audio/wavaudio.c - emulator-unstable-refactoring - Git at Google

 /*
  * QEMU WAV audio driver
  *
  * Copyright (c) 2007 The Android Open Source Project
  * Copyright (c) 2004-2005 Vassili Karpov (malc)
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 #include "hw/hw.h"
 #include "qemu/timer.h"
 #include "audio.h"

 #define AUDIO_CAP "wav"
 #include "audio_int.h"

 #define  WAV_AUDIO_IN  1

 /** VOICE OUT  (Saving to a .WAV file)
  **/
 typedef struct WAVVoiceOut {
     HWVoiceOut hw;
     FILE *f;
     int64_t old_ticks;
     void *pcm_buf;
     int total_samples;
 } WAVVoiceOut;

 static struct {
     struct audsettings settings;
     const char *wav_path;
 } conf_out = {
     {
         44100,
         2,
         AUD_FMT_S16,
         0
     },
     "qemu.wav"
 };

 static int wav_out_run (HWVoiceOut *hw, int live)
 {
     WAVVoiceOut *wav = (WAVVoiceOut *) hw;
     int rpos, decr, samples;
     uint8_t *dst;
     struct st_sample *src;
     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     int64_t ticks = now - wav->old_ticks;
     int64_t bytes =
         muldiv64 (ticks, hw->info.bytes_per_second, get_ticks_per_sec ());

     if (bytes > INT_MAX) {
         samples = INT_MAX >> hw->info.shift;
     }
     else {
         samples = bytes >> hw->info.shift;
     }

     wav->old_ticks = now;
     decr = audio_MIN (live, samples);
     samples = decr;
     rpos = hw->rpos;
     while (samples) {
         int left_till_end_samples = hw->samples - rpos;
         int convert_samples = audio_MIN (samples, left_till_end_samples);

         src = hw->mix_buf + rpos;
         dst = advance (wav->pcm_buf, rpos << hw->info.shift);

         hw->clip (dst, src, convert_samples);
         if (fwrite (dst, convert_samples << hw->info.shift, 1, wav->f) != 1) {
             dolog ("wav_run_out: fwrite of %d bytes failed\nReaons: %s\n",
                    convert_samples << hw->info.shift, strerror (errno));
         }

         rpos = (rpos + convert_samples) % hw->samples;
         samples -= convert_samples;
         wav->total_samples += convert_samples;
     }

     hw->rpos = rpos;
     return decr;
 }

 static int wav_out_write (SWVoiceOut *sw, void *buf, int len)
 {
     return audio_pcm_sw_write (sw, buf, len);
 }

 /* VICE code: Store number as little endian. */
 static void le_store (uint8_t *buf, uint32_t val, int len)
 {
     int i;
     for (i = 0; i < len; i++) {
         buf[i] = (uint8_t) (val & 0xff);
         val >>= 8;
     }
 }

 static int wav_out_init (HWVoiceOut *hw, struct audsettings *as)
 {
     WAVVoiceOut *wav = (WAVVoiceOut *) hw;
     int bits16 = 0, stereo = 0;
     uint8_t hdr[] = {
         0x52, 0x49, 0x46, 0x46, 0x00, 0x00, 0x00, 0x00, 0x57, 0x41, 0x56,
         0x45, 0x66, 0x6d, 0x74, 0x20, 0x10, 0x00, 0x00, 0x00, 0x01, 0x00,
         0x02, 0x00, 0x44, 0xac, 0x00, 0x00, 0x10, 0xb1, 0x02, 0x00, 0x04,
         0x00, 0x10, 0x00, 0x64, 0x61, 0x74, 0x61, 0x00, 0x00, 0x00, 0x00
     };
     struct audsettings wav_as = conf_out.settings;

