frame.h

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#define AST_OPTION_FLAG_ACCEPT		1
#define AST_OPTION_FLAG_REJECT		2
#define AST_OPTION_FLAG_QUERY		4
#define AST_OPTION_FLAG_ANSWER		5
#define AST_OPTION_FLAG_WTF		6

/*! Verify touchtones by muting audio transmission 
	(and reception) and verify the tone is still present */
#define AST_OPTION_TONE_VERIFY		1		

/*! Put a compatible channel into TDD (TTY for the hearing-impared) mode */
#define	AST_OPTION_TDD			2

/*! Relax the parameters for DTMF reception (mainly for radio use) */
#define	AST_OPTION_RELAXDTMF		3

/*! Set (or clear) Audio (Not-Clear) Mode */
#define	AST_OPTION_AUDIO_MODE		4

/*! Set channel transmit gain 
 * Option data is a single signed char
   representing number of decibels (dB)
   to set gain to (on top of any gain
   specified in channel driver)
*/
#define AST_OPTION_TXGAIN		5

/*! Set channel receive gain
 * Option data is a single signed char
   representing number of decibels (dB)
   to set gain to (on top of any gain
   specified in channel driver)
*/
#define AST_OPTION_RXGAIN		6

/* set channel into "Operator Services" mode */
#define	AST_OPTION_OPRMODE		7

/*! Explicitly enable or disable echo cancelation for the given channel */
#define	AST_OPTION_ECHOCAN		8

/* !
 * Read-only. Allows query current status of T38 on the channel.
 * data: ast_t38state
 */
#define AST_OPTION_T38_STATE		10

struct oprmode {
	struct ast_channel *peer;
	int mode;
} ;

struct ast_option_header {
	/* Always keep in network byte order */
#if __BYTE_ORDER == __BIG_ENDIAN
        uint16_t flag:3;
        uint16_t option:13;
#else
#if __BYTE_ORDER == __LITTLE_ENDIAN
        uint16_t option:13;
        uint16_t flag:3;
#else
#error Byte order not defined
#endif
#endif
		uint8_t data[0];
};


/*! \brief Definition of supported media formats (codecs) */
struct ast_format_list {
	int bits;	/*!< bitmask value */
	char *name;	/*!< short name */
	int samplespersecond; /*!< Number of samples per second (8000/16000) */
	char *desc;	/*!< Description */
	int fr_len;	/*!< Single frame length in bytes */
	int min_ms;	/*!< Min value */
	int max_ms;	/*!< Max value */
	int inc_ms;	/*!< Increment */
	int def_ms;	/*!< Default value */
	unsigned int flags;	/*!< Smoother flags */
	int cur_ms;	/*!< Current value */
};


/*! \brief  Requests a frame to be allocated 
 * 
 * \param source 
 * Request a frame be allocated.  source is an optional source of the frame, 
 * len is the requested length, or "0" if the caller will supply the buffer 
 */
#if 0 /* Unimplemented */
struct ast_frame *ast_fralloc(char *source, int len);
#endif

/*!  
 * \brief Frees a frame 
 * 
 * \param fr Frame to free
 * \param cache Whether to consider this frame for frame caching
 */
void ast_frame_free(struct ast_frame *fr, int cache);

#define ast_frfree(fr) ast_frame_free(fr, 1)

/*! \brief Makes a frame independent of any static storage
 * \param fr frame to act upon
 * Take a frame, and if it's not been malloc'd, make a malloc'd copy
 * and if the data hasn't been malloced then make the
 * data malloc'd.  If you need to store frames, say for queueing, then
 * you should call this function.
 * \return Returns a frame on success, NULL on error
 */
struct ast_frame *ast_frisolate(struct ast_frame *fr);

/*! \brief Copies a frame 
 * \param fr frame to copy
 * Duplicates a frame -- should only rarely be used, typically frisolate is good enough
 * \return Returns a frame on success, NULL on error
 */
struct ast_frame *ast_frdup(const struct ast_frame *fr);

void ast_swapcopy_samples(void *dst, const void *src, int samples);

