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ffmpeg / libavcodec / shorten.c @ 72415b2a

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1
/*
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 * Shorten decoder
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 * Copyright (c) 2005 Jeff Muizelaar
4
 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
21

    
22
/**
23
 * @file libavcodec/shorten.c
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 * Shorten decoder
25
 * @author Jeff Muizelaar
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 *
27
 */
28

    
29
#define DEBUG
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#include <limits.h>
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#include "avcodec.h"
32
#include "get_bits.h"
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#include "golomb.h"
34

    
35
#define MAX_CHANNELS 8
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#define MAX_BLOCKSIZE 65535
37

    
38
#define OUT_BUFFER_SIZE 16384
39

    
40
#define ULONGSIZE 2
41

    
42
#define WAVE_FORMAT_PCM 0x0001
43

    
44
#define DEFAULT_BLOCK_SIZE 256
45

    
46
#define TYPESIZE 4
47
#define CHANSIZE 0
48
#define LPCQSIZE 2
49
#define ENERGYSIZE 3
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#define BITSHIFTSIZE 2
51

    
52
#define TYPE_S16HL 3
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#define TYPE_S16LH 5
54

    
55
#define NWRAP 3
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#define NSKIPSIZE 1
57

    
58
#define LPCQUANT 5
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#define V2LPCQOFFSET (1 << LPCQUANT)
60

    
61
#define FNSIZE 2
62
#define FN_DIFF0        0
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#define FN_DIFF1        1
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#define FN_DIFF2        2
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#define FN_DIFF3        3
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#define FN_QUIT         4
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#define FN_BLOCKSIZE    5
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#define FN_BITSHIFT     6
69
#define FN_QLPC         7
70
#define FN_ZERO         8
71
#define FN_VERBATIM     9
72

    
73
#define VERBATIM_CKSIZE_SIZE 5
74
#define VERBATIM_BYTE_SIZE 8
75
#define CANONICAL_HEADER_SIZE 44
76

    
77
typedef struct ShortenContext {
78
    AVCodecContext *avctx;
79
    GetBitContext gb;
80

    
81
    int min_framesize, max_framesize;
82
    int channels;
83

    
84
    int32_t *decoded[MAX_CHANNELS];
85
    int32_t *offset[MAX_CHANNELS];
86
    uint8_t *bitstream;
87
    int bitstream_size;
88
    int bitstream_index;
89
    unsigned int allocated_bitstream_size;
90
    int header_size;
91
    uint8_t header[OUT_BUFFER_SIZE];
92
    int version;
93
    int cur_chan;
94
    int bitshift;
95
    int nmean;
96
    int internal_ftype;
97
    int nwrap;
98
    int blocksize;
99
    int bitindex;
100
    int32_t lpcqoffset;
101
} ShortenContext;
102

    
103
static av_cold int shorten_decode_init(AVCodecContext * avctx)
104
{
105
    ShortenContext *s = avctx->priv_data;
106
    s->avctx = avctx;
107
    avctx->sample_fmt = SAMPLE_FMT_S16;
108

    
109
    return 0;
110
}
111

    
112
static int allocate_buffers(ShortenContext *s)
113
{
114
    int i, chan;
115
    for (chan=0; chan<s->channels; chan++) {
116
        if(FFMAX(1, s->nmean) >= UINT_MAX/sizeof(int32_t)){
117
            av_log(s->avctx, AV_LOG_ERROR, "nmean too large\n");
118
            return -1;
119
        }
120
        if(s->blocksize + s->nwrap >= UINT_MAX/sizeof(int32_t) || s->blocksize + s->nwrap <= (unsigned)s->nwrap){
121
            av_log(s->avctx, AV_LOG_ERROR, "s->blocksize + s->nwrap too large\n");
122
            return -1;
123
        }
124

    
125
        s->offset[chan] = av_realloc(s->offset[chan], sizeof(int32_t)*FFMAX(1, s->nmean));
126

