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mpv/libao2/ao_alsa9.c

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/*
ao_alsa9 - ALSA-0.9.x output plugin for MPlayer
(C) Alex Beregszaszi <alex@naxine.org>
modified for real alsa-0.9.0-support by Joy Winter <joy@pingfm.org>
additional AC3 passthrough support by Andy Lo A Foe <andy@alsaplayer.org>
08/22/2002 iec958-init rewritten and merged with common init, joy
Any bugreports regarding to this driver are welcome.
*/
#include <errno.h>
#include <sys/time.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <sys/poll.h>
#include "../config.h"
#if HAVE_SYS_ASOUNDLIB_H
#include <sys/asoundlib.h>
#elif HAVE_ALSA_ASOUNDLIB_H
#include <alsa/asoundlib.h>
#else
#error "asoundlib.h is not in sys/ or alsa/ - please bugreport"
#endif
#include "audio_out.h"
#include "audio_out_internal.h"
#include "afmt.h"
extern int verbose;
static ao_info_t info =
{
"ALSA-0.9.x audio output",
"alsa9",
"Alex Beregszaszi <alex@naxine.org>, Joy Winter <joy@pingfm.org>",
"under developement"
};
LIBAO_EXTERN(alsa9)
static snd_pcm_t *alsa_handler;
static snd_pcm_format_t alsa_format;
static snd_pcm_hw_params_t *alsa_hwparams;
static snd_pcm_sw_params_t *alsa_swparams;
const char *alsa_device;
/* possible 4096, original 8192
* was only needed for calculating chunksize? */
static int alsa_fragsize = 4096;
/* 16 sets buffersize to 16 * chunksize is as default 1024
* which seems to be good avarge for most situations
* so buffersize is 16384 frames by default */
static int alsa_fragcount = 16;
static int chunk_size = 1024; //is alsa_fragsize / 4
static size_t bits_per_sample, bits_per_frame;
static size_t chunk_bytes;
int ao_mmap = 0;
int ao_noblock = 0;
int first = 1;
static int open_mode;
static int set_block_mode;
#define ALSA_DEVICE_SIZE 48
#undef BUFFERTIME
#define SET_CHUNKSIZE
#undef USE_POLL
/* to set/get/query special features/parameters */
static int control(int cmd, int arg)
{
switch(cmd) {
case AOCONTROL_QUERY_FORMAT:
return CONTROL_TRUE;
case AOCONTROL_GET_VOLUME:
case AOCONTROL_SET_VOLUME:
#ifndef WORDS_BIGENDIAN
{ //seems to be a problem on macs?
{
ao_control_vol_t *vol = (ao_control_vol_t *)arg;
int err;
snd_mixer_t *handle;
snd_mixer_elem_t *elem;
snd_mixer_selem_id_t *sid;
const char *mix_name = "PCM";
char *card = "default";
long pmin, pmax;
long get_vol, set_vol;
float calc_vol, diff, f_multi;
if(ao_data.format == AFMT_AC3)
return CONTROL_TRUE;
//allocate simple id
snd_mixer_selem_id_alloca(&sid);
//sets simple-mixer index and name
snd_mixer_selem_id_set_index(sid, 0);
snd_mixer_selem_id_set_name(sid, mix_name);
if ((err = snd_mixer_open(&handle, 0)) < 0) {
printf("alsa-control: mixer open error: %s\n", snd_strerror(err));
return CONTROL_ERROR;
}
if ((err = snd_mixer_attach(handle, card)) < 0) {
printf("alsa-control: mixer attach %s error: %s", card, snd_strerror(err));
snd_mixer_close(handle);
return CONTROL_ERROR;
}
if ((err = snd_mixer_selem_register(handle, NULL, NULL)) < 0) {
printf("alsa-control: mixer register error: %s", snd_strerror(err));
snd_mixer_close(handle);
return CONTROL_ERROR;
}
err = snd_mixer_load(handle);
if (err < 0) {
printf("alsa-control: mixer load error: %s", snd_strerror(err));
snd_mixer_close(handle);
return CONTROL_ERROR;
}
