6735l1.txt0100664000204600003300000000224310115455501011440 0ustar jillljedit#include int main() { int val; printf("ALSA library version: %s\n", SND_LIB_VERSION_STR); printf("\nPCM stream types:\n"); for (val = 0; val <= SND_PCM_STREAM_LAST; val++) printf(" %s\n", snd_pcm_stream_name((snd_pcm_stream_t)val)); printf("\nPCM access types:\n"); for (val = 0; val <= SND_PCM_ACCESS_LAST; val++) printf(" %s\n", snd_pcm_access_name((snd_pcm_access_t)val)); printf("\nPCM formats:\n"); for (val = 0; val <= SND_PCM_FORMAT_LAST; val++) if (snd_pcm_format_name((snd_pcm_format_t)val) != NULL) printf(" %s (%s)\n", snd_pcm_format_name((snd_pcm_format_t)val), snd_pcm_format_description( (snd_pcm_format_t)val)); printf("\nPCM subformats:\n"); for (val = 0; val <= SND_PCM_SUBFORMAT_LAST; val++) printf(" %s (%s)\n", snd_pcm_subformat_name(( snd_pcm_subformat_t)val), snd_pcm_subformat_description(( snd_pcm_subformat_t)val)); printf("\nPCM states:\n"); for (val = 0; val <= SND_PCM_STATE_LAST; val++) printf(" %s\n", snd_pcm_state_name((snd_pcm_state_t)val)); return 0; } 6735l2.txt0100664000204600003300000001114210115455501011437 0ustar jillljedit/* This example opens the default PCM device, sets some parameters, and then displays the value of most of the hardware parameters. It does not perform any sound playback or recording. */ /* Use the newer ALSA API */ #define ALSA_PCM_NEW_HW_PARAMS_API /* All of the ALSA library API is defined * in this header */ #include int main() { int rc; snd_pcm_t *handle; snd_pcm_hw_params_t *params; unsigned int val, val2; int dir; snd_pcm_uframes_t frames; /* Open PCM device for playback. */ rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0); if (rc < 0) { fprintf(stderr, "unable to open pcm device: %s\n", snd_strerror(rc)); exit(1); } /* Allocate a hardware parameters object. */ snd_pcm_hw_params_alloca(¶ms); /* Fill it in with default values. */ snd_pcm_hw_params_any(handle, params); /* Set the desired hardware parameters. */ /* Interleaved mode */ snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED); /* Signed 16-bit little-endian format */ snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE); /* Two channels (stereo) */ snd_pcm_hw_params_set_channels(handle, params, 2); /* 44100 bits/second sampling rate (CD quality) */ val = 44100; snd_pcm_hw_params_set_rate_near(handle, params, &val, &dir); /* Write the parameters to the driver */ rc = snd_pcm_hw_params(handle, params); if (rc < 0) { fprintf(stderr, "unable to set hw parameters: %s\n", snd_strerror(rc)); exit(1); } /* Display information about the PCM interface */ printf("PCM handle name = '%s'\n", snd_pcm_name(handle)); printf("PCM state = %s\n", snd_pcm_state_name(snd_pcm_state(handle))); snd_pcm_hw_params_get_access(params, (snd_pcm_access_t *) &val); printf("access type = %s\n", snd_pcm_access_name((snd_pcm_access_t)val)); snd_pcm_hw_params_get_format(params, &val); printf("format = '%s' (%s)\n", snd_pcm_format_name((snd_pcm_format_t)val), snd_pcm_format_description( (snd_pcm_format_t)val)); snd_pcm_hw_params_get_subformat(params, (snd_pcm_subformat_t *)&val); printf("subformat = '%s' (%s)\n", snd_pcm_subformat_name((snd_pcm_subformat_t)val), snd_pcm_subformat_description( (snd_pcm_subformat_t)val)); snd_pcm_hw_params_get_channels(params, &val); printf("channels = %d\n", val); snd_pcm_hw_params_get_rate(params, &val, &dir); printf("rate = %d bps\n", val); snd_pcm_hw_params_get_period_time(params, &val, &dir); printf("period time = %d us\n", val); snd_pcm_hw_params_get_period_size(params, &frames, &dir); printf("period size = %d frames\n", (int)frames); snd_pcm_hw_params_get_buffer_time(params, &val, &dir); printf("buffer time = %d us\n", val); snd_pcm_hw_params_get_buffer_size(params, (snd_pcm_uframes_t *) &val); printf("buffer size = %d frames\n", val); snd_pcm_hw_params_get_periods(params, &val, &dir); printf("periods per buffer = %d frames\n", val); snd_pcm_hw_params_get_rate_numden(params, &val, &val2); printf("exact rate = %d/%d bps\n", val, val2); val = snd_pcm_hw_params_get_sbits(params); printf("significant bits = %d\n", val); snd_pcm_hw_params_get_tick_time(params, &val, &dir); printf("tick time = %d us\n", val); val = snd_pcm_hw_params_is_batch(params); printf("is batch = %d\n", val); val = snd_pcm_hw_params_is_block_transfer(params); printf("is block transfer = %d\n", val); val = snd_pcm_hw_params_is_double(params); printf("is double = %d\n", val); val = snd_pcm_hw_params_is_half_duplex(params); printf("is half duplex = %d\n", val); val = snd_pcm_hw_params_is_joint_duplex(params); printf("is joint duplex = %d\n", val); val = snd_pcm_hw_params_can_overrange(params); printf("can overrange = %d\n", val); val = snd_pcm_hw_params_can_mmap_sample_resolution(params); printf("can mmap = %d\n", val); val = snd_pcm_hw_params_can_pause(params); printf("can pause = %d\n", val); val = snd_pcm_hw_params_can_resume(params); printf("can resume = %d\n", val); val = snd_pcm_hw_params_can_sync_start(params); printf("can sync start = %d\n", val); snd_pcm_close(handle); return 0; } 6735l3.txt0100664000204600003300000000571110115455501011445 0ustar jillljedit/* Example 3 - Simple sound playback This example reads standard from input and writes to the default PCM device for 5 seconds of data. */ /* Use the newer ALSA API */ #define ALSA_PCM_NEW_HW_PARAMS_API #include int main() { long loops; int rc; int size; snd_pcm_t *handle; snd_pcm_hw_params_t *params; unsigned int val; int dir; snd_pcm_uframes_t frames; char *buffer; /* Open PCM device for playback. */ rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0); if (rc < 0) { fprintf(stderr, "unable to open pcm device: %s\n", snd_strerror(rc)); exit(1); } /* Allocate a hardware parameters object. */ snd_pcm_hw_params_alloca(¶ms); /* Fill it in with default values. */ snd_pcm_hw_params_any(handle, params); /* Set the desired hardware parameters. */ /* Interleaved mode */ snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED); /* Signed 16-bit little-endian format */ snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE); /* Two channels (stereo) */ snd_pcm_hw_params_set_channels(handle, params, 2); /* 44100 bits/second sampling rate (CD quality) */ val = 44100; snd_pcm_hw_params_set_rate_near(handle, params, &val, &dir); /* Set period size to 32 frames. */ frames = 32; snd_pcm_hw_params_set_period_size_near(handle, params, &frames, &dir); /* Write the parameters to the driver */ rc = snd_pcm_hw_params(handle, params); if (rc < 0) { fprintf(stderr, "unable to set hw parameters: %s\n", snd_strerror(rc)); exit(1); } /* Use a buffer large enough to hold one period */ snd_pcm_hw_params_get_period_size(params, &frames, &dir); size = frames * 4; /* 2 bytes/sample, 2 channels */ buffer = (char *) malloc(size); /* We want to loop for 5 seconds */ snd_pcm_hw_params_get_period_time(params, &val, &dir); /* 5 seconds in microseconds divided by * period time */ loops = 5000000 / val; while (loops > 0) { loops--; rc = read(0, buffer, size); if (rc == 0) { fprintf(stderr, "end of file on input\n"); break; } else if (rc != size) { fprintf(stderr, "short read: read %d bytes\n", rc); } rc = snd_pcm_writei(handle, buffer, frames); if (rc == -EPIPE) { /* EPIPE means underrun */ fprintf(stderr, "underrun occurred\n"); snd_pcm_prepare(handle); } else if (rc < 0) { fprintf(stderr, "error from writei: %s\n", snd_strerror(rc)); } else if (rc != (int)frames) { fprintf(stderr, "short write, write %d frames\n", rc); } } snd_pcm_drain(handle); snd_pcm_close(handle); free(buffer); return 0; } 6735l4.txt0100664000204600003300000000544710115455501011454 0ustar jillljedit/* Example 4 - Simple sound recording This example reads from the default PCM device and writes to standard output for 5 seconds of data. */ /* Use the newer ALSA API */ #define ALSA_PCM_NEW_HW_PARAMS_API #include int main() { long loops; int rc; int size; snd_pcm_t *handle; snd_pcm_hw_params_t *params; unsigned int val; int dir; snd_pcm_uframes_t frames; char *buffer; /* Open PCM device for recording (capture). */ rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_CAPTURE, 0); if (rc < 0) { fprintf(stderr, "unable to open pcm device: %s\n", snd_strerror(rc)); exit(1); } /* Allocate a hardware parameters object. */ snd_pcm_hw_params_alloca(¶ms); /* Fill it in with default values. */ snd_pcm_hw_params_any(handle, params); /* Set the desired hardware parameters. */ /* Interleaved mode */ snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED); /* Signed 16-bit little-endian format */ snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE); /* Two channels (stereo) */ snd_pcm_hw_params_set_channels(handle, params, 2); /* 44100 bits/second sampling rate (CD quality) */ val = 44100; snd_pcm_hw_params_set_rate_near(handle, params, &val, &dir); /* Set period size to 32 frames. */ frames = 32; snd_pcm_hw_params_set_period_size_near(handle, params, &frames, &dir); /* Write the parameters to the driver */ rc = snd_pcm_hw_params(handle, params); if (rc < 0) { fprintf(stderr, "unable to set hw parameters: %s\n", snd_strerror(rc)); exit(1); } /* Use a buffer large enough to hold one period */ snd_pcm_hw_params_get_period_size(params, &frames, &dir); size = frames * 4; /* 2 bytes/sample, 2 channels */ buffer = (char *) malloc(size); /* We want to loop for 5 seconds */ snd_pcm_hw_params_get_period_time(params, &val, &dir); loops = 5000000 / val; while (loops > 0) { loops--; rc = snd_pcm_readi(handle, buffer, frames); if (rc == -EPIPE) { /* EPIPE means overrun */ fprintf(stderr, "overrun occurred\n"); snd_pcm_prepare(handle); } else if (rc < 0) { fprintf(stderr, "error from read: %s\n", snd_strerror(rc)); } else if (rc != (int)frames) { fprintf(stderr, "short read, read %d frames\n", rc); } rc = write(1, buffer, size); if (rc != size) fprintf(stderr, "short write: wrote %d bytes\n", rc); } snd_pcm_drain(handle); snd_pcm_close(handle); free(buffer); return 0; }