    
127
        s->decoded[chan] = av_realloc(s->decoded[chan], sizeof(int32_t)*(s->blocksize + s->nwrap));
128
        for (i=0; i<s->nwrap; i++)
129
            s->decoded[chan][i] = 0;
130
        s->decoded[chan] += s->nwrap;
131
    }
132
    return 0;
133
}
134

    
135

    
136
static inline unsigned int get_uint(ShortenContext *s, int k)
137
{
138
    if (s->version != 0)
139
        k = get_ur_golomb_shorten(&s->gb, ULONGSIZE);
140
    return get_ur_golomb_shorten(&s->gb, k);
141
}
142

    
143

    
144
static void fix_bitshift(ShortenContext *s, int32_t *buffer)
145
{
146
    int i;
147

    
148
    if (s->bitshift != 0)
149
        for (i = 0; i < s->blocksize; i++)
150
            buffer[s->nwrap + i] <<= s->bitshift;
151
}
152

    
153

    
154
static void init_offset(ShortenContext *s)
155
{
156
    int32_t mean = 0;
157
    int  chan, i;
158
    int nblock = FFMAX(1, s->nmean);
159
    /* initialise offset */
160
    switch (s->internal_ftype)
161
    {
162
        case TYPE_S16HL:
163
        case TYPE_S16LH:
164
            mean = 0;
165
            break;
166
        default:
167
            av_log(s->avctx, AV_LOG_ERROR, "unknown audio type");
168
            abort();
169
    }
170

    
171
    for (chan = 0; chan < s->channels; chan++)
172
        for (i = 0; i < nblock; i++)
173
            s->offset[chan][i] = mean;
174
}
175

    
176
static inline int get_le32(GetBitContext *gb)
177
{
178
    return bswap_32(get_bits_long(gb, 32));
179
}
180

    
181
static inline short get_le16(GetBitContext *gb)
182
{
183
    return bswap_16(get_bits_long(gb, 16));
184
}
185

    
186
static int decode_wave_header(AVCodecContext *avctx, uint8_t *header, int header_size)
187
{
188
    GetBitContext hb;
189
    int len;
190
    int chunk_size;
191
    short wave_format;
192

    
193
    init_get_bits(&hb, header, header_size*8);
194
    if (get_le32(&hb) != MKTAG('R','I','F','F')) {
195
        av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
196
        return -1;
197
    }
198

    
199
    chunk_size = get_le32(&hb);
200

    
201
    if (get_le32(&hb) != MKTAG('W','A','V','E')) {
202
        av_log(avctx, AV_LOG_ERROR, "missing WAVE tag\n");
203
        return -1;
204
    }
205

    
206
    while (get_le32(&hb) != MKTAG('f','m','t',' ')) {
207
        len = get_le32(&hb);
208
        skip_bits(&hb, 8*len);
209
    }
210
    len = get_le32(&hb);
211

    
212
    if (len < 16) {
213
        av_log(avctx, AV_LOG_ERROR, "fmt chunk was too short\n");
214
        return -1;
215
    }
216

    
217
    wave_format = get_le16(&hb);
218

    
219
    switch (wave_format) {
220
        case WAVE_FORMAT_PCM:
221
            break;
222
        default:
223
            av_log(avctx, AV_LOG_ERROR, "unsupported wave format\n");
224
            return -1;
225
    }
226

    
227
    avctx->channels = get_le16(&hb);
228
    avctx->sample_rate = get_le32(&hb);
229
    avctx->bit_rate = get_le32(&hb) * 8;
230
    avctx->block_align = get_le16(&hb);
231
    avctx->bits_per_coded_sample = get_le16(&hb);
232

    
233
    if (avctx->bits_per_coded_sample != 16) {
234
        av_log(avctx, AV_LOG_ERROR, "unsupported number of bits per sample\n");
235
        return -1;
236
    }
237

