rdesktop/trunk/rdpsnd.c

/* -*- c-basic-offset: 8 -*-
   rdesktop: A Remote Desktop Protocol client.
   Sound Channel Process Functions
   Copyright (C) Matthew Chapman 2003
   Copyright (C) GuoJunBo guojunbo@ict.ac.cn 2003

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <assert.h>

#include "rdesktop.h"
#include "rdpsnd.h"
#include "rdpsnd_dsp.h"

#define RDPSND_CLOSE            1
#define RDPSND_WRITE            2
#define RDPSND_SET_VOLUME       3
#define RDPSND_UNKNOWN4         4
#define RDPSND_COMPLETION       5
#define RDPSND_SERVERTICK       6
#define RDPSND_NEGOTIATE        7

#define MAX_FORMATS             10
#define MAX_QUEUE               10

BOOL g_dsp_busy = False;
int g_dsp_fd;

static VCHANNEL *rdpsnd_channel;
static struct audio_driver *drivers = NULL;
struct audio_driver *current_driver = NULL;

static BOOL device_open;
static WAVEFORMATEX formats[MAX_FORMATS];
static unsigned int format_count;
static unsigned int current_format;
unsigned int queue_hi, queue_lo;
struct audio_packet packet_queue[MAX_QUEUE];

void (*wave_out_play) (void);

static STREAM
rdpsnd_init_packet(uint16 type, uint16 size)
{
        STREAM s;

        s = channel_init(rdpsnd_channel, size + 4);
        out_uint16_le(s, type);
        out_uint16_le(s, size);
        return s;
}

static void
rdpsnd_send(STREAM s)
{
#ifdef RDPSND_DEBUG
        printf("RDPSND send:\n");
        hexdump(s->channel_hdr + 8, s->end - s->channel_hdr - 8);
#endif

        channel_send(s, rdpsnd_channel);
}

void
rdpsnd_send_completion(uint16 tick, uint8 packet_index)
{
        STREAM s;

        s = rdpsnd_init_packet(RDPSND_COMPLETION, 4);
        out_uint16_le(s, tick);
        out_uint8(s, packet_index);
        out_uint8(s, 0);
        s_mark_end(s);
        rdpsnd_send(s);
}

static void
rdpsnd_process_negotiate(STREAM in)
{
        unsigned int in_format_count, i;
        WAVEFORMATEX *format;
        STREAM out;
        BOOL device_available = False;
        int readcnt;
        int discardcnt;

        in_uint8s(in, 14);      /* flags, volume, pitch, UDP port */
        in_uint16_le(in, in_format_count);
        in_uint8s(in, 4);       /* pad, status, pad */

        if (current_driver->wave_out_open())
        {
                current_driver->wave_out_close();
                device_available = True;
        }

        format_count = 0;
        if (s_check_rem(in, 18 * in_format_count))
        {
                for (i = 0; i < in_format_count; i++)
                {
                        format = &formats[format_count];
                        in_uint16_le(in, format->wFormatTag);
                        in_uint16_le(in, format->nChannels);
                        in_uint32_le(in, format->nSamplesPerSec);
                        in_uint32_le(in, format->nAvgBytesPerSec);
                        in_uint16_le(in, format->nBlockAlign);
                        in_uint16_le(in, format->wBitsPerSample);
                        in_uint16_le(in, format->cbSize);

                        /* read in the buffer of unknown use */
                        readcnt = format->cbSize;
                        discardcnt = 0;
                        if (format->cbSize > MAX_CBSIZE)
                        {
                                fprintf(stderr, "cbSize too large for buffer: %d\n",
                                        format->cbSize);
                                readcnt = MAX_CBSIZE;
                                discardcnt = format->cbSize - MAX_CBSIZE;
                        }
                        in_uint8a(in, format->cb, readcnt);
                        in_uint8s(in, discardcnt);

