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-rw-r--r--include/osmocom/gapk/codecs.h71
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diff --git a/include/osmocom/gapk/codecs.h b/include/osmocom/gapk/codecs.h
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+/* Codecs handling */
+
+/*
+ * This file is part of gapk (GSM Audio Pocket Knife).
+ *
+ * gapk 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * gapk 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 gapk. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GAPK_CODECS_H__
+#define __GAPK_CODECS_H__
+
+#include <stdint.h>
+
+#define FR_CANON_LEN 33
+#define HR_CANON_LEN 14
+#define EFR_CANON_LEN 31
+#define PCM_CANON_LEN (160*sizeof(uint16_t))
+#define HR_REF_ENC_LEN (20 * sizeof(uint16_t))
+#define HR_REF_DEC_LEN (22 * sizeof(uint16_t))
+
+enum codec_type {
+ CODEC_INVALID = 0,
+ CODEC_PCM, /* 16 bits PCM samples */
+ CODEC_HR, /* GSM Half Rate codec GSM 06.20 */
+ CODEC_FR, /* GSM Full Rate codec GSM 06.10 */
+ CODEC_EFR, /* GSM Enhanced Full Rate codec GSM 06.60 */
+ CODEC_AMR, /* GSM Adaptive Multi Rate codec GSM 26.071 */
+ _CODEC_MAX,
+};
+
+#include <osmocom/gapk/formats.h> /* need to import here because or enum interdep */
+
+/*! call-back for actual codec conversion function
+ * \param[in] state opaque state pointer (returned by codec->init)
+ * \param[out] dst caller-allocated buffer for output data
+ * \param[in] src input data
+ * \param[in] src_len length of input data \a src
+ * \returns number of output bytes written to \a dst; negative on error */
+typedef int (*codec_conv_cb_t)(void *state, uint8_t *dst, const uint8_t *src, unsigned int src_len);
+
+struct codec_desc {
+ enum codec_type type;
+ const char * name;
+ const char * description;
+ /*! canonical frame size (in bytes); 0 in case of variable length */
+ unsigned int canon_frame_len;
+
+ enum format_type codec_enc_format_type; /* what the encoder provides */
+ enum format_type codec_dec_format_type; /* what to give the decoder */
+ /*! codec initialization function pointer, returns opaque state */
+ void * (*codec_init)(void);
+ /*! codec exit function pointer, gets passed opaque state */
+ void (*codec_exit)(void *state);
+ codec_conv_cb_t codec_encode;
+ codec_conv_cb_t codec_decode;
+};
+
+const struct codec_desc *codec_get_from_type(enum codec_type type);
+
+#endif /* __GAPK_CODECS_H__ */