opus_celt: move quantization and band decoding to opus_pvq.c

A huge amount can be reused by the encoder, as the only thing
which needs to be done would be to add a 10 line celt_icwrsi,
a wrapper around it (celt_alg_quant) and templating the
ff_celt_decode_band to replace entropy decoding functions
with entropy encoding.

There is no performance loss but in fact a performance gain of
around 6% which is caused by the compiler being able to optimize
the decoding more efficiently.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/libavcodec/opus_pvq.h b/libavcodec/opus_pvq.h
new file mode 100644
index 0000000000..1083f35db9
--- /dev/null
+++ b/libavcodec/opus_pvq.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2012 Andrew D'Addesio
+ * Copyright (c) 2013-2014 Mozilla Corporation
+ * Copyright (c) 2016 Rostislav Pehlivanov <atomnuker@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_OPUS_PVQ_H
+#define AVCODEC_OPUS_PVQ_H
+
+#include "opus.h"
+#include "opus_celt.h"
+
+/* Decodes a band using PVQ */
+uint32_t ff_celt_decode_band(CeltContext *s, OpusRangeCoder *rc, const int band,
+                             float *X, float *Y, int N, int b, uint32_t blocks,
+                             float *lowband, int duration, float *lowband_out, int level,
+                             float gain, float *lowband_scratch, int fill);
+
+#endif /* AVCODEC_OPUS_PVQ_H */