elem = snd_mixer_find_selem(handle, sid);
if (!elem) {
printf("alsa-control: unable to find simple control '%s',%i\n", snd_mixer_selem_id_get_name(sid), snd_mixer_selem_id_get_index(sid));
snd_mixer_close(handle);
return CONTROL_ERROR;
}
snd_mixer_selem_get_playback_volume_range(elem,&pmin,&pmax);
f_multi = (100 / (float)pmax);
if (cmd == AOCONTROL_SET_VOLUME) {
diff = (vol->left+vol->right) / 2;
set_vol = rint(diff / f_multi);
if (set_vol < 0)
set_vol = 0;
else if (set_vol > pmax)
set_vol = pmax;
//setting channels
if ((err = snd_mixer_selem_set_playback_volume(elem, 0, set_vol)) < 0) {
printf("alsa-control: error setting left channel, %s",snd_strerror(err));
return CONTROL_ERROR;
}
if ((err = snd_mixer_selem_set_playback_volume(elem, 1, set_vol)) < 0) {
printf("alsa-control: error setting right channel, %s",snd_strerror(err));
return CONTROL_ERROR;
}
//printf("diff=%f, set_vol=%i, pmax=%i, mult=%f\n", diff, set_vol, pmax, f_multi);
}
else {
snd_mixer_selem_get_playback_volume(elem, 0, &get_vol);
calc_vol = get_vol;
calc_vol = rintf(calc_vol * f_multi);
vol->left = vol->right = (int)calc_vol;
//printf("get_vol = %i, calc=%i\n",get_vol, calc_vol);
}
snd_mixer_close(handle);
return CONTROL_OK;
}
}// end big-endian
#endif
#ifdef WORDS_BIGENDIAN
{
{
return (CONTROL_UNKNOWN);
}
}
#endif
} //end witch
return(CONTROL_UNKNOWN);
}
/*
open & setup audio device
return: 1=success 0=fail
*/
static int init(int rate_hz, int channels, int format, int flags)
{
int err;
int cards = -1;
int period_val;
snd_pcm_info_t *alsa_info;
char *str_block_mode;
int device_set = 0;
printf("alsa-init: testing and bugreports are welcome.\n");
printf("alsa-init: requested format: %d Hz, %d channels, %s\n", rate_hz,
channels, audio_out_format_name(format));
alsa_handler = NULL;
if (verbose)
printf("alsa-init: compiled for ALSA-%s\n", SND_LIB_VERSION_STR);
if ((err = snd_card_next(&cards)) < 0 || cards < 0)
{
printf("alsa-init: no soundcards found: %s\n", snd_strerror(err));
return(0);
}
ao_data.samplerate = rate_hz;
ao_data.bps = channels; /* really this is bytes per frame so bad varname */
ao_data.format = format;
ao_data.channels = channels;
ao_data.outburst = OUTBURST;
//ao_data.buffersize = MAX_OUTBURST; // was 16384
switch (format)
{
case AFMT_S8:
alsa_format = SND_PCM_FORMAT_S8;
break;
case AFMT_U8:
alsa_format = SND_PCM_FORMAT_U8;
break;
case AFMT_U16_LE:
alsa_format = SND_PCM_FORMAT_U16_LE;
break;
case AFMT_U16_BE:
alsa_format = SND_PCM_FORMAT_U16_BE;
break;
#ifndef WORDS_BIGENDIAN
case AFMT_AC3:
#endif
case AFMT_S16_LE:
alsa_format = SND_PCM_FORMAT_S16_LE;
break;
#ifdef WORDS_BIGENDIAN
case AFMT_AC3:
#endif
case AFMT_S16_BE:
alsa_format = SND_PCM_FORMAT_S16_BE;
break;
case AFMT_S32_LE:
alsa_format = SND_PCM_FORMAT_S32_LE;
break;
case AFMT_S32_BE:
alsa_format = SND_PCM_FORMAT_S32_BE;
break;
default:
alsa_format = SND_PCM_FORMAT_MPEG;
break;
}
switch(alsa_format)
{
case SND_PCM_FORMAT_S16_LE:
case SND_PCM_FORMAT_U16_LE:
ao_data.bps *= 2;
break;
case SND_PCM_FORMAT_S32_LE:
case SND_PCM_FORMAT_S32_BE:
ao_data.bps *= 4;
break;
case -1:
printf("alsa-init: invalid format (%s) requested - output disabled\n",
audio_out_format_name(format));
return(0);
default:
break;
}
if (ao_subdevice) {
//start parsing ao_subdevice, ugly and not thread safe!