    
238
    len -= 16;
239
    if (len > 0)
240
        av_log(avctx, AV_LOG_INFO, "%d header bytes unparsed\n", len);
241

    
242
    return 0;
243
}
244

    
245
static int16_t * interleave_buffer(int16_t *samples, int nchan, int blocksize, int32_t **buffer) {
246
    int i, chan;
247
    for (i=0; i<blocksize; i++)
248
        for (chan=0; chan < nchan; chan++)
249
            *samples++ = FFMIN(buffer[chan][i], 32768);
250
    return samples;
251
}
252

    
253
static void decode_subframe_lpc(ShortenContext *s, int channel, int residual_size, int pred_order)
254
{
255
    int sum, i, j;
256
    int coeffs[pred_order];
257

    
258
    for (i=0; i<pred_order; i++)
259
        coeffs[i] = get_sr_golomb_shorten(&s->gb, LPCQUANT);
260

    
261
    for (i=0; i < s->blocksize; i++) {
262
        sum = s->lpcqoffset;
263
        for (j=0; j<pred_order; j++)
264
            sum += coeffs[j] * s->decoded[channel][i-j-1];
265
        s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + (sum >> LPCQUANT);
266
    }
267
}
268

    
269

    
270
static int shorten_decode_frame(AVCodecContext *avctx,
271
        void *data, int *data_size,
272
        AVPacket *avpkt)
273
{
274
    const uint8_t *buf = avpkt->data;
275
    int buf_size = avpkt->size;
276
    ShortenContext *s = avctx->priv_data;
277
    int i, input_buf_size = 0;
278
    int16_t *samples = data;
279
    if(s->max_framesize == 0){
280
        s->max_framesize= 1024; // should hopefully be enough for the first header
281
        s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
282
    }
283

    
284
    if(1 && s->max_framesize){//FIXME truncated
285
        buf_size= FFMIN(buf_size, s->max_framesize - s->bitstream_size);
286
        input_buf_size= buf_size;
287

    
288
        if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){
289
            //                printf("memmove\n");
290
            memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
291
            s->bitstream_index=0;
292
        }
293
        memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
294
        buf= &s->bitstream[s->bitstream_index];
295
        buf_size += s->bitstream_size;
296
        s->bitstream_size= buf_size;
297

    
298
        if(buf_size < s->max_framesize){
299
            //dprintf(avctx, "wanna more data ... %d\n", buf_size);
300
            *data_size = 0;
301
            return input_buf_size;
302
        }
303
    }
304
    init_get_bits(&s->gb, buf, buf_size*8);
305
    skip_bits(&s->gb, s->bitindex);
306
    if (!s->blocksize)
307
    {
308
        int maxnlpc = 0;
309
        /* shorten signature */
310
        if (get_bits_long(&s->gb, 32) != AV_RB32("ajkg")) {
311
            av_log(s->avctx, AV_LOG_ERROR, "missing shorten magic 'ajkg'\n");
312
            return -1;
313
        }
314

    
315
        s->lpcqoffset = 0;
316
        s->blocksize = DEFAULT_BLOCK_SIZE;
317
        s->channels = 1;
318
        s->nmean = -1;
319
        s->version = get_bits(&s->gb, 8);
320
        s->internal_ftype = get_uint(s, TYPESIZE);
321

    
322
        s->channels = get_uint(s, CHANSIZE);
323
        if (s->channels > MAX_CHANNELS) {
324
            av_log(s->avctx, AV_LOG_ERROR, "too many channels: %d\n", s->channels);
325
            return -1;
326
        }
327

    
328
        /* get blocksize if version > 0 */
329
        if (s->version > 0) {
330
            int skip_bytes;
331
            s->blocksize = get_uint(s, av_log2(DEFAULT_BLOCK_SIZE));
332
            maxnlpc = get_uint(s, LPCQSIZE);
333
            s->nmean = get_uint(s, 0);
334

