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mpv/libao2/ao_nas.c
arpi 033d4f505a Fixes:
- missing check in init
- missing brackets causing failure
- nas_aformat_to_auformat not working properly
- fix hang that was finally reproducible with high disk activity
- don't cut of audio on uninit(), wait for buffer to empty

It also simplifies the event_handler, making it more readable and
implements Sidik Isani's suggestion to make the buffer size dependent on
bytes per second. I've been using it for two days and found no further
problems.

patch by Tobias Diedrich <td@sim.uni-hannover.de>


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@7733 b3059339-0415-0410-9bf9-f77b7e298cf2
2002-10-13 22:00:15 +00:00

557 lines
14 KiB
C

/*
* NAS output plugin for mplayer
*
* based on the libaudiooss parts rewritten by me, which were
* originally based on the NAS output plugin for xmms.
*
* xmms plugin by Willem Monsuwe
* adapted for libaudiooss by Jon Trulson
* further modified by Erik Inge Bolsø
* largely rewritten and used for this
* plugin by Tobias Diedrich
*
* Theory of operation:
*
* The NAS consists of two parts, a server daemon and a client.
* We setup the server to use a buffer of size bytes_per_second
* with a low watermark of buffer_size - NAS_FRAG_SIZE.
* Upon starting the flow the server will generate a buffer underrun
* event and the event handler will fill the buffer for the first time.
* Now the server will generate a lowwater event when the server buffer
* falls below the low watermark value. The event handler gets called
* again and refills the buffer by the number of bytes requested by the
* server (usually a multiple of 4096). To prevent stuttering on
* startup (start of playing, seeks, unpausing) the client buffer should
* be bigger than the server buffer. (For debugging we also do some
* accounting of what we think how much of the server buffer is filled)
*/
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <audio/audiolib.h>
#include "../mp_msg.h"
#include "audio_out.h"
#include "audio_out_internal.h"
#include "afmt.h"
#define NAS_FRAG_SIZE 4096
static char *nas_event_types[] = {
"Undefined",
"Undefined",
"ElementNotify",
"GrabNotify",
"MonitorNotify",
"BucketNotify",
"DeviceNotify"
};
static char *nas_elementnotify_kinds[] = {
"LowWater",
"HighWater",
"State",
"Unknown"
};
static char *nas_states[] = {
"Stop",
"Start",
"Pause",
"Any"
};
static char *nas_reasons[] = {
"User",
"Underrun",
"Overrun",
"EOF",
"Watermark",
"Hardware",
"Any"
};
static char* nas_reason(unsigned int reason)
{
if (reason > 6) reason = 6;
return nas_reasons[reason];
}
static char* nas_elementnotify_kind(unsigned int kind)
{
if (kind > 2) kind = 3;
return nas_elementnotify_kinds[kind];
}
static char* nas_event_type(unsigned int type) {
if (type > 6) type = 0;
return nas_event_types[type];
}
static char* nas_state(unsigned int state) {
if (state>3) state = 3;
return nas_states[state];
}
static ao_info_t info =
{
"NAS audio output",
"nas",
"Tobias Diedrich",
""
};
struct ao_nas_data {
AuServer *aud;
AuFlowID flow;
AuDeviceID dev;
unsigned int state;
int expect_underrun;
void *client_buffer;
void *server_buffer;
int client_buffer_size;
int client_buffer_used;
int server_buffer_size;
int server_buffer_used;
pthread_mutex_t buffer_mutex;
pthread_t event_thread;
int stop_thread;
};
static struct ao_nas_data *nas_data;
LIBAO_EXTERN(nas)
static void nas_print_error(AuServer *aud, char *prefix, AuStatus as)
{
char s[100];
AuGetErrorText(aud, as, s, 100);
mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: %s: returned status %d (%s)\n", prefix, as, s);
}
static int nas_readBuffer(struct ao_nas_data *nas_data, int num)
{
AuStatus as;
pthread_mutex_lock(&nas_data->buffer_mutex);
mp_msg(MSGT_AO, MSGL_DBG2, "ao_nas: nas_readBuffer(): num=%d client=%d/%d server=%d/%d\n",
num,
nas_data->client_buffer_used, nas_data->client_buffer_size,
nas_data->server_buffer_used, nas_data->server_buffer_size);
if (nas_data->client_buffer_used == 0) {
mp_msg(MSGT_AO, MSGL_DBG2, "ao_nas: buffer is empty, nothing read.\n");
pthread_mutex_unlock(&nas_data->buffer_mutex);
return 0;
}
if (nas_data->client_buffer_used < num)
num = nas_data->client_buffer_used;
/*
* It is not appropriate to call AuWriteElement() here because the
* buffer is locked and delays writing to the network will cause
* other threads to block waiting for buffer_mutex. Instead the
* data is copied to "server_buffer" and written it to the network
* outside of the locked section of code.
