buffer_size =snd_pcm_hw_params_get_buffer_size(params);/* set period time */err = snd_pcm_hw_params_set_period_time_near(handle, params, period_time, &dir);if(err <0) {printf("Unable to set period time %i for playback: %s\n", period_time, snd_strerror(err));returnerr; } p...
inParams.channels :outParams.channels; param.sampleFormat=(outParams.sampleFormat<=AV_SAMPLE_FMT_NONE||outParams.sampleFormat>=AV_SAMPLE_FMT_NB) ?inParams.sampleFormat :outParams.sampleFormat; param.sampleRate=(outParams.sampleRate<1) ?inParams.sampleRate :outParams.sampleRate; return param; }...
接下来,我们可以通过以下代码来读取一个PCM格式的音频文件: importwave# 打开PCM格式的音频文件withwave.open('audio.pcm','rb')aswf:# 获取音频文件的信息params=wf.getparams()# 读取音频数据data=wf.readframes(params.nframes) 1. 2. 3. 4. 5. 6. 7. 8. 9. 上面的代码首先打开名为audio.pcm的PCM格...
/* 对pcm设备节点的操作 */ struct pcm *pcm_open(unsigned int card, unsigned int device, unsigned int flags, struct pcm_config *config); int pcm_close(struct pcm *pcm); int pcm_is_ready(struct pcm *pcm); /* 获取pcm设备的能力 */ struct pcm_params *pcm_params_get(unsigned int card,...
fprintf(stderr, "get_wav_header_info() failed!\n"); return -1; } if(check_wav_format(wav)<0) return -1; return 0; } int set_params(pcm_container *pcm, wav_format *wav) { snd_pcm_hw_params_t *hwparams; uint32_t buffer_time, period_time; ...
int snd_pcm_hw_params_set_access(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, snd_pcm_access_t _access); 读取指定PCM硬件参数的样本格式: int snd_pcm_hw_params_get_format(const snd_pcm_hw_params_t *params, snd_pcm_format_t *val); ...
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_peri...
{snd_pcm_uframes_tframe_num;snd_pcm_uframes_tframe_size;/* 一帧的大小 */unsignedintchannels=2;/* 双声道 */unsignedintformat_sbits=16;/* 数据格式: 有符号16位格式 *//* 获取一个播放周期的帧数 */snd_pcm_hw_params_get_period_size(params,&frame_num,0);frame_size=channels*format_s...
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_...
if (snd_pcm_hw_params_mall)()return -1;// Now start the playback if (snd_pcm_prepare())return -1;if (snd_pcm_start()return -1;// Finally, get the data and output it through the PCM driver for (int i = 0; i snd_pcm_ writei(card, data[i], 1);// When we&...