move the decode context and some macro constants to a new file, ac3dec.h

Originally committed as revision 13697 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 122 insertions, 0 deletions

diff --git a/libavcodec/ac3dec.h b/libavcodec/ac3dec.h
new file mode 100644
index 0000000000..95d9fbf0d1
--- /dev/null
+++ b/libavcodec/ac3dec.h
@@ -0,0 +1,122 @@
+/*
+ * Common code between AC3 and E-AC3 decoder
+ * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
+ *
+ * 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
+ */
+
+/**
+ * @file ac3.h
+ * Common code between AC3 and E-AC3 decoder.
+ */
+
+#ifndef FFMPEG_AC3DEC_H
+#define FFMPEG_AC3DEC_H
+
+#include "libavutil/random.h"
+#include "ac3tab.h"
+#include "ac3.h"
+#include "bitstream.h"
+#include "dsputil.h"
+
+/* override ac3.h to include coupling channel */
+#undef AC3_MAX_CHANNELS
+#define AC3_MAX_CHANNELS 7
+#define CPL_CH 0
+
+#define AC3_OUTPUT_LFEON  8
+
+typedef struct {
+    int num_blocks;                         ///< number of audio blocks
+    int channel_mode;                       ///< channel mode (acmod)
+    int block_switch[AC3_MAX_CHANNELS];     ///< block switch flags
+    int dither_flag[AC3_MAX_CHANNELS];      ///< dither flags
+    int dither_all;                         ///< true if all channels are dithered
+    int cpl_in_use;                         ///< coupling in use
+    int channel_in_cpl[AC3_MAX_CHANNELS];   ///< channel in coupling
+    int phase_flags_in_use;                 ///< phase flags in use
+    int phase_flags[18];                    ///< phase flags
+    int cpl_band_struct[18];                ///< coupling band structure
+    int num_rematrixing_bands;              ///< number of rematrixing bands
+    int rematrixing_flags[4];               ///< rematrixing flags
+    int exp_strategy[AC3_MAX_CHANNELS];     ///< exponent strategies
+    int snr_offset[AC3_MAX_CHANNELS];       ///< signal-to-noise ratio offsets
+    int fast_gain[AC3_MAX_CHANNELS];        ///< fast gain values (signal-to-mask ratio)
+    int dba_mode[AC3_MAX_CHANNELS];         ///< delta bit allocation mode
+    int dba_nsegs[AC3_MAX_CHANNELS];        ///< number of delta segments
+    uint8_t dba_offsets[AC3_MAX_CHANNELS][8]; ///< delta segment offsets
+    uint8_t dba_lengths[AC3_MAX_CHANNELS][8]; ///< delta segment lengths
+    uint8_t dba_values[AC3_MAX_CHANNELS][8];  ///< delta values for each segment
+
+    int sample_rate;                        ///< sample frequency, in Hz
+    int bit_rate;                           ///< stream bit rate, in bits-per-second
+    int frame_type;                         ///< frame type (strmtyp)
+    int substreamid;                        ///< substream identification
+    int frame_size;                         ///< current frame size, in bytes
+
+    int channels;                           ///< number of total channels
+    int fbw_channels;                       ///< number of full-bandwidth channels
+    int lfe_on;                             ///< lfe channel in use
+    int lfe_ch;                             ///< index of LFE channel
+    int output_mode;                        ///< output channel configuration
+    int out_channels;                       ///< number of output channels
+
+    int center_mix_level;                   ///< Center mix level index
+    int surround_mix_level;                 ///< Surround mix level index
+    float downmix_coeffs[AC3_MAX_CHANNELS][2];  ///< stereo downmix coefficients
+    float downmix_coeff_adjust[2];          ///< adjustment needed for each output channel when downmixing
+    float dynamic_range[2];                 ///< dynamic range
+    int   cpl_coords[AC3_MAX_CHANNELS][18]; ///< coupling coordinates
+    int   num_cpl_bands;                    ///< number of coupling bands
+    int   num_cpl_subbands;                 ///< number of coupling sub bands
+    int   start_freq[AC3_MAX_CHANNELS];     ///< start frequency bin
+    int   end_freq[AC3_MAX_CHANNELS];       ///< end frequency bin
+    AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters
+
+    int num_exp_groups[AC3_MAX_CHANNELS];   ///< Number of exponent groups
+    int8_t  dexps[AC3_MAX_CHANNELS][256];   ///< decoded exponents
+    uint8_t bap[AC3_MAX_CHANNELS][256];     ///< bit allocation pointers
+    int16_t psd[AC3_MAX_CHANNELS][256];     ///< scaled exponents
+    int16_t band_psd[AC3_MAX_CHANNELS][50]; ///< interpolated exponents
+    int16_t mask[AC3_MAX_CHANNELS][50];     ///< masking curve values
+
+    int fixed_coeffs[AC3_MAX_CHANNELS][256];    ///> fixed-point transform coefficients
+    DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][256]);  ///< transform coefficients
+    int downmixed;                              ///< indicates if coeffs are currently downmixed
+
+    /* For IMDCT. */
+    MDCTContext imdct_512;                  ///< for 512 sample IMDCT
+    MDCTContext imdct_256;                  ///< for 256 sample IMDCT
+    DSPContext  dsp;                        ///< for optimization
+    float       add_bias;                   ///< offset for float_to_int16 conversion
+    float       mul_bias;                   ///< scaling for float_to_int16 conversion
+
+    DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS][256]);       ///< output after imdct transform and windowing
+    DECLARE_ALIGNED_16(short, int_output[AC3_MAX_CHANNELS-1][256]); ///< final 16-bit integer output
+    DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS][256]);        ///< delay - added to the next block
+    DECLARE_ALIGNED_16(float, tmp_imdct[256]);                      ///< temporary storage for imdct transform
+    DECLARE_ALIGNED_16(float, tmp_output[512]);                     ///< temporary storage for output before windowing
+    DECLARE_ALIGNED_16(float, window[256]);                         ///< window coefficients
+
+    /* Miscellaneous. */
+    GetBitContext gbc;                      ///< bitstream reader
+    AVRandomState dith_state;               ///< for dither generation
+    AVCodecContext *avctx;                  ///< parent context
+    uint8_t *input_buffer;                  ///< temp buffer to prevent overread
+} AC3DecodeContext;
+
+#endif /* FFMPEG_AC3DEC_H */