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mpv/audio/out/ao_oss.c
wm4 396756e58a ao_oss: prevent hang when unpausing after device was lost
Pausing/unpausing while the audio device can't be reopened, and then
unpausing again when the device is finally reopened, can hang the
player for a while.

This happens because p->prepause_samples grows without bounds each
time the player is unpaused while the device is lost. On unpause,
ao_oss plays prepause_samples of silence to compensate for A/V timing
issues due to the partially lost buffer (we can't pause the device at
an arbitrary sample position, and the current period will be lost).
This in turn will make the player appear to be frozen if too much
audio is queued. (Normally, play() must never block, but here it
happens because more data is written than get_space() reports. A
better implementation would never let prepause_samples grow larger
than the period size.)

The unbounded growth happens because get_space() always returns that
the device can be written while the device is lost. So limit it to
200ms. (A better implementation would limit it to the period size.)

Also see #1080.
2014-09-17 00:33:40 +02:00

645 lines
18 KiB
C

/*
* OSS audio output driver
*
* This file is part of MPlayer.
*
* Original author: A'rpi
* Support for >2 output channels added 2001-11-25
* - Steve Davies <steve@daviesfam.org>
*
* MPlayer 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.
*
* MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <poll.h>
#include <errno.h>
#include <string.h>
#include <strings.h>
#include "config.h"
#include "options/options.h"
#include "common/msg.h"
#include "osdep/timer.h"
#if HAVE_SYS_SOUNDCARD_H
#include <sys/soundcard.h>
#else
#if HAVE_SOUNDCARD_H
#include <soundcard.h>
#endif
#endif
#include "audio/format.h"
#include "ao.h"
#include "internal.h"
// Define to 0 if the device must be reopened to reset it (stop all playback,
// clear the buffer), and the device should be closed when unused.
// Define to 1 if SNDCTL_DSP_RESET should be used to reset without close.
#define KEEP_DEVICE (defined(SNDCTL_DSP_RESET) && !defined(__NetBSD__))
struct priv {
int audio_fd;
int prepause_samples;
int oss_mixer_channel;
int audio_delay_method;
int buffersize;
int outburst;
bool device_failed;
double audio_end;
char *dsp;
char *oss_mixer_device;
char *cfg_oss_mixer_channel;
};
static const char *const mixer_channels[SOUND_MIXER_NRDEVICES] = SOUND_DEVICE_NAMES;
/* like alsa except for 6.1 and 7.1, from pcm/matrix_map.h */
static const struct mp_chmap oss_layouts[MP_NUM_CHANNELS + 1] = {
{0}, // empty
MP_CHMAP_INIT_MONO, // mono
MP_CHMAP2(FL, FR), // stereo
MP_CHMAP3(FL, FR, LFE), // 2.1
MP_CHMAP4(FL, FR, BL, BR), // 4.0
MP_CHMAP5(FL, FR, BL, BR, FC), // 5.0
MP_CHMAP6(FL, FR, BL, BR, FC, LFE), // 5.1
MP_CHMAP7(FL, FR, BL, BR, FC, LFE, BC), // 6.1
MP_CHMAP8(FL, FR, BL, BR, FC, LFE, SL, SR), // 7.1
};
static const int format_table[][2] = {
{AFMT_U8, AF_FORMAT_U8},
{AFMT_S8, AF_FORMAT_S8},
{AFMT_U16_LE, AF_FORMAT_U16_LE},
{AFMT_U16_BE, AF_FORMAT_U16_BE},
{AFMT_S16_LE, AF_FORMAT_S16_LE},
{AFMT_S16_BE, AF_FORMAT_S16_BE},
#ifdef AFMT_S24_PACKED
{AFMT_S24_PACKED, AF_FORMAT_S24_LE},
#endif
#ifdef AFMT_U24_LE
