3 * Copyright (c) 2007 Konstantin Shishkov
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * @file libavcodec/mpc8.c Musepack SV8 decoder
24 * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
25 * divided into 32 subbands.
28 #include "libavutil/lfg.h"
30 #include "bitstream.h"
32 #include "mpegaudio.h"
39 static VLC band_vlc
, scfi_vlc
[2], dscf_vlc
[2], res_vlc
[2];
40 static VLC q1_vlc
, q2_vlc
[2], q3_vlc
[2], quant_vlc
[4][2], q9up_vlc
;
42 static const int q3_offsets
[2] = { MPC8_Q3_OFFSET
, MPC8_Q4_OFFSET
};
43 static const int quant_offsets
[6] = { MPC8_Q5_OFFSET
, MPC8_Q6_OFFSET
, MPC8_Q7_OFFSET
, MPC8_Q8_OFFSET
};
45 static inline int mpc8_dec_base(GetBitContext
*gb
, int k
, int n
)
47 int code
= get_bits(gb
, mpc8_cnk_len
[k
-1][n
-1] - 1);
49 if (code
>= mpc8_cnk_lost
[k
-1][n
-1])
50 code
= ((code
<< 1) | get_bits1(gb
)) - mpc8_cnk_lost
[k
-1][n
-1];
55 static inline int mpc8_dec_enum(GetBitContext
*gb
, int k
, int n
)
58 const uint32_t * C
= mpc8_cnk
[k
-1];
59 int code
= mpc8_dec_base(gb
, k
, n
);
74 static inline int mpc8_get_mod_golomb(GetBitContext
*gb
, int m
)
76 if(mpc8_cnk_len
[0][m
] < 1) return 0;
77 return mpc8_dec_base(gb
, 1, m
+1);
80 static int mpc8_get_mask(GetBitContext
*gb
, int size
, int t
)
85 mask
= mpc8_dec_enum(gb
, FFMIN(t
, size
- t
), size
);
86 if((t
<< 1) > size
) mask
= ~mask
;
91 static av_cold
int mpc8_decode_init(AVCodecContext
* avctx
)
94 MPCContext
*c
= avctx
->priv_data
;
96 static int vlc_initialized
= 0;
98 if(avctx
->extradata_size
< 2){
99 av_log(avctx
, AV_LOG_ERROR
, "Too small extradata size (%i)!\n", avctx
->extradata_size
);
102 memset(c
->oldDSCF
, 0, sizeof(c
->oldDSCF
));
103 av_lfg_init(&c
->rnd
, 0xDEADBEEF);
104 dsputil_init(&c
->dsp
, avctx
);
108 init_get_bits(&gb
, avctx
->extradata
, 16);
110 skip_bits(&gb
, 3);//sample rate
111 c
->maxbands
= get_bits(&gb
, 5) + 1;
112 skip_bits(&gb
, 4);//channels
113 c
->MSS
= get_bits1(&gb
);
114 c
->frames
= 1 << (get_bits(&gb
, 3) * 2);
116 if(vlc_initialized
) return 0;
117 av_log(avctx
, AV_LOG_DEBUG
, "Initing VLC\n");
119 init_vlc(&band_vlc
, MPC8_BANDS_BITS
, MPC8_BANDS_SIZE
,
120 mpc8_bands_bits
, 1, 1,
121 mpc8_bands_codes
, 1, 1, INIT_VLC_USE_STATIC
);
