g722: Split out g722_qmf_apply() function into g722dsp.c

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 47 insertions, 0 deletions

diff --git a/libavcodec/g722dsp.c b/libavcodec/g722dsp.c
new file mode 100644
index 0000000..1fefc6b
--- /dev/null
+++ b/libavcodec/g722dsp.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2015 Peter Meerwald <pmeerw@pmeerw.net>
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "g722dsp.h"
+#include "mathops.h"
+
+/*
+ * quadrature mirror filter (QMF) coefficients (ITU-T G.722 Table 11) inlined
+ * in code below: 3, -11, 12, 32, -210, 951, 3876, -805, 362, -156, 53, -11
+ */
+static const int16_t qmf_coeffs[12] = {
+    3, -11, 12, 32, -210, 951, 3876, -805, 362, -156, 53, -11,
+};
+
+static void g722_apply_qmf(const int16_t *prev_samples, int *xout1, int *xout2)
+{
+    int i;
+
+    *xout1 = 0;
+    *xout2 = 0;
+    for (i = 0; i < 12; i++) {
+        MAC16(*xout2, prev_samples[2*i  ], qmf_coeffs[i   ]);
+        MAC16(*xout1, prev_samples[2*i+1], qmf_coeffs[11-i]);
+    }
+}
+
+av_cold void ff_g722dsp_init(G722DSPContext *c)
+{
+    c->apply_qmf = g722_apply_qmf;
+}