1/*
2 * Functions common to fixed/float MPEG-4 Parametric Stereo decoding
3 * Copyright (c) 2010 Alex Converse <alex.converse@gmail.com>
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22#include <stdint.h>
23#include "libavutil/common.h"
24#include "libavutil/thread.h"
25#include "aacps.h"
26#include "get_bits.h"
27#include "aacpsdata.c"
28
29static const int8_t num_env_tab[2][4] = {
30    { 0, 1, 2, 4, },
31    { 1, 2, 3, 4, },
32};
33
34static const int8_t nr_iidicc_par_tab[] = {
35    10, 20, 34, 10, 20, 34,
36};
37
38static const int8_t nr_iidopd_par_tab[] = {
39     5, 11, 17,  5, 11, 17,
40};
41
42enum {
43    huff_iid_df1,
44    huff_iid_dt1,
45    huff_iid_df0,
46    huff_iid_dt0,
47    huff_icc_df,
48    huff_icc_dt,
49    huff_ipd_df,
50    huff_ipd_dt,
51    huff_opd_df,
52    huff_opd_dt,
53};
54
55static const int huff_iid[] = {
56    huff_iid_df0,
57    huff_iid_df1,
58    huff_iid_dt0,
59    huff_iid_dt1,
60};
61
62static VLC vlc_ps[10];
63
64#define READ_PAR_DATA(PAR, OFFSET, MASK, ERR_CONDITION, NB_BITS, MAX_DEPTH) \
65/** \
66 * Read Inter-channel Intensity Difference/Inter-Channel Coherence/ \
67 * Inter-channel Phase Difference/Overall Phase Difference parameters from the \
68 * bitstream. \
69 * \
70 * @param avctx contains the current codec context \
71 * @param gb    pointer to the input bitstream \
72 * @param ps    pointer to the Parametric Stereo context \
73 * @param PAR   pointer to the parameter to be read \
74 * @param e     envelope to decode \
75 * @param dt    1: time delta-coded, 0: frequency delta-coded \
76 */ \
77static int read_ ## PAR ## _data(AVCodecContext *avctx, GetBitContext *gb, PSCommonContext *ps, \
78                        int8_t (*PAR)[PS_MAX_NR_IIDICC], int table_idx, int e, int dt) \
79{ \
80    int b, num = ps->nr_ ## PAR ## _par; \
81    const VLCElem *vlc_table = vlc_ps[table_idx].table; \
82    if (dt) { \
83        int e_prev = e ? e - 1 : ps->num_env_old - 1; \
84        e_prev = FFMAX(e_prev, 0); \
85        for (b = 0; b < num; b++) { \
86            int val = PAR[e_prev][b] + get_vlc2(gb, vlc_table, NB_BITS, MAX_DEPTH) - OFFSET; \
87            if (MASK) val &= MASK; \
88            PAR[e][b] = val; \
89            if (ERR_CONDITION) \
90                goto err; \
91        } \
92    } else { \
93        int val = 0; \
94        for (b = 0; b < num; b++) { \
95            val += get_vlc2(gb, vlc_table, NB_BITS, MAX_DEPTH) - OFFSET; \
96            if (MASK) val &= MASK; \
97            PAR[e][b] = val; \
98            if (ERR_CONDITION) \
99                goto err; \
100        } \
101    } \
102    return 0; \
103err: \
104    av_log(avctx, AV_LOG_ERROR, "illegal "#PAR"\n"); \
105    return AVERROR_INVALIDDATA; \
106}
107
108READ_PAR_DATA(iid,    huff_offset[table_idx],    0, FFABS(ps->iid_par[e][b]) > 7 + 8 * ps->iid_quant, 9, 3)
109READ_PAR_DATA(icc,    huff_offset[table_idx],    0, ps->icc_par[e][b] > 7U, 9, 2)
110READ_PAR_DATA(ipdopd,                      0, 0x07, 0, 5, 1)
111
112static int ps_read_extension_data(GetBitContext *gb, PSCommonContext *ps,
113                                  int ps_extension_id)
114{
115    int e;
116    int count = get_bits_count(gb);
117
118    if (ps_extension_id)
119        return 0;
120
121    ps->enable_ipdopd = get_bits1(gb);
122    if (ps->enable_ipdopd) {
123        for (e = 0; e < ps->num_env; e++) {
124            int dt = get_bits1(gb);
125            read_ipdopd_data(NULL, gb, ps, ps->ipd_par, dt ? huff_ipd_dt : huff_ipd_df, e, dt);
126            dt = get_bits1(gb);
127            read_ipdopd_data(NULL, gb, ps, ps->opd_par, dt ? huff_opd_dt : huff_opd_df, e, dt);
128        }
129    }
130    skip_bits1(gb);      //reserved_ps
131    return get_bits_count(gb) - count;
132}
133
134int ff_ps_read_data(AVCodecContext *avctx, GetBitContext *gb_host,