     (void) as;

     stereo = wav_as.nchannels == 2;
     switch (wav_as.fmt) {
     case AUD_FMT_S8:
     case AUD_FMT_U8:
         bits16 = 0;
         break;

     case AUD_FMT_S16:
     case AUD_FMT_U16:
         bits16 = 1;
         break;

     case AUD_FMT_S32:
     case AUD_FMT_U32:
         dolog ("WAVE files can not handle 32bit formats\n");
         return -1;
     }

     hdr[34] = bits16 ? 0x10 : 0x08;

     wav_as.endianness = 0;
     audio_pcm_init_info (&hw->info, &wav_as);

     hw->samples = 1024;
     wav->pcm_buf = audio_calloc (AUDIO_FUNC, hw->samples, 1 << hw->info.shift);
     if (!wav->pcm_buf) {
         dolog ("Could not allocate buffer (%d bytes)\n",
                hw->samples << hw->info.shift);
         return -1;
     }

     le_store (hdr + 22, hw->info.nchannels, 2);
     le_store (hdr + 24, hw->info.freq, 4);
     le_store (hdr + 28, hw->info.freq << (bits16 + stereo), 4);
     le_store (hdr + 32, 1 << (bits16 + stereo), 2);

     wav->f = fopen (conf_out.wav_path, "wb");
     if (!wav->f) {
         dolog ("Failed to open wave file `%s'\nReason: %s\n",
                conf_out.wav_path, strerror (errno));
         g_free (wav->pcm_buf);
         wav->pcm_buf = NULL;
         return -1;
     }

     if (fwrite (hdr, sizeof (hdr), 1, wav->f) != 1) {
         dolog ("wav_init_out: failed to write header\nReason: %s\n",
                strerror(errno));
         return -1;
     }
     return 0;
 }

 static void wav_out_fini (HWVoiceOut *hw)
 {
     WAVVoiceOut *wav = (WAVVoiceOut *) hw;
     uint8_t rlen[4];
     uint8_t dlen[4];
     uint32_t datalen = wav->total_samples << hw->info.shift;
     uint32_t rifflen = datalen + 36;

     if (!wav->f) {
         return;
     }

     le_store (rlen, rifflen, 4);
     le_store (dlen, datalen, 4);

     fseek (wav->f, 4, SEEK_SET);
     fwrite(rlen, 4, 1, wav->f);

     fseek (wav->f, 32, SEEK_CUR);
     fwrite(dlen, 4, 1, wav->f);

     fclose (wav->f);
     wav->f = NULL;

     g_free (wav->pcm_buf);
     wav->pcm_buf = NULL;
 }

 static int wav_out_ctl (HWVoiceOut *hw, int cmd, ...)
 {
     (void) hw;
     (void) cmd;
     return 0;
 }


 #if WAV_AUDIO_IN

 /** WAV IN (Reading from a .WAV file)
  **/

  static struct {
     const char *wav_path;
 } conf_in = {
     "qemu.wav"
 };

 typedef struct WAVVoiceIn {
     HWVoiceIn  hw;
     FILE*      f;
     int64_t    old_ticks;
     void*      pcm_buf;
     int        total_samples;
     int        total_size;
 } WAVVoiceIn;


 static int
 le_read( const uint8_t*  p, int  size ) {
     int  shift  = 0;
     int  result = 0;
     for ( ; size > 0; size-- ) {
         result = result | (p[0] << shift);
         p     += 1;
         shift += 8;
     }
     return  result;
 }

 static int
 wav_in_init (HWVoiceIn *hw, struct audsettings *as)
 {
     WAVVoiceIn*  wav = (WAVVoiceIn *) hw;
     const char*  path = conf_in.wav_path;
     uint8_t      hdr[44];
     struct audsettings wav_as = *as;
     int           nchannels, freq, format, bits;

     wav->f = fopen (path, "rb");
     if (wav->f == NULL) {
         dolog("Failed to open wave file '%s'\nReason: %s\n", path,
               strerror(errno));
         return -1;
     }

     if (fread(hdr, sizeof(hdr), 1, wav->f) != 1) {
         dolog("File '%s' doesn't seem to be a .wav file\n", path);
         goto Fail;
     }

     /* check that this is a wave file */
     if ( hdr[0] != 'R' || hdr[1] != 'I' || hdr[2] != 'F' || hdr[3] != 'F' ||
          hdr[8] != 'W' || hdr[9] != 'A' || hdr[10]!= 'V' || hdr[11]!= 'E' ||
          hdr[12]!= 'f' || hdr[13]!= 'm' || hdr[14]!= 't' || hdr[15]!= ' ' ||
          hdr[40]!= 'd' || hdr[41]!= 'a' || hdr[42]!= 't' || hdr[43]!= 'a') {
          dolog("File '%s' is not a valid .wav file\n", path);
          goto Fail;
     }

     nchannels   = le_read( hdr+22, 2 );
     freq        = le_read( hdr+24, 4 );
     format      = le_read( hdr+32, 2 );
     bits        = le_read( hdr+34, 2 );

     wav->total_size = le_read( hdr+40, 4 );

