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libvorbisenc documentation

libvorbisenc release 1.1 - 20040709

vorbis_encode_ctl

declared in "vorbis/libvorbisenc.h";

This function implements a generic interface to miscellaneous encoder settings similar to the clasasic 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 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, vorbis_encode_ctl() must be called before vorbis_encode_setup_init().




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

Parameters

vi
File pointer to an initialized vorbis_info struct.

request
Specifies the desired action; possible request fields are detailed below.

arg
void * pointing to a data structure matching the request argument.

Requests

OV_ECTL_RATEMANAGE2_GET
Argument: struct ovectl_ratemanage2_arg *
Used to query the current encoder bitrate management setting. Also used to initialize fields of an ovectl_ratemanage2_arg structure for use with OV_ECTL_RATEMANAGE2_SET.

OV_ECTL_RATEMANAGE2_SET
Argument: struct ovectl_ratemanage2_arg *
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.

OV_ECTL_LOWPASS_GET
Argument: double *
Returns the current encoder hard-lowpass setting (kHz) in the double pointed to by arg.

OV_ECTL_LOWPASS_SET
Argument: double *
Sets the encoder hard-lowpass to the value (kHz) pointed to by arg. Valid lowpass settings range from 2 to 99.

OV_ECTL_IBLOCK_GET
Argument: double *
Returns the current encoder impulse block setting in the double pointed to by arg.

OV_ECTL_IBLOCK_SET
Argument: double *
Sets the impulse block bias to the the value pointed to by arg; 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.

OV_ECTL_RATEMANAGE_GET [deprecated]
Argument: struct ovectl_ratemanage_arg *
Old interface to querying bitrate management settings; deprecated after move to bit-reservoir style management in 1.1 rendered this interface partially obsolete. Please use OV_ECTL_RATEMANGE2_GET instead.

OV_ECTL_RATEMANAGE_SET [deprecated]
Argument: struct ovectl_ratemanage_arg *
Old interface to modifying bitrate management settings; deprecated after move to bit-reservoir style management in 1.1 rendered this interface partially obsolete. Please use OV_ECTL_RATEMANGE2_SET instead.

OV_ECTL_RATEMANAGE_AVG [deprecated]
Argument: struct ovectl_ratemanage_arg *
Old interface to setting average-bitrate encoding mode; deprecated after move to bit-reservoir style management in 1.1 rendered this interface partially obsolete. Please use OV_ECTL_RATEMANGE2_SET instead.

OV_ECTL_RATEMANAGE_HARD [deprecated]
Argument: struct ovectl_ratemanage_arg *
Old interface to setting bounded-bitrate encoding modes; deprecated after move to bit-reservoir style management in 1.1 rendered this interface partially obsolete. Please use OV_ECTL_RATEMANGE2_SET instead.

Return Values

vorbis_encode_ctl() returns zero on success, placing any further return information (such as the result of a query) into the storage pointed to by *arg. On error, vorbis_encode_ctl() may return one of the following error codes:
OV_EINVAL
Invalid argument, or an attempt to modify a setting after calling vorbis_encode_setup_init().

OV_EIMPL
Unimplemented or unknown request




copyright © 2004 xiph.org

Ogg Vorbis
team@vorbis.org

libvorbisenc documentation

libvorbisenc release 1.1 - 20040709