diff --git a/audio/out/ao_alsa.c b/audio/out/ao_alsa.c
index 5816ee5f5f..0d1c589e34 100644
--- a/audio/out/ao_alsa.c
+++ b/audio/out/ao_alsa.c
@@ -436,6 +436,8 @@ static int init(struct ao *ao)
             (p->alsa, alsa_hwparams, SND_PCM_ACCESS_RW_INTERLEAVED);
     CHECK_ALSA_ERROR("Unable to set access type");
 
+    ao->format = af_fmt_from_planar(ao->format);
+
     p->alsa_fmt = find_alsa_format(ao->format);
     if (p->alsa_fmt == SND_PCM_FORMAT_UNKNOWN) {
         p->alsa_fmt = SND_PCM_FORMAT_S16;
diff --git a/audio/out/ao_coreaudio.c b/audio/out/ao_coreaudio.c
index da526ada20..4823eb43e1 100644
--- a/audio/out/ao_coreaudio.c
+++ b/audio/out/ao_coreaudio.c
@@ -285,6 +285,8 @@ static int init(struct ao *ao)
     // Save selected device id
     p->device = selected_device;
 
+    ao->format = af_fmt_from_planar(ao->format);
+
     bool supports_digital = false;
     /* Probe whether device support S/PDIF stream output if input is AC3 stream. */
     if (AF_FORMAT_IS_AC3(ao->format)) {
diff --git a/audio/out/ao_dsound.c b/audio/out/ao_dsound.c
index 464947c0dc..58812d80e6 100644
--- a/audio/out/ao_dsound.c
+++ b/audio/out/ao_dsound.c
@@ -388,7 +388,7 @@ static int init(struct ao *ao)
     WAVEFORMATEXTENSIBLE wformat;
     DSBUFFERDESC dsbpridesc;
     DSBUFFERDESC dsbdesc;
-    int format = ao->format;
+    int format = af_fmt_from_planar(ao->format);
     int rate = ao->samplerate;
 
     if (AF_FORMAT_IS_AC3(format))
diff --git a/audio/out/ao_lavc.c b/audio/out/ao_lavc.c
index 4364b9054d..b849f9b2b4 100644
--- a/audio/out/ao_lavc.c
+++ b/audio/out/ao_lavc.c
@@ -105,6 +105,7 @@ static int init(struct ao *ao)
     ac->stream->codec->channel_layout = mp_chmap_to_lavc(&ao->channels);
 
     ac->stream->codec->sample_fmt = AV_SAMPLE_FMT_NONE;
+    ao->format = af_fmt_from_planar(ao->format);
 
     {
         // first check if the selected format is somewhere in the list of
diff --git a/audio/out/ao_null.c b/audio/out/ao_null.c
index ff6b12a1a6..75e812b238 100644
--- a/audio/out/ao_null.c
+++ b/audio/out/ao_null.c
@@ -51,6 +51,8 @@ static int init(struct ao *ao)
     struct priv *priv = talloc_zero(ao, struct priv);
     ao->priv = priv;
 
+    ao->format = af_fmt_from_planar(ao->format);
+
     struct mp_chmap_sel sel = {0};
     mp_chmap_sel_add_any(&sel);
     if (!ao_chmap_sel_adjust(ao, &sel, &ao->channels))
diff --git a/audio/out/ao_oss.c b/audio/out/ao_oss.c
index db9847851d..a97424c1cb 100644
--- a/audio/out/ao_oss.c
+++ b/audio/out/ao_oss.c
@@ -261,6 +261,8 @@ static int init(struct ao *ao)
     fcntl(p->audio_fd, F_SETFD, FD_CLOEXEC);
 #endif
 
