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 /********************************************************************

  *                                                                  *

  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *

  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *

  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *

  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *

  *                                                                  *

  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2001             *

  * by the Xiph.Org Foundation http://www.xiph.org/                  *

  *                                                                  *

  ********************************************************************

  function: vorbis encode-engine setup

  last mod: $Id: vorbisenc.h 17021 2010-03-24 09:29:41Z xiphmont $

  ********************************************************************/

 /** \file

  * Libvorbisenc is a convenient API for setting up an encoding

  * environment using libvorbis. Libvorbisenc encapsulates the

  * actions needed to set up the encoder properly.

  */

 #ifndef _OV_ENC_H_

 #define _OV_ENC_H_

 #ifdef __cplusplus

 extern "C"

 {

 #endif /* __cplusplus */

 #include "codec.h"

 /**

  * This is the primary function within libvorbisenc for setting up managed

  * bitrate modes.

  *

  * Before this function is called, the \ref vorbis_info

  * struct should be initialized by using vorbis_info_init() from the libvorbis

  * API.  After encoding, vorbis_info_clear() should be called.

  *

  * The max_bitrate, nominal_bitrate, and min_bitrate settings are used to set

  * constraints for the encoded file.  This function uses these settings to

  * select the appropriate encoding mode and set it up.

  *

  * \param vi               Pointer to an initialized \ref vorbis_info struct.

  * \param channels         The number of channels to be encoded.

  * \param rate             The sampling rate of the source audio.

  * \param max_bitrate      Desired maximum bitrate (limit). -1 indicates unset.

  * \param nominal_bitrate  Desired average, or central, bitrate. -1 indicates unset.

  * \param min_bitrate      Desired minimum bitrate. -1 indicates unset.

  *

  * \return Zero for success, and negative values for failure.

  *

  * \retval 0          Success.

  * \retval OV_EFAULT  Internal logic fault; indicates a bug or heap/stack corruption.

  * \retval OV_EINVAL  Invalid setup request, eg, out of range argument.

  * \retval OV_EIMPL   Unimplemented mode; unable to comply with bitrate request.

  */

 extern int vorbis_encode_init(vorbis_info *vi,

                               long channels,

                               long rate,

                               long max_bitrate,

                               long nominal_bitrate,

                               long min_bitrate);

 /**

  * This function performs step-one of a three-step bitrate-managed encode

  * setup.  It functions similarly to the one-step setup performed by \ref

  * vorbis_encode_init but allows an application to make further encode setup

  * tweaks using \ref vorbis_encode_ctl before finally calling \ref

  * vorbis_encode_setup_init to complete the setup process.

  *

  * Before this function is called, the \ref vorbis_info struct should be

  * initialized by using vorbis_info_init() from the libvorbis API.  After

  * encoding, vorbis_info_clear() should be called.

  *

  * The max_bitrate, nominal_bitrate, and min_bitrate settings are used to set

  * constraints for the encoded file.  This function uses these settings to

  * select the appropriate encoding mode and set it up.

  *

  * \param vi                Pointer to an initialized vorbis_info struct.

  * \param channels          The number of channels to be encoded.

  * \param rate              The sampling rate of the source audio.

  * \param max_bitrate       Desired maximum bitrate (limit). -1 indicates unset.

  * \param nominal_bitrate   Desired average, or central, bitrate. -1 indicates unset.

  * \param min_bitrate       Desired minimum bitrate. -1 indicates unset.

  *

  * \return Zero for success, and negative for failure.

  *

  * \retval 0           Success

  * \retval OV_EFAULT   Internal logic fault; indicates a bug or heap/stack corruption.

  * \retval OV_EINVAL   Invalid setup request, eg, out of range argument.

  * \retval OV_EIMPL    Unimplemented mode; unable to comply with bitrate request.

  */

 extern int vorbis_encode_setup_managed(vorbis_info *vi,

                                        long channels,

                                        long rate,

                                        long max_bitrate,

                                        long nominal_bitrate,

                                        long min_bitrate);

 /**

  * This function performs step-one of a three-step variable bitrate

  * (quality-based) encode setup.  It functions similarly to the one-step setup

  * performed by \ref vorbis_encode_init_vbr() but allows an application to

  * make further encode setup tweaks using \ref vorbis_encode_ctl() before

  * finally calling \ref vorbis_encode_setup_init to complete the setup

  * process.

