alsa-player 可播放wav和rawdata文件

//File : snd.c //Author : Loon <sepnic@gmail.com> #include <assert.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> #include <alsa/asoundlib.h> #include "snd.h" typedef struct SND_Container { snd_pcm_t *handle; snd_output_t *log; snd_pcm_uframes_t chunk_size; snd_pcm_uframes_t buffer_size; snd_pcm_format_t format; uint16_t channels; size_t chunk_bytes; size_t bits_per_sample; size_t bits_per_frame; uint8_t *data_buf; } SND_Container_t; static SND_Container_t playback; static SND_Container_t capture; ////////////////////////// private function ////////////////////////////// ssize_t SND_readPcm(SND_Container_t *snd, uint8_t * buffer, size_t rcount) { ssize_t r; size_t result = 0; size_t count = rcount; uint8_t *data = buffer; if (count != snd->chunk_size) { count = snd->chunk_size; } while (count > 0) { r = snd_pcm_readi(snd->handle, data, count); if (r == -EAGAIN || (r >= 0 && (size_t)r < count)) { snd_pcm_wait(snd->handle, 1000); } else if (r == -EPIPE) { snd_pcm_prepare(snd->handle); fprintf(stderr, "<<<<<<<<<<<<<<< Buffer Overrun >>>>>>>>>>>>>>>\n"); } else if (r == -ESTRPIPE) { fprintf(stderr, "<<<<<<<<<<<<<<< Need suspend >>>>>>>>>>>>>>>\n"); } else if (r < 0) { fprintf(stderr, "Error snd_pcm_writei: [%s]", snd_strerror(r)); return -1; } if (r > 0) { result += r; count -= r; data += r * snd->bits_per_frame / 8; } } return rcount; } ssize_t SND_writePcm(SND_Container_t *snd, uint8_t * buffer, size_t wcount) { ssize_t r; ssize_t result = 0; uint8_t *data = buffer; if (wcount < snd->chunk_size) { snd_pcm_format_set_silence(snd->format, data + wcount * snd->bits_per_frame / 8, (snd->chunk_size - wcount) * snd->channels); wcount = snd->chunk_size; } while (wcount > 0) { r = snd_pcm_writei(snd->handle, data, wcount); if (r == -EAGAIN || (r >= 0 && (size_t)r < wcount)) { snd_pcm_wait(snd->handle, 1000); } else if (r == -EPIPE) { snd_pcm_prepare(snd->handle); fprintf(stderr, "<<<<<<<<<<<<<<< Buffer Underrun >>>>>>>>>>>>>>>\n"); } else if (r == -ESTRPIPE) { fprintf(stderr, "<<<<<<<<<<<<<<< Need suspend >>>>>>>>>>>>>>>\n"); } else if (r < 0) { fprintf(stderr, "Error snd_pcm_writei: [%s]", snd_strerror(r)); return -1; } if (r > 0) { result += r; wcount -= r; data += r * snd->bits_per_frame / 8; } } return result; } snd_pcm_format_t SND_P_getFormat(int sample_length) { switch (sample_length) { case 16: return SND_PCM_FORMAT_S16_LE; break; case 8: return SND_PCM_FORMAT_U8; break; default: return SND_PCM_FORMAT_UNKNOWN; break; } return SND_PCM_FORMAT_UNKNOWN; } int SND_setParams(SND_Container_t *snd, int channels, int sample_rate, int sample_length) { snd_pcm_hw_params_t *hwparams; uint32_t exact_rate; uint32_t buffer_time, period_time; snd_pcm_format_t format = SND_P_getFormat(sample_length); /* Allocate the snd_pcm_hw_params_t structure on the stack. */ snd_pcm_hw_params_alloca(&hwparams); /* Init hwparams with full configuration space */ if (snd_pcm_hw_params_any(snd->handle, hwparams) < 0) { fprintf(stderr, "Error snd_pcm_hw_params_any\n"); goto err; } if (snd_pcm_hw_params_set_access(snd->handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) { fprintf(stderr, "Error snd_pcm_hw_params_set_access\n"); goto err; } /* Set sample format */ if (snd_pcm_hw_params_set_format(snd->handle, hwparams, format) < 0) { fprintf(stderr, "Error snd_pcm_hw_params_set_format\n"); goto err; } snd->format = format; /* Set number of channels */ if (snd_pcm_hw_params_set_channels(snd->handle, hwparams, channels) < 0) { fprintf(stderr, "Error snd_pcm_hw_params_set_channels\n"); goto err; } snd->channels = channels; /* Set sample rate. If the exact rate is not supported */ /* by the hardware, use nearest possible rate. */ exact_rate = sample_rate; if (snd_pcm_hw_params_set_rate_near(snd->handle, hwparams, &exact_rate, 0) < 0) { fprintf(stderr, "Error snd_pcm_hw_params_set_rate_near\n"); goto err; } if (sample_rate != exact_rate) { fprintf(stderr, "The rate %d Hz is not supported by your hardware.