123 init_vlc(&q1_vlc
, MPC8_Q1_BITS
, MPC8_Q1_SIZE
,
125 mpc8_q1_codes
, 1, 1, INIT_VLC_USE_STATIC
);
126 init_vlc(&q9up_vlc
, MPC8_Q9UP_BITS
, MPC8_Q9UP_SIZE
,
127 mpc8_q9up_bits
, 1, 1,
128 mpc8_q9up_codes
, 1, 1, INIT_VLC_USE_STATIC
);
130 init_vlc(&scfi_vlc
[0], MPC8_SCFI0_BITS
, MPC8_SCFI0_SIZE
,
131 mpc8_scfi0_bits
, 1, 1,
132 mpc8_scfi0_codes
, 1, 1, INIT_VLC_USE_STATIC
);
133 init_vlc(&scfi_vlc
[1], MPC8_SCFI1_BITS
, MPC8_SCFI1_SIZE
,
134 mpc8_scfi1_bits
, 1, 1,
135 mpc8_scfi1_codes
, 1, 1, INIT_VLC_USE_STATIC
);
137 init_vlc(&dscf_vlc
[0], MPC8_DSCF0_BITS
, MPC8_DSCF0_SIZE
,
138 mpc8_dscf0_bits
, 1, 1,
139 mpc8_dscf0_codes
, 1, 1, INIT_VLC_USE_STATIC
);
140 init_vlc(&dscf_vlc
[1], MPC8_DSCF1_BITS
, MPC8_DSCF1_SIZE
,
141 mpc8_dscf1_bits
, 1, 1,
142 mpc8_dscf1_codes
, 1, 1, INIT_VLC_USE_STATIC
);
144 init_vlc_sparse(&q3_vlc
[0], MPC8_Q3_BITS
, MPC8_Q3_SIZE
,
147 mpc8_q3_syms
, 1, 1, INIT_VLC_USE_STATIC
);
148 init_vlc_sparse(&q3_vlc
[1], MPC8_Q4_BITS
, MPC8_Q4_SIZE
,
151 mpc8_q4_syms
, 1, 1, INIT_VLC_USE_STATIC
);
153 for(i
= 0; i
< 2; i
++){
154 init_vlc(&res_vlc
[i
], MPC8_RES_BITS
, MPC8_RES_SIZE
,
155 &mpc8_res_bits
[i
], 1, 1,
156 &mpc8_res_codes
[i
], 1, 1, INIT_VLC_USE_STATIC
);
158 init_vlc(&q2_vlc
[i
], MPC8_Q2_BITS
, MPC8_Q2_SIZE
,
159 &mpc8_q2_bits
[i
], 1, 1,
160 &mpc8_q2_codes
[i
], 1, 1, INIT_VLC_USE_STATIC
);
162 init_vlc(&quant_vlc
[0][i
], MPC8_Q5_BITS
, MPC8_Q5_SIZE
,
163 &mpc8_q5_bits
[i
], 1, 1,
164 &mpc8_q5_codes
[i
], 1, 1, INIT_VLC_USE_STATIC
);
165 init_vlc(&quant_vlc
[1][i
], MPC8_Q6_BITS
, MPC8_Q6_SIZE
,
166 &mpc8_q6_bits
[i
], 1, 1,
167 &mpc8_q6_codes
[i
], 1, 1, INIT_VLC_USE_STATIC
);
168 init_vlc(&quant_vlc
[2][i
], MPC8_Q7_BITS
, MPC8_Q7_SIZE
,
169 &mpc8_q7_bits
[i
], 1, 1,
170 &mpc8_q7_codes
[i
], 1, 1, INIT_VLC_USE_STATIC
);
171 init_vlc(&quant_vlc
[3][i
], MPC8_Q8_BITS
, MPC8_Q8_SIZE
,
172 &mpc8_q8_bits
[i
], 1, 1,
173 &mpc8_q8_codes
[i
], 1, 1, INIT_VLC_USE_STATIC
);
176 avctx
->sample_fmt
= SAMPLE_FMT_S16
;
177 avctx
->channel_layout
= (avctx
->channels
==2) ? CH_LAYOUT_STEREO
: CH_LAYOUT_MONO
;
181 static int mpc8_decode_frame(AVCodecContext
* avctx
,
182 void *data
, int *data_size
,
183 const uint8_t * buf
, int buf_size
)
185 MPCContext