  *

  * Before this function is called, the \ref vorbis_info struct should be

  * initialized by using \ref vorbis_info_init() from the libvorbis API.  After

  * encoding, vorbis_info_clear() should be called.

  *

  * \param vi        Pointer to an initialized vorbis_info struct.

  * \param channels  The number of channels to be encoded.

  * \param rate      The sampling rate of the source audio.

  * \param quality   Desired quality level, currently from -0.1 to 1.0 (lo to hi).

  *

  * \return Zero for success, and negative values for failure.

  *

  * \retval  0          Success

  * \retval  OV_EFAULT  Internal logic fault; indicates a bug or heap/stack corruption.

  * \retval  OV_EINVAL  Invalid setup request, eg, out of range argument.

  * \retval  OV_EIMPL   Unimplemented mode; unable to comply with quality level request.

  */

 extern int vorbis_encode_setup_vbr(vorbis_info *vi,

                                   long channels,

                                   long rate,

                                   float quality

                                   );

 /**

  * This is the primary function within libvorbisenc for setting up variable

  * bitrate ("quality" based) modes.

  *

  *

  * Before this function is called, the vorbis_info struct should be

  * initialized by using vorbis_info_init() from the libvorbis API. After

  * encoding, vorbis_info_clear() should be called.

  *

  * \param vi           Pointer to an initialized vorbis_info struct.

  * \param channels     The number of channels to be encoded.

  * \param rate         The sampling rate of the source audio.

  * \param base_quality Desired quality level, currently from -0.1 to 1.0 (lo to hi).

  *

  *

  * \return Zero for success, or a negative number for failure.

  *

  * \retval 0           Success

  * \retval OV_EFAULT   Internal logic fault; indicates a bug or heap/stack corruption.

  * \retval OV_EINVAL   Invalid setup request, eg, out of range argument.

  * \retval OV_EIMPL    Unimplemented mode; unable to comply with quality level request.

  */

 extern int vorbis_encode_init_vbr(vorbis_info *vi,

                                   long channels,

                                   long rate,

                                   float base_quality

                                   );

 /**

  * This function performs the last stage of three-step encoding setup, as

  * described in the API overview under managed bitrate modes.

  *

  * Before this function is called, the \ref vorbis_info struct should be

  * initialized by using vorbis_info_init() from the libvorbis API, one of

  * \ref vorbis_encode_setup_managed() or \ref vorbis_encode_setup_vbr() called to

  * initialize the high-level encoding setup, and \ref vorbis_encode_ctl()

  * called if necessary to make encoding setup changes.

  * vorbis_encode_setup_init() finalizes the highlevel encoding structure into

  * a complete encoding setup after which the application may make no further

  * setup changes.

  *

  * After encoding, vorbis_info_clear() should be called.

  *

  * \param vi Pointer to an initialized \ref vorbis_info struct.

  *

  * \return Zero for success, and negative values for failure.

  *

  * \retval  0           Success.

  * \retval  OV_EFAULT  Internal logic fault; indicates a bug or heap/stack corruption.

  *

  * \retval OV_EINVAL   Attempt to use vorbis_encode_setup_init() without first

  * calling one of vorbis_encode_setup_managed() or vorbis_encode_setup_vbr() to

  * initialize the high-level encoding setup

  *

  */

 extern int vorbis_encode_setup_init(vorbis_info *vi);

 /**

  * This function implements a generic interface to miscellaneous encoder

  * settings similar to the classic UNIX 'ioctl()' system call.  Applications

  * may use vorbis_encode_ctl() to query or set bitrate management or quality

  * mode details by using one of several \e request arguments detailed below.

  * vorbis_encode_ctl() must be called after one of

  * vorbis_encode_setup_managed() or vorbis_encode_setup_vbr().  When used

  * to modify settings, \ref vorbis_encode_ctl() must be called before \ref

  * vorbis_encode_setup_init().

  *

  * \param vi      Pointer to an initialized vorbis_info struct.

  *

  * \param number Specifies the desired action; See \ref encctlcodes "the list

  * of available requests".

  *

  * \param arg void * pointing to a data structure matching the request

  * argument.

  *

  * \retval 0          Success. Any further return information (such as the result of a

  * query) is placed into the storage pointed to by *arg.

