libavcodec/psymodel.h File Reference

#include "avcodec.h"

Go to the source code of this file.

Data Structures
struct	FFPsyBand
	single band psychoacoustic information More...
struct	FFPsyChannel
	single channel psychoacoustic information More...
struct	FFPsyChannelGroup
	psychoacoustic information for an arbitrary group of channels More...
struct	FFPsyWindowInfo
	windowing related information More...
struct	FFPsyContext
	context used by psychoacoustic model More...
struct	FFPsyModel
	codec-specific psychoacoustic model implementation More...
Defines
#define	PSY_MAX_BANDS   128
	maximum possible number of bands
#define	PSY_MAX_CHANS   20
	maximum number of channels
Functions
av_cold int	ff_psy_init (FFPsyContext *ctx, AVCodecContext *avctx, int num_lens, const uint8_t **bands, const int *num_bands, int num_groups, const uint8_t *group_map)
	Initialize psychoacoustic model.
FFPsyChannelGroup *	ff_psy_find_group (FFPsyContext *ctx, int channel)
	Determine what group a channel belongs to.
av_cold void	ff_psy_end (FFPsyContext *ctx)
	Cleanup model context at the end.
av_cold struct FFPsyPreprocessContext *	ff_psy_preprocess_init (AVCodecContext *avctx)
	psychoacoustic model audio preprocessing initialization
void	ff_psy_preprocess (struct FFPsyPreprocessContext *ctx, float **audio, int channels)
	Preprocess several channel in audio frame in order to compress it better.
av_cold void	ff_psy_preprocess_end (struct FFPsyPreprocessContext *ctx)
	Cleanup audio preprocessing module.

---

Define Documentation

#define PSY_MAX_BANDS   128

maximum possible number of bands

Definition at line 28 of file psymodel.h.

#define PSY_MAX_CHANS   20

maximum number of channels

Definition at line 30 of file psymodel.h.

---

Function Documentation

av_cold void ff_psy_end

(

FFPsyContext *

ctx

)

Cleanup model context at the end.

Parameters:

ctx

model context

Definition at line 73 of file psymodel.c.

Referenced by aac_encode_end().

FFPsyChannelGroup* ff_psy_find_group	(	FFPsyContext *	ctx,
		int	channel
	)

Determine what group a channel belongs to.

Parameters:

	ctx	psymodel context
	channel	channel to locate the group for

Returns:

pointer to the FFPsyChannelGroup this channel belongs to

Definition at line 63 of file psymodel.c.

Referenced by psy_3gpp_analyze().

av_cold int ff_psy_init	(	FFPsyContext *	ctx,
		AVCodecContext *	avctx,
		int	num_lens,
		const uint8_t **	bands,
		const int *	num_bands,
		int	num_groups,
		const uint8_t *	group_map
	)

Initialize psychoacoustic model.

Parameters:

	ctx	model context
	avctx	codec context
	num_lens	number of possible frame lengths
	bands	scalefactor band lengths for all frame lengths
	num_bands	number of scalefactor bands for all frame lengths
	num_groups	number of channel groups
	group_map	array with # of channels in group - 1, for each group

Returns:

zero if successful, a negative value if not

Definition at line 28 of file psymodel.c.

Referenced by aac_encode_init().

void ff_psy_preprocess	(	struct FFPsyPreprocessContext *	ctx,
		float **	audio,
		int	channels
	)

Preprocess several channel in audio frame in order to compress it better.

Parameters:

	ctx	preprocessing context
	audio	samples to be filtered (in place)
	channels	number of channel to preprocess

Definition at line 115 of file psymodel.c.

Referenced by aac_encode_frame().

av_cold void ff_psy_preprocess_end

(

struct FFPsyPreprocessContext *

ctx

)

Cleanup audio preprocessing module.

Definition at line 127 of file psymodel.c.

Referenced by aac_encode_end().

av_cold struct FFPsyPreprocessContext* ff_psy_preprocess_init

(

AVCodecContext *

avctx

)

[read]

psychoacoustic model audio preprocessing initialization

Definition at line 92 of file psymodel.c.

Referenced by aac_encode_init().