2 * QEMU OSS Audio output driver
4 * Copyright (c) 2003 Vassili Karpov (malc)
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
35 #include <sys/types.h>
36 #include <sys/ioctl.h>
37 #include <sys/soundcard.h>
40 /* http://www.df.lth.se/~john_e/gems/gem002d.html */
41 /* http://www.multi-platforms.com/Tips/PopCount.htm */
42 static inline uint32_t popcount (uint32_t u)
44 u = ((u&0x55555555) + ((u>>1)&0x55555555));
45 u = ((u&0x33333333) + ((u>>2)&0x33333333));
46 u = ((u&0x0f0f0f0f) + ((u>>4)&0x0f0f0f0f));
47 u = ((u&0x00ff00ff) + ((u>>8)&0x00ff00ff));
48 u = ( u&0x0000ffff) + (u>>16);
52 static inline uint32_t lsbindex (uint32_t u)
54 return popcount ((u&-u)-1);
57 #define MIN(a, b) ((a)>(b)?(b):(a))
58 #define MAX(a, b) ((a)<(b)?(b):(a))
60 #define DEREF(x) (void)x
61 #define log(...) fprintf (stderr, "oss: " __VA_ARGS__)
62 #define ERRFail(...) do { \
64 fprintf (stderr, "oss: " __VA_ARGS__); \
65 fprintf (stderr, "system error: %s\n", strerror (_errno)); \
68 #define Fail(...) do { \
69 fprintf (stderr, "oss: " __VA_ARGS__); \
70 fprintf (stderr, "\n"); \
75 #define lwarn(...) fprintf (stderr, "oss: " __VA_ARGS__)
76 #define linfo(...) fprintf (stderr, "oss: " __VA_ARGS__)
77 #define ldebug(...) fprintf (stderr, "oss: " __VA_ARGS__)
85 #define IOCTL(args) do { \
86 int ret = ioctl args; \
90 ldebug ("ioctl " #args " = %d\n", ret); \
93 static int audio_fd = -1;
95 static int conf_nfrags = 4;
96 static int conf_fragsize;
100 static int nchannels;
107 static int bytes_per_second;
109 static enum {DONT, DSP, TID} estimate = TID;
111 static void (*copy_fn)(void *, void *, int);
113 static void copy_no_conversion (void *dst, void *src, int size)
115 memcpy (dst, src, size);
118 static void copy_u16_to_s16 (void *dst, void *src, int size)
126 for (i = 0; i < size / 2; i++) {
127 out[i] = in[i] + 0x8000;
131 static void pab (struct audio_buf_info *abinfo)
135 ldebug ("fragments %d, fragstotal %d, fragsize %d, bytes %d\n"
136 "rpos %d, wpos %d, live %d\n",
144 void AUD_reset (int rfreq, int rnchannels, audfmt_e rfmt)
149 if (-1 == audio_fd) {
150 AUD_open (rfreq, rnchannels, rfmt);
158 copy_fn = copy_no_conversion;
163 Fail ("can not play 8bit signed");
168 copy_fn = copy_no_conversion;
175 copy_fn = copy_u16_to_s16;
183 if ((fmt_ == fmt) && (bits16 + 1 == nchannels) && (rfreq == freq))
186 AUD_open (rfreq, rnchannels, rfmt);
190 void AUD_open (int rfreq, int rnchannels, audfmt_e rfmt)
194 struct audio_buf_info abinfo;
206 copy_fn = copy_no_conversion;
211 Fail ("can not play 8bit signed");
216 copy_fn = copy_no_conversion;
223 copy_fn = copy_u16_to_s16;
239 audio_fd = open ("/dev/dsp", O_WRONLY | O_NONBLOCK);
240 if (-1 == audio_fd) {
241 ERRFail ("can not open /dev/dsp");
246 _nchannels = rnchannels;
248 IOCTL ((audio_fd, SNDCTL_DSP_RESET, 1));
249 IOCTL ((audio_fd, SNDCTL_DSP_SAMPLESIZE, &_fmt));
250 IOCTL ((audio_fd, SNDCTL_DSP_CHANNELS, &_nchannels));
251 IOCTL ((audio_fd, SNDCTL_DSP_SPEED, &_freq));
252 IOCTL ((audio_fd, SNDCTL_DSP_NONBLOCK));
256 The argument to this call is an integer encoded as 0xMMMMSSSS (in
257 hex). The 16 least significant bits determine the fragment
258 size. The size is 2^SSSS. For examp le SSSS=0008 gives fragment
259 size of 256 bytes (2^8). The minimum is 16 bytes (SSSS=4) and the
260 maximum is total_buffer_size/2. Some devices or processor
261 architectures may require larger fragments - in this case the
262 requested fragment size is automatically increased.