                        if (device_available && current_driver->wave_out_format_supported(format))
                        {
                                format_count++;
                                if (format_count == MAX_FORMATS)
                                        break;
                        }
                }
        }

        out = rdpsnd_init_packet(RDPSND_NEGOTIATE | 0x200, 20 + 18 * format_count);
        out_uint32_le(out, 3);  /* flags */
        out_uint32(out, 0xffffffff);    /* volume */
        out_uint32(out, 0);     /* pitch */
        out_uint16(out, 0);     /* UDP port */

        out_uint16_le(out, format_count);
        out_uint8(out, 0x95);   /* pad? */
        out_uint16_le(out, 2);  /* status */
        out_uint8(out, 0x77);   /* pad? */

        for (i = 0; i < format_count; i++)
        {
                format = &formats[i];
                out_uint16_le(out, format->wFormatTag);
                out_uint16_le(out, format->nChannels);
                out_uint32_le(out, format->nSamplesPerSec);
                out_uint32_le(out, format->nAvgBytesPerSec);
                out_uint16_le(out, format->nBlockAlign);
                out_uint16_le(out, format->wBitsPerSample);
                out_uint16(out, 0);     /* cbSize */
        }

        s_mark_end(out);
        rdpsnd_send(out);
}

static void
rdpsnd_process_servertick(STREAM in)
{
        uint16 tick1, tick2;
        STREAM out;

        /* in_uint8s(in, 4); unknown */
        in_uint16_le(in, tick1);
        in_uint16_le(in, tick2);

        out = rdpsnd_init_packet(RDPSND_SERVERTICK | 0x2300, 4);
        out_uint16_le(out, tick1);
        out_uint16_le(out, tick2);
        s_mark_end(out);
        rdpsnd_send(out);
}

static void
rdpsnd_process(STREAM s)
{
        uint8 type;
        uint16 datalen;
        uint32 volume;
        static uint16 tick, format;
        static uint8 packet_index;
        static BOOL awaiting_data_packet;
        static unsigned char missing_bytes[4] = { 0, 0, 0, 0 };

#ifdef RDPSND_DEBUG
        printf("RDPSND recv:\n");
        hexdump(s->p, s->end - s->p);
#endif

        if (awaiting_data_packet)
        {
                if (format >= MAX_FORMATS)
                {
                        error("RDPSND: Invalid format index\n");
                        return;
                }

                if (!device_open || (format != current_format))
                {
                        if (!device_open && !current_driver->wave_out_open())
                        {
                                rdpsnd_send_completion(tick, packet_index);
                                return;
                        }
                        if (!current_driver->wave_out_set_format(&formats[format]))
                        {
                                rdpsnd_send_completion(tick, packet_index);
                                current_driver->wave_out_close();
                                device_open = False;
                                return;
                        }
                        device_open = True;
                        current_format = format;
                }

                /* Insert the 4 missing bytes retrieved from last RDPSND_WRITE */
                memcpy(s->data, missing_bytes, 4);

                current_driver->
                        wave_out_write(rdpsnd_dsp_process
                                       (s, current_driver, &formats[current_format]), tick,
                                       packet_index);
                awaiting_data_packet = False;
                return;
        }

        in_uint8(s, type);
        in_uint8s(s, 1);        /* unknown? */
        in_uint16_le(s, datalen);

        switch (type)
        {
                case RDPSND_WRITE:
                        in_uint16_le(s, tick);
                        in_uint16_le(s, format);
                        in_uint8(s, packet_index);
                        /* Here are our lost bytes, but why? */
                        memcpy(missing_bytes, s->end - 4, 4);
                        awaiting_data_packet = True;
                        break;
                case RDPSND_CLOSE:
                        current_driver->wave_out_close();
                        device_open = False;
                        break;
                case RDPSND_NEGOTIATE:
                        rdpsnd_process_negotiate(s);
                        break;
                case RDPSND_SERVERTICK:
                        rdpsnd_process_servertick(s);
                        break;
                case RDPSND_SET_VOLUME:
                        in_uint32(s, volume);
                        if (device_open)
                        {
                                current_driver->wave_out_volume((volume & 0xffff),
                                                                (volume & 0xffff0000) >> 16);
                        }
                        break;
                default:
                        unimpl("RDPSND packet type %d\n", type);
                        break;
        }
}