*c
= avctx
->priv_data
;
186 GetBitContext gb2
, *gb
= &gb2
;
187 int i
, j
, k
, ch
, cnt
, res
, t
;
188 Band
*bands
= c
->bands
;
190 int maxband
, keyframe
;
193 keyframe
= c
->cur_frame
== 0;
196 memset(c
->Q
, 0, sizeof(c
->Q
));
197 c
->last_bits_used
= 0;
199 init_get_bits(gb
, buf
, buf_size
* 8);
200 skip_bits(gb
, c
->last_bits_used
& 7);
203 maxband
= mpc8_get_mod_golomb(gb
, c
->maxbands
+ 1);
205 maxband
= c
->last_max_band
+ get_vlc2(gb
, band_vlc
.table
, MPC8_BANDS_BITS
, 2);
206 if(maxband
> 32) maxband
-= 33;
208 c
->last_max_band
= maxband
;
210 /* read subband indexes */
212 last
[0] = last
[1] = 0;
213 for(i
= maxband
- 1; i
>= 0; i
--){
214 for(ch
= 0; ch
< 2; ch
++){
215 last
[ch
] = get_vlc2(gb
, res_vlc
[last
[ch
] > 2].table
, MPC8_RES_BITS
, 2) + last
[ch
];
216 if(last
[ch
] > 15) last
[ch
] -= 17;
217 bands
[i
].res
[ch
] = last
[ch
];
224 for(i
= 0; i
< maxband
; i
++)
225 if(bands
[i
].res
[0] || bands
[i
].res
[1])
227 t
= mpc8_get_mod_golomb(gb
, cnt
);
228 mask
= mpc8_get_mask(gb
, cnt
, t
);
229 for(i
= maxband
- 1; i
>= 0; i
--)
230 if(bands
[i
].res
[0] || bands
[i
].res
[1]){
231 bands
[i
].msf
= mask
& 1;
236 for(i
= maxband
; i
< c
->maxbands
; i
++)
237 bands
[i
].res
[0] = bands
[i
].res
[1] = 0;
240 for(i
= 0; i
< 32; i
++)
241 c
->oldDSCF
[0][i
] = c
->oldDSCF
[1][i
] = 1;
244 for(i
= 0; i
< maxband
; i
++){
245 if(bands
[i
].res
[0] || bands
[i
].res
[1]){
246 cnt
= !!bands
[i
].res
[0] + !!bands
[i
].res
[1] - 1;
248 t
= get_vlc2(gb
, scfi_vlc
[cnt
].table
, scfi_vlc
[cnt
].bits
, 1);
249 if(bands
[i
].res
[0]) bands
[i
].scfi
[0] = t
>> (2 * cnt
);
250 if(bands
[i
].res
[1]) bands
[i
].scfi
[1] = t
& 3;
255 for(i
= 0; i
< maxband
; i
++){
256 for(ch
= 0; ch
< 2; ch
++){
257 if(!bands
[i
].res
[ch
]) continue;
259 if(c
->oldDSCF
[ch
][i
]){
260 bands
[i
].scf_idx
[ch
][0] = get_bits(gb
, 7) - 6;
261 c
->oldDSCF
[ch
][i
] = 0;
263 t
= get_vlc2(gb
, dscf_vlc
[1].table
, MPC8_DSCF1_BITS
, 2);
265 t
+= get_bits(gb
, 6);
266 bands
[i
].scf_idx
[ch
][0] = ((bands
[i
].scf_idx
[ch
][2] + t
- 25) & 0x7F) - 6;
268 for(j
= 0; j
< 2; j
++){
269 if((bands
[i
].scfi
[ch
] << j
) & 2)
270 bands
[i
].scf_idx
[ch
][j
+ 1] = bands
[i
].scf_idx
[ch
][j