    
335
            skip_bytes = get_uint(s, NSKIPSIZE);
336
            for (i=0; i<skip_bytes; i++) {
337
                skip_bits(&s->gb, 8);
338
            }
339
        }
340
        s->nwrap = FFMAX(NWRAP, maxnlpc);
341

    
342
        if (allocate_buffers(s))
343
            return -1;
344

    
345
        init_offset(s);
346

    
347
        if (s->version > 1)
348
            s->lpcqoffset = V2LPCQOFFSET;
349

    
350
        if (get_ur_golomb_shorten(&s->gb, FNSIZE) != FN_VERBATIM) {
351
            av_log(s->avctx, AV_LOG_ERROR, "missing verbatim section at beginning of stream\n");
352
            return -1;
353
        }
354

    
355
        s->header_size = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
356
        if (s->header_size >= OUT_BUFFER_SIZE || s->header_size < CANONICAL_HEADER_SIZE) {
357
            av_log(s->avctx, AV_LOG_ERROR, "header is wrong size: %d\n", s->header_size);
358
            return -1;
359
        }
360

    
361
        for (i=0; i<s->header_size; i++)
362
            s->header[i] = (char)get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
363

    
364
        if (decode_wave_header(avctx, s->header, s->header_size) < 0)
365
            return -1;
366

    
367
        s->cur_chan = 0;
368
        s->bitshift = 0;
369
    }
370
    else
371
    {
372
        int cmd;
373
        int len;
374
        cmd = get_ur_golomb_shorten(&s->gb, FNSIZE);
375
        switch (cmd) {
376
            case FN_ZERO:
377
            case FN_DIFF0:
378
            case FN_DIFF1:
379
            case FN_DIFF2:
380
            case FN_DIFF3:
381
            case FN_QLPC:
382
                {
383
                    int residual_size = 0;
384
                    int channel = s->cur_chan;
385
                    int32_t coffset;
386
                    if (cmd != FN_ZERO) {
387
                        residual_size = get_ur_golomb_shorten(&s->gb, ENERGYSIZE);
388
                        /* this is a hack as version 0 differed in defintion of get_sr_golomb_shorten */
389
                        if (s->version == 0)
390
                            residual_size--;
391
                    }
392

    
393
                    if (s->nmean == 0)
394
                        coffset = s->offset[channel][0];
395
                    else {
396
                        int32_t sum = (s->version < 2) ? 0 : s->nmean / 2;
397
                        for (i=0; i<s->nmean; i++)
398
                            sum += s->offset[channel][i];
399
                        coffset = sum / s->nmean;
400
                        if (s->version >= 2)
401
                            coffset >>= FFMIN(1, s->bitshift);
402
                    }
403
                    switch (cmd) {
404
                        case FN_ZERO:
405
                            for (i=0; i<s->blocksize; i++)
406
                                s->decoded[channel][i] = 0;
407
                            break;
408
                        case FN_DIFF0:
409
                            for (i=0; i<s->blocksize; i++)
410
                                s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + coffset;
411
                            break;
412
                        case FN_DIFF1:
413
                            for (i=0; i<s->blocksize; i++)
414
                                s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + s->decoded[channel][i - 1];
415
                            break;
416
                        case FN_DIFF2:
417
                            for (i=0; i<s->blocksize; i++)
418
                                s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 2*s->decoded[channel][i-1]
419
                                                                                                      -   s->decoded[channel][i-2];
420
                            break;
421
                        case FN_DIFF3:
422
                            for (i=0; i<s->blocksize; i++)
423
                                s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 3*s->decoded[channel][i-1]
424
                                                                                                      - 3*s->decoded[channel][i-2]
425
                                                                                                      +   s->decoded[channel][i-3];
426
                            break;
427
                        case FN_QLPC:
428
                            {
429
                                int pred_order = get_ur_golomb_shorten(&s->gb, LPCQSIZE);
430
                                for (i=0; i<pred_order; i++)
431
                                    s->decoded[channel][i - pred_order] -= coffset;
432
                                decode_subframe_lpc(s, channel, residual_size, pred_order);
433
                                if (coffset != 0)
434
                                    for (i=0; i < s->blocksize; i++)
435
                                        s->decoded[channel][i] += coffset;
436
                            }
437
                    }
438
                    if (s->nmean > 0) {
439
                        int32_t sum = (s->version < 2) ? 0 : s->blocksize / 2;
440
                        for (i=0; i<s->blocksize; i++)
441
                            sum += s->decoded[channel][i];
442

