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1 /*
2  * Copyright (C) 2016 foo86
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_DCA_CORE_H
22 #define AVCODEC_DCA_CORE_H
23 
24 #include "libavutil/common.h"
25 #include "libavutil/float_dsp.h"
26 #include "libavutil/fixed_dsp.h"
27 #include "libavutil/mem_internal.h"
28 
29 #include "avcodec.h"
30 #include "internal.h"
31 #include "get_bits.h"
32 #include "dca.h"
33 #include "dca_exss.h"
34 #include "dcadsp.h"
35 #include "dcadct.h"
36 #include "dcamath.h"
37 #include "dcahuff.h"
38 #include "fft.h"
39 #include "synth_filter.h"
40 
41 #define DCA_CHANNELS            7
42 #define DCA_SUBBANDS            32
43 #define DCA_SUBBANDS_X96        64
44 #define DCA_SUBFRAMES           16
45 #define DCA_SUBBAND_SAMPLES     8
46 #define DCA_PCMBLOCK_SAMPLES    32
47 #define DCA_LFE_HISTORY         8
48 #define DCA_ABITS_MAX           26
49 
50 #define DCA_CORE_CHANNELS_MAX       6
51 #define DCA_DMIX_CHANNELS_MAX       4
52 #define DCA_XXCH_CHANNELS_MAX       2
53 #define DCA_EXSS_CHANNELS_MAX       8
54 #define DCA_EXSS_CHSETS_MAX         4
55 
56 #define DCA_FILTER_MODE_X96     0x01
57 #define DCA_FILTER_MODE_FIXED   0x02
58 
59 enum DCACoreAudioMode {
60     DCA_AMODE_MONO,             // Mode 0: A (mono)
61     DCA_AMODE_MONO_DUAL,        // Mode 1: A + B (dual mono)
62     DCA_AMODE_STEREO,           // Mode 2: L + R (stereo)
63     DCA_AMODE_STEREO_SUMDIFF,   // Mode 3: (L+R) + (L-R) (sum-diff)
64     DCA_AMODE_STEREO_TOTAL,     // Mode 4: LT + RT (left and right total)
65     DCA_AMODE_3F,               // Mode 5: C + L + R
66     DCA_AMODE_2F1R,             // Mode 6: L + R + S
67     DCA_AMODE_3F1R,             // Mode 7: C + L + R + S
68     DCA_AMODE_2F2R,             // Mode 8: L + R + SL + SR
69     DCA_AMODE_3F2R,             // Mode 9: C + L + R + SL + SR
70 
71     DCA_AMODE_COUNT
72 };
73 
74 enum DCACoreExtAudioType {
75     DCA_EXT_AUDIO_XCH   = 0,
76     DCA_EXT_AUDIO_X96   = 2,
77     DCA_EXT_AUDIO_XXCH  = 6
78 };
79 
80 enum DCACoreLFEFlag {
81     DCA_LFE_FLAG_NONE,
82     DCA_LFE_FLAG_128,
83     DCA_LFE_FLAG_64,
84     DCA_LFE_FLAG_INVALID
85 };
86 
87 typedef struct DCADSPData {
88     union {
89         struct {
90             DECLARE_ALIGNED(32, float, hist1)[1024];
91             DECLARE_ALIGNED(32, float, hist2)[64];
92         } flt;
93         struct {
94             DECLARE_ALIGNED(32, int32_t, hist1)[1024];
95             DECLARE_ALIGNED(32, int32_t, hist2)[64];
96         } fix;
97     } u;
98     int offset;
99 } DCADSPData;
100 
101 typedef struct DCACoreDecoder {
102     AVCodecContext  *avctx;
103     GetBitContext   gb;
104     GetBitContext   gb_in;
105 
106     // Bit stream header
107     int     crc_present;        ///< CRC present flag
108     int     npcmblocks;         ///< Number of PCM sample blocks
109     int     frame_size;         ///< Primary frame byte size
110     int     audio_mode;         ///< Audio channel arrangement
111     int     sample_rate;        ///< Core audio sampling frequency
112     int     bit_rate;           ///< Transmission bit rate
113     int     drc_present;        ///< Embedded dynamic range flag
114     int     ts_present;         ///< Embedded time stamp flag
115     int     aux_present;        ///< Auxiliary data flag
116     int     ext_audio_type;     ///< Extension audio descriptor flag
117     int     ext_audio_present;  ///< Extended coding flag
118     int     sync_ssf;           ///< Audio sync word insertion flag
119     int     lfe_present;        ///< Low frequency effects flag
120     int     predictor_history;  ///< Predictor history flag switch
121     int     filter_perfect;     ///< Multirate interpolator switch
122     int     source_pcm_res;     ///< Source PCM resolution
123     int     es_format;          ///< Extended surround (ES) mastering flag
