audio: add AVChannelLayout helpers to convert from/to mp_chmap

This is the new FFmpeg channel layout structure, which now
combines channel count and layout into a single location.

Only unspecified (channel count only) and native (channel layout
mask based) layouts are currently supported for the initial move
towards non-deprecated APIs.

2 files changed, 83 insertions, 0 deletions

diff --git a/audio/chmap_avchannel.c b/audio/chmap_avchannel.c
new file mode 100644
index 0000000000..ec961de422
--- /dev/null
+++ b/audio/chmap_avchannel.c
@@ -0,0 +1,51 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libavutil/channel_layout.h>
+
+#include "chmap.h"
+#include "chmap_avchannel.h"
+
+bool mp_chmap_from_av_layout(struct mp_chmap *dst, const AVChannelLayout *src)
+{
+    *dst = (struct mp_chmap) {0};
+
+    switch (src->order) {
+    case AV_CHANNEL_ORDER_UNSPEC:
+        mp_chmap_from_channels(dst, src->nb_channels);
+        return dst->num == src->nb_channels;
+    case AV_CHANNEL_ORDER_NATIVE:
+        mp_chmap_from_lavc(dst, src->u.mask);
+        return dst->num == src->nb_channels;
+    default:
+        // TODO: handle custom layouts
+        return false;
+    }
+}
+
+void mp_chmap_to_av_layout(AVChannelLayout *dst, const struct mp_chmap *src)
+{
+    *dst = (AVChannelLayout){
+        .order = AV_CHANNEL_ORDER_UNSPEC,
+        .nb_channels = src->num,
+    };
+
+    // TODO: handle custom layouts
+    if (!mp_chmap_is_unknown(src)) {
+        av_channel_layout_from_mask(dst, mp_chmap_to_lavc(src));
+    }
+}
diff --git a/audio/chmap_avchannel.h b/audio/chmap_avchannel.h
new file mode 100644
index 0000000000..e136ccc7ce
--- /dev/null
+++ b/audio/chmap_avchannel.h
@@ -0,0 +1,32 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <libavutil/channel_layout.h>
+
+#include "config.h"
+
+#include "chmap.h"
+
+#if HAVE_AV_CHANNEL_LAYOUT
+
+bool mp_chmap_from_av_layout(struct mp_chmap *dst, const AVChannelLayout *src);
+
+void mp_chmap_to_av_layout(AVChannelLayout *dst, const struct mp_chmap *src);
+
+#endif