     /* perform some sainty checks */
     switch (nchannels) {
         case 1:
         case 2: break;
         default:
             dolog("unsupported number of channels (%d) in '%s'\n",
                   nchannels, path);
             goto Fail;
     }

     switch (format) {
         case 1:
         case 2:
         case 4: break;
         default:
             dolog("unsupported bytes per sample (%d) in '%s'\n",
                   format, path);
             goto Fail;
     }

     if (format*8/nchannels != bits) {
         dolog("invalid bits per sample (%d, expected %d) in '%s'\n",
               bits, format*8/nchannels, path);
         goto Fail;
     }

     wav_as.nchannels  = nchannels;
     wav_as.fmt        = (bits == 8) ? AUD_FMT_U8 : AUD_FMT_S16;
     wav_as.freq       = freq;
     wav_as.endianness = 0;  /* always little endian */

     audio_pcm_init_info (&hw->info, &wav_as);

     hw->samples  = 1024;
     wav->pcm_buf = audio_calloc (AUDIO_FUNC, hw->samples, 1 << hw->info.shift);
     if (!wav->pcm_buf) {
         goto Fail;
     }
     return 0;

 Fail:
     fclose (wav->f);
     wav->f = NULL;
     return -1;
 }


 static void wav_in_fini (HWVoiceIn *hw)
 {
     WAVVoiceIn *wav = (WAVVoiceIn *) hw;

     if (!wav->f) {
         return;
     }

     fclose (wav->f);
     wav->f = NULL;

     g_free (wav->pcm_buf);
     wav->pcm_buf = NULL;
 }

 static int wav_in_run (HWVoiceIn *hw)
 {
     WAVVoiceIn*   wav = (WAVVoiceIn *) hw;
     int           wpos, live, decr, samples;
     uint8_t*      src;
     struct st_sample*  dst;

     int64_t  now   = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     int64_t  ticks = now - wav->old_ticks;
     int64_t  bytes = muldiv64(ticks, hw->info.bytes_per_second, get_ticks_per_sec());

     if (bytes > INT_MAX) {
         samples = INT_MAX >> hw->info.shift;
     }
     else {
         samples = bytes >> hw->info.shift;
     }

     live = audio_pcm_hw_get_live_in (hw);
     if (!live) {
         return 0;
     }

     wav->old_ticks = now;

     decr    = audio_MIN (live, samples);
     samples = decr;
     wpos    = hw->wpos;
     while (samples) {
         int left_till_end_samples = hw->samples - wpos;
         int convert_samples       = audio_MIN (samples, left_till_end_samples);

         dst = hw->conv_buf + wpos;
         src = advance (wav->pcm_buf, wpos << hw->info.shift);

         clearerr(wav->f);
         size_t read_bytes = fread(src, 1, convert_samples << hw->info.shift, wav->f);
         if (read_bytes == 0 && ferror(wav->f) != EINTR)
             return 0;

         size_t read_samples = read_bytes >> hw->info.shift;
         memcpy (dst, src, read_bytes);

         wpos                = (wpos + read_samples) % hw->samples;
         samples            -= read_samples;
         wav->total_samples += read_samples;
     }

     hw->wpos = wpos;
     return decr;
 }

 static int wav_in_read (SWVoiceIn *sw, void *buf, int len)
 {
     return audio_pcm_sw_read (sw, buf, len);
 }

 static int wav_in_ctl (HWVoiceIn *hw, int cmd, ...)
 {
     (void) hw;
     (void) cmd;
     return 0;
 }

 #endif  /* WAV_AUDIO_IN */

 /** COMMON CODE
  **/
 static void *wav_audio_init (void)
 {
     return &conf_out;
 }

 static void wav_audio_fini (void *opaque)
 {
     (void) opaque;
     ldebug ("wav_fini");
 }

 static struct audio_option wav_options[] = {
     {"FREQUENCY", AUD_OPT_INT, &conf_out.settings.freq,
      "Frequency", NULL, 0},