  *

  * \retval OV_EINVAL  Invalid argument, or an attempt to modify a setting after

  * calling vorbis_encode_setup_init().

  *

  * \retval OV_EIMPL   Unimplemented or unknown request

  */

 extern int vorbis_encode_ctl(vorbis_info *vi,int number,void *arg);

 /**

  * \deprecated This is a deprecated interface. Please use vorbis_encode_ctl()

  * with the \ref ovectl_ratemanage2_arg struct and \ref

  * OV_ECTL_RATEMANAGE2_GET and \ref OV_ECTL_RATEMANAGE2_SET calls in new code.

  *

  * The \ref ovectl_ratemanage_arg structure is used with vorbis_encode_ctl()

  * and the \ref OV_ECTL_RATEMANAGE_GET, \ref OV_ECTL_RATEMANAGE_SET, \ref

  * OV_ECTL_RATEMANAGE_AVG, \ref OV_ECTL_RATEMANAGE_HARD calls in order to

  * query and modify specifics of the encoder's bitrate management

  * configuration.

 */

 struct ovectl_ratemanage_arg {

   int    management_active; /**< nonzero if bitrate management is active*/

 /** hard lower limit (in kilobits per second) below which the stream bitrate

     will never be allowed for any given bitrate_hard_window seconds of time.*/

   long   bitrate_hard_min;

 /** hard upper limit (in kilobits per second) above which the stream bitrate

     will never be allowed for any given bitrate_hard_window seconds of time.*/

   long   bitrate_hard_max;

 /** the window period (in seconds) used to regulate the hard bitrate minimum

     and maximum*/

   double bitrate_hard_window;

 /** soft lower limit (in kilobits per second) below which the average bitrate

     tracker will start nudging the bitrate higher.*/

   long   bitrate_av_lo;

 /** soft upper limit (in kilobits per second) above which the average bitrate

     tracker will start nudging the bitrate lower.*/

   long   bitrate_av_hi;

 /** the window period (in seconds) used to regulate the average bitrate

     minimum and maximum.*/

   double bitrate_av_window;

 /** Regulates the relative centering of the average and hard windows; in

     libvorbis 1.0 and 1.0.1, the hard window regulation overlapped but

     followed the average window regulation. In libvorbis 1.1 a bit-reservoir

     interface replaces the old windowing interface; the older windowing

     interface is simulated and this field has no effect.*/

   double bitrate_av_window_center;

 };

 /**

  * \name struct ovectl_ratemanage2_arg

  *

  * The ovectl_ratemanage2_arg structure is used with vorbis_encode_ctl() and

  * the OV_ECTL_RATEMANAGE2_GET and OV_ECTL_RATEMANAGE2_SET calls in order to

  * query and modify specifics of the encoder's bitrate management

  * configuration.

  *

 */

 struct ovectl_ratemanage2_arg {

   int    management_active; /**< nonzero if bitrate management is active */

 /** Lower allowed bitrate limit in kilobits per second */

   long   bitrate_limit_min_kbps;

 /** Upper allowed bitrate limit in kilobits per second */

   long   bitrate_limit_max_kbps;

   long   bitrate_limit_reservoir_bits; /**<Size of the bitrate reservoir in bits */

 /** Regulates the bitrate reservoir's preferred fill level in a range from 0.0

  * to 1.0; 0.0 tries to bank bits to buffer against future bitrate spikes, 1.0

  * buffers against future sudden drops in instantaneous bitrate. Default is

  * 0.1

  */

   double bitrate_limit_reservoir_bias;

 /** Average bitrate setting in kilobits per second */

   long   bitrate_average_kbps;

 /** Slew rate limit setting for average bitrate adjustment; sets the minimum

  *  time in seconds the bitrate tracker may swing from one extreme to the

  *  other when boosting or damping average bitrate.

  */

   double bitrate_average_damping;

 };

 /**

  * \name vorbis_encode_ctl() codes

  *

  * \anchor encctlcodes

  *

  * These values are passed as the \c number parameter of vorbis_encode_ctl().

  * The type of the referent of that function's \c arg pointer depends on these

  * codes.

  */

 /*@{*/

 /**

  * Query the current encoder bitrate management setting.

  *

  *Argument: <tt>struct ovectl_ratemanage2_arg *</tt>

  *

  * Used to query the current encoder bitrate management setting. Also used to

  * initialize fields of an ovectl_ratemanage2_arg structure for use with

  * \ref OV_ECTL_RATEMANAGE2_SET.

