audio-channels: make method to get default channel-mask

Add a new method to get the default channel-mask. Use the new method on audiodecoder and audioconvert. API: gst_audio_channel_get_default_mask()
2024-06-26 09:50:39 +00:00 · 2015-11-05 10:40:18 +01:00 · 2015-11-05 10:40:18 +01:00 · f86ed8cdf6
parent 4a85438e5b
commit f86ed8cdf6
5 changed files with 59 additions and 141 deletions
--- a/gst-libs/gst/audio/audio-channels.c
+++ b/gst-libs/gst/audio/audio-channels.c
@ -459,3 +459,56 @@ gst_audio_channel_positions_to_valid_order (GstAudioChannelPosition * position,

  return TRUE;
 }
+
+#define _P(pos) (G_GUINT64_CONSTANT (1) << GST_AUDIO_CHANNEL_POSITION_ ##pos)
+
+static const guint64 default_masks[] = {
+  /* 1 channel */
+  0,
+  /* 2 channels */
+  _P (FRONT_LEFT) | _P (FRONT_RIGHT),
+  /* 3 channels (2.1) */
+  _P (FRONT_LEFT) | _P (FRONT_RIGHT) | _P (LFE1),
+  /* 4 channels (4.0) */
+  _P (FRONT_LEFT) | _P (FRONT_RIGHT) | _P (REAR_LEFT) | _P (REAR_RIGHT),
+  /* 5 channels */
+  _P (FRONT_LEFT) | _P (FRONT_RIGHT) | _P (REAR_LEFT) | _P (REAR_RIGHT)
+      | _P (FRONT_CENTER),
+  /* 6 channels (5.1) */
+  _P (FRONT_LEFT) |
+      _P (FRONT_RIGHT) |
+      _P (REAR_LEFT) | _P (REAR_RIGHT) | _P (FRONT_CENTER) | _P (LFE1),
+  /* 7 channels (6.1) */
+  _P (FRONT_LEFT) |
+      _P (FRONT_RIGHT) |
+      _P (REAR_LEFT) |
+      _P (REAR_RIGHT) | _P (FRONT_CENTER) | _P (LFE1) | _P (REAR_CENTER),
+  /* 8 channels (7.1) */
+  _P (FRONT_LEFT) |
+      _P (FRONT_RIGHT) |
+      _P (REAR_LEFT) |
+      _P (REAR_RIGHT) |
+      _P (FRONT_CENTER) | _P (LFE1) | _P (SIDE_LEFT) | _P (SIDE_RIGHT),
+};
+
+/**
+ * gst_audio_channel_get_default_mask:
+ * @channels: the number of channels
+ *
+ * Get the default channel-mask for the given number of channels.
+ *
+ * Returns: the default channel-mask for @channels or 0 when there is no default
+ * mask.
+ *
+ * Since: 1.8
+ */
+guint64
+gst_audio_channel_get_default_mask (gint channels)
+{
+  g_return_val_if_fail (channels > 0, 0);
+
+  if (channels > 8)
+    return 0;
+
+  return default_masks[channels - 1];
+}
--- a/gst-libs/gst/audio/audio-channels.h
+++ b/gst-libs/gst/audio/audio-channels.h
@ -160,6 +160,7 @@ gboolean       gst_audio_get_channel_reorder_map (gint channels,
                                                  const GstAudioChannelPosition * from,
                                                  const GstAudioChannelPosition * to,
                                                  gint *reorder_map);
+guint64        gst_audio_channel_get_default_mask (gint channels);

 G_END_DECLS

--- a/gst-libs/gst/audio/gstaudiodecoder.c
+++ b/gst-libs/gst/audio/gstaudiodecoder.c
@ -290,70 +290,6 @@ struct _GstAudioDecoderPrivate
  gboolean use_default_pad_acceptcaps;
 };