     {"FORMAT", AUD_OPT_FMT, &conf_out.settings.fmt,
      "Format", NULL, 0},

     {"DAC_FIXED_CHANNELS", AUD_OPT_INT, &conf_out.settings.nchannels,
      "Number of channels (1 - mono, 2 - stereo)", NULL, 0},

     {"PATH", AUD_OPT_STR, &conf_out.wav_path,
      "Path to output .wav file", NULL, 0},

 #if WAV_AUDIO_IN
     {"IN_PATH", AUD_OPT_STR, &conf_in.wav_path,
      "Path to input .wav file", NULL, 0},
 #endif
     {NULL, 0, NULL, NULL, NULL, 0}
 };

 struct audio_pcm_ops wav_pcm_ops = {
     wav_out_init,
     wav_out_fini,
     wav_out_run,
     wav_out_write,
     wav_out_ctl,

 #if WAV_AUDIO_IN
     wav_in_init,
     wav_in_fini,
     wav_in_run,
     wav_in_read,
     wav_in_ctl
 #else
     NULL,
     NULL,
     NULL,
     NULL,
     NULL
 #endif
 };

 struct audio_driver wav_audio_driver = {
     INIT_FIELD (name           = ) "wav",
     INIT_FIELD (descr          = )
     "WAV file read/write (www.wikipedia.org/wiki/WAV)",
     INIT_FIELD (options        = ) wav_options,
     INIT_FIELD (init           = ) wav_audio_init,
     INIT_FIELD (fini           = ) wav_audio_fini,
     INIT_FIELD (pcm_ops        = ) &wav_pcm_ops,
     INIT_FIELD (can_be_default = ) 0,
 #if WAV_AUDIO_IN
     INIT_FIELD (max_voices_in  = ) 1,
     INIT_FIELD (max_voices_out = ) 1,
     INIT_FIELD (voice_size_out = ) sizeof (WAVVoiceOut),
     INIT_FIELD (voice_size_in  = ) sizeof (WAVVoiceIn)
 #else
     INIT_FIELD (max_voices_out = ) 1,
     INIT_FIELD (max_voices_in  = ) 0,
     INIT_FIELD (voice_size_out = ) sizeof (WAVVoiceOut),
     INIT_FIELD (voice_size_in  = ) 0
 #endif
 };
	/*
	* QEMU WAV audio driver
	*
	* Copyright (c) 2007 The Android Open Source Project
	* Copyright (c) 2004-2005 Vassili Karpov (malc)
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/
	#include "hw/hw.h"
	#include "qemu/timer.h"
	#include "audio.h"

	#define AUDIO_CAP "wav"
	#include "audio_int.h"

	#define WAV_AUDIO_IN 1

	/** VOICE OUT (Saving to a .WAV file)
	**/
	typedef struct WAVVoiceOut {
	HWVoiceOut hw;
	FILE *f;
	int64_t old_ticks;
	void *pcm_buf;
	int total_samples;
	} WAVVoiceOut;

	static struct {
	struct audsettings settings;
	const char *wav_path;
	} conf_out = {
	{
	44100,
	2,
	AUD_FMT_S16,
	0
	},
	"qemu.wav"
	};

	static int wav_out_run (HWVoiceOut *hw, int live)
	{
	WAVVoiceOut wav = (WAVVoiceOut ) hw;
	int rpos, decr, samples;
	uint8_t *dst;
	struct st_sample *src;
	int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
	int64_t ticks = now - wav->old_ticks;
	int64_t bytes =
	muldiv64 (ticks, hw->info.bytes_per_second, get_ticks_per_sec ());

	if (bytes > INT_MAX) {
	samples = INT_MAX >> hw->info.shift;
	}
	else {
	samples = bytes >> hw->info.shift;
	}

	wav->old_ticks = now;
	decr = audio_MIN (live, samples);
	samples = decr;
	rpos = hw->rpos;
	while (samples) {
	int left_till_end_samples = hw->samples - rpos;
	int convert_samples = audio_MIN (samples, left_till_end_samples);

	src = hw->mix_buf + rpos;
	dst = advance (wav->pcm_buf, rpos << hw->info.shift);

	hw->clip (dst, src, convert_samples);
	if (fwrite (dst, convert_samples << hw->info.shift, 1, wav->f) != 1) {
	dolog ("wav_run_out: fwrite of %d bytes failed\nReaons: %s\n",
	convert_samples << hw->info.shift, strerror (errno));
	}

	rpos = (rpos + convert_samples) % hw->samples;
	samples -= convert_samples;
	wav->total_samples += convert_samples;
	}

	hw->rpos = rpos;
	return decr;
	}

	static int wav_out_write (SWVoiceOut sw, void buf, int len)
	{
	return audio_pcm_sw_write (sw, buf, len);
	}