264 So ahem... 4096 = 2^12, and grand total 0x0004000c
267 mmmmssss = (conf_nfrags << 16) | conf_fragsize;
268 IOCTL ((audio_fd, SNDCTL_DSP_SETFRAGMENT, &mmmmssss));
270 linfo ("_fmt = %d, fmt = %d\n"
271 "_channels = %d, rnchannels = %d\n"
272 "_freq = %d, freq = %d\n",
274 _nchannels, rnchannels,
278 Fail ("format %d != %d", _fmt, fmt_);
281 if (_nchannels != rnchannels) {
282 Fail ("channels %d != %d", _nchannels, rnchannels);
285 if (_freq != rfreq) {
286 Fail ("freq %d != %d", _freq, rfreq);
289 IOCTL ((audio_fd, SNDCTL_DSP_GETOSPACE, &abinfo));
291 nfrags = abinfo.fragstotal;
292 fragsize = abinfo.fragsize;
295 nchannels = rnchannels;
296 atom <<= nchannels >> 1;
297 bufsize = nfrags * fragsize;
299 bytes_per_second = (freq << (nchannels >> 1)) << bits16;
301 linfo ("bytes per second %d\n", bytes_per_second);
303 linfo ("fragments %d, fragstotal %d, fragsize %d, bytes %d, bufsize %d\n",
311 buf = malloc (bufsize);
322 int AUD_write (void *in_buf, int size)
327 to_copy = MIN (bufsize - live, size);
337 copy = MIN (temp, bufsize - wpos);
338 copy_fn (out + wpos, in, copy);
341 if (wpos == bufsize) {
357 struct audio_buf_info abinfo;
362 res = ioctl (audio_fd, SNDCTL_DSP_GETOSPACE, &abinfo);
368 lwarn ("SNDCTL_DSP_GETOSPACE failed with %s\n", strerror (err));
371 bytes = abinfo.bytes;
372 bytes = MIN (live, bytes);
374 bytes = (bytes / fragsize) * fragsize;
378 int left, play, written;
380 left = bufsize - rpos;
381 play = MIN (left, bytes);
382 written = write (audio_fd, (void *) ((uint32_t) buf + rpos), play);
385 if (EAGAIN == errno || EINTR == errno) {
389 ERRFail ("write audio");
398 if (rpos == bufsize) {
404 static int get_dsp_bytes (void)
407 struct count_info info;
409 res = ioctl (audio_fd, SNDCTL_DSP_GETOPTR, &info);
414 lwarn ("SNDCTL_DSP_GETOPTR failed with %s\n", strerror (err));
418 ldebug ("bytes %d\n", info.bytes);
423 void AUD_adjust_estimate (int _leftover)
425 leftover = _leftover;
428 int AUD_get_free (void)
432 free = bufsize - live;
444 static int old_bytes;
447 bytes = get_dsp_bytes ();
451 elapsed = bytes - old_bytes;
453 ldebug ("dsp elapsed %d bytes\n", elapsed);
459 static uint64_t old_ticks;
460 uint64_t ticks, delta;
464 ticks = qemu_get_clock(rt_clock);
465 delta = ticks - old_ticks;
468 ua_elapsed = (delta * bytes_per_second) / 1000;
469 al_elapsed = ua_elapsed & ~3ULL;
471 ldebug ("tid elapsed %llu bytes\n", ua_elapsed);
473 if (al_elapsed > (uint64_t) INT_MAX)
476 elapsed = al_elapsed;
482 if (elapsed > free) {
483 lwarn ("audio can not keep up elapsed %d free %d\n", elapsed, free);
491 int AUD_get_live (void)
496 int AUD_get_buffer_size (void)
504 int _fragsize = 4096;
509 if (0 != (fsp & (fsp - 1))) {
510 Fail ("fragment size %d is not power of 2", fsp);
513 conf_fragsize = lsbindex (fsp);
522 int AUD_write (void *in_buf, int size)
527 void AUD_reset (int rfreq, int rnchannels, audfmt_e rfmt)
531 void AUD_adjust_estimate (int _leftover)
535 int AUD_get_free (void)
540 int AUD_get_live (void)
545 int AUD_get_buffer_size (void)