124     int     sumdiff_front;      ///< Front sum/difference flag
125     int     sumdiff_surround;   ///< Surround sum/difference flag
126 
127     // Primary audio coding header
128     int         nsubframes;     ///< Number of subframes
129     int         nchannels;      ///< Number of primary audio channels (incl. extension channels)
130     int         ch_mask;        ///< Speaker layout mask (incl. LFE and extension channels)
131     int8_t      nsubbands[DCA_CHANNELS];                ///< Subband activity count
132     int8_t      subband_vq_start[DCA_CHANNELS];         ///< High frequency VQ start subband
133     int8_t      joint_intensity_index[DCA_CHANNELS];    ///< Joint intensity coding index
134     int8_t      transition_mode_sel[DCA_CHANNELS];      ///< Transient mode code book
135     int8_t      scale_factor_sel[DCA_CHANNELS];         ///< Scale factor code book
136     int8_t      bit_allocation_sel[DCA_CHANNELS];       ///< Bit allocation quantizer select
137     int8_t      quant_index_sel[DCA_CHANNELS][DCA_CODE_BOOKS];  ///< Quantization index codebook select
138     int32_t     scale_factor_adj[DCA_CHANNELS][DCA_CODE_BOOKS]; ///< Scale factor adjustment
139 
140     // Primary audio coding side information
141     int8_t      nsubsubframes[DCA_SUBFRAMES];   ///< Subsubframe count for each subframe
142     int8_t      prediction_mode[DCA_CHANNELS][DCA_SUBBANDS_X96];            ///< Prediction mode
143     int16_t     prediction_vq_index[DCA_CHANNELS][DCA_SUBBANDS_X96];        ///< Prediction coefficients VQ address
144     int8_t      bit_allocation[DCA_CHANNELS][DCA_SUBBANDS_X96];             ///< Bit allocation index
145     int8_t      transition_mode[DCA_SUBFRAMES][DCA_CHANNELS][DCA_SUBBANDS]; ///< Transition mode
146     int32_t     scale_factors[DCA_CHANNELS][DCA_SUBBANDS][2];               ///< Scale factors (2x for transients and X96)
147     int8_t      joint_scale_sel[DCA_CHANNELS];                              ///< Joint subband codebook select
148     int32_t     joint_scale_factors[DCA_CHANNELS][DCA_SUBBANDS_X96];        ///< Scale factors for joint subband coding
149 
150     // Auxiliary data
151     int     prim_dmix_embedded; ///< Auxiliary dynamic downmix flag
152     int     prim_dmix_type;     ///< Auxiliary primary channel downmix type
153     int     prim_dmix_coeff[DCA_DMIX_CHANNELS_MAX * DCA_CORE_CHANNELS_MAX]; ///< Dynamic downmix code coefficients
154 
155     // Core extensions
156     int     ext_audio_mask;     ///< Bit mask of fully decoded core extensions
157 
158     // XCH extension data
159     int     xch_pos;    ///< Bit position of XCH frame in core substream
160 
161     // XXCH extension data
162     int     xxch_crc_present;       ///< CRC presence flag for XXCH channel set header
163     int     xxch_mask_nbits;        ///< Number of bits for loudspeaker mask
164     int     xxch_core_mask;         ///< Core loudspeaker activity mask
165     int     xxch_spkr_mask;         ///< Loudspeaker layout mask
166     int     xxch_dmix_embedded;     ///< Downmix already performed by encoder
167     int     xxch_dmix_scale_inv;    ///< Downmix scale factor
168     int     xxch_dmix_mask[DCA_XXCH_CHANNELS_MAX];  ///< Downmix channel mapping mask
169     int     xxch_dmix_coeff[DCA_XXCH_CHANNELS_MAX * DCA_CORE_CHANNELS_MAX];     ///< Downmix coefficients
170     int     xxch_pos;   ///< Bit position of XXCH frame in core substream
171 
172     // X96 extension data
173     int     x96_rev_no;         ///< X96 revision number
174     int     x96_crc_present;    ///< CRC presence flag for X96 channel set header
175     int     x96_nchannels;      ///< Number of primary channels in X96 extension
176     int     x96_high_res;       ///< X96 high resolution flag
177     int     x96_subband_start;  ///< First encoded subband in X96 extension