static BOOL
rdpsnd_auto_open(void)
{
        static BOOL failed = False;

        if (!failed)
        {
                struct audio_driver *auto_driver = current_driver;

                current_driver = drivers;
                while (current_driver != NULL)
                {
                        DEBUG(("trying %s...\n", current_driver->name));
                        if (current_driver->wave_out_open())
                        {
                                DEBUG(("selected %s\n", current_driver->name));
                                return True;
                        }
                        g_dsp_fd = 0;
                        current_driver = current_driver->next;
                }

                warning("no working audio-driver found\n");
                failed = True;
                current_driver = auto_driver;
        }

        return False;
}

static void
rdpsnd_register_drivers(char *options)
{
        struct audio_driver **reg;

        /* The order of registrations define the probe-order
           when opening the device for the first time */
        reg = &drivers;
#if defined(RDPSND_ALSA)
        *reg = alsa_register(options);
        assert(*reg);
        reg = &((*reg)->next);
#endif
#if defined(RDPSND_SUN)
        *reg = sun_register(options);
        assert(*reg);
        reg = &((*reg)->next);
#endif
#if defined(RDPSND_OSS)
        *reg = oss_register(options);
        assert(*reg);
        reg = &((*reg)->next);
#endif
#if defined(RDPSND_SGI)
        *reg = sgi_register(options);
        assert(*reg);
        reg = &((*reg)->next);
#endif
#if defined(RDPSND_LIBAO)
        *reg = libao_register(options);
    assert(*reg);
        reg = &((*reg)->next);
#endif
}

BOOL
rdpsnd_init(char *optarg)
{
        static struct audio_driver auto_driver;
        struct audio_driver *pos;
        char *driver = NULL, *options = NULL;

        drivers = NULL;

        rdpsnd_channel =
                channel_register("rdpsnd", CHANNEL_OPTION_INITIALIZED | CHANNEL_OPTION_ENCRYPT_RDP,
                                 rdpsnd_process);

        if (rdpsnd_channel == NULL)
        {
                error("channel_register\n");
                return False;
        }

        if (optarg != NULL && strlen(optarg) > 0)
        {
                driver = options = optarg;

                while (*options != '\0' && *options != ':')
                        options++;

                if (*options == ':')
                {
                        *options = '\0';
                        options++;
                }

                if (*options == '\0')
                        options = NULL;
        }

        rdpsnd_register_drivers(options);

        if (!driver)
        {
                auto_driver.wave_out_open = &rdpsnd_auto_open;
                current_driver = &auto_driver;
                return True;
        }

        pos = drivers;
        while (pos != NULL)
        {
                if (!strcmp(pos->name, driver))
                {
                        DEBUG(("selected %s\n", pos->name));
                        current_driver = pos;
                        return True;
                }
                pos = pos->next;
        }
        return False;
}

void
rdpsnd_show_help(void)
{
        struct audio_driver *pos;

        rdpsnd_register_drivers(NULL);

        pos = drivers;
        while (pos != NULL)
        {
                fprintf(stderr, "                     %s:\t%s\n", pos->name, pos->description);
                pos = pos->next;
        }
}

void
rdpsnd_play(void)
{
        current_driver->wave_out_play();
}

void
rdpsnd_queue_write(STREAM s, uint16 tick, uint8 index)
{
        struct audio_packet *packet = &packet_queue[queue_hi];
        unsigned int next_hi = (queue_hi + 1) % MAX_QUEUE;

        if (next_hi == queue_lo)
        {
                error("No space to queue audio packet\n");
                return;
        }

        queue_hi = next_hi;

        packet->s = *s;
        packet->tick = tick;
        packet->index = index;

        if (!g_dsp_busy)
                current_driver->wave_out_play();
}

struct audio_packet *
rdpsnd_queue_current_packet(void)
{
        return &packet_queue[queue_lo];
}