//maybe there's a better way?
int i2 = 1;
int i3 = 0;
char *sub_str;
char *token_str[3];
char* test_str = strdup(ao_subdevice);
if ((strcspn(ao_subdevice, ":")) > 0) {
sub_str = strtok(test_str, ":");
*(token_str) = sub_str;
while (((sub_str = strtok(NULL, ":")) != NULL) && (i2 <= 3)) {
*(token_str+i2) = sub_str;
i2 += 1;
}
for (i3=0; i3 <= i2-1; i3++) {
if (strcmp(*(token_str + i3), "mmap") == 0) {
ao_mmap = 1;
}
else if (strcmp(*(token_str+i3), "noblock") == 0) {
ao_noblock = 1;
}
else if (strcmp(*(token_str+i3), "hw") == 0) {
if ((i3 < i2-1) && (strcmp(*(token_str+i3+1), "noblock") != 0) && (strcmp(*(token_str+i3+1), "mmap") != 0)) {
alsa_device = alloca(ALSA_DEVICE_SIZE);
snprintf(alsa_device, ALSA_DEVICE_SIZE, "hw:%s", *(token_str+(i3+1)));
device_set = 1;
}
else {
alsa_device = *(token_str+i3);
device_set = 1;
}
}
else if (device_set == 0 && (!ao_mmap || !ao_noblock)) {
alsa_device = *(token_str+i3);
device_set = 1;
}
}
}
} //end parsing ao_subdevice
/* switch for spdif
* sets opening sequence for SPDIF
* sets also the playback and other switches 'on the fly'
* while opening the abstract alias for the spdif subdevice
* 'iec958'
*/
if (format == AFMT_AC3) {
char devstr[128];
unsigned char s[4];
int err, c;
switch (channels) {
case 1:
case 2:
s[0] = IEC958_AES0_NONAUDIO |
IEC958_AES0_CON_EMPHASIS_NONE;
s[1] = IEC958_AES1_CON_ORIGINAL |
IEC958_AES1_CON_PCM_CODER;
s[2] = 0;
s[3] = IEC958_AES3_CON_FS_48000;
sprintf(devstr, "iec958:AES0=0x%x,AES1=0x%x,AES2=0x%x,AES3=0x%x",
s[0], s[1], s[2], s[3]);
if (verbose)
printf("alsa-spdif-init: playing AC3, %i channels\n", channels);
break;
case 4:
strcpy(devstr, "surround40");
break;
case 6:
strcpy(devstr, "surround51");
break;
default:
fprintf(stderr, "%d channels are not supported\n", channels);
exit (0);
}
alsa_device = devstr;
}
if (alsa_device == NULL)
{
int tmp_device, tmp_subdevice, err;
if ((err = snd_pcm_info_malloc(&alsa_info)) < 0)
{
printf("alsa-init: memory allocation error: %s\n", snd_strerror(err));
return(0);
}
if ((alsa_device = alloca(ALSA_DEVICE_SIZE)) == NULL)
{
printf("alsa-init: memory allocation error: %s\n", strerror(errno));
return(0);
}
if ((tmp_device = snd_pcm_info_get_device(alsa_info)) < 0)
{
printf("alsa-init: cant get device\n");
return(0);
}
if ((tmp_subdevice = snd_pcm_info_get_subdevice(alsa_info)) < 0)
{
printf("alsa-init: cant get subdevice\n");
return(0);
}
if (verbose)
printf("alsa-init: got device=%i, subdevice=%i\n", tmp_device, tmp_subdevice);
if ((err = snprintf(alsa_device, ALSA_DEVICE_SIZE, "hw:%1d,%1d", tmp_device, tmp_subdevice)) <= 0)
{
printf("alsa-init: cant wrote device-id\n");
}
snd_pcm_info_free(alsa_info);
printf("alsa-init: %d soundcard%s found, using: %s\n", cards+1,
(cards >= 0) ? "" : "s", alsa_device);
} else if (strcmp(alsa_device, "help") == 0) {
printf("alsa-help: available options are:\n");
printf(" mmap: sets mmap-mode\n");
printf(" noblock: sets noblock-mode\n");
printf(" device-name: sets device name\n");
printf(" example -ao alsa9:mmap:noblock:hw:0,3 sets noblock-mode,\n");
