hw_params_is_batch(params); printf("%30s: %s\n", "Batch Transfer", (val ? "Yes" : "No")); val = snd_pcm_hw_params_is_block_transfer(params); printf("%30s: %s\n", "Block Transfer", (val ? "Yes" : "No")); val = snd_pcm_hw_params_is_double(params); printf("%30s: %s\n", "Double Buffering", (val ? "Yes" : "No")); val = snd_pcm_hw_params_is_half_duplex(params); printf("%30s: %s\n", "Half Duplex Only", (val ? "Yes" : "No")); val = snd_pcm_hw_params_is_joint_duplex(params); printf("%30s: %s\n", "Joint Duplex Capable", (val ? "Yes" : "No")); val = snd_pcm_hw_params_can_overrange(params); printf("%30s: %s\n", "Support Overrange Detection", (val ? "Yes" : "No")); val = snd_pcm_hw_params_can_mmap_sample_resolution(params); printf("%30s: %s\n", "Support Sample-res Mmap", (val ? "Yes" : "No")); val = snd_pcm_hw_params_can_pause(params); printf("%30s: %s\n", "Can Pause", (val ? "Yes" : "No")); val = snd_pcm_hw_params_can_resume(params); printf("%30s: %s\n", "Can Resume", (val ? "Yes" : "No")); val = snd_pcm_hw_params_can_sync_start(params); printf("%30s: %s\n", "Support Sync Start", (val ? "Yes" : "No")); result = snd_pcm_close(handle); if (result < 0) showErrorAndExit(result, "Error: Could not close PCM device: %s\n"); return 0; }