135                    PSCommonContext *ps, int bits_left)
136{
137    int e;
138    int bit_count_start = get_bits_count(gb_host);
139    int header;
140    int bits_consumed;
141    GetBitContext gbc = *gb_host, *gb = &gbc;
142
143    header = get_bits1(gb);
144    if (header) {     //enable_ps_header
145        ps->enable_iid = get_bits1(gb);
146        if (ps->enable_iid) {
147            int iid_mode = get_bits(gb, 3);
148            if (iid_mode > 5) {
149                av_log(avctx, AV_LOG_ERROR, "iid_mode %d is reserved.\n",
150                       iid_mode);
151                goto err;
152            }
153            ps->nr_iid_par    = nr_iidicc_par_tab[iid_mode];
154            ps->iid_quant     = iid_mode > 2;
155            ps->nr_ipdopd_par = nr_iidopd_par_tab[iid_mode];
156        }
157        ps->enable_icc = get_bits1(gb);
158        if (ps->enable_icc) {
159            ps->icc_mode = get_bits(gb, 3);
160            if (ps->icc_mode > 5) {
161                av_log(avctx, AV_LOG_ERROR, "icc_mode %d is reserved.\n",
162                       ps->icc_mode);
163                goto err;
164            }
165            ps->nr_icc_par = nr_iidicc_par_tab[ps->icc_mode];
166        }
167        ps->enable_ext = get_bits1(gb);
168    }
169
170    ps->frame_class = get_bits1(gb);
171    ps->num_env_old = ps->num_env;
172    ps->num_env     = num_env_tab[ps->frame_class][get_bits(gb, 2)];
173
174    ps->border_position[0] = -1;
175    if (ps->frame_class) {
176        for (e = 1; e <= ps->num_env; e++) {
177            ps->border_position[e] = get_bits(gb, 5);
178            if (ps->border_position[e] < ps->border_position[e-1]) {
179                av_log(avctx, AV_LOG_ERROR, "border_position non monotone.\n");
180                goto err;
181            }
182        }
183    } else
184        for (e = 1; e <= ps->num_env; e++)
185            ps->border_position[e] = (e * numQMFSlots >> ff_log2_tab[ps->num_env]) - 1;
186
187    if (ps->enable_iid) {
188        for (e = 0; e < ps->num_env; e++) {
189            int dt = get_bits1(gb);
190            if (read_iid_data(avctx, gb, ps, ps->iid_par, huff_iid[2*dt+ps->iid_quant], e, dt))
191                goto err;
192        }
193    } else
194        memset(ps->iid_par, 0, sizeof(ps->iid_par));
195
196    if (ps->enable_icc)
197        for (e = 0; e < ps->num_env; e++) {
198            int dt = get_bits1(gb);
199            if (read_icc_data(avctx, gb, ps, ps->icc_par, dt ? huff_icc_dt : huff_icc_df, e, dt))
200                goto err;
201        }
202    else
203        memset(ps->icc_par, 0, sizeof(ps->icc_par));
204
205    if (ps->enable_ext) {
206        int cnt = get_bits(gb, 4);
207        if (cnt == 15) {
208            cnt += get_bits(gb, 8);
209        }
210        cnt *= 8;
211        while (cnt > 7) {
212            int ps_extension_id = get_bits(gb, 2);
213            cnt -= 2 + ps_read_extension_data(gb, ps, ps_extension_id);
214        }
215        if (cnt < 0) {
216            av_log(avctx, AV_LOG_ERROR, "ps extension overflow %d\n", cnt);
217            goto err;
218        }
219        skip_bits(gb, cnt);
220    }
221
222    ps->enable_ipdopd &= !PS_BASELINE;
223
224    //Fix up envelopes
225    if (!ps->num_env || ps->border_position[ps->num_env] < numQMFSlots - 1) {
226        //Create a fake envelope
227        int source = ps->num_env ? ps->num_env - 1 : ps->num_env_old - 1;
228        int b;
229        if (source >= 0 && source != ps->num_env) {
230            if (ps->enable_iid) {
231                memcpy(ps->iid_par+ps->num_env, ps->iid_par+source, sizeof(ps->iid_par[0]));
232            }
233            if (ps->enable_icc) {
234                memcpy(ps->icc_par+ps->num_env, ps->icc_par+source, sizeof(ps->icc_par[0]));
