3 * Copyright (c) 2008 Vladimir Voroshilov
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
30 #include "libavutil/avutil.h"
35 #include "celp_math.h"
36 #include "acelp_filters.h"
37 #include "acelp_pitch_delay.h"
38 #include "acelp_vectors.h"
42 * minimum quantized LSF value (3.2.4)
48 * maximum quantized LSF value (3.2.4)
51 #define LSFQ_MAX 25681
54 * minimum LSF distance (3.2.4)
57 #define LSFQ_DIFF_MIN 321
60 * minimum gain pitch value (3.8, Equation 47)
63 #define SHARP_MIN 3277
66 * maximum gain pitch value (3.8, Equation 47)
67 * (EE) This does not comply with the specification.
68 * Specification says about 0.8, which should be
69 * 13107 in (1.14), but reference C code uses
70 * 13017 (equals to 0.7945) instead of it.
72 #define SHARP_MAX 13017
75 uint8_t ac_index_bits
[2]; ///< adaptive codebook index for second subframe (size in bits)
76 uint8_t parity_bit
; ///< parity bit for pitch delay
77 uint8_t gc_1st_index_bits
; ///< gain codebook (first stage) index (size in bits)
78 uint8_t gc_2nd_index_bits
; ///< gain codebook (second stage) index (size in bits)
79 uint8_t fc_signs_bits
; ///< number of pulses in fixed-codebook vector
80 uint8_t fc_indexes_bits
; ///< size (in bits) of fixed-codebook index entry
81 } G729FormatDescription
;
84 int pitch_delay_int_prev
; ///< integer part of previous subframe's pitch delay (4.1.3)
86 /// (2.13) LSP quantizer outputs
87 int16_t past_quantizer_output_buf
[MA_NP
+ 1][10];
88 int16_t* past_quantizer_outputs
[MA_NP
+ 1];
90 int16_t lsfq
[10]; ///< (2.13) quantized LSF coefficients from previous frame
91 int16_t lsp_buf
[2][10]; ///< (0.15) LSP coefficients (previous and current frames) (3.2.5)
92 int16_t *lsp
[2]; ///< pointers to lsp_buf
95 static const G729FormatDescription format_g729_8k
= {
96 .ac_index_bits
= {8,5},
98 .gc_1st_index_bits
= GC_1ST_IDX_BITS_8K
,
99 .gc_2nd_index_bits
= GC_2ND_IDX_BITS_8K
,
101 .fc_indexes_bits
= 13,
104 static const G729FormatDescription format_g729d_6k4
= {
105 .ac_index_bits
= {8,4},
107 .gc_1st_index_bits
= GC_1ST_IDX_BITS_6K4
,
108 .gc_2nd_index_bits
= GC_2ND_IDX_BITS_6K4
,
110 .fc_indexes_bits
= 9,
114 * \brief pseudo random number generator
116 static inline uint16_t g729_prng(uint16_t value
)
118 return 31821 * value
+ 13849;
122 * Get parity bit of bit 2..7
124 static inline int get_parity(uint8_t value
)
126 return (0x6996966996696996ULL
>> (value
>> 2)) & 1;
129 static void lsf_decode(int16_t* lsfq
, int16_t* past_quantizer_outputs
[MA_NP
+ 1],
130 int16_t ma_predictor
,
131 int16_t vq_1st
, int16_t vq_2nd_low
, int16_t vq_2nd_high
)
134 static const uint8_t min_distance
[2]={10, 5}; //(2.13)
135 int16_t* quantizer_output
= past_quantizer_outputs
[MA_NP
];
137 for (i
= 0; i
< 5; i
++) {
138 quantizer_output
[i
] = cb_lsp_1st
[vq_1st
][i
] + cb_lsp_2nd
[vq_2nd_low
][i
];
139 quantizer_output
[i
+ 5] = cb_lsp_1st
[vq_1st
][i
+ 5] + cb_lsp_2nd