{AFMT_U24_LE, AF_FORMAT_U24_LE},
#endif
#ifdef AFMT_U24_BE
{AFMT_U24_BE, AF_FORMAT_U24_BE},
#endif
#ifdef AFMT_S24_LE
{AFMT_S24_LE, AF_FORMAT_S24_LE},
#endif
#ifdef AFMT_S24_BE
{AFMT_S24_BE, AF_FORMAT_S24_BE},
#endif
#ifdef AFMT_U32_LE
{AFMT_U32_LE, AF_FORMAT_U32_LE},
#endif
#ifdef AFMT_U32_BE
{AFMT_U32_BE, AF_FORMAT_U32_BE},
#endif
#ifdef AFMT_S32_LE
{AFMT_S32_LE, AF_FORMAT_S32_LE},
#endif
#ifdef AFMT_S32_BE
{AFMT_S32_BE, AF_FORMAT_S32_BE},
#endif
#ifdef AFMT_FLOAT
{AFMT_FLOAT, AF_FORMAT_FLOAT},
#endif
// SPECIALS
#ifdef AFMT_MPEG
{AFMT_MPEG, AF_FORMAT_MPEG2},
#endif
#ifdef AFMT_AC3
{AFMT_AC3, AF_FORMAT_AC3},
#endif
{-1, -1}
};
static int format2oss(int format)
{
for (int n = 0; format_table[n][0] != -1; n++) {
if (format_table[n][1] == format)
return format_table[n][0];
}
return -1;
}
static int oss2format(int format)
{
for (int n = 0; format_table[n][0] != -1; n++) {
if (format_table[n][0] == format)
return format_table[n][1];
}
return -1;
}
#ifdef SNDCTL_DSP_GETPLAYVOL
static int volume_oss4(struct ao *ao, ao_control_vol_t *vol, int cmd)
{
struct priv *p = ao->priv;
int v;
if (p->audio_fd < 0)
return CONTROL_ERROR;
if (cmd == AOCONTROL_GET_VOLUME) {
if (ioctl(p->audio_fd, SNDCTL_DSP_GETPLAYVOL, &v) == -1)
return CONTROL_ERROR;
vol->right = (v & 0xff00) >> 8;
vol->left = v & 0x00ff;
return CONTROL_OK;
} else if (cmd == AOCONTROL_SET_VOLUME) {
v = ((int) vol->right << 8) | (int) vol->left;
if (ioctl(p->audio_fd, SNDCTL_DSP_SETPLAYVOL, &v) == -1)
return CONTROL_ERROR;
return CONTROL_OK;
} else
return CONTROL_UNKNOWN;
}
#endif
// to set/get/query special features/parameters
static int control(struct ao *ao, enum aocontrol cmd, void *arg)
{
struct priv *p = ao->priv;
switch (cmd) {
case AOCONTROL_GET_VOLUME:
case AOCONTROL_SET_VOLUME: {
ao_control_vol_t *vol = (ao_control_vol_t *)arg;
int fd, v, devs;
#ifdef SNDCTL_DSP_GETPLAYVOL
// Try OSS4 first
if (volume_oss4(ao, vol, cmd) == CONTROL_OK)
return CONTROL_OK;
#endif
if (AF_FORMAT_IS_AC3(ao->format))
return CONTROL_TRUE;
if ((fd = open(p->oss_mixer_device, O_RDONLY)) != -1) {
ioctl(fd, SOUND_MIXER_READ_DEVMASK, &devs);
if (devs & (1 << p->oss_mixer_channel)) {
if (cmd == AOCONTROL_GET_VOLUME) {
ioctl(fd, MIXER_READ(p->oss_mixer_channel), &v);
vol->right = (v & 0xFF00) >> 8;
vol->left = v & 0x00FF;
} else {
v = ((int)vol->right << 8) | (int)vol->left;
ioctl(fd, MIXER_WRITE(p->oss_mixer_channel), &v);
}
} else {
close(fd);
return CONTROL_ERROR;
}
close(fd);
return CONTROL_OK;
}
return CONTROL_ERROR;
}
#ifdef SNDCTL_DSP_GETPLAYVOL
case AOCONTROL_HAS_SOFT_VOLUME:
return CONTROL_TRUE;
#endif
}
return CONTROL_UNKNOWN;
}
// 1: ok, 0: not writable, -1: error
static int device_writable(struct ao *ao)
{
struct priv *p = ao->priv;
struct pollfd fd = {.fd = p->audio_fd, .events = POLLOUT};
return poll(&fd, 1, 0);
}
static void close_device(struct ao *ao)
{
struct priv *p = ao->priv;
p->device_failed = false;
if (p->audio_fd == -1)
return;
#if defined(SNDCTL_DSP_RESET)
ioctl(p->audio_fd, SNDCTL_DSP_RESET, NULL);
#endif
close(p->audio_fd);
p->audio_fd = -1;
}
// close audio device
static void uninit(struct ao *ao)
{
close_device(ao);
}
static int reopen_device(struct ao *ao, bool allow_format_changes)
{
struct priv *p = ao->priv;
