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alsa: sanitize channel map

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Remove unknown channels
Remove duplicate channels
Fill unknown channels with default channels
This commit is contained in:
Wim Taymans 2018-10-17 12:44:05 +02:00
parent e22762d502
commit 6590d3a258
1 changed files with 66 additions and 0 deletions
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66
spa/plugins/alsa/alsa-utils.c
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@ -144,11 +144,76 @@ static const struct chmap_info chmap_info[] = {
[SND_CHMAP_BRC] = { SND_CHMAP_BRC, SPA_AUDIO_CHANNEL_BRC },
};
#define _M(ch) (1LL << SND_CHMAP_ ##ch)
struct def_mask {
int channels;
uint64_t mask;
};
static const struct def_mask default_layouts[] = {
{ 0, 0 },
{ 1, _M(MONO) },
{ 2, _M(FL) | _M(FR) },
{ 3, _M(FL) | _M(FR) | _M(LFE) },
{ 4, _M(FL) | _M(FR) | _M(RL) |_M(RR) },
{ 5, _M(FL) | _M(FR) | _M(RL) |_M(RR) | _M(FC) },
{ 6, _M(FL) | _M(FR) | _M(RL) |_M(RR) | _M(FC) | _M(LFE) },
{ 7, _M(FL) | _M(FR) | _M(RL) |_M(RR) | _M(SL) | _M(SR) | _M(FC) },
{ 8, _M(FL) | _M(FR) | _M(RL) |_M(RR) | _M(SL) | _M(SR) | _M(FC) | _M(LFE) },
};
static enum spa_audio_channel chmap_position_to_channel(enum snd_pcm_chmap_position pos)
{
return chmap_info[pos].channel;
}
static void sanitize_map(snd_pcm_chmap_t* map)
{
uint64_t mask = 0, p, dup = 0;
const struct def_mask *def;
int i, j, pos;
for (i = 0; i < map->channels; i++) {
if (map->pos[i] < 0 || map->pos[i] > SND_CHMAP_LAST)
map->pos[i] = SND_CHMAP_UNKNOWN;
p = 1LL << map->pos[i];
if (mask & p) {
/* duplicate channel */
for (j = 0; j <= i; j++)
if (map->pos[j] == map->pos[i])
map->pos[j] = SND_CHMAP_UNKNOWN;
dup |= p;
p = 1LL << SND_CHMAP_UNKNOWN;
}
mask |= p;
}
if ((mask & (1LL << SND_CHMAP_UNKNOWN)) == 0)
return;
def = &default_layouts[map->channels];
/* remove duplicates */
mask &= ~dup;
/* keep unassigned channels */
mask = def->mask & ~mask;
pos = 0;
for (i = 0; i < map->channels; i++) {
if (map->pos[i] == SND_CHMAP_UNKNOWN) {
do {
mask >>= 1;
pos++;
}
while (mask != 0 && (mask & 1) == 0);
map->pos[i] = mask ? pos : 0;
}
}
}
int
spa_alsa_enum_format(struct state *state, uint32_t *index,
const struct spa_pod *filter,
@ -251,6 +316,7 @@ spa_alsa_enum_format(struct state *state, uint32_t *index,
map = &maps[*index]->map;
spa_log_debug(state->log, "map %d channels", map->channels);
sanitize_map(map);
spa_pod_builder_int(&b, map->channels);
spa_pod_builder_prop(&b, SPA_FORMAT_AUDIO_position, 0);