QNX系统中播放wav文件

QNX 中播放音频，用的是libasound 库。
官方提供的 wave.c 的代码，用于播放一个wav格式的音频文件。
但在QNX 6.6 虚拟机里一直播放不了，原因是虚拟机没有/dev/snd/ 而且该目录下也没什么设备。继续看官方的帮助文档，是要运行/sbin/io-audio加载声卡驱动才能播放。

The io-audio command can load the following shared objects:

deva-ctrl-4dwave.so
Sound driver for the Trident 4DWave!.
deva-ctrl-audiopci.so
Sound driver for the AudioPCI chip family.
deva-ctrl-cs4281.so
Sound driver for the CS4281.
deva-ctrl-cs46xx.so
Sound driver for the CS46xx family of chips.
deva-ctrl-cyberpro5.so
Sound driver for the CyberPro5XXX.
deva-ctrl-ess1938.so
Sound driver for the ESS1938.
deva-ctrl-geode.so
Sound driver for the National Semiconductor Geode family of chips.
deva-ctrl-i8x0.so
Sound driver for the Intel 8X0.
deva-ctrl-nmg6.so
Sound driver for the Neomagic 6 family of chips.
deva-ctrl-sb.so
Sound driver for Sound Blaster 16 and compatible soundcards.
deva-ctrl-via686.so
Sound driver for the VIA686.
deva-ctrl-vortex.so
Sound driver for the Vortex.
deva-ctrl-ymfds1.so
Sound driver for the Yamaha DS1.
deva-mixer-ac97.so
Mixer DLL for the AC97 codec.
deva-ak4531.so
Mixer DLL for the AK4531 codec.
deva-util-restore.so
Shared object used to restore an audio driver’s state.

在虚拟机内执行：

/sbin/io-audio -d audiopci

加载驱动后，出现了/dev/snd/ 目录，而且目录下有文件

# /sbin/io-audio -d audiopci    # ls /dev/snd/controlC0        mixerC0D0        pcmC0D0c         pcmC0D0p         pcmC0D1p         pcmPreferredc    pcmPreferredp

这样就可以用官网那个例子进行播放了，播放命令如下：

# ./playWave -a 0:0 Wave1.wav       Using card 0 device 0 SampleRate = 11025, Channels = 2, SampleBits = 16Format Signed 16-bit Little Endian Frag Size 131072 Total Frags 2 Rate 11025 Voices 2 Mixer Pcm Group [PCM]

---

将wave.c 中调音量等复杂功能裁剪掉，写成一个只播放的demo:

