1 files changed, 56 insertions, 0 deletions
diff --git a/src/modules/echo-cancel/null.c b/src/modules/echo-cancel/null.c
new file mode 100644
index 0000000..c8ecf27
--- /dev/null
+++ b/src/modules/echo-cancel/null.c
@@ -0,0 +1,56 @@
+/***
+    Copyright 2012 Peter Meerwald <p.meerwald@bct-electronic.com>
+
+    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.
+
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <pulse/cdecl.h>
+
+PA_C_DECL_BEGIN
+#include <pulsecore/core-util.h>
+#include <pulsecore/modargs.h>
+#include "echo-cancel.h"
+PA_C_DECL_END
+
+bool pa_null_ec_init(pa_core *c, pa_echo_canceller *ec,
+                     pa_sample_spec *rec_ss, pa_channel_map *rec_map,
+                     pa_sample_spec *play_ss, pa_channel_map *play_map,
+                     pa_sample_spec *out_ss, pa_channel_map *out_map,
+                     uint32_t *nframes, const char *args) {
+    char strss_source[PA_SAMPLE_SPEC_SNPRINT_MAX];
+    char strss_sink[PA_SAMPLE_SPEC_SNPRINT_MAX];
+
+    *nframes = 256;
+    ec->params.null.out_ss = *out_ss;
+
+    *rec_ss = *out_ss;
+    *rec_map = *out_map;
+
+    pa_log_debug("null AEC: nframes=%u, sample spec source=%s, sample spec sink=%s", *nframes,
+                 pa_sample_spec_snprint(strss_source, sizeof(strss_source), out_ss),
+                 pa_sample_spec_snprint(strss_sink, sizeof(strss_sink), play_ss));
+
+    return true;
+}
+
+void pa_null_ec_run(pa_echo_canceller *ec, const uint8_t *rec, const uint8_t *play, uint8_t *out) {
+    /* The null implementation simply copies the recorded buffer to the output
+       buffer and ignores the play buffer. */
+    memcpy(out, rec, 256 * pa_frame_size(&ec->params.null.out_ss));
+}
+
+void pa_null_ec_done(pa_echo_canceller *ec) {
+}