ref: b9745c60a1bf2a3876e411d38c67a0980d70e3a3
dir: /sys/src/cmd/audio/libvorbis/vorbis/vorbisenc.h/
/******************************************************************** * * * 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