[vq_2nd_high
][i
+ 5];
142 for (j
= 0; j
< 2; j
++) {
143 for (i
= 1; i
< 10; i
++) {
144 int diff
= (quantizer_output
[i
- 1] - quantizer_output
[i
] + min_distance
[j
]) >> 1;
146 quantizer_output
[i
- 1] -= diff
;
147 quantizer_output
[i
] += diff
;
152 for (i
= 0; i
< 10; i
++) {
153 int sum
= quantizer_output
[i
] * cb_ma_predictor_sum
[ma_predictor
][i
];
154 for (j
= 0; j
< MA_NP
; j
++)
155 sum
+= past_quantizer_outputs
[j
][i
] * cb_ma_predictor
[ma_predictor
][j
][i
];
160 /* Rotate past_quantizer_outputs. */
161 memmove(past_quantizer_outputs
+ 1, past_quantizer_outputs
, MA_NP
* sizeof(int16_t*));
162 past_quantizer_outputs
[0] = quantizer_output
;
164 ff_acelp_reorder_lsf(lsfq
, LSFQ_DIFF_MIN
, LSFQ_MIN
, LSFQ_MAX
, 10);
167 static av_cold
int decoder_init(AVCodecContext
* avctx
)
169 G729Context
* ctx
= avctx
->priv_data
;
172 if (avctx
->channels
!= 1) {
173 av_log(avctx
, AV_LOG_ERROR
, "Only mono sound is supported (requested channels: %d).\n", avctx
->channels
);
174 return AVERROR_NOFMT
;
177 /* Both 8kbit/s and 6.4kbit/s modes uses two subframes per frame. */
178 avctx
->frame_size
= SUBFRAME_SIZE
<< 1;
180 for (k
= 0; k
< MA_NP
+ 1; k
++) {
181 ctx
->past_quantizer_outputs
[k
] = ctx
->past_quantizer_output_buf
[k
];
182 for (i
= 1; i
< 11; i
++)
183 ctx
->past_quantizer_outputs
[k
][i
- 1] = (18717 * i
) >> 3;
186 ctx
->lsp
[0] = ctx
->lsp_buf
[0];
187 ctx
->lsp
[1] = ctx
->lsp_buf
[1];
188 memcpy(ctx
->lsp
[0], lsp_init
, 10 * sizeof(int16_t));
193 static int decode_frame(AVCodecContext
*avctx
, void *data
, int *data_size
,
196 const uint8_t *buf
= avpkt
->data
;
197 int buf_size
= avpkt
->size
;
198 int16_t *out_frame
= data
;
200 G729FormatDescription format
;
201 int frame_erasure
= 0; ///< frame erasure detected during decoding
202 int bad_pitch
= 0; ///< parity check failed
204 G729Context
*ctx
= avctx
->priv_data
;
205 int16_t lp
[2][11]; // (3.12)
206 uint8_t ma_predictor
; ///< switched MA predictor of LSP quantizer
207 uint8_t quantizer_1st
; ///< first stage vector of quantizer
208 uint8_t quantizer_2nd_lo
; ///< second stage lower vector of quantizer (size in bits)
209 uint8_t quantizer_2nd_hi
; ///< second stage higher vector of quantizer (size in bits)
211 int pitch_delay_int
; // pitch delay, integer part
212 int pitch_delay_3x
; // pitch delay, multiplied by 3
214 if (*data_size
< SUBFRAME_SIZE
<< 2) {
215 av_log(avctx
, AV_LOG_ERROR
, "Error processing packet: output buffer too small\n");
219 if (buf_size
== 10) {
220 format
= format_g729_8k
;
221 av_log(avctx
, AV_LOG_DEBUG
, "Packet type: %s\n", "G.729 @ 8kbit/s");
222 } else if (buf_size
== 8) {
223 format
= format_g729d_6k4
;
224 av_log(avctx
, AV_LOG_DEBUG
, "Packet type: %s\n", "G.729D @ 6.4kbit/s");
226 av_log(avctx
, AV_LOG_ERROR
, "Packet size %d is unknown.\n", buf_size
);
227 return (AVERROR_NOFMT
);
230 for (i
=0; i
< buf_size