178     int     x96_rand;           ///< Random seed for generating samples for unallocated X96 subbands
179     int     x96_pos;            ///< Bit position of X96 frame in core substream
180 
181     // Sample buffers
182     unsigned int    x96_subband_size;
183     int32_t         *x96_subband_buffer;    ///< X96 subband sample buffer base
184     int32_t         *x96_subband_samples[DCA_CHANNELS][DCA_SUBBANDS_X96];   ///< X96 subband samples
185 
186     unsigned int    subband_size;
187     int32_t         *subband_buffer;    ///< Subband sample buffer base
188     int32_t         *subband_samples[DCA_CHANNELS][DCA_SUBBANDS];   ///< Subband samples
189     int32_t         *lfe_samples;    ///< Decimated LFE samples
190 
191     // DSP contexts
192     DCADSPData              dcadsp_data[DCA_CHANNELS];    ///< FIR history buffers
193     DCADSPContext           *dcadsp;
194     DCADCTContext           dcadct;
195     FFTContext              imdct[2];
196     SynthFilterContext      synth;
197     AVFloatDSPContext       *float_dsp;
198     AVFixedDSPContext       *fixed_dsp;
199 
200     // PCM output data
201     unsigned int    output_size;
202     void            *output_buffer;                         ///< PCM output buffer base
203     int32_t         *output_samples[DCA_SPEAKER_COUNT];     ///< PCM output for fixed point mode
204     int32_t         output_history_lfe_fixed;               ///< LFE PCM history for X96 filter
205     float           output_history_lfe_float;               ///< LFE PCM history for X96 filter
206 
207     int     ch_remap[DCA_SPEAKER_COUNT];   ///< Channel to speaker map
208     int     request_mask;   ///< Requested channel layout (for stereo downmix)
209 
210     int     npcmsamples;    ///< Number of PCM samples per channel
211     int     output_rate;    ///< Output sample rate (1x or 2x header rate)
212 
213     int     filter_mode;    ///< Previous filtering mode for detecting changes
214 } DCACoreDecoder;
215 
ff_dca_core_map_spkr(DCACoreDecoder * core,int spkr)216 static inline int ff_dca_core_map_spkr(DCACoreDecoder *core, int spkr)
217 {
218     if (core->ch_mask & (1U << spkr))
219         return spkr;
220     if (spkr == DCA_SPEAKER_Lss && (core->ch_mask & DCA_SPEAKER_MASK_Ls))
221         return DCA_SPEAKER_Ls;
222     if (spkr == DCA_SPEAKER_Rss && (core->ch_mask & DCA_SPEAKER_MASK_Rs))
223         return DCA_SPEAKER_Rs;
224     return -1;
225 }
226 
ff_dca_core_dequantize(int32_t * output,const int32_t * input,int32_t step_size,int32_t scale,int residual,int len)227 static inline void ff_dca_core_dequantize(int32_t *output, const int32_t *input,
228                                           int32_t step_size, int32_t scale, int residual, int len)
229 {
230     // Account for quantizer step size
231     int64_t step_scale = (int64_t)step_size * scale;
232     int n, shift = 0;
233 
234     // Limit scale factor resolution to 22 bits
235     if (step_scale > (1 << 23)) {
236         shift = av_log2(step_scale >> 23) + 1;
237         step_scale >>= shift;
238     }
239 
240     // Scale the samples
241     if (residual) {
242         for (n = 0; n < len; n++)
243             output[n] += clip23(norm__(input[n] * step_scale, 22 - shift));
244     } else {
245         for (n = 0; n < len; n++)
246             output[n]  = clip23(norm__(input[n] * step_scale, 22 - shift));
247     }
248 }
249 
250 int ff_dca_core_parse(DCACoreDecoder *s, uint8_t *data, int size);
251 int ff_dca_core_parse_exss(DCACoreDecoder *s, uint8_t *data, DCAExssAsset *asset);
252 int ff_dca_core_filter_fixed(DCACoreDecoder *s, int x96_synth);
253 int ff_dca_core_filter_frame(DCACoreDecoder *s, AVFrame *frame);
254 av_cold void ff_dca_core_flush(DCACoreDecoder *s);
255 av_cold int ff_dca_core_init(DCACoreDecoder *s);
256 av_cold void ff_dca_core_close(DCACoreDecoder *s);
257 
258 #endif
259