235            }
236            if (ps->enable_ipdopd) {
237                memcpy(ps->ipd_par+ps->num_env, ps->ipd_par+source, sizeof(ps->ipd_par[0]));
238                memcpy(ps->opd_par+ps->num_env, ps->opd_par+source, sizeof(ps->opd_par[0]));
239            }
240        }
241        if (ps->enable_iid){
242            for (b = 0; b < ps->nr_iid_par; b++) {
243                if (FFABS(ps->iid_par[ps->num_env][b]) > 7 + 8 * ps->iid_quant) {
244                    av_log(avctx, AV_LOG_ERROR, "iid_par invalid\n");
245                    goto err;
246                }
247            }
248        }
249        if (ps->enable_icc){
250            for (b = 0; b < ps->nr_iid_par; b++) {
251                if (ps->icc_par[ps->num_env][b] > 7U) {
252                    av_log(avctx, AV_LOG_ERROR, "icc_par invalid\n");
253                    goto err;
254                }
255            }
256        }
257        ps->num_env++;
258        ps->border_position[ps->num_env] = numQMFSlots - 1;
259    }
260
261
262    ps->is34bands_old = ps->is34bands;
263    if (!PS_BASELINE && (ps->enable_iid || ps->enable_icc))
264        ps->is34bands = (ps->enable_iid && ps->nr_iid_par == 34) ||
265                        (ps->enable_icc && ps->nr_icc_par == 34);
266
267    //Baseline
268    if (!ps->enable_ipdopd) {
269        memset(ps->ipd_par, 0, sizeof(ps->ipd_par));
270        memset(ps->opd_par, 0, sizeof(ps->opd_par));
271    }
272
273    if (header)
274        ps->start = 1;
275
276    bits_consumed = get_bits_count(gb) - bit_count_start;
277    if (bits_consumed <= bits_left) {
278        skip_bits_long(gb_host, bits_consumed);
279        return bits_consumed;
280    }
281    av_log(avctx, AV_LOG_ERROR, "Expected to read %d PS bits actually read %d.\n", bits_left, bits_consumed);
282err:
283    ps->start = 0;
284    skip_bits_long(gb_host, bits_left);
285    memset(ps->iid_par, 0, sizeof(ps->iid_par));
286    memset(ps->icc_par, 0, sizeof(ps->icc_par));
287    memset(ps->ipd_par, 0, sizeof(ps->ipd_par));
288    memset(ps->opd_par, 0, sizeof(ps->opd_par));
289    return bits_left;
290}
291
292#define PS_INIT_VLC_STATIC(num, nb_bits, size)                          \
293    INIT_VLC_STATIC(&vlc_ps[num], nb_bits, ps_tmp[num].table_size / ps_tmp[num].elem_size,    \
294                    ps_tmp[num].ps_bits, 1, 1,                                          \
295                    ps_tmp[num].ps_codes, ps_tmp[num].elem_size, ps_tmp[num].elem_size, \
296                    size);
297
298#define PS_VLC_ROW(name) \
299    { name ## _codes, name ## _bits, sizeof(name ## _codes), sizeof(name ## _codes[0]) }
300
301static av_cold void ps_init_common(void)
302{
303    // Syntax initialization
304    static const struct {
305        const void *ps_codes, *ps_bits;
306        const unsigned int table_size, elem_size;
307    } ps_tmp[] = {
308        PS_VLC_ROW(huff_iid_df1),
309        PS_VLC_ROW(huff_iid_dt1),
310        PS_VLC_ROW(huff_iid_df0),
311        PS_VLC_ROW(huff_iid_dt0),
312        PS_VLC_ROW(huff_icc_df),
313        PS_VLC_ROW(huff_icc_dt),
314        PS_VLC_ROW(huff_ipd_df),
315        PS_VLC_ROW(huff_ipd_dt),
316        PS_VLC_ROW(huff_opd_df),
317        PS_VLC_ROW(huff_opd_dt),
318    };
319
320    PS_INIT_VLC_STATIC(0, 9, 1544);
321    PS_INIT_VLC_STATIC(1, 9,  832);
322    PS_INIT_VLC_STATIC(2, 9, 1024);
323    PS_INIT_VLC_STATIC(3, 9, 1036);
324    PS_INIT_VLC_STATIC(4, 9,  544);
325    PS_INIT_VLC_STATIC(5, 9,  544);
326    PS_INIT_VLC_STATIC(6, 5,   32);
327    PS_INIT_VLC_STATIC(7, 5,   32);
328    PS_INIT_VLC_STATIC(8, 5,   32);
329    PS_INIT_VLC_STATIC(9, 5,   32);
330}
331
332av_cold void ff_ps_init_common(void)
333{
334    static AVOnce init_static_once = AV_ONCE_INIT;
335    ff_thread_once(&init_static_once, ps_init_common);
336}
337