  */

 #define OV_ECTL_RATEMANAGE2_GET      0x14

 /**

  * Set the current encoder bitrate management settings.

  *

  * Argument: <tt>struct ovectl_ratemanage2_arg *</tt>

  *

  * Used to set the current encoder bitrate management settings to the values

  * listed in the ovectl_ratemanage2_arg. Passing a NULL pointer will disable

  * bitrate management.

 */

 #define OV_ECTL_RATEMANAGE2_SET      0x15

 /**

  * Returns the current encoder hard-lowpass setting (kHz) in the double

  * pointed to by arg.

  *

  * Argument: <tt>double *</tt>

 */

 #define OV_ECTL_LOWPASS_GET          0x20

 /**

  *  Sets the encoder hard-lowpass to the value (kHz) pointed to by arg. Valid

  *  lowpass settings range from 2 to 99.

  *

  * Argument: <tt>double *</tt>

 */

 #define OV_ECTL_LOWPASS_SET          0x21

 /**

  *  Returns the current encoder impulse block setting in the double pointed

  *  to by arg.

  *

  * Argument: <tt>double *</tt>

 */

 #define OV_ECTL_IBLOCK_GET           0x30

 /**

  *  Sets the impulse block bias to the the value pointed to by arg.

  *

  * Argument: <tt>double *</tt>

  *

  *  Valid range is -15.0 to 0.0 [default]. A negative impulse block bias will

  *  direct to encoder to use more bits when incoding short blocks that contain

  *  strong impulses, thus improving the accuracy of impulse encoding.

  */

 #define OV_ECTL_IBLOCK_SET           0x31

 /**

  *  Returns the current encoder coupling setting in the int pointed

  *  to by arg.

  *

  * Argument: <tt>int *</tt>

 */

 #define OV_ECTL_COUPLING_GET         0x40

 /**

  *  Enables/disables channel coupling in multichannel encoding according to arg.

  *

  * Argument: <tt>int *</tt>

  *

  *  Zero disables channel coupling for multichannel inputs, nonzer enables

  *  channel coupling.  Setting has no effect on monophonic encoding or

  *  multichannel counts that do not offer coupling.  At present, coupling is

  *  available for stereo and 5.1 encoding.

  */

 #define OV_ECTL_COUPLING_SET         0x41

   /* deprecated rate management supported only for compatibility */

 /**

  * Old interface to querying bitrate management settings.

  *

  * Deprecated after move to bit-reservoir style management in 1.1 rendered

  * this interface partially obsolete.

  * \deprecated Please use \ref OV_ECTL_RATEMANAGE2_GET instead.

  *

  * Argument: <tt>struct ovectl_ratemanage_arg *</tt>

  */

 #define OV_ECTL_RATEMANAGE_GET       0x10

 /**

  * Old interface to modifying bitrate management settings.

  *

  *  deprecated after move to bit-reservoir style management in 1.1 rendered

  *  this interface partially obsolete.

  *

  * \deprecated Please use \ref OV_ECTL_RATEMANAGE2_SET instead.

  *

  * Argument: <tt>struct ovectl_ratemanage_arg *</tt>

  */

 #define OV_ECTL_RATEMANAGE_SET       0x11

 /**

  * Old interface to setting average-bitrate encoding mode.

  *

  * Deprecated after move to bit-reservoir style management in 1.1 rendered

  * this interface partially obsolete.

  *

  *  \deprecated Please use \ref OV_ECTL_RATEMANAGE2_SET instead.

  *

  * Argument: <tt>struct ovectl_ratemanage_arg *</tt>

  */

 #define OV_ECTL_RATEMANAGE_AVG       0x12

 /**

  * Old interface to setting bounded-bitrate encoding modes.

  *

  * deprecated after move to bit-reservoir style management in 1.1 rendered

  * this interface partially obsolete.

  *

  *  \deprecated Please use \ref OV_ECTL_RATEMANAGE2_SET instead.

  *

  * Argument: <tt>struct ovectl_ratemanage_arg *</tt>

  */

 #define OV_ECTL_RATEMANAGE_HARD      0x13

 /*@}*/

 #ifdef __cplusplus

 }

 #endif /* __cplusplus */

 #endif