int oss_format;
int samplerate = ao->samplerate;
int format = ao->format;
struct mp_chmap channels = ao->channels;
#ifdef __linux__
p->audio_fd = open(p->dsp, O_WRONLY | O_NONBLOCK);
#else
p->audio_fd = open(p->dsp, O_WRONLY);
#endif
if (p->audio_fd < 0) {
MP_ERR(ao, "Can't open audio device %s: %s\n", p->dsp, strerror(errno));
goto fail;
}
#ifdef __linux__
/* Remove the non-blocking flag */
if (fcntl(p->audio_fd, F_SETFL, 0) < 0) {
MP_ERR(ao, "Can't make file descriptor blocking: %s\n", strerror(errno));
goto fail;
}
#endif
#if defined(FD_CLOEXEC) && defined(F_SETFD)
fcntl(p->audio_fd, F_SETFD, FD_CLOEXEC);
#endif
if (AF_FORMAT_IS_AC3(format)) {
ioctl(p->audio_fd, SNDCTL_DSP_SPEED, &samplerate);
}
ac3_retry:
if (AF_FORMAT_IS_AC3(format))
format = AF_FORMAT_AC3;
oss_format = format2oss(format);
if (oss_format == -1) {
MP_VERBOSE(ao, "Unknown/not supported internal format: %s\n",
af_fmt_to_str(format));
#if defined(AFMT_S32_LE) && defined(AFMT_S32_BE)
#if BYTE_ORDER == BIG_ENDIAN
oss_format = AFMT_S32_BE;
#else
oss_format = AFMT_S32_LE;
#endif
format = AF_FORMAT_S32;
#elif defined(AFMT_S24_LE) && defined(AFMT_S24_BE)
#if BYTE_ORDER == BIG_ENDIAN
oss_format = AFMT_S24_BE;
#else
oss_format = AFMT_S24_LE;
#endif
format = AF_FORMAT_S24;
#else
#if BYTE_ORDER == BIG_ENDIAN
oss_format = AFMT_S16_BE;
#else
oss_format = AFMT_S16_LE;
#endif
format = AF_FORMAT_S16;
#endif
}
if (ioctl(p->audio_fd, SNDCTL_DSP_SETFMT, &oss_format) < 0 ||
oss_format != format2oss(format))
{
MP_WARN(ao, "Can't set audio device %s to %s output, trying %s...\n",
p->dsp, af_fmt_to_str(format),
af_fmt_to_str(AF_FORMAT_S16));
format = AF_FORMAT_S16;
goto ac3_retry;
}
format = oss2format(oss_format);
if (format == -1) {
MP_ERR(ao, "Unknown/Unsupported OSS format: %x.\n", oss_format);
goto fail;
}
MP_VERBOSE(ao, "sample format: %s\n", af_fmt_to_str(format));
if (!AF_FORMAT_IS_AC3(format)) {
struct mp_chmap_sel sel = {0};
for (int n = 0; n < MP_NUM_CHANNELS + 1; n++)
mp_chmap_sel_add_map(&sel, &oss_layouts[n]);
if (!ao_chmap_sel_adjust(ao, &sel, &channels))
goto fail;
int reqchannels = channels.num;
// We only use SNDCTL_DSP_CHANNELS for >2 channels, in case some drivers don't have it
if (reqchannels > 2) {
int nchannels = reqchannels;
if (ioctl(p->audio_fd, SNDCTL_DSP_CHANNELS, &nchannels) == -1 ||
nchannels != reqchannels)
{
MP_ERR(ao, "Failed to set audio device to %d channels.\n",
reqchannels);
goto fail;
}
} else {
int c = reqchannels - 1;
if (ioctl(p->audio_fd, SNDCTL_DSP_STEREO, &c) == -1) {
MP_ERR(ao, "Failed to set audio device to %d channels.\n",
reqchannels);
goto fail;
}
if (!ao_chmap_sel_get_def(ao, &sel, &channels, c + 1))
goto fail;
}
MP_VERBOSE(ao, "using %d channels (requested: %d)\n",
channels.num, reqchannels);
// set rate
ioctl(p->audio_fd, SNDCTL_DSP_SPEED, &samplerate);
MP_VERBOSE(ao, "using %d Hz samplerate\n", samplerate);
}
audio_buf_info zz = {0};
if (ioctl(p->audio_fd, SNDCTL_DSP_GETOSPACE, &zz) == -1) {
int r = 0;
MP_WARN(ao, "driver doesn't support SNDCTL_DSP_GETOSPACE\n");
if (ioctl(p->audio_fd, SNDCTL_DSP_GETBLKSIZE, &r) == -1)
MP_VERBOSE(ao, "%d bytes/frag (config.h)\n", p->outburst);
else {
p->outburst = r;
MP_VERBOSE(ao, "%d bytes/frag (GETBLKSIZE)\n", p->outburst);
}
} else {
