1/*
2 * TTA (The Lossless True Audio) decoder
3 * Copyright (c) 2006 Alex Beregszaszi
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/**
23 * @file
24 * TTA (The Lossless True Audio) decoder
25 * @see http://www.true-audio.com/
26 * @see http://tta.corecodec.org/
27 * @author Alex Beregszaszi
28 */
29
30#define BITSTREAM_READER_LE
31#include <limits.h>
32#include "ttadata.h"
33#include "ttadsp.h"
34#include "avcodec.h"
35#include "get_bits.h"
36#include "thread.h"
37#include "unary.h"
38#include "internal.h"
39#include "libavutil/crc.h"
40#include "libavutil/intreadwrite.h"
41#include "libavutil/opt.h"
42
43#define FORMAT_SIMPLE    1
44#define FORMAT_ENCRYPTED 2
45
46typedef struct TTAContext {
47    AVClass *class;
48    AVCodecContext *avctx;
49    const AVCRC *crc_table;
50
51    int format, channels, bps;
52    unsigned data_length;
53    int frame_length, last_frame_length;
54
55    int32_t *decode_buffer;
56
57    uint8_t crc_pass[8];
58    uint8_t *pass;
59    TTAChannel *ch_ctx;
60    TTADSPContext dsp;
61} TTAContext;
62
63static const int64_t tta_channel_layouts[7] = {
64    AV_CH_LAYOUT_STEREO,
65    AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
66    AV_CH_LAYOUT_QUAD,
67    0,
68    AV_CH_LAYOUT_5POINT1_BACK,
69    AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER,
70    AV_CH_LAYOUT_7POINT1_WIDE
71};
72
73static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
74{
75    uint32_t crc, CRC;
76
77    CRC = AV_RL32(buf + buf_size);
78    crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
79    if (CRC != (crc ^ 0xFFFFFFFFU)) {
80        av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
81        return AVERROR_INVALIDDATA;
82    }
83
84    return 0;
85}
86
87static uint64_t tta_check_crc64(uint8_t *pass)
88{
89    uint64_t crc = UINT64_MAX, poly = 0x42F0E1EBA9EA3693U;
90    uint8_t *end = pass + strlen(pass);
91    int i;
92
93    while (pass < end) {
94        crc ^= (uint64_t)*pass++ << 56;
95        for (i = 0; i < 8; i++)
96            crc = (crc << 1) ^ (poly & (((int64_t) crc) >> 63));
97    }
98
99    return crc ^ UINT64_MAX;
100}
101
102static int allocate_buffers(AVCodecContext *avctx)
103{
104    TTAContext *s = avctx->priv_data;
105
106    if (s->bps < 3) {
107        s->decode_buffer = av_mallocz_array(sizeof(int32_t)*s->frame_length, s->channels);
108        if (!s->decode_buffer)
109            return AVERROR(ENOMEM);
110    } else
111        s->decode_buffer = NULL;
112    s->ch_ctx = av_malloc_array(avctx->channels, sizeof(*s->ch_ctx));
113    if (!s->ch_ctx) {
114        av_freep(&s->decode_buffer);
115        return AVERROR(ENOMEM);
116    }
117
118    return 0;
119}
120
121static av_cold int tta_decode_init(AVCodecContext * avctx)
122{
123    TTAContext *s = avctx->priv_data;
124    GetBitContext gb;
125    int total_frames;
126
127    s->avctx = avctx;
128
129    // 30bytes includes TTA1 header
130    if (avctx->extradata_size < 22)
131        return AVERROR_INVALIDDATA;
132
133    s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
134    init_get_bits8(&gb, avctx->extradata, avctx->extradata_size);
135    if (show_bits_long(&gb, 32) == AV_RL32("TTA1")) {
136        /* signature */
137        skip_bits_long(&gb, 32);
138
139        s->format = get_bits(&gb, 16);
140        if (s->format > 2) {
141            av_log(avctx, AV_LOG_ERROR, "Invalid format\n");
142            return AVERROR_INVALIDDATA;
143        }
144        if (s->format == FORMAT_ENCRYPTED) {
145            if (!s->pass) {
146                av_log(avctx, AV_LOG_ERROR, "Missing password for encrypted stream. Please use the -password option\n");
147                return AVERROR(EINVAL);
148            }
149            AV_WL64(s->crc_pass, tta_check_crc64(s->pass));
150        }
151        avctx->channels = s->channels = get_bits(&gb, 16);
152        if (s->channels > 1 && s->channels < 9)
153            avctx->channel_layout = tta_channel_layouts[s->channels-2];
154        avctx->bits_per_raw_sample = get_bits(&gb, 16);
155        s->bps = (avctx->bits_per_raw_sample + 7) / 8;
156        avctx->sample_rate = get_bits_long(&gb, 32);
157        s->data_length = get_bits_long(&gb, 32);
158        skip_bits_long(&gb, 32); // CRC32 of header
159
160        if (s->channels == 0) {
161            av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
162            return AVERROR_INVALIDDATA;
163        } else if (avctx->sample_rate == 0) {
164            av_log(avctx, AV_LOG_ERROR, "Invalid samplerate\n");