*
* (Note: Rather than these two buffers, a single circular buffer
* could eliminate the memcpy/memmove steps.)
*/
memcpy(nas_data->server_buffer, nas_data->client_buffer, num);
nas_data->client_buffer_used -= num;
nas_data->server_buffer_used += num;
memmove(nas_data->client_buffer, nas_data->client_buffer + num, nas_data->client_buffer_used);
pthread_mutex_unlock(&nas_data->buffer_mutex);
/*
* Now write the new buffer to the network.
*/
AuWriteElement(nas_data->aud, nas_data->flow, 0, num, nas_data->server_buffer, AuFalse, &as);
if (as != AuSuccess)
nas_print_error(nas_data->aud, "nas_readBuffer(): AuWriteElement", as);
return num;
}
static void nas_writeBuffer(struct ao_nas_data *nas_data, void *data, int len)
{
pthread_mutex_lock(&nas_data->buffer_mutex);
mp_msg(MSGT_AO, MSGL_DBG2, "ao_nas: nas_writeBuffer(): len=%d client=%d/%d server=%d/%d\n",
len, nas_data->client_buffer_used, nas_data->client_buffer_size,
nas_data->server_buffer_used, nas_data->server_buffer_size);
memcpy(nas_data->client_buffer + nas_data->client_buffer_used, data, len);
nas_data->client_buffer_used += len;
pthread_mutex_unlock(&nas_data->buffer_mutex);
}
static int nas_empty_event_queue(struct ao_nas_data *nas_data)
{
AuEvent ev;
int result = 0;
while (AuScanForTypedEvent(nas_data->aud, AuEventsQueuedAfterFlush,
AuTrue, AuEventTypeElementNotify, &ev)) {
AuDispatchEvent(nas_data->aud, &ev);
result = 1;
}
return result;
}
static void *nas_event_thread_start(void *data)
{
struct ao_nas_data *nas_data = data;
do {
mp_msg(MSGT_AO, MSGL_DBG2,
"ao_nas: event thread heartbeat (state=%s)\n",
nas_state(nas_data->state));
nas_empty_event_queue(nas_data);
usleep(1000);
} while (!nas_data->stop_thread);
return NULL;
}
static AuBool nas_error_handler(AuServer* aud, AuErrorEvent* ev)
{
char s[100];
AuGetErrorText(aud, ev->error_code, s, 100);
mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: error [%s]\n"
"error_code: %d\n"
"request_code: %d\n"
"minor_code: %d\n",
s,
ev->error_code,
ev->request_code,
ev->minor_code);
return AuTrue;
}
static AuBool nas_event_handler(AuServer *aud, AuEvent *ev, AuEventHandlerRec *hnd)
{
AuElementNotifyEvent *event = (AuElementNotifyEvent *) ev;
struct ao_nas_data *nas_data = hnd->data;
mp_msg(MSGT_AO, MSGL_DBG2, "ao_nas: event_handler(): type %s kind %s state %s->%s reason %s numbytes %d expect_underrun %d\n",
nas_event_type(event->type),
nas_elementnotify_kind(event->kind),
nas_state(event->prev_state),
nas_state(event->cur_state),
nas_reason(event->reason),
event->num_bytes,
nas_data->expect_underrun);
nas_data->server_buffer_used -= event->num_bytes;
if (nas_data->server_buffer_used < 0)
nas_data->server_buffer_used = 0;
switch (event->reason) {
case AuReasonWatermark:
nas_readBuffer(nas_data, event->num_bytes);
break;
case AuReasonUnderrun:
// buffer underrun -> refill buffer
nas_data->server_buffer_used = 0;
if (nas_data->expect_underrun) {
nas_data->expect_underrun = 0;
} else {
mp_msg(MSGT_AO, MSGL_WARN,
"ao_nas: Buffer underrun.\n");
mp_msg(MSGT_AO, MSGL_HINT,
"Possible reasons are:"
"1) Network congestion."
"2) Your NAS server is too slow."