/* Helpers for byteswapping native samples to/from 
   little-endian and big-endian. */
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define ast_frame_byteswap_le(fr) do { ; } while(0)
#define ast_frame_byteswap_be(fr) do { struct ast_frame *__f = (fr); ast_swapcopy_samples(__f->data, __f->data, __f->samples); } while(0)
#else
#define ast_frame_byteswap_le(fr) do { struct ast_frame *__f = (fr); ast_swapcopy_samples(__f->data, __f->data, __f->samples); } while(0)
#define ast_frame_byteswap_be(fr) do { ; } while(0)
#endif


/*! \brief Get the name of a format
 * \param format id of format
 * \return A static string containing the name of the format or "unknown" if unknown.
 */
char* ast_getformatname(int format);

/*! \brief Get the names of a set of formats
 * \param buf a buffer for the output string
 * \param size size of buf (bytes)
 * \param format the format (combined IDs of codecs)
 * Prints a list of readable codec names corresponding to "format".
 * ex: for format=AST_FORMAT_GSM|AST_FORMAT_SPEEX|AST_FORMAT_ILBC it will return "0x602 (GSM|SPEEX|ILBC)"
 * \return The return value is buf.
 */
char* ast_getformatname_multiple(char *buf, size_t size, int format);

/*!
 * \brief Gets a format from a name.
 * \param name string of format
 * \return This returns the form of the format in binary on success, 0 on error.
 */
int ast_getformatbyname(const char *name);

/*! \brief Get a name from a format 
 * Gets a name from a format
 * \param codec codec number (1,2,4,8,16,etc.)
 * \return This returns a static string identifying the format on success, 0 on error.
 */
char *ast_codec2str(int codec);

/*! \name AST_Smoother 
*/
/*@{ */
/*! \page ast_smooth The AST Frame Smoother
The ast_smoother interface was designed specifically
to take frames of variant sizes and produce frames of a single expected
size, precisely what you want to do.

The basic interface is:

- Initialize with ast_smoother_new()
- Queue input frames with ast_smoother_feed()
- Get output frames with ast_smoother_read()
- when you're done, free the structure with ast_smoother_free()
- Also see ast_smoother_test_flag(), ast_smoother_set_flags(), ast_smoother_get_flags(), ast_smoother_reset()
*/
struct ast_smoother;

struct ast_smoother *ast_smoother_new(int bytes);
void ast_smoother_set_flags(struct ast_smoother *smoother, int flags);
int ast_smoother_get_flags(struct ast_smoother *smoother);
int ast_smoother_test_flag(struct ast_smoother *s, int flag);
void ast_smoother_free(struct ast_smoother *s);
void ast_smoother_reset(struct ast_smoother *s, int bytes);
int __ast_smoother_feed(struct ast_smoother *s, struct ast_frame *f, int swap);
struct ast_frame *ast_smoother_read(struct ast_smoother *s);
#define ast_smoother_feed(s,f) __ast_smoother_feed(s, f, 0)
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define ast_smoother_feed_be(s,f) __ast_smoother_feed(s, f, 1)
#define ast_smoother_feed_le(s,f) __ast_smoother_feed(s, f, 0)
#else
#define ast_smoother_feed_be(s,f) __ast_smoother_feed(s, f, 0)
#define ast_smoother_feed_le(s,f) __ast_smoother_feed(s, f, 1)
#endif
/*@} Doxygen marker */

struct ast_format_list *ast_get_format_list_index(int index);
struct ast_format_list *ast_get_format_list(size_t *size);
void ast_frame_dump(const char *name, struct ast_frame *f, char *prefix);

/*! \page AudioCodecPref Audio Codec Preferences

	In order to negotiate audio codecs in the order they are configured
	in \<channel\>.conf for a device, we set up codec preference lists
	in addition to the codec capabilities setting. The capabilities
	setting is a bitmask of audio and video codecs with no internal
	order. This will reflect the offer given to the other side, where
	the prefered codecs will be added to the top of the list in the
	order indicated by the "allow" lines in the device configuration.
	
