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22 #ifndef AVCODEC_PSYMODEL_H
23 #define AVCODEC_PSYMODEL_H
28 #define PSY_MAX_BANDS 128
30 #define PSY_MAX_CHANS 20
35 #define AAC_CUTOFF_FROM_BITRATE(bit_rate,channels,sample_rate) (bit_rate ? FFMIN3(FFMIN3( \
36 FFMAX(bit_rate/channels/5, bit_rate/channels*15/32 - 5500), \
37 3000 + bit_rate/channels/4, \
38 12000 + bit_rate/channels/16), \
40 sample_rate / 2): (sample_rate / 2))
41 #define AAC_CUTOFF(s) ( \
42 (s->flags & AV_CODEC_FLAG_QSCALE) \
43 ? s->sample_rate / 2 \
44 : AAC_CUTOFF_FROM_BITRATE(s->bit_rate, s->ch_layout.nb_channels, s->sample_rate) \
158 const uint8_t **
bands,
const int *num_bands,
159 int num_groups,
const uint8_t *group_map);
void ff_psy_preprocess_end(struct FFPsyPreprocessContext *ctx)
Cleanup audio preprocessing module.
FFPsyChannelGroup * group
channel group information
single channel psychoacoustic information
int bits
number of bits used in the bitresevoir
int size
size of the bitresevoir in bits
int num_groups
number of channel groups
void ff_psy_end(FFPsyContext *ctx)
Cleanup model context at the end.
int window_shape
window shape (sine/KBD/whatever)
void ff_psy_preprocess(struct FFPsyPreprocessContext *ctx, float **audio, int channels)
Preprocess several channel in audio frame in order to compress it better.
FFPsyChannel * ch[PSY_MAX_CHANS]
pointers to the individual channels in the group
struct FFPsyPreprocessContext * ff_psy_preprocess_init(AVCodecContext *avctx)
psychoacoustic model audio preprocessing initialization
int(* init)(FFPsyContext *apc)
int * num_bands
number of scalefactor bands for possible frame sizes
windowing related information
uint8_t num_ch
number of channels in this group
static const float bands[]
int window_type[3]
window type (short/long/transitional, etc.) - current, previous and next
int num_lens
number of scalefactor band sets
single band psychoacoustic information
uint8_t ** bands
scalefactor band sizes for possible frame sizes
int grouping[8]
window grouping (for e.g. AAC)
#define PSY_MAX_BANDS
maximum possible number of bands
float clipping[8]
maximum absolute normalized intensity in the given window for clip avoidance
uint8_t coupling[PSY_MAX_BANDS]
allow coupling for this band in the group
FFPsyBand psy_bands[PSY_MAX_BANDS]
channel bands information
FFPsyWindowInfo(* window)(FFPsyContext *ctx, const float *audio, const float *la, int channel, int prev_type)
Suggest window sequence for channel.
FFPsyChannelGroup * ff_psy_find_group(FFPsyContext *ctx, int channel)
Determine what group a channel belongs to.
FFPsyChannel * ch
single channel information
#define PSY_MAX_CHANS
maximum number of channels
int * window_sizes
sequence of window sizes inside one frame (for eg. WMA)
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.
struct FFPsyContext::@196 bitres
int alloc
number of bits allocated by the psy, or -1 if no allocation was done
void(* end)(FFPsyContext *apc)
psychoacoustic information for an arbitrary group of channels
void(* analyze)(FFPsyContext *ctx, int channel, const float **coeffs, const FFPsyWindowInfo *wi)
Perform psychoacoustic analysis and set band info (threshold, energy) for a group of channels.
void * model_priv_data
psychoacoustic model implementation private data
main external API structure.
AVCodecContext * avctx
encoder context
codec-specific psychoacoustic model implementation
int cutoff
lowpass frequency cutoff for analysis
const struct FFPsyModel * model
encoder-specific model functions
float entropy
total PE for this channel
context used by psychoacoustic model
int num_windows
number of windows in a frame