[vlc-devel] [PATCH 10/10] pulse: handle DTS-HD

[Thomas Guillem]

---
 modules/audio_output/pulse.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/modules/audio_output/pulse.c b/modules/audio_output/pulse.c
index 6986febebc..282cc0630a 100644
--- a/modules/audio_output/pulse.c
+++ b/modules/audio_output/pulse.c
@@ -687,10 +687,8 @@ static const char *str_map(const char *key, const char *const table[][2],
      return (r != NULL) ? r[1] : NULL;
 }
 
-/**
- * Create a PulseAudio playback stream, a.k.a. a sink input.
- */
-static int Start(audio_output_t *aout, audio_sample_format_t *restrict pfmt)
+static int Restart(audio_output_t *aout, audio_sample_format_t *restrict pfmt,
+                   bool force_dts_core)
 {
     aout_sys_t *sys = aout->sys;
 
@@ -735,6 +733,17 @@ static int Start(audio_output_t *aout, audio_sample_format_t *restrict pfmt)
             ss.format = PA_SAMPLE_S16NE;
             break;*/
         case VLC_CODEC_DTS:
+            if (fmt.i_rate >= 48000 && !force_dts_core)
+            {
+                /* Try to configure the output rate (IEC958 rate) at 192kHz.
+                 * Indeed, DTS-HD (and other DTS extensions) can only be
+                 * transmitted at 192kHz minimum. We'll also be able to
+                 * transmit DTS-Core only at this rate. */
+
+                 /* FIXME: DTS-X and DTS-HDMA @192kHz should be transmitted at
+                  * 768kHz. This is not possible (for now) with pulse audio. */
+                fmt.i_rate = 192000;
+            }
             fmt.i_format = VLC_CODEC_SPDIFL;
             fmt.i_bytes_per_frame = 4;
             fmt.i_frame_length = 1;
@@ -923,8 +932,19 @@ static int Start(audio_output_t *aout, audio_sample_format_t *restrict pfmt)
                                    cvolume, NULL) < 0
      || stream_wait(s, sys->mainloop)) {
         if (encoding != PA_ENCODING_INVALID)
+        {
+            if (pfmt->i_format == VLC_CODEC_DTS && fmt.i_rate == 192000
+             && !force_dts_core)
+            {
+                msg_Warn(aout, "configuring DTS at 192kHz IEC958 rate failed "
+                         "(HDMI), fallback to 48kHz (S/PDIF)");
+                pa_threaded_mainloop_unlock(sys->mainloop);
+                Stop(aout);
+                return Restart(aout, pfmt, true);
+            }
             vlc_pa_error(aout, "digital pass-through stream connection failure",
                          sys->context);
+        }
         else
             vlc_pa_error(aout, "stream connection failure", sys->context);
         goto fail;
@@ -954,6 +974,14 @@ fail:
 }
 
 /**
+ * Create a PulseAudio playback stream, a.k.a. a sink input.
+ */
+static int Start(audio_output_t *aout, audio_sample_format_t *restrict pfmt)
+{
+    return Restart(aout, pfmt, false);
+}
+
+/**
  * Removes a PulseAudio playback stream
  */
 static void Stop(audio_output_t *aout)
-- 
2.11.0