-//* Default channel layouts taken from audioconvert */
-static const GstAudioChannelPosition default_positions[8][8] = {
-  /* 1 channel */
-  {
-        GST_AUDIO_CHANNEL_POSITION_MONO,
-      },
-  /* 2 channels */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-      },
-  /* 3 channels (2.1) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_LFE1,
-      },
-  /* 4 channels (4.0) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-      },
-  /* 5 channels */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
-      },
-  /* 6 channels (5.1) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
-        GST_AUDIO_CHANNEL_POSITION_LFE1,
-      },
-  /* 7 channels (6.1) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
-        GST_AUDIO_CHANNEL_POSITION_LFE1,
-        GST_AUDIO_CHANNEL_POSITION_REAR_CENTER,
-      },
-  /* 8 channels (7.1) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
-        GST_AUDIO_CHANNEL_POSITION_LFE1,
-        GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT,
-      }
-};
-
 static void gst_audio_decoder_finalize (GObject * object);
 static void gst_audio_decoder_set_property (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec);
@ -2069,12 +2005,8 @@ gst_audio_decoder_negotiate_default_caps (GstAudioDecoder * dec)
  /* Need to add a channel-mask if channels > 2 */
  gst_structure_get_int (structure, "channels", &channels);
  if (channels > 2 && !gst_structure_has_field (structure, "channel-mask")) {
-    if (channels <= 8) {
-      channel_mask = 0;
-      for (i = 0; i < channels; i++)
-        channel_mask |=
-            G_GUINT64_CONSTANT (1) << default_positions[channels - 1][i];
-
+    channel_mask = gst_audio_channel_get_default_mask (channels);
+    if (channel_mask != 0) {
      gst_structure_set (structure, "channel-mask",
          GST_TYPE_BITMASK, channel_mask, NULL);
    } else {
--- a/gst/audioconvert/gstaudioconvert.c
+++ b/gst/audioconvert/gstaudioconvert.c
@ -346,69 +346,6 @@ gst_audio_convert_transform_caps (GstBaseTransform * btrans,
  return result;
 }

-static const GstAudioChannelPosition default_positions[8][8] = {
-  /* 1 channel */
-  {
-        GST_AUDIO_CHANNEL_POSITION_MONO,
-      },
-  /* 2 channels */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-      },
-  /* 3 channels (2.1) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_LFE1,
-      },
-  /* 4 channels (4.0) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-      },
-  /* 5 channels */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
-      },
-  /* 6 channels (5.1) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
-        GST_AUDIO_CHANNEL_POSITION_LFE1,
-      },
-  /* 7 channels (6.1) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
-        GST_AUDIO_CHANNEL_POSITION_LFE1,
-        GST_AUDIO_CHANNEL_POSITION_REAR_CENTER,
-      },
-  /* 8 channels (7.1) */
-  {
-        GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
-        GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
-        GST_AUDIO_CHANNEL_POSITION_LFE1,
-        GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,
-        GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT,
-      }
-};
-
 static gint
 n_bits_set (guint64 x)
 {
@ -683,15 +620,9 @@ gst_audio_convert_fixate_channels (GstBaseTransform * base, GstStructure * ins,
   * and try to add/remove channels from the input layout, or pick a default
   * layout based on LFE-presence in input layout, but let's save that for
   * another day) */
-  if (out_chans > 0 && out_chans <= G_N_ELEMENTS (default_positions[0])) {
-    gint i;
-
+  if (out_chans > 0
+      && (out_mask = gst_audio_channel_get_default_mask (out_chans))) {
    GST_DEBUG_OBJECT (base, "using default channel layout as fallback");
-
-    out_mask = 0;
-    for (i = 0; i < out_chans; i++)
-      out_mask |= G_GUINT64_CONSTANT (1) << default_positions[out_chans - 1][i];
-
    gst_structure_set (outs, "channel-mask", GST_TYPE_BITMASK, out_mask, NULL);
  } else {
    GST_ERROR_OBJECT (base, "Have no default layout for %d channels",
--- a/win32/common/libgstaudio.def
+++ b/win32/common/libgstaudio.def
@ -27,6 +27,7 @@ EXPORTS
 	gst_audio_cd_src_add_track
 	gst_audio_cd_src_get_type
 	gst_audio_cd_src_mode_get_type
+	gst_audio_channel_get_default_mask
 	gst_audio_channel_position_get_type
 	gst_audio_channel_positions_from_mask
 	gst_audio_channel_positions_to_mask