BOOL
rdpsnd_queue_empty(void)
{
        return (queue_lo == queue_hi);
}

void
rdpsnd_queue_init(void)
{
        queue_lo = queue_hi = 0;
}

void
rdpsnd_queue_next(void)
{
        xfree(packet_queue[queue_lo].s.data);
        queue_lo = (queue_lo + 1) % MAX_QUEUE;
}

int
rdpsnd_queue_next_tick(void)
{
        if (((queue_lo + 1) % MAX_QUEUE) != queue_hi)
        {
                return packet_queue[(queue_lo + 1) % MAX_QUEUE].tick;
        }
        else
        {
                return (packet_queue[queue_lo].tick + 65535) % 65536;
        }
}
1	/* -- c-basic-offset: 8 --
2	rdesktop: A Remote Desktop Protocol client.
3	Sound Channel Process Functions
4	Copyright (C) Matthew Chapman 2003
5	Copyright (C) GuoJunBo guojunbo@ict.ac.cn 2003
6
7	This program is free software; you can redistribute it and/or modify
8	it under the terms of the GNU General Public License as published by
9	the Free Software Foundation; either version 2 of the License, or
10	(at your option) any later version.
11
12	This program is distributed in the hope that it will be useful,
13	but WITHOUT ANY WARRANTY; without even the implied warranty of
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	GNU General Public License for more details.
16
17	You should have received a copy of the GNU General Public License
18	along with this program; if not, write to the Free Software
19	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20	*/
21
22	#include <assert.h>
23
24	#include "rdesktop.h"
25	#include "rdpsnd.h"
26	#include "rdpsnd_dsp.h"
27
28	#define RDPSND_CLOSE 1
29	#define RDPSND_WRITE 2
30	#define RDPSND_SET_VOLUME 3
31	#define RDPSND_UNKNOWN4 4
32	#define RDPSND_COMPLETION 5
33	#define RDPSND_SERVERTICK 6
34	#define RDPSND_NEGOTIATE 7
35
36	#define MAX_FORMATS 10
37	#define MAX_QUEUE 10
38
39	BOOL g_dsp_busy = False;
40	int g_dsp_fd;
41
42	static VCHANNEL *rdpsnd_channel;
43	static struct audio_driver *drivers = NULL;
44	struct audio_driver *current_driver = NULL;
45
46	static BOOL device_open;
47	static WAVEFORMATEX formats[MAX_FORMATS];
48	static unsigned int format_count;
49	static unsigned int current_format;
50	unsigned int queue_hi, queue_lo;
51	struct audio_packet packet_queue[MAX_QUEUE];
52
53	void (*wave_out_play) (void);
54
55	static STREAM
56	rdpsnd_init_packet(uint16 type, uint16 size)
57	{
58	STREAM s;
59
60	s = channel_init(rdpsnd_channel, size + 4);
61	out_uint16_le(s, type);
62	out_uint16_le(s, size);
63	return s;
64	}
65
66	static void
67	rdpsnd_send(STREAM s)
68	{
69	#ifdef RDPSND_DEBUG
70	printf("RDPSND send:\n");
71	hexdump(s->channel_hdr + 8, s->end - s->channel_hdr - 8);
72	#endif
73
74	channel_send(s, rdpsnd_channel);
75	}
76
77	void
78	rdpsnd_send_completion(uint16 tick, uint8 packet_index)
79	{
80	STREAM s;
81
82	s = rdpsnd_init_packet(RDPSND_COMPLETION, 4);
83	out_uint16_le(s, tick);
84	out_uint8(s, packet_index);
85	out_uint8(s, 0);
86	s_mark_end(s);
87	rdpsnd_send(s);
88	}
89
90	static void