printf(" mmap-mode and the device-name as first card third device\n");
return(0);
} else {
printf("alsa-init: soundcard set to %s\n", alsa_device);
}
//setting modes for block or nonblock-mode
if (ao_noblock) {
open_mode = SND_PCM_NONBLOCK;
set_block_mode = 1;
str_block_mode = "nonblock-mode";
}
else {
open_mode = 0;
set_block_mode = 0;
str_block_mode = "block-mode";
}
//sets buff/chunksize if its set manually
if (ao_data.buffersize) {
switch (ao_data.buffersize)
{
case 1:
alsa_fragcount = 16;
chunk_size = 512;
if (verbose) {
printf("alsa-init: buffersize set manually to 8192\n");
printf("alsa-init: chunksize set manually to 512\n");
}
break;
case 2:
alsa_fragcount = 8;
chunk_size = 1024;
if (verbose) {
printf("alsa-init: buffersize set manually to 8192\n");
printf("alsa-init: chunksize set manually to 1024\n");
}
break;
case 3:
alsa_fragcount = 32;
chunk_size = 512;
if (verbose) {
printf("alsa-init: buffersize set manually to 16384\n");
printf("alsa-init: chunksize set manually to 512\n");
}
break;
case 4:
alsa_fragcount = 16;
chunk_size = 1024;
if (verbose) {
printf("alsa-init: buffersize set manually to 16384\n");
printf("alsa-init: chunksize set manually to 1024\n");
}
break;
default:
alsa_fragcount = 16;
if (ao_mmap)
chunk_size = 512;
else
chunk_size = 1024;
break;
}
}
if (!alsa_handler) {
//modes = 0, SND_PCM_NONBLOCK, SND_PCM_ASYNC
if ((err = snd_pcm_open(&alsa_handler, alsa_device, SND_PCM_STREAM_PLAYBACK, open_mode)) < 0)
{
if (ao_noblock) {
printf("alsa-init: open in nonblock-mode failed, trying to open in block-mode\n");
if ((err = snd_pcm_open(&alsa_handler, alsa_device, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
printf("alsa-init: playback open error: %s\n", snd_strerror(err));
return(0);
} else {
set_block_mode = 0;
str_block_mode = "block-mode";
}
} else {
printf("alsa-init: playback open error: %s\n", snd_strerror(err));
return(0);
}
}
if ((err = snd_pcm_nonblock(alsa_handler, set_block_mode)) < 0) {
printf("alsa-init: error set block-mode %s\n", snd_strerror(err));
}
else if (verbose) {
printf("alsa-init: pcm opend in %s\n", str_block_mode);
}
snd_pcm_hw_params_alloca(&alsa_hwparams);
snd_pcm_sw_params_alloca(&alsa_swparams);
// setting hw-parameters
if ((err = snd_pcm_hw_params_any(alsa_handler, alsa_hwparams)) < 0)
{
printf("alsa-init: unable to get initial parameters: %s\n",
snd_strerror(err));
return(0);
}
if (ao_mmap) {
snd_pcm_access_mask_t *mask = alloca(snd_pcm_access_mask_sizeof());
snd_pcm_access_mask_none(mask);
snd_pcm_access_mask_set(mask, SND_PCM_ACCESS_MMAP_INTERLEAVED);
snd_pcm_access_mask_set(mask, SND_PCM_ACCESS_MMAP_NONINTERLEAVED);
snd_pcm_access_mask_set(mask, SND_PCM_ACCESS_MMAP_COMPLEX);
err = snd_pcm_hw_params_set_access_mask(alsa_handler, alsa_hwparams, mask);
printf("alsa-init: mmap set\n");
} else {
err = snd_pcm_hw_params_set_access(alsa_handler, alsa_hwparams,SND_PCM_ACCESS_RW_INTERLEAVED);
}
if (err < 0) {
printf("alsa-init: unable to set access type: %s\n", snd_strerror(err));
return (0);
}
if ((err = snd_pcm_hw_params_set_format(alsa_handler, alsa_hwparams,
