diff --git a/include/osmocom/core/Makefile.am b/include/osmocom/core/Makefile.am
index 6109f47..b21e047 100644
--- a/include/osmocom/core/Makefile.am
+++ b/include/osmocom/core/Makefile.am
@@ -3,7 +3,7 @@
 		   gsmtap.h write_queue.h \
 		   logging.h rate_ctr.h gsmtap_util.h \
 		   plugin.h crc16.h panic.h process.h msgfile.h \
-		   backtrace.h
+		   backtrace.h conv.h
 
 if ENABLE_TALLOC
 osmocore_HEADERS += talloc.h
diff --git a/include/osmocom/core/conv.h b/include/osmocom/core/conv.h
new file mode 100644
index 0000000..af676ee
--- /dev/null
+++ b/include/osmocom/core/conv.h
@@ -0,0 +1,101 @@
+/*
+ * conv.h
+ *
+ * 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.
+ */
+
+#ifndef __OSMO_CONV_H__
+#define __OSMO_CONV_H__
+
+#include <stdint.h>
+
+#include <osmocom/core/bits.h>
+
+struct osmo_conv_code {
+	int N;
+	int K;
+	int len;
+
+	const uint8_t (*next_output)[2];
+	const uint8_t (*next_state)[2];
+
+	const uint8_t *next_term_output;
+	const uint8_t *next_term_state;
+
+	const int *puncture;
+};
+
+
+/* Encoding */
+
+	/* Low level API */
+struct osmo_conv_encoder {
+	const struct osmo_conv_code *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);
+int  osmo_conv_encode_raw(struct osmo_conv_encoder *encoder,
+                          const ubit_t *input, ubit_t *output, int n);
+int  osmo_conv_encode_finish(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 */
+struct osmo_conv_decoder {
+	const struct osmo_conv_code *code;
+
+	int n_states;
+
+	int len;		/* Max o_idx (excl. termination) */
+
+	int o_idx;		/* output index */
+	int p_idx;		/* puncture index */
+
+	unsigned int *ae;	/* accumulater 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);
+void osmo_conv_decode_reset(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_finish(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_finish);
+
+	/* All-in-one */
+int osmo_conv_decode(const struct osmo_conv_code *code,
+                     const sbit_t *input, ubit_t *output);
+
+
+#endif /* __OSMO_CONV_H__ */