"Try renicing your nasd to e.g. -15.\n");
}
if (nas_readBuffer(nas_data,
nas_data->server_buffer_size -
nas_data->server_buffer_used) != 0) {
event->cur_state = AuStateStart;
break;
}
mp_msg(MSGT_AO, MSGL_DBG2,
"ao_nas: Can't refill buffer, stopping flow.\n");
AuStopFlow(nas_data->aud, nas_data->flow, NULL);
break;
default:
break;
}
nas_data->state=event->cur_state;
return AuTrue;
}
static AuDeviceID nas_find_device(AuServer *aud, int nch)
{
int i;
for (i = 0; i < AuServerNumDevices(aud); i++) {
AuDeviceAttributes *dev = AuServerDevice(aud, i);
if ((AuDeviceKind(dev) == AuComponentKindPhysicalOutput) &&
AuDeviceNumTracks(dev) == nch) {
return AuDeviceIdentifier(dev);
}
}
return AuNone;
}
static unsigned int nas_aformat_to_auformat(unsigned int *format)
{
switch (*format) {
case AFMT_U8:
return AuFormatLinearUnsigned8;
case AFMT_S8:
return AuFormatLinearSigned8;
case AFMT_U16_LE:
return AuFormatLinearUnsigned16LSB;
case AFMT_U16_BE:
return AuFormatLinearUnsigned16MSB;
#ifndef WORDS_BIGENDIAN
default:
*format=AFMT_S16_LE;
#endif
case AFMT_S16_LE:
return AuFormatLinearSigned16LSB;
#ifdef WORDS_BIGENDIAN
default:
*format=AFMT_S16_BE;
#endif
case AFMT_S16_BE:
return AuFormatLinearSigned16MSB;
case AFMT_MU_LAW:
return AuFormatULAW8;
}
}
// to set/get/query special features/parameters
static int control(int cmd,int arg){
return -1;
}
// open & setup audio device
// return: 1=success 0=fail
static int init(int rate,int channels,int format,int flags)
{
AuElement elms[3];
AuStatus as;
unsigned char auformat = nas_aformat_to_auformat(&format);
int bytes_per_sample = channels * AuSizeofFormat(auformat);
int buffer_size;
char *server;
nas_data=malloc(sizeof(struct ao_nas_data));
memset(nas_data, 0, sizeof(struct ao_nas_data));
mp_msg(MSGT_AO, MSGL_V, "ao2: %d Hz %d chans %s\n",rate,channels,
audio_out_format_name(format));
ao_data.format = format;
ao_data.samplerate = rate;
ao_data.channels = channels;
ao_data.outburst = NAS_FRAG_SIZE;
ao_data.bps = rate * bytes_per_sample;
buffer_size = ao_data.bps; /* buffer 1 second */
/*
* round up to multiple of NAS_FRAG_SIZE
* divide by 3 first because of 2:1 split
*/
buffer_size = (buffer_size/3 + NAS_FRAG_SIZE-1) & ~(NAS_FRAG_SIZE-1);
ao_data.buffersize = buffer_size*3;
nas_data->client_buffer_size = buffer_size*2;
nas_data->client_buffer = malloc(nas_data->client_buffer_size);
nas_data->server_buffer_size = buffer_size;
nas_data->server_buffer = malloc(nas_data->server_buffer_size);
if (!bytes_per_sample) {
mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: init(): Zero bytes per sample -> nosound\n");
return 0;
}
if (!(server = getenv("AUDIOSERVER")) &&
!(server = getenv("DISPLAY"))) {
mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: init(): AUDIOSERVER environment variable not set -> nosound\n");
return 0;
}
mp_msg(MSGT_AO, MSGL_V, "ao_nas: init(): Using audioserver %s\n", server);
nas_data->aud = AuOpenServer(server, 0, NULL, 0, NULL, NULL);
if (!nas_data->aud) {
mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: init(): Can't open nas audio server -> nosound\n");
return 0;
}
while (channels>1) {
nas_data->dev = nas_find_device(nas_data->aud, channels);
if (nas_data->dev != AuNone &&
((nas_data->flow = AuCreateFlow(nas_data->aud, NULL)) != 0))
break;
channels--;
}
if (nas_data->flow == 0) {
mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: init(): Can't find a suitable output device -> nosound\n");
AuCloseServer(nas_data->aud);
nas_data->aud = 0;
return 0;
}
AuMakeElementImportClient(elms, rate, auformat, channels, AuTrue,
buffer_size / bytes_per_sample,
(buffer_size - NAS_FRAG_SIZE) /
bytes_per_sample, 0, NULL);
AuMakeElementExportDevice(elms+1, 0, nas_data->dev, rate,