#include <errno.h>#include <fcntl.h>#include <gulliver.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/ioctl.h>#include <sys/select.h>#include <sys/stat.h>#include <sys/termio.h>#include <sys/types.h>#include <unistd.h>#include <sys/slogcodes.h>#include <ctype.h>#include <limits.h>#include <sys/asoundlib.h>#define max(a,b) (a>b)?a:b#define min(a,b) (a<b)?a:bconst char *kRiffId = "RIFF";const char *kWaveId = "WAVE";typedef struct{    char    tag[4];    long    length;}RiffTag;typedef struct{    char    Riff[4];    long    Size;    char    Wave[4];}RiffHdr;typedef struct{    short   FormatTag;    short   Channels;    long    SamplesPerSec;    long    AvgBytesPerSec;    short   BlockAlign;    short   BitsPerSample;}WaveHdr;int err (char *msg){    perror (msg);    return -1;}int FindTag (FILE * fp, const char *tag){    int     retVal;    RiffTag tagBfr = { "", 0 };    retVal = 0;    // Keep reading until we find the tag or hit the EOF.    while (fread ((unsigned char *) &tagBfr, sizeof (tagBfr), 1, fp))    {        // If this is our tag, set the length and break.        if (strncmp (tag, tagBfr.tag, sizeof tagBfr.tag) == 0)        {            retVal = ENDIAN_LE32 (tagBfr.length);            break;        }        // Skip ahead the specified number of bytes in the stream        fseek (fp, tagBfr.length, SEEK_CUR);    }    // Return the result of our operation    return (retVal);}int CheckHdr (FILE * fp){    RiffHdr riffHdr = { "", 0 };    // Read the header and, if successful, play the file    // file or WAVE file.    if (fread ((unsigned char *) &riffHdr, sizeof (RiffHdr), 1, fp) == 0)        return 0;    if (strncmp (riffHdr.Riff, kRiffId, strlen (kRiffId)) ||        strncmp (riffHdr.Wave, kWaveId, strlen (kWaveId)))        return -1;    return 0;}int dev_raw (int fd){    struct termios termios_p;    if (tcgetattr (fd, &termios_p))        return (-1);    termios_p.c_cc[VMIN] = 1;    termios_p.c_cc[VTIME] = 0;    termios_p.c_lflag &= ~(ECHO | ICANON | ISIG | ECHOE | ECHOK | ECHONL);    termios_p.c_oflag &= ~(OPOST);    return (tcsetattr (fd, TCSANOW, &termios_p));}int dev_unraw (int fd){    struct termios termios_p;    if (tcgetattr (fd, &termios_p))        return (-1);    termios_p.c_lflag |= (ECHO | ICANON | ISIG | ECHOE | ECHOK | ECHONL);    termios_p.c_oflag |= (OPOST);    return (tcsetattr (fd, TCSAFLUSH, &termios_p));}//*****************************************************************************// ./playWave Wave1.wav//*****************************************************************************int main (int argc, char **argv){    snd_pcm_t *pcm_handle;    FILE   *file1;    WaveHdr wavHdr1;    int     mSamples;    int     mSampleRate;    int     mSampleChannels;    int     mSampleBits;    char   *mSampleBfr1;    int     verbose = 0;    int     rtn;    snd_pcm_channel_info_t pi;    snd_mixer_t *mixer_handle;    snd_mixer_group_t group;    snd_pcm_channel_params_t pp;    snd_pcm_channel_setup_t setup;    int     bsize, n, N = 0;    fd_set  rfds, wfds;    int     num_frags = -1;    char    name[_POSIX_PATH_MAX] ="pcmC0D0p";    int     card = -1;    int     dev = 0;    //两种方式打开音频设备; 首选 打开设备 /dev/snd/pcmC0D0p , 设备名根据实际情况变化;    if (name[0] != '\0')        printf ("Using device /dev/snd/%s\n", name);    else        printf ("Using card %d device %d \n", card, dev);    setvbuf (stdin, NULL, _IONBF, 0);    if (name[0] != '\0')    {        snd_pcm_info_t info;        if ((rtn = snd_pcm_open_name (&pcm_handle, name, SND_PCM_OPEN_PLAYBACK)) < 0)        {            return err ((char *)"open_name");        }        rtn = snd_pcm_info (pcm_handle, &info);        card = info.card;    }    else    {        if (card == -1)        {            if ((rtn = snd_pcm_open_preferred (&pcm_handle, &card, &dev, SND_PCM_OPEN_PLAYBACK)) < 0)                return err ((char *)"device open");        }        else        {            if ((rtn = snd_pcm_open (&pcm_handle, card, dev, SND_PCM_OPEN_PLAYBACK)) < 0)                return err ((char *)"device open");        }    }    if (argc < 2)        return err ((char *)"no file specified");    if ((file1 = fopen (argv[1], "r")) == 0)        return err ((char *)"file open #1");    if (CheckHdr (file1) == -1)        return err ((char *)"CheckHdr #1");    mSamples = FindTag (file1, "fmt ");    fread (&wavHdr1, sizeof (wavHdr1), 1, file1);    fseek (file1, (mSamples - sizeof (WaveHdr)), SEEK_CUR);    mSampleRate = ENDIAN_LE32 (wavHdr1.SamplesPerSec);    mSampleChannels = ENDIAN_LE16 (wavHdr1.Channels);    mSampleBits = ENDIAN_LE16 (wavHdr1.BitsPerSample);    printf ("SampleRate = %d, Channels = %d, SampleBits = %d\n", mSampleRate, mSampleChannels,        mSampleBits);    /* disabling mmap is not actually required in this example but it is included to     * demonstrate how it is used when it is required.     */    if ((rtn = snd_pcm_plugin_set_disable (pcm_handle, PLUGIN_DISABLE_MMAP)) < 0)    {        fprintf (stderr, "snd_pcm_plugin_set_disable failed: %s\n", snd_strerror (rtn));        return -1;    }    memset (&pi, 0, sizeof (pi));    pi.channel = SND_PCM_CHANNEL_PLAYBACK;    if ((rtn = snd_pcm_plugin_info (pcm_handle, &pi)) < 0)    {        fprintf (stderr, "snd_pcm_plugin_info failed: %s\n", snd_strerror (rtn));        return -1;    }    memset (&pp, 0, sizeof (pp));    pp.mode = SND_PCM_MODE_BLOCK;    pp.channel = SND_PCM_CHANNEL_PLAYBACK;    pp.start_mode = SND_PCM_START_FULL;    pp.stop_mode = SND_PCM_STOP_STOP;    pp.buf.block.frag_size = pi.max_fragment_size;    pp.buf.block.frags_max = num_frags;    pp.buf.block.frags_min = 1;    pp.format.interleave = 1;    pp.format.rate = mSampleRate;    pp.format.voices = mSampleChannels;    if (ENDIAN_LE16 (wavHdr1.FormatTag) == 6)        pp.format.format = SND_PCM_SFMT_A_LAW;    else if (ENDIAN_LE16 (wavHdr1.FormatTag) == 7)        pp.format.format = SND_PCM_SFMT_MU_LAW;    else if (mSampleBits == 8)        pp.format.format = SND_PCM_SFMT_U8;    else if (mSampleBits == 24)        pp.format.format = SND_PCM_SFMT_S24;    else        pp.format.format = SND_PCM_SFMT_S16_LE;    strcpy (pp.sw_mixer_subchn_name, "Wave playback channel");    if ((rtn = snd_pcm_plugin_params (pcm_handle, &pp)) < 0)    {        fprintf (stderr, "snd_pcm_plugin_params failed: %s\n", snd_strerror (rtn));        return -1;    }    if ((rtn = snd_pcm_plugin_prepare (pcm_handle, SND_PCM_CHANNEL_PLAYBACK)) < 0)        fprintf (stderr, "snd_pcm_plugin_prepare failed: %s\n", snd_strerror (rtn));    memset (&setup, 0, sizeof (setup));    memset (&group, 0, sizeof (group));    setup.channel = SND_PCM_CHANNEL_PLAYBACK;    setup.mixer_gid = &group.gid;    if ((rtn = snd_pcm_plugin_setup (pcm_handle, &setup)) < 0)    {        fprintf (stderr, "snd_pcm_plugin_setup failed: %s\n", snd_strerror (rtn));        return -1;    }    printf ("Format %s \n", snd_pcm_get_format_name (setup.format.format));    printf ("Frag Size %d \n", setup.buf.block.frag_size);    printf ("Total Frags %d \n", setup.buf.block.frags);    printf ("Rate %d \n", setup.format.rate);    printf ("Voices %d \n", setup.format.voices);    bsize = setup.buf.block.frag_size;    if (group.gid.name[0] == 0)    {        printf ("Mixer Pcm Group [%s] Not Set \n", group.gid.name);        exit (-1);    }    printf ("Mixer Pcm Group [%s]\n", group.gid.name);    if ((rtn = snd_mixer_open (&mixer_handle, card, setup.mixer_device)) < 0)    {        fprintf (stderr, "snd_mixer_open failed: %s\n", snd_strerror (rtn));        return -1;    }    mSamples = FindTag (file1, "data");    mSampleBfr1 = (char *)malloc (bsize);    FD_ZERO (&rfds);    FD_ZERO (&wfds);    n = 1;    while (N < mSamples && n > 0)    {        if (tcgetpgrp (0) == getpid ())            FD_SET (STDIN_FILENO, &rfds);        FD_SET (snd_mixer_file_descriptor (mixer_handle), &rfds);        FD_SET (snd_pcm_file_descriptor (pcm_handle, SND_PCM_CHANNEL_PLAYBACK), &wfds);        rtn = max (snd_mixer_file_descriptor (mixer_handle),            snd_pcm_file_descriptor (pcm_handle, SND_PCM_CHANNEL_PLAYBACK));        if (select (rtn + 1, &rfds, &wfds, NULL, NULL) == -1)            return err ((char *)"select");        if (FD_ISSET (STDIN_FILENO, &rfds))        {            if ((rtn = snd_mixer_group_read (mixer_handle, &group)) < 0)                fprintf (stderr, "snd_mixer_group_read failed: %s\n", snd_strerror (rtn));            dev_raw (fileno (stdin));        }        if (FD_ISSET (snd_mixer_file_descriptor (mixer_handle), &rfds))        {            snd_mixer_callbacks_t callbacks = { 0, 0, 0, 0 };            snd_mixer_read (mixer_handle, &callbacks);        }        if (FD_ISSET (snd_pcm_file_descriptor (pcm_handle, SND_PCM_CHANNEL_PLAYBACK), &wfds))        {            snd_pcm_channel_status_t status;            int     written = 0;            if ((n = fread (mSampleBfr1, 1, min (mSamples - N, bsize), file1)) <= 0)                continue;            written = snd_pcm_plugin_write (pcm_handle, mSampleBfr1, n);            if (verbose)                printf ("bytes written = %d \n", written);            if (written < n)            {                memset (&status, 0, sizeof (status));                status.channel = SND_PCM_CHANNEL_PLAYBACK;                if (snd_pcm_plugin_status (pcm_handle, &status) < 0)                {                    fprintf (stderr, "underrun: playback channel status error\n");                    exit (1);                }                if (status.status == SND_PCM_STATUS_READY ||                    status.status == SND_PCM_STATUS_UNDERRUN)                {                    if (snd_pcm_plugin_prepare (pcm_handle, SND_PCM_CHANNEL_PLAYBACK) < 0)                    {                        fprintf (stderr, "underrun: playback channel prepare error\n");                        exit (1);                    }                }                if (written < 0)                    written = 0;                written += snd_pcm_plugin_write (pcm_handle, mSampleBfr1 + written, n - written);            }            N += written;        }    }    n = snd_pcm_plugin_flush (pcm_handle, SND_PCM_CHANNEL_PLAYBACK);    rtn = snd_mixer_close (mixer_handle);    rtn = snd_pcm_close (pcm_handle);    fclose (file1);    return (0);}