	/* VICE code: Store number as little endian. */
	static void le_store (uint8_t *buf, uint32_t val, int len)
	{
	int i;
	for (i = 0; i < len; i++) {
	buf[i] = (uint8_t) (val & 0xff);
	val >>= 8;
	}
	}

	static int wav_out_init (HWVoiceOut hw, struct audsettings as)
	{
	WAVVoiceOut wav = (WAVVoiceOut ) hw;
	int bits16 = 0, stereo = 0;
	uint8_t hdr[] = {
	0x52, 0x49, 0x46, 0x46, 0x00, 0x00, 0x00, 0x00, 0x57, 0x41, 0x56,
	0x45, 0x66, 0x6d, 0x74, 0x20, 0x10, 0x00, 0x00, 0x00, 0x01, 0x00,
	0x02, 0x00, 0x44, 0xac, 0x00, 0x00, 0x10, 0xb1, 0x02, 0x00, 0x04,
	0x00, 0x10, 0x00, 0x64, 0x61, 0x74, 0x61, 0x00, 0x00, 0x00, 0x00
	};
	struct audsettings wav_as = conf_out.settings;

	(void) as;

	stereo = wav_as.nchannels == 2;
	switch (wav_as.fmt) {
	case AUD_FMT_S8:
	case AUD_FMT_U8:
	bits16 = 0;
	break;

	case AUD_FMT_S16:
	case AUD_FMT_U16:
	bits16 = 1;
	break;

	case AUD_FMT_S32:
	case AUD_FMT_U32:
	dolog ("WAVE files can not handle 32bit formats\n");
	return -1;
	}

	hdr[34] = bits16 ? 0x10 : 0x08;

	wav_as.endianness = 0;
	audio_pcm_init_info (&hw->info, &wav_as);

	hw->samples = 1024;
	wav->pcm_buf = audio_calloc (AUDIO_FUNC, hw->samples, 1 << hw->info.shift);
	if (!wav->pcm_buf) {
	dolog ("Could not allocate buffer (%d bytes)\n",
	hw->samples << hw->info.shift);
	return -1;
	}

	le_store (hdr + 22, hw->info.nchannels, 2);
	le_store (hdr + 24, hw->info.freq, 4);
	le_store (hdr + 28, hw->info.freq << (bits16 + stereo), 4);
	le_store (hdr + 32, 1 << (bits16 + stereo), 2);

	wav->f = fopen (conf_out.wav_path, "wb");
	if (!wav->f) {
	dolog ("Failed to open wave file `%s'\nReason: %s\n",
	conf_out.wav_path, strerror (errno));
	g_free (wav->pcm_buf);
	wav->pcm_buf = NULL;
	return -1;
	}

	if (fwrite (hdr, sizeof (hdr), 1, wav->f) != 1) {
	dolog ("wav_init_out: failed to write header\nReason: %s\n",
	strerror(errno));
	return -1;
	}
	return 0;
	}

	static void wav_out_fini (HWVoiceOut *hw)
	{
	WAVVoiceOut wav = (WAVVoiceOut ) hw;
	uint8_t rlen[4];
	uint8_t dlen[4];
	uint32_t datalen = wav->total_samples << hw->info.shift;
	uint32_t rifflen = datalen + 36;

	if (!wav->f) {
	return;
	}

	le_store (rlen, rifflen, 4);
	le_store (dlen, datalen, 4);

	fseek (wav->f, 4, SEEK_SET);
	fwrite(rlen, 4, 1, wav->f);

	fseek (wav->f, 32, SEEK_CUR);
	fwrite(dlen, 4, 1, wav->f);

	fclose (wav->f);
	wav->f = NULL;

	g_free (wav->pcm_buf);
	wav->pcm_buf = NULL;
	}

	static int wav_out_ctl (HWVoiceOut *hw, int cmd, ...)
	{
	(void) hw;
	(void) cmd;
	return 0;
	}