AuUnlimitedSamples, 0, NULL);
AuSetElements(nas_data->aud, nas_data->flow, AuTrue, 2, elms, &as);
if (as != AuSuccess) {
nas_print_error(nas_data->aud, "init(): AuSetElements", as);
AuCloseServer(nas_data->aud);
nas_data->aud = 0;
return 0;
}
AuRegisterEventHandler(nas_data->aud, AuEventHandlerIDMask |
AuEventHandlerTypeMask,
AuEventTypeElementNotify, nas_data->flow,
nas_event_handler, (AuPointer) nas_data);
AuSetErrorHandler(nas_data->aud, nas_error_handler);
nas_data->state=AuStateStop;
nas_data->expect_underrun=0;
pthread_mutex_init(&nas_data->buffer_mutex, NULL);
pthread_create(&nas_data->event_thread, NULL, &nas_event_thread_start, nas_data);
return 1;
}
// close audio device
static void uninit(){
mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: uninit()\n");
nas_data->expect_underrun = 1;
while (nas_data->state != AuStateStop) usleep(1000);
nas_data->stop_thread = 1;
pthread_join(nas_data->event_thread, NULL);
AuCloseServer(nas_data->aud);
nas_data->aud = 0;
free(nas_data->client_buffer);
free(nas_data->server_buffer);
}
// stop playing and empty buffers (for seeking/pause)
static void reset(){
AuStatus as;
mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: reset()\n");
pthread_mutex_lock(&nas_data->buffer_mutex);
nas_data->client_buffer_used = 0;
pthread_mutex_unlock(&nas_data->buffer_mutex);
while (nas_data->state != AuStateStop) {
AuStopFlow(nas_data->aud, nas_data->flow, &as);
if (as != AuSuccess)
nas_print_error(nas_data->aud, "reset(): AuStopFlow", as);
usleep(1000);
}
}
// stop playing, keep buffers (for pause)
static void audio_pause()
{
AuStatus as;
mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: audio_pause()\n");
AuStopFlow(nas_data->aud, nas_data->flow, &as);
}
// resume playing, after audio_pause()
static void audio_resume()
{
AuStatus as;
mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: audio_resume()\n");
AuStartFlow(nas_data->aud, nas_data->flow, &as);
if (as != AuSuccess)
nas_print_error(nas_data->aud,
"play(): AuStartFlow", as);
}
// return: how many bytes can be played without blocking
static int get_space()
{
int result;
mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: get_space()\n");
pthread_mutex_lock(&nas_data->buffer_mutex);
result = nas_data->client_buffer_size - nas_data->client_buffer_used;
pthread_mutex_unlock(&nas_data->buffer_mutex);
return result;
}
// plays 'len' bytes of 'data'
// it should round it down to outburst*n
// return: number of bytes played
static int play(void* data,int len,int flags)
{
int maxbursts, playbursts, writelen;
AuStatus as;
mp_msg(MSGT_AO, MSGL_DBG3,
"ao_nas: play(%p, %d, %d)\n",
data, len, flags);
if (len == 0)
return 0;
pthread_mutex_lock(&nas_data->buffer_mutex);
maxbursts = (nas_data->client_buffer_size -
nas_data->client_buffer_used) / ao_data.outburst;
playbursts = len / ao_data.outburst;
writelen = (playbursts > maxbursts ? maxbursts : playbursts) *
ao_data.outburst;
pthread_mutex_unlock(&nas_data->buffer_mutex);
nas_writeBuffer(nas_data, data, writelen);
if (nas_data->state != AuStateStart &&
maxbursts == playbursts) {
mp_msg(MSGT_AO, MSGL_DBG2, "ao_nas: play(): Starting flow.\n");
nas_data->expect_underrun = 1;
AuStartFlow(nas_data->aud, nas_data->flow, &as);
if (as != AuSuccess)
nas_print_error(nas_data->aud, "play(): AuStartFlow", as);
}
return writelen;
}
// return: delay in seconds between first and last sample in buffer
static float get_delay()
{
float result;
mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: get_delay()\n");
pthread_mutex_lock(&nas_data->buffer_mutex);
result = ((float)(nas_data->client_buffer_used +
nas_data->server_buffer_used)) /
(float)ao_data.bps;
pthread_mutex_unlock(&nas_data->buffer_mutex);
return result;
}