91	rdpsnd_process_negotiate(STREAM in)
92	{
93	unsigned int in_format_count, i;
94	WAVEFORMATEX *format;
95	STREAM out;
96	BOOL device_available = False;
97	int readcnt;
98	int discardcnt;
99
100	in_uint8s(in, 14); /* flags, volume, pitch, UDP port */
101	in_uint16_le(in, in_format_count);
102	in_uint8s(in, 4); /* pad, status, pad */
103
104	if (current_driver->wave_out_open())
105	{
106	current_driver->wave_out_close();
107	device_available = True;
108	}
109
110	format_count = 0;
111	if (s_check_rem(in, 18 * in_format_count))
112	{
113	for (i = 0; i < in_format_count; i++)
114	{
115	format = &formats[format_count];
116	in_uint16_le(in, format->wFormatTag);
117	in_uint16_le(in, format->nChannels);
118	in_uint32_le(in, format->nSamplesPerSec);
119	in_uint32_le(in, format->nAvgBytesPerSec);
120	in_uint16_le(in, format->nBlockAlign);
121	in_uint16_le(in, format->wBitsPerSample);
122	in_uint16_le(in, format->cbSize);
123
124	/* read in the buffer of unknown use */
125	readcnt = format->cbSize;
126	discardcnt = 0;
127	if (format->cbSize > MAX_CBSIZE)
128	{
129	fprintf(stderr, "cbSize too large for buffer: %d\n",
130	format->cbSize);
131	readcnt = MAX_CBSIZE;
132	discardcnt = format->cbSize - MAX_CBSIZE;
133	}
134	in_uint8a(in, format->cb, readcnt);
135	in_uint8s(in, discardcnt);
136
137	if (device_available && current_driver->wave_out_format_supported(format))
138	{
139	format_count++;
140	if (format_count == MAX_FORMATS)
141	break;
142	}
143	}
144	}
145
146	out = rdpsnd_init_packet(RDPSND_NEGOTIATE \| 0x200, 20 + 18 * format_count);
147	out_uint32_le(out, 3); /* flags */
148	out_uint32(out, 0xffffffff); /* volume */
149	out_uint32(out, 0); /* pitch */
150	out_uint16(out, 0); /* UDP port */
151
152	out_uint16_le(out, format_count);
153	out_uint8(out, 0x95); /* pad? */
154	out_uint16_le(out, 2); /* status */
155	out_uint8(out, 0x77); /* pad? */
156
157	for (i = 0; i < format_count; i++)
158	{
159	format = &formats[i];
160	out_uint16_le(out, format->wFormatTag);
161	out_uint16_le(out, format->nChannels);
162	out_uint32_le(out, format->nSamplesPerSec);
163	out_uint32_le(out, format->nAvgBytesPerSec);
164	out_uint16_le(out, format->nBlockAlign);
165	out_uint16_le(out, format->wBitsPerSample);
166	out_uint16(out, 0); /* cbSize */
167	}
168
169	s_mark_end(out);
170	rdpsnd_send(out);
171	}
172
173	static void
174	rdpsnd_process_servertick(STREAM in)
175	{
176	uint16 tick1, tick2;
177	STREAM out;
178
179	/* in_uint8s(in, 4); unknown */
180	in_uint16_le(in, tick1);
181	in_uint16_le(in, tick2);
182
183	out = rdpsnd_init_packet(RDPSND_SERVERTICK \| 0x2300, 4);
184	out_uint16_le(out, tick1);
185	out_uint16_le(out, tick2);
186	s_mark_end(out);
187	rdpsnd_send(out);
188	}
189
190	static void
191	rdpsnd_process(STREAM s)
192	{
193	uint8 type;
194	uint16 datalen;
195	uint32 volume;
196	static uint16 tick, format;
197	static uint8 packet_index;
198	static BOOL awaiting_data_packet;
199	static unsigned char missing_bytes[4] = { 0, 0, 0, 0 };
200
