- /* determine logarithm (log2) of the fragment size */
- while ((1 << fragment_spec) < afmt->fragment_size)
- fragment_spec++;
-
- /* use two fragments (play one fragment, prepare the other);
- one fragment would result in interrupted audio output, more
- than two fragments would raise audio output latency to much */
- fragment_spec |= 0x00020000;
-
- /* Example for fragment specification:
- - 2 buffers / 512 bytes (giving 1/16 second resolution for 8 kHz)
- - (with stereo the effective buffer size will shrink to 256)
- => fragment_size = 0x00020009 */
-
- if (ioctl(audio.device_fd, SNDCTL_DSP_SETFRAGMENT, &fragment_spec) < 0)
- Error(ERR_EXIT_SOUND_SERVER,
- "cannot set fragment size of /dev/dsp -- no sounds");
-
- i = 0;
- afmt->format = 0;
- while (formats[i].format_result != -1)
- {
- unsigned int audio_format = formats[i].format_ioctl;
- if (ioctl(audio.device_fd, SNDCTL_DSP_SETFMT, &audio_format) == 0)
- {
- afmt->format = formats[i].format_result;
- break;
- }
- }
-
- if (afmt->format == 0) /* no supported audio format found */
- Error(ERR_EXIT_SOUND_SERVER,
- "cannot set audio format of /dev/dsp -- no sounds");
-
- /* try if we can use stereo sound */
- afmt->stereo = TRUE;
- if (ioctl(audio.device_fd, SNDCTL_DSP_STEREO, &stereo) < 0)
- afmt->stereo = FALSE;
-
- if (ioctl(audio.device_fd, SNDCTL_DSP_SPEED, &afmt->sample_rate) < 0)
- Error(ERR_EXIT_SOUND_SERVER,
- "cannot set sample rate of /dev/dsp -- no sounds");
-
- /* get the real fragmentation size; this should return 512 */
- if (ioctl(audio.device_fd, SNDCTL_DSP_GETBLKSIZE, &fragment_size_query) < 0)
- Error(ERR_EXIT_SOUND_SERVER,
- "cannot get fragment size of /dev/dsp -- no sounds");
- if (fragment_size_query != afmt->fragment_size)
- Error(ERR_EXIT_SOUND_SERVER,
- "cannot set fragment size of /dev/dsp -- no sounds");
-}
-#endif /* AUDIO_LINUX_IOCTL */
-
-#if defined(PLATFORM_NETBSD)
-static void InitAudioDevice_NetBSD(struct AudioFormatInfo *afmt)
-{
- audio_info_t a_info;
- boolean stereo = TRUE;
-
- AUDIO_INITINFO(&a_info);
- a_info.play.encoding = AUDIO_ENCODING_LINEAR8;
- a_info.play.precision = 8;
- a_info.play.channels = 2;
- a_info.play.sample_rate = sample_rate;
- a_info.blocksize = fragment_size;
-
- afmt->format = AUDIO_FORMAT_U8;
- afmt->stereo = TRUE;
-
- if (ioctl(audio.device_fd, AUDIO_SETINFO, &a_info) < 0)
- {
- /* try to disable stereo */
- a_info.play.channels = 1;
-
- afmt->stereo = FALSE;
-
- if (ioctl(audio.device_fd, AUDIO_SETINFO, &a_info) < 0)
- Error(ERR_EXIT_SOUND_SERVER,
- "cannot set sample rate of /dev/audio -- no sounds");
- }
-}
-#endif /* PLATFORM_NETBSD */
-
-#if defined(PLATFORM_HPUX)
-static void InitAudioDevice_HPUX(struct AudioFormatInfo *afmt)
-{
- struct audio_describe ainfo;
- int audio_ctl;
-
- audio_ctl = open("/dev/audioCtl", O_WRONLY | O_NDELAY);
- if (audio_ctl == -1)
- Error(ERR_EXIT_SOUND_SERVER, "cannot open /dev/audioCtl -- no sounds");
-
- if (ioctl(audio_ctl, AUDIO_DESCRIBE, &ainfo) == -1)
- Error(ERR_EXIT_SOUND_SERVER, "no audio info -- no sounds");
-
- if (ioctl(audio_ctl, AUDIO_SET_DATA_FORMAT, AUDIO_FORMAT_ULAW) == -1)
- Error(ERR_EXIT_SOUND_SERVER, "ulaw audio not available -- no sounds");
-
- ioctl(audio_ctl, AUDIO_SET_CHANNELS, 1);
- ioctl(audio_ctl, AUDIO_SET_SAMPLE_RATE, 8000);
-
- afmt->format = AUDIO_FORMAT_U8;
- afmt->stereo = FALSE;
- afmt->sample_rate = 8000;
-
- close(audio_ctl);
-}
-#endif /* PLATFORM_HPUX */
-
-#if defined(PLATFORM_UNIX)
-static void InitAudioDevice(struct AudioFormatInfo *afmt)
-{
- afmt->stereo = TRUE;
- afmt->format = AUDIO_FORMAT_UNKNOWN;
- afmt->sample_rate = DEFAULT_AUDIO_SAMPLE_RATE;
- afmt->fragment_size = DEFAULT_AUDIO_FRAGMENT_SIZE;
-
-#if defined(AUDIO_LINUX_IOCTL)
- InitAudioDevice_Linux(afmt);
-#elif defined(PLATFORM_NETBSD)
- InitAudioDevice_NetBSD(afmt);
-#elif defined(PLATFORM_HPUX)
- InitAudioDevice_HPUX(afmt);
-#else
- /* generic /dev/audio stuff might be placed here */
-#endif
-}
-#endif /* PLATFORM_UNIX */
-
-#if defined(PLATFORM_UNIX) && !defined(AUDIO_STREAMING_DSP)
-
-/* these two are stolen from "sox"... :) */
-
-/*
-** This routine converts from linear to ulaw.
-**
-** Craig Reese: IDA/Supercomputing Research Center
-** Joe Campbell: Department of Defense
-** 29 September 1989
-**
-** References:
-** 1) CCITT Recommendation G.711 (very difficult to follow)
-** 2) "A New Digital Technique for Implementation of Any
-** Continuous PCM Companding Law," Villeret, Michel,
-** et al. 1973 IEEE Int. Conf. on Communications, Vol 1,
-** 1973, pg. 11.12-11.17
-** 3) MIL-STD-188-113,"Interoperability and Performance Standards
-** for Analog-to_Digital Conversion Techniques,"
-** 17 February 1987
-**
-** Input: Signed 16 bit linear sample
-** Output: 8 bit ulaw sample
-*/
-
-#define ZEROTRAP /* turn on the trap as per the MIL-STD */
-#define BIAS 0x84 /* define the add-in bias for 16 bit samples */
-#define CLIP 32635
-
-static unsigned char linear_to_ulaw(int sample)
-{
- static int exp_lut[256] =
- {
- 0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,
- 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
- 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
- 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
- 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
- 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
- 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
- 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
- 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
- };
-
- int sign, exponent, mantissa;
- unsigned char ulawbyte;