; i
++)
231 frame_erasure
|= buf
[i
];
232 frame_erasure
= !frame_erasure
;
234 init_get_bits(&gb
, buf
, buf_size
);
236 ma_predictor
= get_bits(&gb
, 1);
237 quantizer_1st
= get_bits(&gb
, VQ_1ST_BITS
);
238 quantizer_2nd_lo
= get_bits(&gb
, VQ_2ND_BITS
);
239 quantizer_2nd_hi
= get_bits(&gb
, VQ_2ND_BITS
);
241 lsf_decode(ctx
->lsfq
, ctx
->past_quantizer_outputs
,
243 quantizer_1st
, quantizer_2nd_lo
, quantizer_2nd_hi
);
245 ff_acelp_lsf2lsp(ctx
->lsp
[1], ctx
->lsfq
, 10);
247 ff_acelp_lp_decode(&lp
[0][0], &lp
[1][0], ctx
->lsp
[1], ctx
->lsp
[0], 10);
249 FFSWAP(int16_t*, ctx
->lsp
[1], ctx
->lsp
[0]);
251 for (i
= 0; i
< 2; i
++) {
252 uint8_t ac_index
; ///< adaptive codebook index
253 uint8_t pulses_signs
; ///< fixed-codebook vector pulse signs
254 int fc_indexes
; ///< fixed-codebook indexes
255 uint8_t gc_1st_index
; ///< gain codebook (first stage) index
256 uint8_t gc_2nd_index
; ///< gain codebook (second stage) index
258 ac_index
= get_bits(&gb
, format
.ac_index_bits
[i
]);
259 if(!i
&& format
.parity_bit
)
260 bad_pitch
= get_parity(ac_index
) == get_bits1(&gb
);
261 fc_indexes
= get_bits(&gb
, format
.fc_indexes_bits
);
262 pulses_signs
= get_bits(&gb
, format
.fc_signs_bits
);
263 gc_1st_index
= get_bits(&gb
, format
.gc_1st_index_bits
);
264 gc_2nd_index
= get_bits(&gb
, format
.gc_2nd_index_bits
);
268 pitch_delay_3x
= 3 * ctx
->pitch_delay_int_prev
;
270 pitch_delay_3x
= ff_acelp_decode_8bit_to_1st_delay3(ac_index
);
272 int pitch_delay_min
= av_clip(ctx
->pitch_delay_int_prev
- 5,
273 PITCH_DELAY_MIN
, PITCH_DELAY_MAX
- 9);
275 if(packet_type
== FORMAT_G729D_6K4
)
276 pitch_delay_3x
= ff_acelp_decode_4bit_to_2nd_delay3(ac_index
, pitch_delay_min
);
278 pitch_delay_3x
= ff_acelp_decode_5_6_bit_to_2nd_delay3(ac_index
, pitch_delay_min
);
281 /* Round pitch delay to nearest (used everywhere except ff_acelp_interpolate). */
282 pitch_delay_int
= (pitch_delay_3x
+ 1) / 3;
284 ff_acelp_weighted_vector_sum(fc
+ pitch_delay_int
,
285 fc
+ pitch_delay_int
,
287 av_clip(ctx
->gain_pitch
, SHARP_MIN
, SHARP_MAX
),
289 SUBFRAME_SIZE
- pitch_delay_int
);
292 ctx
->gain_pitch
= (29491 * ctx
->gain_pitch
) >> 15; // 0.90 (0.15)
293 ctx
->gain_code
= ( 2007 * ctx
->gain_code
) >> 11; // 0.98 (0.11)
295 gain_corr_factor
= 0;
297 ctx
->gain_pitch
= cb_gain_1st_8k
[gc_1st_index
][0] +
298 cb_gain_2nd_8k
[gc_2nd_index
][0];
299 gain_corr_factor
= cb_gain_1st_8k
[gc_1st_index
][1] +
300 cb_gain_2nd_8k
[gc_2nd_index
][1];
302 ff_acelp_weighted_vector_sum(ctx
->exc
+ i
* SUBFRAME_SIZE
,
303 ctx
->exc
+ i
* SUBFRAME_SIZE
, fc
,
304 (!voicing
&& frame_erasure
) ? 0 : ctx
->gain_pitch
,
305 ( voicing
&& frame_erasure
) ? 0 : ctx
->gain_code
,
306 1 << 13, 14, SUBFRAME_SIZE
);
308 ctx
->pitch_delay_int_prev
= pitch_delay_int
;
311 *data_size
= SUBFRAME_SIZE
<< 2;
315 AVCodec g729_decoder
=
325 .long_name
= NULL_IF_CONFIG_SMALL("G.729"),