201	#ifdef RDPSND_DEBUG
202	printf("RDPSND recv:\n");
203	hexdump(s->p, s->end - s->p);
204	#endif
205
206	if (awaiting_data_packet)
207	{
208	if (format >= MAX_FORMATS)
209	{
210	error("RDPSND: Invalid format index\n");
211	return;
212	}
213
214	if (!device_open \|\| (format != current_format))
215	{
216	if (!device_open && !current_driver->wave_out_open())
217	{
218	rdpsnd_send_completion(tick, packet_index);
219	return;
220	}
221	if (!current_driver->wave_out_set_format(&formats[format]))
222	{
223	rdpsnd_send_completion(tick, packet_index);
224	current_driver->wave_out_close();
225	device_open = False;
226	return;
227	}
228	device_open = True;
229	current_format = format;
230	}
231
232	/* Insert the 4 missing bytes retrieved from last RDPSND_WRITE */
233	memcpy(s->data, missing_bytes, 4);
234
235	current_driver->
236	wave_out_write(rdpsnd_dsp_process
237	(s, current_driver, &formats[current_format]), tick,
238	packet_index);
239	awaiting_data_packet = False;
240	return;
241	}
242
243	in_uint8(s, type);
244	in_uint8s(s, 1); /* unknown? */
245	in_uint16_le(s, datalen);
246
247	switch (type)
248	{
249	case RDPSND_WRITE:
250	in_uint16_le(s, tick);
251	in_uint16_le(s, format);
252	in_uint8(s, packet_index);
253	/* Here are our lost bytes, but why? */
254	memcpy(missing_bytes, s->end - 4, 4);
255	awaiting_data_packet = True;
256	break;
257	case RDPSND_CLOSE:
258	current_driver->wave_out_close();
259	device_open = False;
260	break;
261	case RDPSND_NEGOTIATE:
262	rdpsnd_process_negotiate(s);
263	break;
264	case RDPSND_SERVERTICK:
265	rdpsnd_process_servertick(s);
266	break;
267	case RDPSND_SET_VOLUME:
268	in_uint32(s, volume);
269	if (device_open)
270	{
271	current_driver->wave_out_volume((volume & 0xffff),
272	(volume & 0xffff0000) >> 16);
273	}
274	break;
275	default:
276	unimpl("RDPSND packet type %d\n", type);
277	break;
278	}
279	}
280
281	static BOOL
282	rdpsnd_auto_open(void)
283	{
284	static BOOL failed = False;
285
286	if (!failed)
287	{
288	struct audio_driver *auto_driver = current_driver;
289
290	current_driver = drivers;
291	while (current_driver != NULL)
292	{
293	DEBUG(("trying %s...\n", current_driver->name));
294	if (current_driver->wave_out_open())
295	{
296	DEBUG(("selected %s\n", current_driver->name));
297	return True;
298	}
299	g_dsp_fd = 0;
300	current_driver = current_driver->next;
301	}
302
303	warning("no working audio-driver found\n");
304	failed = True;
305	current_driver = auto_driver;
306	}
307
308	return False;
309	}
310
311	static void
312	rdpsnd_register_drivers(char *options)
313	{
314	struct audio_driver **reg;
315
316	/* The order of registrations define the probe-order
317	when opening the device for the first time */
318	reg = &drivers;
319	#if defined(RDPSND_ALSA)
320	*reg = alsa_register(options);
321	assert(*reg);
322	reg = &((*reg)->next);
323	#endif
324	#if defined(RDPSND_SUN)
325	*reg = sun_register(options);
326	assert(*reg);
327	reg = &((*reg)->next);
328	#endif
329	#if defined(RDPSND_OSS)