];
272 t
= get_vlc2(gb
, dscf_vlc
[0].table
, MPC8_DSCF0_BITS
, 2);
274 t
= 64 + get_bits(gb
, 6);
275 bands
[i
].scf_idx
[ch
][j
+ 1] = ((bands
[i
].scf_idx
[ch
][j
] + t
- 25) & 0x7F) - 6;
281 for(i
= 0, off
= 0; i
< maxband
; i
++, off
+= SAMPLES_PER_BAND
){
282 for(ch
= 0; ch
< 2; ch
++){
283 res
= bands
[i
].res
[ch
];
286 for(j
= 0; j
< SAMPLES_PER_BAND
; j
++)
287 c
->Q
[ch
][off
+ j
] = (av_lfg_get(&c
->rnd
) & 0x3FC) - 510;
292 for(j
= 0; j
< SAMPLES_PER_BAND
; j
+= SAMPLES_PER_BAND
/ 2){
293 cnt
= get_vlc2(gb
, q1_vlc
.table
, MPC8_Q1_BITS
, 2);
294 t
= mpc8_get_mask(gb
, 18, cnt
);
295 for(k
= 0; k
< SAMPLES_PER_BAND
/ 2; k
++, t
<<= 1)
296 c
->Q
[ch
][off
+ j
+ k
] = (t
& 0x20000) ? (get_bits1(gb
) << 1) - 1 : 0;
300 cnt
= 6;//2*mpc8_thres[res]
301 for(j
= 0; j
< SAMPLES_PER_BAND
; j
+= 3){
302 t
= get_vlc2(gb
, q2_vlc
[cnt
> 3].table
, MPC8_Q2_BITS
, 2);
303 c
->Q
[ch
][off
+ j
+ 0] = mpc8_idx50
[t
];
304 c
->Q
[ch
][off
+ j
+ 1] = mpc8_idx51
[t
];
305 c
->Q
[ch
][off
+ j
+ 2] = mpc8_idx52
[t
];
306 cnt
= (cnt
>> 1) + mpc8_huffq2
[t
];
311 for(j
= 0; j
< SAMPLES_PER_BAND
; j
+= 2){
312 t
= get_vlc2(gb
, q3_vlc
[res
- 3].table
, MPC8_Q3_BITS
, 2) + q3_offsets
[res
- 3];
313 c
->Q
[ch
][off
+ j
+ 1] = t
>> 4;
314 c
->Q
[ch
][off
+ j
+ 0] = (t
& 8) ? (t
& 0xF) - 16 : (t
& 0xF);
321 cnt
= 2 * mpc8_thres
[res
];
322 for(j
= 0; j
< SAMPLES_PER_BAND
; j
++){
323 t
= get_vlc2(gb
, quant_vlc
[res
- 5][cnt
> mpc8_thres
[res
]].table
, quant_vlc
[res
- 5][cnt
> mpc8_thres
[res
]].bits
, 2) + quant_offsets
[res
- 5];
324 c
->Q
[ch
][off
+ j
] = t
;
325 cnt
= (cnt
>> 1) + FFABS(c
->Q
[ch
][off
+ j
]);
329 for(j
= 0; j
< SAMPLES_PER_BAND
; j
++){
330 c
->Q
[ch
][off
+ j
] = get_vlc2(gb
, q9up_vlc
.table
, MPC8_Q9UP_BITS
, 2);
332 c
->Q
[ch
][off
+ j
] <<= res
- 9;
333 c
->Q
[ch
][off
+ j
] |= get_bits(gb
, res
- 9);
335 c
->Q
[ch
][off
+ j
] -= (1 << (res
- 2)) - 1;
341 ff_mpc_dequantize_and_synth(c
, maxband
, data
);
345 c
->last_bits_used
= get_bits_count(gb
);
346 if(c
->cur_frame
>= c
->frames
)
348 *data_size
= MPC_FRAME_SIZE
* 4;
350 return c
->cur_frame
? c
->last_bits_used
>> 3 : buf_size
;
353 AVCodec mpc8_decoder
= {
362 .long_name
= NULL_IF_CONFIG_SMALL("Musepack SV8"),