// Replace each channel in a with b (a->num == b->num)
static void replace_submap(struct mp_chmap *dst, struct mp_chmap *a,
struct mp_chmap *b)
{
struct mp_chmap t = *dst;
if (!mp_chmap_is_valid(&t) || mp_chmap_diffn(a, &t) != 0)
return;
assert(a->num == b->num);
for (int n = 0; n < t.num; n++) {
for (int i = 0; i < a->num; i++) {
if (t.speaker[n] == a->speaker[i]) {
t.speaker[n] = b->speaker[i];
break;
}
}
}
if (mp_chmap_is_valid(&t))
*dst = t;
}
static bool ca_layout_to_mp_chmap(struct ao *ao, AudioChannelLayout *layout,
struct mp_chmap *chmap)
{
void *talloc_ctx = talloc_new(NULL);
MP_VERBOSE(ao, "input channel layout:\n");
ca_log_layout(ao, MSGL_V, layout);
AudioChannelLayout *l = ca_layout_to_custom_layout(ao, talloc_ctx, layout);
if (!l)
goto coreaudio_error;
if (l->mNumberChannelDescriptions > MP_NUM_CHANNELS) {
MP_VERBOSE(ao, "layout has too many descriptions (%u, max: %d)\n",
(unsigned) l->mNumberChannelDescriptions, MP_NUM_CHANNELS);
return false;
}
chmap->num = l->mNumberChannelDescriptions;
for (int n = 0; n < l->mNumberChannelDescriptions; n++) {
AudioChannelLabel label = l->mChannelDescriptions[n].mChannelLabel;
int speaker = ca_label_to_mp_speaker_id(label);
if (speaker < 0) {
MP_VERBOSE(ao, "channel label=%u unusable to build channel "
"bitmap, skipping layout\n", (unsigned) label);
goto coreaudio_error;
}
chmap->speaker[n] = speaker;
}
// Remap weird 7.1(rear) layouts correctly.
replace_submap(chmap, CHMAP(6, FL, FR, BL, BR, SDL, SDR),
CHMAP(6, FL, FR, SL, SR, BL, BR));
talloc_free(talloc_ctx);
MP_VERBOSE(ao, "mp chmap: %s\n", mp_chmap_to_str(chmap));
return mp_chmap_is_valid(chmap) && !mp_chmap_is_unknown(chmap);
coreaudio_error:
MP_VERBOSE(ao, "converted input channel layout (failed):\n");
ca_log_layout(ao, MSGL_V, layout);
talloc_free(talloc_ctx);
return false;
}
void mp_audio_set_channels(struct mp_audio *mpa, const struct mp_chmap *chmap)
{
assert(mp_chmap_is_empty(chmap) || mp_chmap_is_valid(chmap));
mpa->channels = *chmap;
mpa->nch = mpa->channels.num;
}
