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_DCADEC_H
22 #define AVCODEC_DCADEC_H
23 
24 #include "libavutil/common.h"
25 #include "libavutil/crc.h"
26 #include "libavutil/float_dsp.h"
27 
28 #include "avcodec.h"
29 #include "get_bits.h"
30 #include "dca.h"
31 #include "dcadsp.h"
32 #include "dca_core.h"
33 #include "dca_exss.h"
34 #include "dca_xll.h"
35 #include "dca_lbr.h"
36 
37 #define DCA_PACKET_CORE         0x01
38 #define DCA_PACKET_EXSS         0x02
39 #define DCA_PACKET_XLL          0x04
40 #define DCA_PACKET_LBR          0x08
41 #define DCA_PACKET_MASK         0x0f
42 
43 #define DCA_PACKET_RECOVERY     0x10    ///< Sync error recovery flag
44 #define DCA_PACKET_RESIDUAL     0x20    ///< Core valid for residual decoding
45 
46 typedef struct DCAContext {
47     const AVClass   *class;       ///< class for AVOptions
48     AVCodecContext  *avctx;
49 
50     DCACoreDecoder core;  ///< Core decoder context
51     DCAExssParser  exss;  ///< EXSS parser context
52     DCAXllDecoder  xll;   ///< XLL decoder context
53     DCALbrDecoder  lbr;   ///< LBR decoder context
54 
55     DCADSPContext   dcadsp;
56 
57     const AVCRC     *crctab;
58 
59     uint8_t         *buffer;    ///< Packet buffer
60     unsigned int    buffer_size;
61 
62     int     packet; ///< Packet flags
63 
64     int     request_channel_layout; ///< Converted from avctx.request_channel_layout
65     int     core_only;              ///< Core only decoding flag
66 } DCAContext;
67 
68 int ff_dca_set_channel_layout(AVCodecContext *avctx, int *ch_remap, int dca_mask);
69 
70 void ff_dca_downmix_to_stereo_fixed(DCADSPContext *dcadsp, int32_t **samples,
71                                     int *coeff_l, int nsamples, int ch_mask);
72 void ff_dca_downmix_to_stereo_float(AVFloatDSPContext *fdsp, float **samples,
73                                     int *coeff_l, int nsamples, int ch_mask);
74 
ff_dca_check_crc(AVCodecContext * avctx,GetBitContext * s,int p1,int p2)75 static inline int ff_dca_check_crc(AVCodecContext *avctx, GetBitContext *s,
76                                    int p1, int p2)
77 {
78     DCAContext *dca = avctx->priv_data;
79 
80     if (!(avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL)))
81         return 0;
82     if (((p1 | p2) & 7) || p1 < 0 || p2 > s->size_in_bits || p2 - p1 < 16)
83         return -1;
84     if (av_crc(dca->crctab, 0xffff, s->buffer + p1 / 8, (p2 - p1) / 8))
85         return -1;
86     return 0;
87 }
88 
ff_dca_seek_bits(GetBitContext * s,int p)89 static inline int ff_dca_seek_bits(GetBitContext *s, int p)
90 {
91     if (p < get_bits_count(s) || p > s->size_in_bits)
92         return -1;
93     skip_bits_long(s, p - get_bits_count(s));
94     return 0;
95 }
96 
97 #endif
98