330	*reg = oss_register(options);
331	assert(*reg);
332	reg = &((*reg)->next);
333	#endif
334	#if defined(RDPSND_SGI)
335	*reg = sgi_register(options);
336	assert(*reg);
337	reg = &((*reg)->next);
338	#endif
339	#if defined(RDPSND_LIBAO)
340	*reg = libao_register(options);
341	assert(*reg);
342	reg = &((*reg)->next);
343	#endif
344	}
345
346	BOOL
347	rdpsnd_init(char *optarg)
348	{
349	static struct audio_driver auto_driver;
350	struct audio_driver *pos;
351	char driver = NULL, options = NULL;
352
353	drivers = NULL;
354
355	rdpsnd_channel =
356	channel_register("rdpsnd", CHANNEL_OPTION_INITIALIZED \| CHANNEL_OPTION_ENCRYPT_RDP,
357	rdpsnd_process);
358
359	if (rdpsnd_channel == NULL)
360	{
361	error("channel_register\n");
362	return False;
363	}
364
365	if (optarg != NULL && strlen(optarg) > 0)
366	{
367	driver = options = optarg;
368
369	while (options != '\0' && options != ':')
370	options++;
371
372	if (*options == ':')
373	{
374	*options = '\0';
375	options++;
376	}
377
378	if (*options == '\0')
379	options = NULL;
380	}
381
382	rdpsnd_register_drivers(options);
383
384	if (!driver)
385	{
386	auto_driver.wave_out_open = &rdpsnd_auto_open;
387	current_driver = &auto_driver;
388	return True;
389	}
390
391	pos = drivers;
392	while (pos != NULL)
393	{
394	if (!strcmp(pos->name, driver))
395	{
396	DEBUG(("selected %s\n", pos->name));
397	current_driver = pos;
398	return True;
399	}
400	pos = pos->next;
401	}
402	return False;
403	}
404
405	void
406	rdpsnd_show_help(void)
407	{
408	struct audio_driver *pos;
409
410	rdpsnd_register_drivers(NULL);
411
412	pos = drivers;
413	while (pos != NULL)
414	{
415	fprintf(stderr, " %s:\t%s\n", pos->name, pos->description);
416	pos = pos->next;
417	}
418	}
419
420	void
421	rdpsnd_play(void)
422	{
423	current_driver->wave_out_play();
424	}
425
426	void
427	rdpsnd_queue_write(STREAM s, uint16 tick, uint8 index)
428	{
429	struct audio_packet *packet = &packet_queue[queue_hi];
430	unsigned int next_hi = (queue_hi + 1) % MAX_QUEUE;
431
432	if (next_hi == queue_lo)
433	{
434	error("No space to queue audio packet\n");
435	return;
436	}
437
438	queue_hi = next_hi;
439
440	packet->s = *s;
441	packet->tick = tick;
442	packet->index = index;
443
444	if (!g_dsp_busy)
445	current_driver->wave_out_play();
446	}
447
448	struct audio_packet *
449	rdpsnd_queue_current_packet(void)
450	{
451	return &packet_queue[queue_lo];
452	}
453
454	BOOL
455	rdpsnd_queue_empty(void)
456	{
457	return (queue_lo == queue_hi);
458	}
459
460	void
461	rdpsnd_queue_init(void)
462	{
463	queue_lo = queue_hi = 0;
464	}
465
466	void
467	rdpsnd_queue_next(void)
468	{
469	xfree(packet_queue[queue_lo].s.data);
470	queue_lo = (queue_lo + 1) % MAX_QUEUE;
471	}
472
473	int
474	rdpsnd_queue_next_tick(void)
475	{
476	if (((queue_lo + 1) % MAX_QUEUE) != queue_hi)
477	{
478	return packet_queue[(queue_lo + 1) % MAX_QUEUE].tick;
479	}
480	else
481	{
482	return (packet_queue[queue_lo].tick + 65535) % 65536;
483	}
484	}