alsa_format)) < 0)
{
printf("alsa-init: unable to set format: %s\n",
snd_strerror(err));
return(0);
}
if ((err = snd_pcm_hw_params_set_channels(alsa_handler, alsa_hwparams,
ao_data.channels)) < 0)
{
printf("alsa-init: unable to set channels: %s\n",
snd_strerror(err));
return(0);
}
if ((err = snd_pcm_hw_params_set_rate_near(alsa_handler, alsa_hwparams, ao_data.samplerate, 0)) < 0)
{
printf("alsa-init: unable to set samplerate-2: %s\n",
snd_strerror(err));
return(0);
}
#ifdef BUFFERTIME
{
int alsa_buffer_time = 500000; /* original 60 */
if ((err = snd_pcm_hw_params_set_buffer_time_near(alsa_handler, alsa_hwparams, alsa_buffer_time, 0)) < 0)
{
printf("alsa-init: unable to set buffer time near: %s\n",
snd_strerror(err));
return(0);
} else
alsa_buffer_time = err;
if ((err = snd_pcm_hw_params_set_period_time_near(alsa_handler, alsa_hwparams, alsa_buffer_time/4, 0)) < 0)
/* original: alsa_buffer_time/ao_data.bps */
{
printf("alsa-init: unable to set period time: %s\n",
snd_strerror(err));
return(0);
}
if (verbose)
printf("alsa-init: buffer_time: %d, period_time :%d\n",alsa_buffer_time, err);
}
#endif
#ifdef SET_CHUNKSIZE
{
//set chunksize
if ((err = snd_pcm_hw_params_set_period_size(alsa_handler, alsa_hwparams, chunk_size, 0)) < 0)
{
printf("alsa-init: unable to set periodsize: %s\n", snd_strerror(err));
return(0);
}
else if (verbose) {
printf("alsa-init: chunksize set to %i\n", chunk_size);
}
//set period_count
if ((period_val = snd_pcm_hw_params_get_periods_max(alsa_hwparams, 0)) < alsa_fragcount) {
alsa_fragcount = period_val;
}
if (verbose)
printf("alsa-init: current val=%i, fragcount=%i\n", period_val, alsa_fragcount);
if ((err = snd_pcm_hw_params_set_periods(alsa_handler, alsa_hwparams, alsa_fragcount, 0)) < 0) {
printf("alsa-init: unable to set periods: %s\n", snd_strerror(err));
}
}
#endif
/* finally install hardware parameters */
if ((err = snd_pcm_hw_params(alsa_handler, alsa_hwparams)) < 0)
{
printf("alsa-init: unable to set hw-parameters: %s\n",
snd_strerror(err));
return(0);
}
// end setting hw-params
// gets buffersize for control
if ((err = snd_pcm_hw_params_get_buffer_size(alsa_hwparams)) < 0)
{
printf("alsa-init: unable to get buffersize: %s\n", snd_strerror(err));
return(0);
}
else {
ao_data.buffersize = err;
if (verbose)
printf("alsa-init: got buffersize=%i\n", ao_data.buffersize);
}
// setting sw-params (only avail-min) if noblocking mode was choosed
if (ao_noblock)
{
if ((err = snd_pcm_sw_params_current(alsa_handler, alsa_swparams)) < 0)
{
printf("alsa-init: unable to get parameters: %s\n",snd_strerror(err));
return(0);
}
//set min available frames to consider pcm ready (4)
//increased for nonblock-mode should be set dynamically later
if ((err = snd_pcm_sw_params_set_avail_min(alsa_handler, alsa_swparams, 4)) < 0)
{
printf("alsa-init: unable to set avail_min %s\n",snd_strerror(err));
return(0);
}
if ((err = snd_pcm_sw_params(alsa_handler, alsa_swparams)) < 0)
{
printf("alsa-init: unable to install sw-params\n");
return(0);
}