MP_VERBOSE(ao, "frags: %3d/%d (%d bytes/frag) free: %6d\n",
zz.fragments, zz.fragstotal, zz.fragsize, zz.bytes);
p->buffersize = zz.bytes;
p->outburst = zz.fragsize;
}
if (allow_format_changes) {
ao->format = format;
ao->samplerate = samplerate;
ao->channels = channels;
} else {
if (format != ao->format || samplerate != ao->samplerate ||
!mp_chmap_equals(&channels, &ao->channels))
{
MP_ERR(ao, "Could not reselect previous audio format.\n");
goto fail;
}
}
p->outburst -= p->outburst % (channels.num * af_fmt2bps(format)); // round down
return 0;
fail:
close_device(ao);
return -1;
}
// open & setup audio device
// return: 0=success -1=fail
static int init(struct ao *ao)
{
struct priv *p = ao->priv;
const char *mchan = NULL;
if (p->cfg_oss_mixer_channel && p->cfg_oss_mixer_channel[0])
mchan = p->cfg_oss_mixer_channel;
if (mchan) {
int fd, devs, i;
if ((fd = open(p->oss_mixer_device, O_RDONLY)) == -1) {
MP_ERR(ao, "Can't open mixer device %s: %s\n",
p->oss_mixer_device, strerror(errno));
} else {
ioctl(fd, SOUND_MIXER_READ_DEVMASK, &devs);
close(fd);
for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
if (!strcasecmp(mixer_channels[i], mchan)) {
if (!(devs & (1 << i))) {
MP_ERR(ao, "Audio card mixer does not have "
"channel '%s', using default.\n", mchan);
i = SOUND_MIXER_NRDEVICES + 1;
break;
}
p->oss_mixer_channel = i;
break;
}
}
if (i == SOUND_MIXER_NRDEVICES) {
MP_ERR(ao, "Audio card mixer does not have "
"channel '%s', using default.\n", mchan);
}
}
} else {
p->oss_mixer_channel = SOUND_MIXER_PCM;
}
MP_VERBOSE(ao, "using '%s' dsp device\n", p->dsp);
MP_VERBOSE(ao, "using '%s' mixer device\n", p->oss_mixer_device);
MP_VERBOSE(ao, "using '%s' mixer device\n", mixer_channels[p->oss_mixer_channel]);
ao->format = af_fmt_from_planar(ao->format);
if (reopen_device(ao, true) < 0)
goto fail;
if (p->buffersize == -1) {
// Measuring buffer size:
void *data = malloc(p->outburst);
if (!data) {
MP_ERR(ao, "Out of memory, or broken outburst size.\n");
goto fail;
}
p->buffersize = 0;
memset(data, 0, p->outburst);
while (p->buffersize < 0x40000 && device_writable(ao) > 0) {
write(p->audio_fd, data, p->outburst);
p->buffersize += p->outburst;
}
free(data);
if (p->buffersize == 0) {
MP_ERR(ao, "Your OSS audio driver DOES NOT support poll().\n");
goto fail;
}
}
return 0;
fail:
uninit(ao);
return -1;
}
static void drain(struct ao *ao)
{
#ifdef SNDCTL_DSP_SYNC
struct priv *p = ao->priv;
// to get the buffer played
if (p->audio_fd != -1)
ioctl(p->audio_fd, SNDCTL_DSP_SYNC, NULL);
#endif
}
// stop playing and empty buffers (for seeking/pause)
static void reset(struct ao *ao)
{
#if KEEP_DEVICE
struct priv *p = ao->priv;
ioctl(p->audio_fd, SNDCTL_DSP_RESET, NULL);
#else
close_device(ao);
#endif
}
// plays 'len' samples of 'data'
// it should round it down to outburst*n
// return: number of samples played
static int play(struct ao *ao, void **data, int samples, int flags)
{
struct priv *p = ao->priv;
int len = samples * ao->sstride;
if (len == 0)
return len;
if (p->audio_fd < 0 && !p->device_failed && reopen_device(ao, false) < 0)
MP_ERR(ao, "Fatal error: *** CANNOT RE-OPEN / RESET AUDIO DEVICE ***\n");
if (p->audio_fd < 0) {
// Let playback continue normally, even with a closed device.