	#if WAV_AUDIO_IN

	/** WAV IN (Reading from a .WAV file)
	**/

	static struct {
	const char *wav_path;
	} conf_in = {
	"qemu.wav"
	};

	typedef struct WAVVoiceIn {
	HWVoiceIn hw;
	FILE* f;
	int64_t old_ticks;
	void* pcm_buf;
	int total_samples;
	int total_size;
	} WAVVoiceIn;


	static int
	le_read( const uint8_t* p, int size ) {
	int shift = 0;
	int result = 0;
	for ( ; size > 0; size-- ) {
	result = result \| (p[0] << shift);
	p += 1;
	shift += 8;
	}
	return result;
	}

	static int
	wav_in_init (HWVoiceIn hw, struct audsettings as)
	{
	WAVVoiceIn* wav = (WAVVoiceIn *) hw;
	const char* path = conf_in.wav_path;
	uint8_t hdr[44];
	struct audsettings wav_as = *as;
	int nchannels, freq, format, bits;

	wav->f = fopen (path, "rb");
	if (wav->f == NULL) {
	dolog("Failed to open wave file '%s'\nReason: %s\n", path,
	strerror(errno));
	return -1;
	}

	if (fread(hdr, sizeof(hdr), 1, wav->f) != 1) {
	dolog("File '%s' doesn't seem to be a .wav file\n", path);
	goto Fail;
	}

	/* check that this is a wave file */
	if ( hdr[0] != 'R' \|\| hdr[1] != 'I' \|\| hdr[2] != 'F' \|\| hdr[3] != 'F' \|\|
	hdr[8] != 'W' \|\| hdr[9] != 'A' \|\| hdr[10]!= 'V' \|\| hdr[11]!= 'E' \|\|
	hdr[12]!= 'f' \|\| hdr[13]!= 'm' \|\| hdr[14]!= 't' \|\| hdr[15]!= ' ' \|\|
	hdr[40]!= 'd' \|\| hdr[41]!= 'a' \|\| hdr[42]!= 't' \|\| hdr[43]!= 'a') {
	dolog("File '%s' is not a valid .wav file\n", path);
	goto Fail;
	}

	nchannels = le_read( hdr+22, 2 );
	freq = le_read( hdr+24, 4 );
	format = le_read( hdr+32, 2 );
	bits = le_read( hdr+34, 2 );

	wav->total_size = le_read( hdr+40, 4 );

	/* perform some sainty checks */
	switch (nchannels) {
	case 1:
	case 2: break;
	default:
	dolog("unsupported number of channels (%d) in '%s'\n",
	nchannels, path);
	goto Fail;
	}

	switch (format) {
	case 1:
	case 2:
	case 4: break;
	default:
	dolog("unsupported bytes per sample (%d) in '%s'\n",
	format, path);
	goto Fail;
	}

	if (format*8/nchannels != bits) {
	dolog("invalid bits per sample (%d, expected %d) in '%s'\n",
	bits, format*8/nchannels, path);
	goto Fail;
	}

	wav_as.nchannels = nchannels;
	wav_as.fmt = (bits == 8) ? AUD_FMT_U8 : AUD_FMT_S16;
	wav_as.freq = freq;
	wav_as.endianness = 0; /* always little endian */

	audio_pcm_init_info (&hw->info, &wav_as);

	hw->samples = 1024;
	wav->pcm_buf = audio_calloc (AUDIO_FUNC, hw->samples, 1 << hw->info.shift);
	if (!wav->pcm_buf) {
	goto Fail;
	}
	return 0;

	Fail:
	fclose (wav->f);
	wav->f = NULL;
	return -1;
	}


	static void wav_in_fini (HWVoiceIn *hw)
	{
	WAVVoiceIn wav = (WAVVoiceIn ) hw;

	if (!wav->f) {
	return;
	}

	fclose (wav->f);
	wav->f = NULL;

	g_free (wav->pcm_buf);
	wav->pcm_buf = NULL;
	}

	static int wav_in_run (HWVoiceIn *hw)
	{
	WAVVoiceIn* wav = (WAVVoiceIn *) hw;
	int wpos, live, decr, samples;
	uint8_t* src;
	struct st_sample* dst;

