vorbis_encode_setup_vbr

declared in "vorbis/libvorbisenc.h";

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 vorbis_encode_init_vbr() but allows an application to make further encode setup tweaks using vorbis_encode_ctl() before finally calling vorbis_encode_setup_init() to complete the setup process.

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.

extern int vorbis_encode_init_vbr(vorbis_info *vi, long channels, long rate, float base_quality);

Parameters

vi

File pointer to an initialized vorbis_info struct.

channels

The number of channels to be encoded.

rate

The sampling rate of the source audio.

base_quality

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

Return Values

0 for success

less than zero for failure:

• OV_EFAULT - Internal logic fault; indicates a bug or heap/stack corruption.
• OV_EINVAL - Invalid setup request, eg, out of range argument.
• OV_EIMPL - Unimplemented mode; unable to comply with quality level request.