p->device_failed = true;
double now = mp_time_sec();
if (p->audio_end < now)
p->audio_end = now;
p->audio_end += samples / (double)ao->samplerate;
return samples;
}
if (len > p->outburst || !(flags & AOPLAY_FINAL_CHUNK)) {
len /= p->outburst;
len *= p->outburst;
}
len = write(p->audio_fd, data[0], len);
return len / ao->sstride;
}
// return: delay in seconds between first and last sample in buffer
static float get_delay(struct ao *ao)
{
struct priv *p = ao->priv;
if (p->audio_fd < 0) {
double rest = p->audio_end - mp_time_sec();
if (rest > 0)
return rest;
return 0;
}
/* Calculate how many bytes/second is sent out */
if (p->audio_delay_method == 2) {
#ifdef SNDCTL_DSP_GETODELAY
int r = 0;
if (ioctl(p->audio_fd, SNDCTL_DSP_GETODELAY, &r) != -1)
return ((float)r) / (float)ao->bps;
#endif
p->audio_delay_method = 1; // fallback if not supported
}
if (p->audio_delay_method == 1) {
audio_buf_info zz = {0};
if (ioctl(p->audio_fd, SNDCTL_DSP_GETOSPACE, &zz) != -1) {
return ((float)(p->buffersize - zz.bytes)) / (float)ao->bps;
}
p->audio_delay_method = 0; // fallback if not supported
}
return ((float)p->buffersize) / (float)ao->bps;
}
// return: how many samples can be played without blocking
static int get_space(struct ao *ao)
{
struct priv *p = ao->priv;
audio_buf_info zz = {0};
if (ioctl(p->audio_fd, SNDCTL_DSP_GETOSPACE, &zz) != -1) {
// calculate exact buffer space:
return zz.fragments * zz.fragsize / ao->sstride;
}
if (p->audio_fd < 0 && p->device_failed && get_delay(ao) > 0.2)
return 0;
if (p->audio_fd < 0 || device_writable(ao) > 0)
return p->outburst / ao->sstride;
return 0;
}
// stop playing, keep buffers (for pause)
static void audio_pause(struct ao *ao)
{
struct priv *p = ao->priv;
p->prepause_samples = get_delay(ao) * ao->samplerate;
#if KEEP_DEVICE
ioctl(p->audio_fd, SNDCTL_DSP_RESET, NULL);
#else
close_device(ao);
#endif
}
// resume playing, after audio_pause()
static void audio_resume(struct ao *ao)
{
struct priv *p = ao->priv;
p->audio_end = 0;
if (p->prepause_samples > 0)
ao_play_silence(ao, p->prepause_samples);
}
#define OPT_BASE_STRUCT struct priv
const struct ao_driver audio_out_oss = {
.description = "OSS/ioctl audio output",
.name = "oss",
.init = init,
.uninit = uninit,
.control = control,
.get_space = get_space,
.play = play,
.get_delay = get_delay,
.pause = audio_pause,
.resume = audio_resume,
.reset = reset,
.drain = drain,
.priv_size = sizeof(struct priv),
.priv_defaults = &(const struct priv) {
.audio_fd = -1,
.audio_delay_method = 2,
.buffersize = -1,
.outburst = 512,
.oss_mixer_channel = SOUND_MIXER_PCM,
.dsp = PATH_DEV_DSP,
.oss_mixer_device = PATH_DEV_MIXER,
},
.options = (const struct m_option[]) {
OPT_STRING("device", dsp, 0),
OPT_STRING("mixer-device", oss_mixer_device, 0),
OPT_STRING("mixer-channel", cfg_oss_mixer_channel, 0),
{0}
},
};