Currently format negotiation is done in
pa_sink_input_new_data_set_sink(), but the new data won't be available
when a router module needs to connect a sink input node to some other
node, so a different function is needed.
It would probably otherwise be possible to convert also
pa_sink_input_new_data_set_sink() to use pa_format_info_negotiate()
internally, but pa_sink_input_new_data_set_sink() doesn't currently
choose the final format, which pa_format_info_negotiate() does. The
reason is probably to allow policy modules to choose the format if
there are multiple alternatives, but I don't know if we really need
that possibility (AFAIK the possibility is not currently used), so
perhaps that conversion should be done to get rid of the duplicated
code?
---
src/Makefile.am | 1 +
src/pulsecore/core-format.c | 51 +++++++++++++++++++++++++++++++++++++++++++++
src/pulsecore/core-format.h | 44 ++++++++++++++++++++++++++++++++++++++
3 files changed, 96 insertions(+)
create mode 100644 src/pulsecore/core-format.c
create mode 100644 src/pulsecore/core-format.h
diff --git a/src/Makefile.am b/src/Makefile.am
index 4efd4c4..168415e 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -871,6 +871,7 @@ libpulsecore_ at PA_MAJORMINOR@_la_SOURCES = \
pulsecore/cli-text.c pulsecore/cli-text.h \
pulsecore/client.c pulsecore/client.h \
pulsecore/card.c pulsecore/card.h \
+ pulsecore/core-format.c pulsecore/core-format.h \
pulsecore/core-scache.c pulsecore/core-scache.h \
pulsecore/core-subscribe.c pulsecore/core-subscribe.h \
pulsecore/core.c pulsecore/core.h \
diff --git a/src/pulsecore/core-format.c b/src/pulsecore/core-format.c
new file mode 100644
index 0000000..6e534f4
--- /dev/null
+++ b/src/pulsecore/core-format.c
@@ -0,0 +1,51 @@
+/***
+ This file is part of PulseAudio.
+
+ Copyright 2013 Intel Corporation
+
+ PulseAudio 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.
+
+ PulseAudio 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with PulseAudio; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "core-format.h"
+
+int pa_format_info_negotiate(pa_idxset *formats_a, pa_idxset *formats_b, const pa_format_info **format) {
+ pa_format_info *a;
+ uint32_t idx_a;
+ pa_format_info *b;
+ uint32_t idx_b;
+
+ pa_assert(formats_a);
+ pa_assert(formats_b);
+ pa_assert(format);
+
+ PA_IDXSET_FOREACH(a, formats_a, idx_a) {
+ PA_IDXSET_FOREACH(b, formats_b, idx_b) {
+ /* pa_format_info_is_compatible() succeeds if the first parameter
+ * is a subset of the second parameter, so b must be the first
+ * parameter. */
+ if (pa_format_info_is_compatible(b, a)) {
+ *format = a;
+ return 0;
+ }
+ }
+ }
+
+ return -PA_ERR_NOTSUPPORTED;
+}
diff --git a/src/pulsecore/core-format.h b/src/pulsecore/core-format.h
new file mode 100644
index 0000000..f492c19
--- /dev/null
+++ b/src/pulsecore/core-format.h
@@ -0,0 +1,44 @@
+#ifndef foocoreformathfoo
+#define foocoreformathfoo
+
+/***
+ This file is part of PulseAudio.
+
+ Copyright 2013 Intel Corporation
+
+ PulseAudio 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.
+
+ PulseAudio 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with PulseAudio; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ USA.
+***/
+
+#include <pulse/format.h>
+
+#include <pulsecore/idxset.h>
+
+/* Selects the first format in formats_a that is compatible with some format in
+ * formats_b, and stores the result in format. Returns a negative error code if
+ * no compatible format can be found.
+ *
+ * Being "compatible" means that format a is a superset of format b (internally
+ * this function uses pa_format_info_compatible(), which defines what
+ * "compatible" means). If you have two format sets, how do you know which one
+ * is going to contain supersets of the other? Currently (as of 2013-11-17)
+ * things are designed so that formats_a should represent stream formats and
+ * formats_b should represent device formats. Hopefully the definition of
+ * "compatible" will change at some point so that it would actually mean that
+ * there's a valid intersection of a and b, because then it wouldn't matter if
+ * the formats are stream or device formats. */
+int pa_format_info_negotiate(pa_idxset *formats_a, pa_idxset *formats_b, const pa_format_info **format);
+
+#endif
--
1.8.3.1