bits_per_sample = snd_pcm_format_physical_width(alsa_format);
bits_per_frame = bits_per_sample * channels;
chunk_bytes = chunk_size * bits_per_frame / 8;
if (verbose) {
printf("alsa-init: bits per sample (bps)=%i, bits per frame (bpf)=%i, chunk_bytes=%i\n",bits_per_sample,bits_per_frame,chunk_bytes);}
}//end swparams
if ((err = snd_pcm_prepare(alsa_handler)) < 0)
{
printf("alsa-init: pcm prepare error: %s\n", snd_strerror(err));
return(0);
}
printf("alsa9: %d Hz/%d channels/%d bpf/%d bytes buffer/%s\n",
ao_data.samplerate, ao_data.channels, ao_data.bps, ao_data.buffersize,
snd_pcm_format_description(alsa_format));
} // end switch alsa_handler (spdif)
return(1);
} // end init
/* close audio device */
static void uninit()
{
if (alsa_handler) {
int err;
if (!ao_noblock) {
if ((err = snd_pcm_drain(alsa_handler)) < 0)
{
printf("alsa-uninit: pcm drain error: %s\n", snd_strerror(err));
return;
}
}
if ((err = snd_pcm_close(alsa_handler)) < 0)
{
printf("alsa-uninit: pcm close error: %s\n", snd_strerror(err));
return;
}
else {
alsa_handler = NULL;
alsa_device = NULL;
printf("alsa-uninit: pcm closed\n");
}
}
else {
printf("alsa-uninit: no handler defined!\n");
}
}
static void audio_pause()
{
int err;
if (!ao_noblock) {
//drain causes error in nonblock-mode!
if ((err = snd_pcm_drain(alsa_handler)) < 0)
{
printf("alsa-pause: pcm drain error: %s\n", snd_strerror(err));
return;
}
}
else {
if (verbose)
printf("alsa-pause: paused nonblock\n");
return;
}
}
static void audio_resume()
{
int err;
if ((err = snd_pcm_prepare(alsa_handler)) < 0)
{
printf("alsa-resume: pcm prepare error: %s\n", snd_strerror(err));
return;
}
}
/* stop playing and empty buffers (for seeking/pause) */
static void reset()
{
int err;
if (!ao_noblock) {
//drain causes error in nonblock-mode!
if ((err = snd_pcm_drain(alsa_handler)) < 0)
{
printf("alsa-pause: pcm drain error: %s\n", snd_strerror(err));
return;
}
if ((err = snd_pcm_prepare(alsa_handler)) < 0)
{
printf("alsa-reset: pcm prepare error: %s\n", snd_strerror(err));
return;
}
} else {
if (verbose)
printf("alsa-reset: reset nonblocked");
return;
}
}
#ifdef USE_POLL
static int wait_for_poll(snd_pcm_t *handle, struct pollfd *ufds, unsigned int count)
{
unsigned short revents;
while (1) {
poll(ufds, count, -1);
snd_pcm_poll_descriptors_revents(handle, ufds, count, &revents);
if (revents & POLLERR)
return -EIO;
if (revents & POLLOUT)
return 0;
}
}
#endif
#ifndef timersub
#define timersub(a, b, result) \
do { \
(result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
(result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
if ((result)->tv_usec < 0) { \
--(result)->tv_sec; \
(result)->tv_usec += 1000000; \
} \
} while (0)
#endif
/* I/O error handler */
static int xrun(u_char *str_mode)
{
int err;
snd_pcm_status_t *status;
snd_pcm_status_alloca(&status);
if ((err = snd_pcm_status(alsa_handler, status))<0) {
printf("status error: %s", snd_strerror(err));
return(0);
}
if (snd_pcm_status_get_state(status) == SND_PCM_STATE_XRUN) {
struct timeval now, diff, tstamp;
gettimeofday(&now, 0);