	int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
	int64_t ticks = now - wav->old_ticks;
	int64_t bytes = muldiv64(ticks, hw->info.bytes_per_second, get_ticks_per_sec());

	if (bytes > INT_MAX) {
	samples = INT_MAX >> hw->info.shift;
	}
	else {
	samples = bytes >> hw->info.shift;
	}

	live = audio_pcm_hw_get_live_in (hw);
	if (!live) {
	return 0;
	}

	wav->old_ticks = now;

	decr = audio_MIN (live, samples);
	samples = decr;
	wpos = hw->wpos;
	while (samples) {
	int left_till_end_samples = hw->samples - wpos;
	int convert_samples = audio_MIN (samples, left_till_end_samples);

	dst = hw->conv_buf + wpos;
	src = advance (wav->pcm_buf, wpos << hw->info.shift);

	clearerr(wav->f);
	size_t read_bytes = fread(src, 1, convert_samples << hw->info.shift, wav->f);
	if (read_bytes == 0 && ferror(wav->f) != EINTR)
	return 0;

	size_t read_samples = read_bytes >> hw->info.shift;
	memcpy (dst, src, read_bytes);

	wpos = (wpos + read_samples) % hw->samples;
	samples -= read_samples;
	wav->total_samples += read_samples;
	}

	hw->wpos = wpos;
	return decr;
	}

	static int wav_in_read (SWVoiceIn sw, void buf, int len)
	{
	return audio_pcm_sw_read (sw, buf, len);
	}

	static int wav_in_ctl (HWVoiceIn *hw, int cmd, ...)
	{
	(void) hw;
	(void) cmd;
	return 0;
	}

	#endif /* WAV_AUDIO_IN */

	/** COMMON CODE
	**/
	static void *wav_audio_init (void)
	{
	return &conf_out;
	}

	static void wav_audio_fini (void *opaque)
	{
	(void) opaque;
	ldebug ("wav_fini");
	}

	static struct audio_option wav_options[] = {
	{"FREQUENCY", AUD_OPT_INT, &conf_out.settings.freq,
	"Frequency", NULL, 0},

	{"FORMAT", AUD_OPT_FMT, &conf_out.settings.fmt,
	"Format", NULL, 0},

	{"DAC_FIXED_CHANNELS", AUD_OPT_INT, &conf_out.settings.nchannels,
	"Number of channels (1 - mono, 2 - stereo)", NULL, 0},

	{"PATH", AUD_OPT_STR, &conf_out.wav_path,
	"Path to output .wav file", NULL, 0},

	#if WAV_AUDIO_IN
	{"IN_PATH", AUD_OPT_STR, &conf_in.wav_path,
	"Path to input .wav file", NULL, 0},
	#endif
	{NULL, 0, NULL, NULL, NULL, 0}
	};

	struct audio_pcm_ops wav_pcm_ops = {
	wav_out_init,
	wav_out_fini,
	wav_out_run,
	wav_out_write,
	wav_out_ctl,

	#if WAV_AUDIO_IN
	wav_in_init,
	wav_in_fini,
	wav_in_run,
	wav_in_read,
	wav_in_ctl
	#else
	NULL,
	NULL,
	NULL,
	NULL,
	NULL
	#endif
	};

	struct audio_driver wav_audio_driver = {
	INIT_FIELD (name = ) "wav",
	INIT_FIELD (descr = )
	"WAV file read/write (www.wikipedia.org/wiki/WAV)",
	INIT_FIELD (options = ) wav_options,
	INIT_FIELD (init = ) wav_audio_init,
	INIT_FIELD (fini = ) wav_audio_fini,
	INIT_FIELD (pcm_ops = ) &wav_pcm_ops,
	INIT_FIELD (can_be_default = ) 0,
	#if WAV_AUDIO_IN
	INIT_FIELD (max_voices_in = ) 1,
	INIT_FIELD (max_voices_out = ) 1,
	INIT_FIELD (voice_size_out = ) sizeof (WAVVoiceOut),
	INIT_FIELD (voice_size_in = ) sizeof (WAVVoiceIn)
	#else
	INIT_FIELD (max_voices_out = ) 1,
	INIT_FIELD (max_voices_in = ) 0,
	INIT_FIELD (voice_size_out = ) sizeof (WAVVoiceOut),
	INIT_FIELD (voice_size_in = ) 0
	#endif
	};