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ao_alsa: simplify dmix non-NA hack

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There's really no need to do this deep in the chmap sslection code. This
will setup the device further than before, but that doesn't matter.
This commit is contained in:
wm4 2015-11-02 23:59:49 +01:00
parent 8d415b2e01
commit e162a5bf04
1 changed files with 43 additions and 58 deletions
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101
audio/out/ao_alsa.c
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@ -84,11 +84,6 @@ struct priv {
MP_WARN(ao, "%s: %s\n", (message), snd_strerror(err)); \
} while (0)
// init_device(), set_chmap()
#define INIT_OK 0
#define INIT_ERROR -1
#define INIT_BRAINDEATH -2
// Common code for handling ENODEV, which happens if a device gets "lost", and
// can't be used anymore. Returns true if alsa_err is not ENODEV.
static bool check_device_present(struct ao *ao, int alsa_err)
@ -350,8 +345,7 @@ static bool query_chmaps(struct ao *ao, struct mp_chmap *chmap)
return ao_chmap_sel_adjust(ao, &chmap_sel, chmap);
}
static int set_chmap(struct ao *ao, struct mp_chmap *dev_chmap, int num_channels,
bool second_try)
static int set_chmap(struct ao *ao, struct mp_chmap *dev_chmap, int num_channels)
{
struct priv *p = ao->priv;
int err;
@ -405,44 +399,15 @@ static int set_chmap(struct ao *ao, struct mp_chmap *dev_chmap, int num_channels
MP_VERBOSE(ao, "user set ignore-chmap; ignoring the channel map.\n");
} else if (af_fmt_is_spdif(ao->format)) {
MP_VERBOSE(ao, "using spdif passthrough; ignoring the channel map.\n");
} else if (mp_chmap_is_valid(&chmap)) {
// Is it one that contains NA channels?
struct mp_chmap without_na = chmap;
mp_chmap_remove_na(&without_na);
if (mp_chmap_is_valid(&without_na) &&
!mp_chmap_equals(&without_na, &chmap) &&
!mp_chmap_equals(&chmap, &ao->channels) &&
without_na.num <= 2 &&
!second_try)
{
// Sometimes, ALSA will advertise certain chmaps, but it's not
// possible to set them. This can happen with dmix: as of
// alsa 1.0.28, dmix can do stereo only, but advertises the
// surround chmaps of the underlying device. In this case,
// e.g. setting 6 channels will succeed, but requesting 5.1
// afterwards will fail. Then it will return something like
// "FL FR NA NA NA NA" as channel map. This means we would
// have to pad stereo output to 6 channels with silence, which
// would require lots of extra processing. You can't change
// the number of channels to 2 either, because the hw params
// are already set! So just fuck it and reopen the device with
// the chmap "cleaned out" of NA entries.
MP_VERBOSE(ao, "Working around braindead ALSA behavior.\n");
ao->channels = without_na;
return INIT_BRAINDEATH;
}
if (chmap.num == num_channels) {
MP_VERBOSE(ao, "using the ALSA channel map.\n");
if (mp_chmap_equals(&chmap, &ao->channels))
MP_VERBOSE(ao, "which is what we requested.\n");
ao->channels = chmap;
} else {
MP_WARN(ao, "ALSA channel map conflicts with channel count!\n");
}
} else {
} else if (!mp_chmap_is_valid(&chmap)) {
MP_WARN(ao, "Got unknown channel map from ALSA.\n");
} else if (chmap.num != num_channels) {
MP_WARN(ao, "ALSA channel map conflicts with channel count!\n");
} else {
MP_VERBOSE(ao, "using the ALSA channel map.\n");
if (mp_chmap_equals(&chmap, &ao->channels))
MP_VERBOSE(ao, "which is what we requested.\n");
ao->channels = chmap;
}
// mpv and ALSA use different conventions for mono
@ -457,7 +422,7 @@ static int set_chmap(struct ao *ao, struct mp_chmap *dev_chmap, int num_channels
return 0;
alsa_error:
return INIT_ERROR;
return -1;
}
#else /* HAVE_CHMAP_API */
@ -564,13 +529,14 @@ static void uninit(struct ao *ao)
int err;
err = snd_pcm_close(p->alsa);
p->alsa = NULL;
CHECK_ALSA_ERROR("pcm close error");
}
alsa_error: ;
}
static int init_device(struct ao *ao, bool second_try)
static int init_device(struct ao *ao)
{
struct priv *p = ao->priv;
int err;
@ -687,12 +653,8 @@ static int init_device(struct ao *ao, bool second_try)
/* end setting hw-params */
err = set_chmap(ao, &dev_chmap, num_channels, second_try);
if (err < 0) {
snd_pcm_close(p->alsa);
p->alsa = NULL;
return err;
}
if (set_chmap(ao, &dev_chmap, num_channels) < 0)
goto alsa_error;
if (num_channels != ao->channels.num) {
int req = ao->channels.num;
@ -749,11 +711,11 @@ static int init_device(struct ao *ao, bool second_try)
if (p->can_pause)
MP_VERBOSE(ao, "pausing supported by device\n");
return INIT_OK;
return 0;
alsa_error:
uninit(ao);
return INIT_ERROR;
return -1;
}
static int init(struct ao *ao)
@ -764,10 +726,33 @@ static int init(struct ao *ao)
MP_VERBOSE(ao, "using ALSA version: %s\n", snd_asoundlib_version());
int r = init_device(ao, false);
if (r == INIT_BRAINDEATH)
r = init_device(ao, true); // retry with normalized channel layout
return r == INIT_OK ? 0 : -1;
int r = init_device(ao);
// Sometimes, ALSA will advertise certain chmaps, but it's not possible to
// set them. This can happen with dmix: as of alsa 1.0.29, dmix can do
// stereo only, but advertises the surround chmaps of the underlying device.
// In this case, e.g. setting 6 channels will succeed, but requesting 5.1
// afterwards will fail. Then it will return something like "FL FR NA NA NA NA"
// as channel map. This means we would have to pad stereo output to 6
// channels with silence, which would require lots of extra processing. You
// can't change the number of channels to 2 either, because the hw params
// are already set! So just fuck it and reopen the device with the chmap
// "cleaned out" of NA entries.
if (r >= 0) {
struct mp_chmap without_na = ao->channels;
mp_chmap_remove_na(&without_na);
if (mp_chmap_is_valid(&without_na) && without_na.num <= 2 &&
ao->channels.num > 2)
{
MP_VERBOSE(ao, "Working around braindead dmix multichannel behavior.\n");
uninit(ao);
ao->channels = without_na;
r = init_device(ao);
}
}
return r;
}
static void drain(struct ao *ao)