Merge the AAC encoder from SoC svn. It is still considered experimental.

Originally committed as revision 19375 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 158 insertions, 0 deletions

diff --git a/libavcodec/psymodel.h b/libavcodec/psymodel.h
new file mode 100644
index 0000000000..5bcf556f0b
--- /dev/null
+++ b/libavcodec/psymodel.h
@@ -0,0 +1,158 @@
+/*
+ * 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
+
+/**
+ * single band psychoacoustic information
+ */
+typedef struct FFPsyBand{
+    int   bits;
+    float energy;
+    float threshold;
+    float distortion;
+    float perceptual_weight;
+}FFPsyBand;
+
+/**
+ * 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)
+    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
+
+    FFPsyBand *psy_bands;             ///< frame bands information
+
+    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
+
+    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);
+    FFPsyWindowInfo (*window)(FFPsyContext *ctx, const int16_t *audio, const int16_t *la, int channel, int prev_type);
+    void (*analyze)(FFPsyContext *ctx, int channel, const float *coeffs, 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
+ *
+ * @return zero if successful, a negative value if not
+ */
+av_cold int ff_psy_init(FFPsyContext *ctx, AVCodecContext *avctx,
+                        int num_lens,
+                        const uint8_t **bands, const int* num_bands);
+
+/**
+ * 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 ff_psy_suggest_window(FFPsyContext *ctx,
+                                      const int16_t *audio, const int16_t *la,
+                                      int channel, int prev_type);
+
+
+/**
+ * Perform psychoacoustic analysis and set band info (threshold, energy).
+ *
+ * @param ctx     model context
+ * @param channel audio channel number
+ * @param coeffs  pointer to the transformed coefficients
+ * @param wi      window information
+ */
+void ff_psy_set_band_info(FFPsyContext *ctx, int channel, const float *coeffs,
+                          FFPsyWindowInfo *wi);
+
+/**
+ * Cleanup model context at the end.
+ *
+ * @param ctx model context
+ */
+av_cold 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
+ */
+av_cold 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 preprocess
+ * @param dest     place to put filtered samples
+ * @param tag      channel number
+ * @param channels number of channel to preprocess (some additional work may be done on stereo pair)
+ */
+void ff_psy_preprocess(struct FFPsyPreprocessContext *ctx,
+                       const int16_t *audio, int16_t *dest,
+                       int tag, int channels);
+
+/**
+ * Cleanup audio preprocessing module.
+ */
+av_cold void ff_psy_preprocess_end(struct FFPsyPreprocessContext *ctx);
+
+#endif /* AVCODEC_PSYMODEL_H */