diff --git a/lib/decoding/osmocom/core/conv.h b/lib/decoding/osmocom/core/conv.h
new file mode 100644
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+++ b/lib/decoding/osmocom/core/conv.h
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+/*! \file conv.h
+ * Osmocom convolutional encoder and decoder. */
+/*
+ * Copyright (C) 2011  Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/*! \defgroup conv Convolutional encoding and decoding routines
+ *  @{
+ * \file conv.h */
+
+#pragma once
+
+#include <stdint.h>
+
+#include <osmocom/core/bits.h>
+
+/*! possibe termination types
+ *
+ *  The termination type will determine which state the encoder/decoder
+ *  can start/end with. This is mostly taken care of in the high level API
+ *  call. So if you use the low level API, you must take care of making the
+ *  proper calls yourself.
+ */
+enum osmo_conv_term {
+	CONV_TERM_FLUSH = 0,	/*!< Flush encoder state */
+	CONV_TERM_TRUNCATION,	/*!< Direct truncation */
+	CONV_TERM_TAIL_BITING,	/*!< Tail biting */
+};
+
+/*! structure describing a given convolutional code
+ *
+ *  The only required fields are N,K and the next_output/next_state arrays. The
+ *  other can be left to default value of zero depending on what the code does.
+ *  If 'len' is left at 0 then only the low level API can be used.
+ */
+struct osmo_conv_code {
+	int N;				/*!< Inverse of code rate */
+	int K;				/*!< Constraint length */
+	int len;			/*!< # of data bits */
+
+	enum osmo_conv_term term;	/*!< Termination type */
+
+	const uint8_t (*next_output)[2];/*!< Next output array */
+	const uint8_t (*next_state)[2];	/*!< Next state array  */
+
+	const uint8_t *next_term_output;/*!< Flush termination output */
+	const uint8_t *next_term_state;	/*!< Flush termination state  */
+
+	const int *puncture;		/*!< Punctured bits indexes */
+};
+
+
+/* Common */
+
+int osmo_conv_get_input_length(const struct osmo_conv_code *code, int len);
+int osmo_conv_get_output_length(const struct osmo_conv_code *code, int len);
+
+
+/* Encoding */
+
+	/* Low level API */
+
+/*! convolutional encoder state */
+struct osmo_conv_encoder {
+	const struct osmo_conv_code *code; /*!< for which code? */
+	int i_idx;	/*!< Next input bit index */
+	int p_idx;	/*!< Current puncture index */
+	uint8_t state;	/*!< Current state */
+};
+
+void osmo_conv_encode_init(struct osmo_conv_encoder *encoder,
+                           const struct osmo_conv_code *code);
+void osmo_conv_encode_load_state(struct osmo_conv_encoder *encoder,
+                                 const ubit_t *input);
+int  osmo_conv_encode_raw(struct osmo_conv_encoder *encoder,
+                          const ubit_t *input, ubit_t *output, int n);
+int  osmo_conv_encode_flush(struct osmo_conv_encoder *encoder, ubit_t *output);
+
+	/* All-in-one */
+int  osmo_conv_encode(const struct osmo_conv_code *code,
+                      const ubit_t *input, ubit_t *output);
+
+
+/* Decoding */
+
+	/* Low level API */
+
+/*! convolutional decoder state */
+struct osmo_conv_decoder {
+	const struct osmo_conv_code *code; /*!< for which code? */
+
+	int n_states;		/*!< number of states */
+
+	int len;		/*!< Max o_idx (excl. termination) */
+
+	int o_idx;		/*!< output index */
+	int p_idx;		/*!< puncture index */
+
+	unsigned int *ae;	/*!< accumulated error */
+	unsigned int *ae_next;	/*!< next accumulated error (tmp in scan) */
+	uint8_t *state_history;	/*!< state history [len][n_states] */
+};
+
+void osmo_conv_decode_init(struct osmo_conv_decoder *decoder,
+                           const struct osmo_conv_code *code,
+                           int len, int start_state);
+void osmo_conv_decode_reset(struct osmo_conv_decoder *decoder, int start_state);
+void osmo_conv_decode_rewind(struct osmo_conv_decoder *decoder);
+void osmo_conv_decode_deinit(struct osmo_conv_decoder *decoder);
+
+int osmo_conv_decode_scan(struct osmo_conv_decoder *decoder,
+                          const sbit_t *input, int n);
+int osmo_conv_decode_flush(struct osmo_conv_decoder *decoder,
+                           const sbit_t *input);
+int osmo_conv_decode_get_output(struct osmo_conv_decoder *decoder,
+                                ubit_t *output, int has_flush, int end_state);
+
+	/* All-in-one */
+int osmo_conv_decode(const struct osmo_conv_code *code,
+                     const sbit_t *input, ubit_t *output);
+
+
+/*! @} */