snd_pcm_status_get_trigger_tstamp(status, &tstamp);
timersub(&now, &tstamp, &diff);
printf("alsa-%s: xrun of at least %.3f msecs. resetting stream\n",
str_mode,
diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
}
if ((err = snd_pcm_prepare(alsa_handler))<0) {
printf("xrun: prepare error: %s", snd_strerror(err));
return(0);
}
return(1); /* ok, data should be accepted again */
}
static int play(void* data, int len, int flags)
{
int result;
if (ao_mmap)
result = play_mmap(data, len);
else
result = play_normal(data, len);
return result;
}
/*
plays 'len' bytes of 'data'
returns: number of bytes played
modified last at 29.06.02 by jp
thanxs for marius <marius@rospot.com> for giving us the light ;)
*/
static int play_normal(void* data, int len)
{
//ao_data.bps is always 4 for 2 chn S16_LE
int num_frames = len / ao_data.bps;
signed short *output_samples=data;
snd_pcm_sframes_t res = 0;
//printf("alsa-play: frames=%i, len=%i",num_frames,len);
if (!alsa_handler) {
printf("alsa-play: device configuration error");
return 0;
}
while (num_frames > 0) {
res = snd_pcm_writei(alsa_handler, (void *)output_samples, num_frames);
if (res == -EAGAIN) {
snd_pcm_wait(alsa_handler, 1000);
}
else if (res == -EPIPE) { /* underrun */
if (xrun("play") <= 0) {
printf("alsa-play: xrun reset error");
return(0);
}
}
else if (res == -ESTRPIPE) { /* suspend */
printf("alsa-play: pcm in suspend mode. trying to resume\n");
while ((res = snd_pcm_resume(alsa_handler)) == -EAGAIN)
sleep(1);
}
else if (res < 0) {
printf("alsa-play: unknown status, trying to reset soundcard\n");
if ((res = snd_pcm_prepare(alsa_handler)) < 0) {
printf("alsa-play: snd prepare error");
return(0);
break;
}
}
if (res > 0) {
output_samples += ao_data.channels * res;
num_frames -= res;
}
} //end while
if (res < 0) {
printf("alsa-play: write error %s", snd_strerror(res));
return 0;
}
return res < 0 ? (int)res : len;
}
/* mmap-mode mainly based on descriptions by Joshua Haberman <joshua@haberman.com>
* 'An overview of the ALSA API' http://people.debian.org/~joshua/x66.html
* and some help by Paul Davis <pbd@op.net> */
static int play_mmap(void* data, int len)
{
snd_pcm_sframes_t commitres, frames_available;
snd_pcm_uframes_t frames_transmit, size, offset;
const snd_pcm_channel_area_t *area;
void *outbuffer;
int err, result;
#ifdef USE_POLL //seems not really be needed
struct pollfd *ufds;
int count;
count = snd_pcm_poll_descriptors_count (alsa_handler);
ufds = malloc(sizeof(struct pollfd) * count);
snd_pcm_poll_descriptors(alsa_handler, ufds, count);
//first wait_for_poll
if (err = (wait_for_poll(alsa_handler, ufds, count) < 0)) {
if (snd_pcm_state(alsa_handler) == SND_PCM_STATE_XRUN ||
snd_pcm_state(alsa_handler) == SND_PCM_STATE_SUSPENDED) {
xrun("play");
}
}
#endif
outbuffer = alloca(ao_data.buffersize);
//don't trust get_space() ;)
frames_available = snd_pcm_avail_update(alsa_handler) * ao_data.bps;
if (frames_available < 0)
xrun("play");
if (frames_available < 4) {
if (first) {
first = 0;
snd_pcm_start(alsa_handler);
}
else { //FIXME should break and return 0?
