Rename ffmpeg-4.2-fit to ffmpeg-4-fit

trunk/3rdparty/ffmpeg-4-fit/libavcodec/psymodel.h

@@ -0,0 +1,204 @@
+/*
+ * audio encoder psychoacoustic model
+ * Copyright (C) 2008 Konstantin Shishkov
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_PSYMODEL_H
+#define AVCODEC_PSYMODEL_H
+
+#include "avcodec.h"
+
+/** maximum possible number of bands */
+#define PSY_MAX_BANDS 128
+/** maximum number of channels */
+#define PSY_MAX_CHANS 20
+
+/* cutoff for VBR is purposely increased, since LP filtering actually
+ * hinders VBR performance rather than the opposite
+ */
+#define AAC_CUTOFF_FROM_BITRATE(bit_rate,channels,sample_rate) (bit_rate ? FFMIN3(FFMIN3( \
+    FFMAX(bit_rate/channels/5, bit_rate/channels*15/32 - 5500), \
+    3000 + bit_rate/channels/4, \
+    12000 + bit_rate/channels/16), \
+    22000, \
+    sample_rate / 2): (sample_rate / 2))
+#define AAC_CUTOFF(s) ( \
+    (s->flags & AV_CODEC_FLAG_QSCALE) \
+    ? s->sample_rate / 2 \
+    : AAC_CUTOFF_FROM_BITRATE(s->bit_rate, s->channels, s->sample_rate) \
+)
+
+/**
+ * single band psychoacoustic information
+ */
+typedef struct FFPsyBand {
+    int   bits;
+    float energy;
+    float threshold;
+    float spread;    /* Energy spread over the band */
+} FFPsyBand;
+
+/**
+ * single channel psychoacoustic information
+ */
+typedef struct FFPsyChannel {
+    FFPsyBand psy_bands[PSY_MAX_BANDS]; ///< channel bands information
+    float     entropy;                  ///< total PE for this channel
+} FFPsyChannel;
+
+/**
+ * psychoacoustic information for an arbitrary group of channels
+ */
+typedef struct FFPsyChannelGroup {
+    FFPsyChannel *ch[PSY_MAX_CHANS];  ///< pointers to the individual channels in the group
+    uint8_t num_ch;                   ///< number of channels in this group
+    uint8_t coupling[PSY_MAX_BANDS];  ///< allow coupling for this band in the group
+} FFPsyChannelGroup;
+
+/**
+ * windowing related information
+ */
+typedef struct FFPsyWindowInfo {
+    int window_type[3];               ///< window type (short/long/transitional, etc.) - current, previous and next
+    int window_shape;                 ///< window shape (sine/KBD/whatever)
+    int num_windows;                  ///< number of windows in a frame
+    int grouping[8];                  ///< window grouping (for e.g. AAC)
+    float clipping[8];                ///< maximum absolute normalized intensity in the given window for clip avoidance
+    int *window_sizes;                ///< sequence of window sizes inside one frame (for eg. WMA)
+} FFPsyWindowInfo;
+
+/**
+ * context used by psychoacoustic model
+ */
+typedef struct FFPsyContext {
+    AVCodecContext *avctx;            ///< encoder context
+    const struct FFPsyModel *model;   ///< encoder-specific model functions
+
+    FFPsyChannel      *ch;            ///< single channel information
+    FFPsyChannelGroup *group;         ///< channel group information
+    int num_groups;                   ///< number of channel groups
+    int cutoff;                       ///< lowpass frequency cutoff for analysis
+
+    uint8_t **bands;                  ///< scalefactor band sizes for possible frame sizes
+    int     *num_bands;               ///< number of scalefactor bands for possible frame sizes
+    int num_lens;                     ///< number of scalefactor band sets
+
+    struct {
+        int size;                     ///< size of the bitresevoir in bits
+        int bits;                     ///< number of bits used in the bitresevoir
+        int alloc;                    ///< number of bits allocated by the psy, or -1 if no allocation was done
+    } bitres;
+
+    void* model_priv_data;            ///< psychoacoustic model implementation private data
+} FFPsyContext;
+
+/**
+ * codec-specific psychoacoustic model implementation
+ */
+typedef struct FFPsyModel {
+    const char *name;
+    int  (*init)   (FFPsyContext *apc);
+
+    /**
+     * Suggest window sequence for channel.
+     *
+     * @param ctx       model context
+     * @param audio     samples for the current frame
+     * @param la        lookahead samples (NULL when unavailable)
+     * @param channel   number of channel element to analyze
+     * @param prev_type previous window type
+     *
+     * @return suggested window information in a structure
+     */
+    FFPsyWindowInfo (*window)(FFPsyContext *ctx, const float *audio, const float *la, int channel, int prev_type);
+
+    /**
+     * Perform psychoacoustic analysis and set band info (threshold, energy) for a group of channels.
+     *
+     * @param ctx      model context
+     * @param channel  channel number of the first channel in the group to perform analysis on
+     * @param coeffs   array of pointers to the transformed coefficients
+     * @param wi       window information for the channels in the group
+     */
+    void (*analyze)(FFPsyContext *ctx, int channel, const float **coeffs, const FFPsyWindowInfo *wi);
+
+    void (*end)    (FFPsyContext *apc);
+} FFPsyModel;
+
+/**
+ * Initialize psychoacoustic model.
+ *
+ * @param ctx        model context
+ * @param avctx      codec context
+ * @param num_lens   number of possible frame lengths
+ * @param bands      scalefactor band lengths for all frame lengths
+ * @param num_bands  number of scalefactor bands for all frame lengths
+ * @param num_groups number of channel groups
+ * @param group_map  array with # of channels in group - 1, for each group
+ *
+ * @return zero if successful, a negative value if not
+ */
+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);
+
+/**
+ * Determine what group a channel belongs to.
+ *
+ * @param ctx     psymodel context
+ * @param channel channel to locate the group for
+ *
+ * @return pointer to the FFPsyChannelGroup this channel belongs to
+ */
+FFPsyChannelGroup *ff_psy_find_group(FFPsyContext *ctx, int channel);
+
+/**
+ * Cleanup model context at the end.
+ *
+ * @param ctx model context
+ */
+void ff_psy_end(FFPsyContext *ctx);
+
+
+/**************************************************************************
+ *                       Audio preprocessing stuff.                       *
+ *       This should be moved into some audio filter eventually.          *
+ **************************************************************************/
+struct FFPsyPreprocessContext;
+
+/**
+ * psychoacoustic model audio preprocessing initialization
+ */
+struct FFPsyPreprocessContext *ff_psy_preprocess_init(AVCodecContext *avctx);
+
+/**
+ * Preprocess several channel in audio frame in order to compress it better.
+ *
+ * @param ctx      preprocessing context
+ * @param audio    samples to be filtered (in place)
+ * @param channels number of channel to preprocess
+ */
+void ff_psy_preprocess(struct FFPsyPreprocessContext *ctx, float **audio, int channels);
+
+/**
+ * Cleanup audio preprocessing module.
+ */
+void ff_psy_preprocess_end(struct FFPsyPreprocessContext *ctx);
+
+#endif /* AVCODEC_PSYMODEL_H */