\n ==> Using %d Hz instead.\n", sample_rate, exact_rate); } if (snd_pcm_hw_params_get_buffer_time_max(hwparams, &buffer_time, 0) < 0) { fprintf(stderr, "Error snd_pcm_hw_params_get_buffer_time_max\n"); goto err; } if (buffer_time > 500000) buffer_time = 500000; period_time = buffer_time / 4; if (snd_pcm_hw_params_set_buffer_time_near(snd->handle, hwparams, &buffer_time, 0) < 0) { fprintf(stderr, "Error snd_pcm_hw_params_set_buffer_time_near\n"); goto err; } if (snd_pcm_hw_params_set_period_time_near(snd->handle, hwparams, &period_time, 0) < 0) { fprintf(stderr, "Error snd_pcm_hw_params_set_period_time_near\n"); goto err; } /* Set hw params */ if (snd_pcm_hw_params(snd->handle, hwparams) < 0) { fprintf(stderr, "Error snd_pcm_hw_params(handle, params)\n"); goto err; } snd_pcm_hw_params_get_period_size(hwparams, &snd->chunk_size, 0); snd_pcm_hw_params_get_buffer_size(hwparams, &snd->buffer_size); if (snd->chunk_size == snd->buffer_size) { fprintf(stderr, ("Can't use period equal to buffer size (%lu == %lu)\n"), snd->chunk_size, snd->buffer_size); goto err; } snd->bits_per_sample = snd_pcm_format_physical_width(snd->format); snd->bits_per_frame = snd->bits_per_sample * snd->channels; snd->chunk_bytes = snd->chunk_size * snd->bits_per_frame / 8; /* Allocate audio data buffer */ snd->data_buf = (uint8_t *)malloc(snd->chunk_bytes); if (!snd->data_buf) { fprintf(stderr, "Error malloc: [data_buf]\n"); goto err; } return 0; err: return -1; } ssize_t SND_P_saveRead(int fd, void *buf, size_t count) { ssize_t result = 0, ret; while (count > 0) { if ((ret = read(fd, buf, count)) == 0) break; if (ret < 0) return result > 0 ? result : ret; count -= ret; result += ret; buf = (char *)buf + ret; } return result; } ////////////////////////// public function ////////////////////////////// int snd_open(snd_stream_type_t stream) { const char *devicename = "default"; snd_pcm_stream_t direction = stream == SND_STREAM_PLAYBACK ? SND_PCM_STREAM_PLAYBACK : SND_PCM_STREAM_CAPTURE; SND_Container_t *snd = stream == SND_STREAM_PLAYBACK ? &playback : &capture; if (snd_output_stdio_attach(&snd->log, stderr, 0) < 0) { fprintf(stderr, "Error snd_output_stdio_attach\n"); goto err; } if (snd_pcm_open(&snd->handle, devicename, direction, 0) < 0) { fprintf(stderr, "Error snd_pcm_open [ %s]\n", devicename); goto err; } return 0; err: if (snd->data_buf) free(snd->data_buf); if (snd->log) snd_output_close(snd->log); if (snd->handle) snd_pcm_close(snd->handle); return -1; } void snd_close(snd_stream_type_t stream) { SND_Container_t *snd = stream == SND_STREAM_PLAYBACK ? &playback : &capture; snd_pcm_drain(snd->handle); free(snd->data_buf); snd_output_close(snd->log); snd_pcm_close(snd->handle); } int snd_set(snd_stream_type_t stream, int channels, int sample_rate, int sample_length) { SND_Container_t *snd = stream == SND_STREAM_PLAYBACK ? &playback : &capture; assert(snd->handle); if (SND_setParams(snd, channels, sample_rate, sample_length) < 0) { fprintf(stderr, "Error snd_set[channels:%d, sample_rate:%dhz, sample_length:%d]\n", channels, sample_rate, sample_length); return -1; } snd_pcm_dump(snd->handle, snd->log); return 0; } int snd_playback(int fd) { int ret; off64_t c = playback.chunk_bytes; ret = SND_P_saveRead(fd, playback.data_buf, c); if (ret <= 0) { fprintf(stderr, "Error safe_read\n"); return -1; } // Transfer to size frame ret = ret * 8 / playback.bits_per_frame; if (SND_writePcm(&playback, playback.data_buf, ret) != ret) { fprintf(stderr, "Error snd_write [SND_writePcm]\n"); return -1; } return 0; } int snd_playback_1(uint8_t *buffer, size_t length) { int write_bytes