+    ao->format = af_fmt_from_planar(ao->format);
+
     if (AF_FORMAT_IS_AC3(ao->format)) {
         ioctl(p->audio_fd, SNDCTL_DSP_SPEED, &ao->samplerate);
     }
diff --git a/audio/out/ao_pcm.c b/audio/out/ao_pcm.c
index f7d793700d..e94e6b569a 100644
--- a/audio/out/ao_pcm.c
+++ b/audio/out/ao_pcm.c
@@ -118,6 +118,9 @@ static int init(struct ao *ao)
     if (!priv->outputfilename)
         priv->outputfilename =
             talloc_strdup(priv, priv->waveheader ? "audiodump.wav" : "audiodump.pcm");
+
+    ao->format = af_fmt_from_planar(ao->format);
+
     if (priv->waveheader) {
         // WAV files must have one of the following formats
 
diff --git a/audio/out/ao_portaudio.c b/audio/out/ao_portaudio.c
index 8b235f8806..d75fad0aca 100644
--- a/audio/out/ao_portaudio.c
+++ b/audio/out/ao_portaudio.c
@@ -242,6 +242,8 @@ static int init(struct ao *ao)
             = Pa_GetDeviceInfo(pa_device)->defaultHighOutputLatency,
     };
 
+    ao->format = af_fmt_from_planar(ao->format);
+
     const struct format_map *fmt = format_maps;
     while (fmt->pa_format) {
         if (fmt->mp_format == ao->format) {
diff --git a/audio/out/ao_pulse.c b/audio/out/ao_pulse.c
index a4da2a179b..1d7fcdd382 100644
--- a/audio/out/ao_pulse.c
+++ b/audio/out/ao_pulse.c
@@ -286,6 +286,8 @@ static int init(struct ao *ao)
     ss.channels = ao->channels.num;
     ss.rate = ao->samplerate;
 
+    ao->format = af_fmt_from_planar(ao->format);
+
     const struct format_map *fmt_map = format_maps;
     while (fmt_map->mp_format != ao->format) {
         if (fmt_map->mp_format == AF_FORMAT_UNKNOWN) {
diff --git a/audio/out/ao_rsound.c b/audio/out/ao_rsound.c
index 162fb21feb..95fadf7188 100644
--- a/audio/out/ao_rsound.c
+++ b/audio/out/ao_rsound.c
@@ -114,6 +114,8 @@ static int init(struct ao *ao)
     rsd_set_param(priv->rd, RSD_SAMPLERATE, &ao->samplerate);
     rsd_set_param(priv->rd, RSD_CHANNELS, &ao->channels.num);
 
+    ao->format = af_fmt_from_planar(ao->format);
+
     int rsd_format = set_format(ao);
     rsd_set_param(priv->rd, RSD_FORMAT, &rsd_format);
 
diff --git a/audio/out/ao_sdl.c b/audio/out/ao_sdl.c
index a42c0812cb..d95a82615b 100644
--- a/audio/out/ao_sdl.c
+++ b/audio/out/ao_sdl.c
@@ -144,6 +144,8 @@ static int init(struct ao *ao)
         return -1;
     }
 
+    ao->format = af_fmt_from_planar(ao->format);
+
     SDL_AudioSpec desired, obtained;
 
     switch (ao->format) {
diff --git a/audio/out/ao_sndio.c b/audio/out/ao_sndio.c
index ab9eaf8197..1786c0158d 100644
--- a/audio/out/ao_sndio.c
+++ b/audio/out/ao_sndio.c
@@ -130,6 +130,9 @@ static int init(struct ao *ao)
         MP_ERR(ao, "can't open sndio %s\n", p->dev);
         goto error;
     }
+
+    ao->format = af_fmt_from_planar(ao->format);
+
     sio_initpar(&p->par);
     for (i = 0, ap = af_to_par;; i++, ap++) {
         if (i == sizeof(af_to_par) / sizeof(struct af_to_par)) {
diff --git a/audio/out/ao_wasapi.c b/audio/out/ao_wasapi.c
index c605e1cd5d..5d9f33278c 100644
--- a/audio/out/ao_wasapi.c
+++ b/audio/out/ao_wasapi.c
@@ -1231,6 +1231,7 @@ static void uninit(struct ao *ao, bool immed)
 static int init(struct ao *ao)
 {
     mp_msg(MSGT_AO, MSGL_V, "ao-wasapi: init!\n");
+    ao->format = af_fmt_from_planar(ao->format);
     struct mp_chmap_sel sel = {0};
     mp_chmap_sel_add_waveext(&sel);
     if (!ao_chmap_sel_adjust(ao, &sel, &ao->channels))