audio: Add new gst_audio_reorder_channels_with_reorder_map()

This allows reordering the samples with a pre-calculated reorder map instead of
calculating it again every time.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8171>

girs/GstAudio-1.0.gir

@@ -11616,6 +11616,12 @@ the @dither and @ns parameters.</doc>
 positions @to. @from and @to must contain the same number of
 positions and the same positions, only in a different order.
 
+This function internally calls gst_audio_get_channel_reorder_map() and
+gst_audio_reorder_channels_with_reorder_map(). It is more efficient to call
+gst_audio_get_channel_reorder_map() once to retrieve the reorder map and
+then call gst_audio_reorder_channels_with_reorder_map() with the same
+reorder map until the channel positions change.
+
 Note: this function assumes the audio data is in interleaved layout</doc>
       <source-position filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.h"/>
       <return-value transfer-ownership="none">
@@ -11656,6 +11662,45 @@ Note: this function assumes the audio data is in interleaved layout</doc>
         </parameter>
       </parameters>
     </function>
+    <function name="audio_reorder_channels_with_reorder_map" c:identifier="gst_audio_reorder_channels_with_reorder_map" version="1.26">
+      <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.c">Reorders @data with the given @reorder_map.
+
+The reorder map can be retrieved for example with
+gst_audio_get_channel_reorder_map().
+
+Note: this function assumes the audio data is in interleaved layout</doc>
+      <source-position filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.h"/>
+      <return-value transfer-ownership="none">
+        <type name="none" c:type="void"/>
+      </return-value>
+      <parameters>
+        <parameter name="data" transfer-ownership="none">
+          <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.c">The pointer to
+  the memory.</doc>
+          <array length="1" zero-terminated="0" c:type="gpointer">
+            <type name="guint8"/>
+          </array>
+        </parameter>
+        <parameter name="size" transfer-ownership="none">
+          <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.c">The size of the memory.</doc>
+          <type name="gsize" c:type="gsize"/>
+        </parameter>
+        <parameter name="bps" transfer-ownership="none">
+          <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.c">The number of bytes per sample.</doc>
+          <type name="gint" c:type="gint"/>
+        </parameter>
+        <parameter name="channels" transfer-ownership="none">
+          <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.c">The number of channels.</doc>
+          <type name="gint" c:type="gint"/>
+        </parameter>
+        <parameter name="reorder_map" transfer-ownership="none">
+          <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.c">The channel reorder map.</doc>
+          <array length="3" zero-terminated="0" c:type="const gint*">
+            <type name="gint" c:type="gint"/>
+          </array>
+        </parameter>
+      </parameters>
+    </function>
     <function name="audio_resampler_new" c:identifier="gst_audio_resampler_new" moved-to="AudioResampler.new">
       <doc xml:space="preserve" filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-resampler.c">Make a new resampler.</doc>
       <source-position filename="../subprojects/gst-plugins-base/gst-libs/gst/audio/audio-resampler.h"/>

subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.c

@@ -182,6 +182,52 @@ check_valid_channel_positions (const GstAudioChannelPosition * position,
   return TRUE;
 }
 
+/**
+ * gst_audio_reorder_channels_with_reorder_map:
+ * @data: (array length=size) (element-type guint8): The pointer to
+ *   the memory.
+ * @size: The size of the memory.
+ * @bps: The number of bytes per sample.
+ * @channels: The number of channels.
+ * @reorder_map: (array length=channels): The channel reorder map.
+ *
+ * Reorders @data with the given @reorder_map.
+ *
+ * The reorder map can be retrieved for example with
+ * gst_audio_get_channel_reorder_map().
+ *
+ * Note: this function assumes the audio data is in interleaved layout
+ *
+ * Since: 1.26
+ */
+void
+gst_audio_reorder_channels_with_reorder_map (gpointer data, gsize size,
+    gint bps, gint channels, const gint * reorder_map)
+{
+  gint bpf = bps * channels;
+  guint8 *ptr = data;
+  gsize n;
+
+  g_return_if_fail (data != NULL);
+  g_return_if_fail (size % (bps * channels) == 0);
+  g_return_if_fail (bps > 0);
+  g_return_if_fail (bps <= 64);
+  g_return_if_fail (channels > 0);
+  g_return_if_fail (channels <= 64);
+  g_return_if_fail (reorder_map != NULL);
+
+  n = size / bpf;
+  for (gsize i = 0; i < n; i++) {
+    guint8 tmp[64 * 8];
+
+    memcpy (tmp, ptr, bpf);
+    for (gint j = 0; j < channels; j++)
+      memcpy (ptr + reorder_map[j] * bps, tmp + j * bps, bps);
+
+    ptr += bpf;
+  }
+}
+
 /**
  * gst_audio_reorder_channels:
  * @data: (array length=size) (element-type guint8): The pointer to
@@ -196,6 +242,12 @@ check_valid_channel_positions (const GstAudioChannelPosition * position,
  * positions @to. @from and @to must contain the same number of
  * positions and the same positions, only in a different order.
  *
+ * This function internally calls gst_audio_get_channel_reorder_map() and
+ * gst_audio_reorder_channels_with_reorder_map(). It is more efficient to call
+ * gst_audio_get_channel_reorder_map() once to retrieve the reorder map and
+ * then call gst_audio_reorder_channels_with_reorder_map() with the same
+ * reorder map until the channel positions change.
+ *
  * Note: this function assumes the audio data is in interleaved layout
  *
  * Returns: %TRUE if the reordering was possible.
@@ -206,11 +258,7 @@ gst_audio_reorder_channels (gpointer data, gsize size, GstAudioFormat format,
     const GstAudioChannelPosition * to)
 {
   const GstAudioFormatInfo *info;
-  gint i, j, n;
   gint reorder_map[64] = { 0, };
-  guint8 *ptr;
-  gint bpf, bps;
-  guint8 tmp[64 * 8];
 
   info = gst_audio_format_get_info (format);
 
@@ -234,19 +282,8 @@ gst_audio_reorder_channels (gpointer data, gsize size, GstAudioFormat format,
   if (!gst_audio_get_channel_reorder_map (channels, from, to, reorder_map))
     return FALSE;
 
-  bps = info->width / 8;
+  gst_audio_reorder_channels_with_reorder_map (data, size, info->width / 8,
-  bpf = bps * channels;
+      channels, reorder_map);
-  ptr = data;
-
-  n = size / bpf;
-  for (i = 0; i < n; i++) {
-
-    memcpy (tmp, ptr, bpf);
-    for (j = 0; j < channels; j++)
-      memcpy (ptr + reorder_map[j] * bps, tmp + j * bps, bps);
-
-    ptr += bpf;
-  }
 
   return TRUE;
 }

subprojects/gst-plugins-base/gst-libs/gst/audio/audio-channels.h

@@ -145,6 +145,12 @@ gboolean       gst_audio_reorder_channels        (gpointer data, gsize size,
                                                   const GstAudioChannelPosition * from,
                                                   const GstAudioChannelPosition * to);
 
+GST_AUDIO_API
+void           gst_audio_reorder_channels_with_reorder_map (gpointer data, gsize size,
+                                                            gint bps,
+                                                            gint channels,
+                                                            const gint *reorder_map);
+
 GST_AUDIO_API
 gboolean       gst_audio_channel_positions_to_valid_order (GstAudioChannelPosition *position,
                                                            gint channels);