    
443
                        for (i=1; i<s->nmean; i++)
444
                            s->offset[channel][i-1] = s->offset[channel][i];
445

    
446
                        if (s->version < 2)
447
                            s->offset[channel][s->nmean - 1] = sum / s->blocksize;
448
                        else
449
                            s->offset[channel][s->nmean - 1] = (sum / s->blocksize) << s->bitshift;
450
                    }
451
                    for (i=-s->nwrap; i<0; i++)
452
                        s->decoded[channel][i] = s->decoded[channel][i + s->blocksize];
453

    
454
                    fix_bitshift(s, s->decoded[channel]);
455

    
456
                    s->cur_chan++;
457
                    if (s->cur_chan == s->channels) {
458
                        samples = interleave_buffer(samples, s->channels, s->blocksize, s->decoded);
459
                        s->cur_chan = 0;
460
                        goto frame_done;
461
                    }
462
                    break;
463
                }
464
                break;
465
            case FN_VERBATIM:
466
                len = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
467
                while (len--) {
468
                    get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
469
                }
470
                break;
471
            case FN_BITSHIFT:
472
                s->bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
473
                break;
474
            case FN_BLOCKSIZE:
475
                s->blocksize = get_uint(s, av_log2(s->blocksize));
476
                break;
477
            case FN_QUIT:
478
                *data_size = 0;
479
                return buf_size;
480
                break;
481
            default:
482
                av_log(avctx, AV_LOG_ERROR, "unknown shorten function %d\n", cmd);
483
                return -1;
484
                break;
485
        }
486
    }
487
frame_done:
488
    *data_size = (int8_t *)samples - (int8_t *)data;
489

    
490
    //    s->last_blocksize = s->blocksize;
491
    s->bitindex = get_bits_count(&s->gb) - 8*((get_bits_count(&s->gb))/8);
492
    i= (get_bits_count(&s->gb))/8;
493
    if (i > buf_size) {
494
        av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
495
        s->bitstream_size=0;
496
        s->bitstream_index=0;
497
        return -1;
498
    }
499
    if (s->bitstream_size) {
500
        s->bitstream_index += i;
501
        s->bitstream_size  -= i;
502
        return input_buf_size;
503
    } else
504
        return i;
505
}
506

    
507
static av_cold int shorten_decode_close(AVCodecContext *avctx)
508
{
509
    ShortenContext *s = avctx->priv_data;
510
    int i;
511

    
512
    for (i = 0; i < s->channels; i++) {
513
        s->decoded[i] -= s->nwrap;
514
        av_freep(&s->decoded[i]);
515
        av_freep(&s->offset[i]);
516
    }
517
    av_freep(&s->bitstream);
518
    return 0;
519
}
520

    
521
static void shorten_flush(AVCodecContext *avctx){
522
    ShortenContext *s = avctx->priv_data;
523

    
524
    s->bitstream_size=
525
        s->bitstream_index= 0;
526
}
527

    
528
AVCodec shorten_decoder = {
529
    "shorten",
530
    AVMEDIA_TYPE_AUDIO,
531
    CODEC_ID_SHORTEN,
532
    sizeof(ShortenContext),
533
    shorten_decode_init,
534
    NULL,
535
    shorten_decode_close,
536
    shorten_decode_frame,
537
    .flush= shorten_flush,
538
    .long_name= NULL_IF_CONFIG_SMALL("Shorten"),
539
};