sbc: implement SBC encoder (low-complexity subband codec)

This was originally based on libsbc, and was fully integrated into ffmpeg.

1 files changed, 83 insertions, 0 deletions

diff --git a/libavcodec/sbcdsp.h b/libavcodec/sbcdsp.h
new file mode 100644
index 0000000000..66ed7d324e
--- /dev/null
+++ b/libavcodec/sbcdsp.h
@@ -0,0 +1,83 @@
+/*
+ * Bluetooth low-complexity, subband codec (SBC)
+ *
+ * Copyright (C) 2017  Aurelien Jacobs <aurel@gnuage.org>
+ * Copyright (C) 2008-2010  Nokia Corporation
+ * Copyright (C) 2004-2010  Marcel Holtmann <marcel@holtmann.org>
+ * Copyright (C) 2004-2005  Henryk Ploetz <henryk@ploetzli.ch>
+ * Copyright (C) 2005-2006  Brad Midgley <bmidgley@xmission.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
+ */
+
+/**
+ * @file
+ * SBC basic "building bricks"
+ */
+
+#ifndef AVCODEC_SBCDSP_H
+#define AVCODEC_SBCDSP_H
+
+#include "sbc.h"
+#include "sbcdsp_data.h"
+
+#define SCALE_OUT_BITS 15
+#define SBC_X_BUFFER_SIZE 328
+
+typedef struct sbc_dsp_context SBCDSPContext;
+
+struct sbc_dsp_context {
+    int position;
+    /* Number of consecutive blocks handled by the encoder */
+    uint8_t increment;
+    DECLARE_ALIGNED(SBC_ALIGN, int16_t, X)[2][SBC_X_BUFFER_SIZE];
+    void (*sbc_analyze_4)(const int16_t *in, int32_t *out, const int16_t *consts);
+    void (*sbc_analyze_8)(const int16_t *in, int32_t *out, const int16_t *consts);
+    /* Polyphase analysis filter for 4 subbands configuration,
+     * it handles "increment" blocks at once */
+    void (*sbc_analyze_4s)(SBCDSPContext *s,
+                           int16_t *x, int32_t *out, int out_stride);
+    /* Polyphase analysis filter for 8 subbands configuration,
+     * it handles "increment" blocks at once */
+    void (*sbc_analyze_8s)(SBCDSPContext *s,
+                           int16_t *x, int32_t *out, int out_stride);
+    /* Process input data (deinterleave, endian conversion, reordering),
+     * depending on the number of subbands and input data byte order */
+    int (*sbc_enc_process_input_4s)(int position, const uint8_t *pcm,
+                                    int16_t X[2][SBC_X_BUFFER_SIZE],
+                                    int nsamples, int nchannels);
+    int (*sbc_enc_process_input_8s)(int position, const uint8_t *pcm,
+                                    int16_t X[2][SBC_X_BUFFER_SIZE],
+                                    int nsamples, int nchannels);
+    /* Scale factors calculation */
+    void (*sbc_calc_scalefactors)(int32_t sb_sample_f[16][2][8],
+                                  uint32_t scale_factor[2][8],
+                                  int blocks, int channels, int subbands);
+    /* Scale factors calculation with joint stereo support */
+    int (*sbc_calc_scalefactors_j)(int32_t sb_sample_f[16][2][8],
+                                   uint32_t scale_factor[2][8],
+                                   int blocks, int subbands);
+};
+
+/*
+ * Initialize pointers to the functions which are the basic "building bricks"
+ * of SBC codec. Best implementation is selected based on target CPU
+ * capabilities.
+ */
+void ff_sbcdsp_init(SBCDSPContext *s);
+
+#endif /* AVCODEC_SBCDSP_H */