	Video codecs are not included in the preference lists since they
	can't be transcoded and we just have to pick whatever is supported
*/

/*! 
 *\brief Initialize an audio codec preference to "no preference".
 * \arg \ref AudioCodecPref 
*/
void ast_codec_pref_init(struct ast_codec_pref *pref);

/*! 
 * \brief Codec located at a particular place in the preference index.
 * \arg \ref AudioCodecPref 
*/
int ast_codec_pref_index(struct ast_codec_pref *pref, int index);

/*! \brief Remove audio a codec from a preference list */
void ast_codec_pref_remove(struct ast_codec_pref *pref, int format);

/*! \brief Append a audio codec to a preference list, removing it first if it was already there 
*/
int ast_codec_pref_append(struct ast_codec_pref *pref, int format);

/*! \brief Prepend an audio codec to a preference list, removing it first if it was already there 
*/
void ast_codec_pref_prepend(struct ast_codec_pref *pref, int format, int only_if_existing);

/*! \brief Select the best audio format according to preference list from supplied options. 
   If "find_best" is non-zero then if nothing is found, the "Best" format of 
   the format list is selected, otherwise 0 is returned. */
int ast_codec_choose(struct ast_codec_pref *pref, int formats, int find_best);

/*! \brief Set packet size for codec
*/
int ast_codec_pref_setsize(struct ast_codec_pref *pref, int format, int framems);

/*! \brief Get packet size for codec
*/
struct ast_format_list ast_codec_pref_getsize(struct ast_codec_pref *pref, int format);

/*! \brief Parse an "allow" or "deny" line in a channel or device configuration 
        and update the capabilities mask and pref if provided.
	Video codecs are not added to codec preference lists, since we can not transcode
	\return Returns number of errors encountered during parsing
 */
int ast_parse_allow_disallow(struct ast_codec_pref *pref, int *mask, const char *list, int allowing);

/*! \brief Dump audio codec preference list into a string */
int ast_codec_pref_string(struct ast_codec_pref *pref, char *buf, size_t size);

/*! \brief Shift an audio codec preference list up or down 65 bytes so that it becomes an ASCII string */
void ast_codec_pref_convert(struct ast_codec_pref *pref, char *buf, size_t size, int right);

/*! \brief Returns the number of samples contained in the frame */
int ast_codec_get_samples(struct ast_frame *f);

/*! \brief Returns the number of bytes for the number of samples of the given format */
int ast_codec_get_len(int format, int samples);

/*! \brief Appends a frame to the end of a list of frames, truncating the maximum length of the list */
struct ast_frame *ast_frame_enqueue(struct ast_frame *head, struct ast_frame *f, int maxlen, int dupe);


/*! \brief Gets duration in ms of interpolation frame for a format */
static inline int ast_codec_interp_len(int format) 
{ 
	return (format == AST_FORMAT_ILBC) ? 30 : 20;
}

/*!
  \brief Adjusts the volume of the audio samples contained in a frame.
  \param f The frame containing the samples (must be AST_FRAME_VOICE and AST_FORMAT_SLINEAR)
  \param adjustment The number of dB to adjust up or down.
  \return 0 for success, non-zero for an error
 */
int ast_frame_adjust_volume(struct ast_frame *f, int adjustment);

/*!
  \brief Sums two frames of audio samples.
  \param f1 The first frame (which will contain the result)
  \param f2 The second frame
  \return 0 for success, non-zero for an error

  The frames must be AST_FRAME_VOICE and must contain AST_FORMAT_SLINEAR samples,
  and must contain the same number of samples.
 */
int ast_frame_slinear_sum(struct ast_frame *f1, struct ast_frame *f2);

/*!
 * \brief Get the sample rate for a given format.
 */
static force_inline int ast_format_rate(int format)
{
	if (format == AST_FORMAT_G722 || format == AST_FORMAT_SLINEAR16)
		return 16000;

	return 8000;
}

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

#endif /* _ASTERISK_FRAME_H */