player: add --audio-wait-open options

Complements the option added in the previous commit.

DOCS/man/options.rst

@@ -1352,6 +1352,14 @@ Audio
 
     Not all AOs support this.
 
+``--audio-wait-open=<secs>``
+    This makes sense for use with ``--audio-stream-silence=yes``. If this option
+    is given, the player will wait for the given amount of seconds after opening
+    the audio device before sending actual audio data to it. Useful if your
+    expensive hardware discards the first 1 or 2 seconds of audio data sent to
+    it. If ``--audio-stream-silence=yes`` is not set, this option will likely
+    just waste time.
+
 Subtitles
 ---------
 

options/options.c

@@ -397,6 +397,7 @@ const m_option_t mp_opts[] = {
     OPT_STRING("audio-client-name", audio_client_name, 0),
     OPT_FLAG("audio-fallback-to-null", ao_null_fallback, 0),
     OPT_FLAG("audio-stream-silence", audio_stream_silence, 0),
+    OPT_FLOATRANGE("audio-wait-open", audio_wait_open, 0, 0, 60),
     OPT_CHOICE("force-window", force_vo, 0,
                ({"no", 0}, {"yes", 1}, {"immediate", 2})),
     OPT_FLAG("taskbar-progress", vo.taskbar_progress, 0),

options/options.h

@@ -88,6 +88,7 @@ typedef struct MPOpts {
     char *audio_client_name;
     int ao_null_fallback;
     int audio_stream_silence;
+    float audio_wait_open;
     int force_vo;
     int softvol;
     float softvol_volume;

player/audio.c

@@ -441,6 +441,9 @@ static void reinit_audio_filters_and_output(struct MPContext *mpctx)
                 mp_audio_config_to_str(&fmt));
         MP_VERBOSE(mpctx, "AO: Description: %s\n", ao_get_description(mpctx->ao));
         update_window_title(mpctx, true);
+
+        ao_c->ao_resume_time =
+            opts->audio_wait_open > 0 ? mp_time_sec() + opts->audio_wait_open : 0;
     }
 
     if (recreate_audio_filters(mpctx) < 0)
@@ -862,6 +865,12 @@ void fill_audio_out_buffers(struct MPContext *mpctx)
         return; // try again next iteration
     }
 
+    if (ao_c->ao_resume_time > mp_time_sec()) {
+        double remaining = ao_c->ao_resume_time - mp_time_sec();
+        mpctx->sleeptime = MPMIN(mpctx->sleeptime, remaining);
+        return;
+    }
+
     if (mpctx->vo_chain && ao_c->pts_reset) {
         MP_VERBOSE(mpctx, "Reset playback due to audio timestamp reset.\n");
         reset_playback_state(mpctx);

player/core.h

@@ -185,6 +185,7 @@ struct ao_chain {
     struct af_stream *af;
     struct ao *ao;
     struct mp_audio_buffer *ao_buffer;
+    double ao_resume_time;
 
     // 1-element input frame queue.
     struct mp_audio *input_frame;