snd_pcm_wait(alsa_handler, -1);
first = 1;
}
}
/* len is simply the available bufferspace got by get_space()
* but real avail_buffer in frames is ab/ao_data.bps */
size = len / ao_data.bps;
//if (verbose)
//printf("len: %i size %i, f_avail %i, bps %i ...\n", len, size, frames_available, ao_data.bps);
frames_transmit = size;
/* prepare areas and set sw-pointers
* frames_transmit returns the real available buffer-size
* sometimes != frames_available cause of ringbuffer 'emulation' */
snd_pcm_mmap_begin(alsa_handler, &area, &offset, &frames_transmit);
/* this is specific to interleaved streams (or non-interleaved
* streams with only one channel) */
outbuffer = ((char *) area->addr + (area->first + area->step * offset) / 8); //8
//write data
memcpy(outbuffer, data, (frames_transmit * ao_data.bps));
commitres = snd_pcm_mmap_commit(alsa_handler, offset, frames_transmit);
if (commitres < 0 || commitres != frames_transmit) {
if (snd_pcm_state(alsa_handler) == SND_PCM_STATE_XRUN ||
snd_pcm_state(alsa_handler) == SND_PCM_STATE_SUSPENDED) {
xrun("play");
}
}
//if (verbose)
//printf("mmap ft: %i, cres: %i\n", frames_transmit, commitres);
/* err = snd_pcm_area_copy(&area, offset, &data, offset, len, alsa_format); */
/* if (err < 0) { */
/* printf("area-copy-error\n"); */
/* return 0; */
/* } */
//calculate written frames!
result = commitres * ao_data.bps;
/* if (verbose) { */
/* if (len == result) */
/* printf("result: %i, frames written: %i ...\n", result, frames_transmit); */
/* else */
/* printf("result: %i, frames written: %i, result != len ...\n", result, frames_transmit); */
/* } */
//mplayer doesn't like -result
if (result < 0)
result = 0;
#ifdef USE_POLL
free(ufds);
#endif
return result;
}
/* how many byes are free in the buffer */
static int get_space()
{
snd_pcm_status_t *status;
int ret;
char *str_status;
//snd_pcm_sframes_t avail_frames = 0;
if ((ret = snd_pcm_status_malloc(&status)) < 0)
{
printf("alsa-space: memory allocation error: %s\n", snd_strerror(ret));
return(0);
}
if ((ret = snd_pcm_status(alsa_handler, status)) < 0)
{
printf("alsa-space: cannot get pcm status: %s\n", snd_strerror(ret));
return(0);
}
switch(snd_pcm_status_get_state(status))
{
case SND_PCM_STATE_OPEN:
str_status = "open";
case SND_PCM_STATE_PREPARED:
if (str_status != "open") {
str_status = "prepared";
first = 1;
ret = snd_pcm_status_get_avail(status) * ao_data.bps;
if (ret == 0) //ugly workaround for hang in mmap-mode
ret = 10;
break;
}
case SND_PCM_STATE_RUNNING:
ret = snd_pcm_status_get_avail(status) * ao_data.bps;
//avail_frames = snd_pcm_avail_update(alsa_handler) * ao_data.bps;
if (str_status != "open" && str_status != "prepared")
str_status = "running";
break;
case SND_PCM_STATE_PAUSED:
if (verbose) printf("alsa-space: paused");
str_status = "paused";
ret = 0;
break;
case SND_PCM_STATE_XRUN:
xrun("space");
str_status = "xrun";
first = 1;
ret = 0;
break;
default:
str_status = "undefined";
ret = snd_pcm_status_get_avail(status) * ao_data.bps;
if (ret <= 0) {
xrun("space");
}
}
if (verbose && str_status != "running")
printf("alsa-space: free space = %i, status=%i, %s --\n", ret, status, str_status);
snd_pcm_status_free(status);
if (ret < 0) {
printf("negative value!!\n");
ret = 0;
}
return(ret);
}
/* delay in seconds between first and last sample in buffer */
static float get_delay()
{
if (alsa_handler) {
snd_pcm_status_t *status;
float ret;
if ((ret = snd_pcm_status_malloc(&status)) < 0)
{
printf("alsa-delay: memory allocation error: %s\n", snd_strerror(ret));
return(0);
}
if ((ret = snd_pcm_status(alsa_handler, status)) < 0)
{
printf("alsa-delay: cannot get pcm status: %s\n", snd_strerror(ret));
return(0);
}
switch(snd_pcm_status_get_state(status))
{
case SND_PCM_STATE_OPEN:
case SND_PCM_STATE_PREPARED:
case SND_PCM_STATE_RUNNING:
ret = (float)snd_pcm_status_get_delay(status)/(float)ao_data.samplerate;
break;
default:
ret = 0;
}
snd_pcm_status_free(status);
if (ret < 0)
ret = 0;
return(ret);
} else {
return(0);
}
}
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