165            return AVERROR_INVALIDDATA;
166        }
167
168        switch(s->bps) {
169        case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
170        case 2:
171            avctx->sample_fmt = AV_SAMPLE_FMT_S16;
172            break;
173        case 3:
174            avctx->sample_fmt = AV_SAMPLE_FMT_S32;
175            break;
176        //case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break;
177        default:
178            av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
179            return AVERROR_INVALIDDATA;
180        }
181
182        // prevent overflow
183        if (avctx->sample_rate > 0x7FFFFFu) {
184            av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
185            return AVERROR(EINVAL);
186        }
187        s->frame_length = 256 * avctx->sample_rate / 245;
188
189        s->last_frame_length = s->data_length % s->frame_length;
190        total_frames = s->data_length / s->frame_length +
191                       (s->last_frame_length ? 1 : 0);
192
193        av_log(avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
194            s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
195            avctx->block_align);
196        av_log(avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
197            s->data_length, s->frame_length, s->last_frame_length, total_frames);
198
199        if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
200            av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
201            return AVERROR_INVALIDDATA;
202        }
203    } else {
204        av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
205        return AVERROR_INVALIDDATA;
206    }
207
208    ff_ttadsp_init(&s->dsp);
209
210    return allocate_buffers(avctx);
211}
212
213static int tta_decode_frame(AVCodecContext *avctx, void *data,
214                            int *got_frame_ptr, AVPacket *avpkt)
215{
216    AVFrame *frame     = data;
217    ThreadFrame tframe = { .f = data };
218    const uint8_t *buf = avpkt->data;
219    int buf_size = avpkt->size;
220    TTAContext *s = avctx->priv_data;
221    GetBitContext gb;
222    int i, ret;
223    int cur_chan = 0, framelen = s->frame_length;
224    int32_t *p;
225
226    if (avctx->err_recognition & AV_EF_CRCCHECK) {
227        if (buf_size < 4 ||
228            (tta_check_crc(s, buf, buf_size - 4) && avctx->err_recognition & AV_EF_EXPLODE))
229            return AVERROR_INVALIDDATA;
230    }
231
232    if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0)
233        return ret;
234
235    /* get output buffer */
236    frame->nb_samples = framelen;
237    if ((ret = ff_thread_get_buffer(avctx, &tframe, 0)) < 0)
238        return ret;
239
240    // decode directly to output buffer for 24-bit sample format
241    if (s->bps == 3)
242        s->decode_buffer = (int32_t *)frame->data[0];
243
244    // init per channel states
245    for (i = 0; i < s->channels; i++) {
246        TTAFilter *filter = &s->ch_ctx[i].filter;
247        s->ch_ctx[i].predictor = 0;
248        ff_tta_filter_init(filter, ff_tta_filter_configs[s->bps-1]);
249        if (s->format == FORMAT_ENCRYPTED) {
250            int i;
251            for (i = 0; i < 8; i++)
252                filter->qm[i] = sign_extend(s->crc_pass[i], 8);
253        }
254        ff_tta_rice_init(&s->ch_ctx[i].rice, 10, 10);
255    }
256
257    i = 0;
258    for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
259        int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
260        TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
261        TTARice *rice = &s->ch_ctx[cur_chan].rice;
262        uint32_t unary, depth, k;
263        int32_t value;
264
265        unary = get_unary(&gb, 0, get_bits_left(&gb));
266
267        if (unary == 0) {
268            depth = 0;
269            k = rice->k0;
270        } else {
271            depth = 1;
272            k = rice->k1;
273            unary--;
274        }
275
276        if (get_bits_left(&gb) < k) {
277            ret = AVERROR_INVALIDDATA;
278            goto error;
279        }
280
281        if (k) {
282            if (k > MIN_CACHE_BITS) {
283                ret = AVERROR_INVALIDDATA;
284                goto error;
285            }
286            value = (unary << k) + get_bits(&gb, k);
287        } else
288            value = unary;
289
290        // FIXME: copy paste from original
291        switch (depth) {
292        case 1:
293            rice->sum1 += value - (rice->sum1 >> 4);
294            if (rice->k1 > 0 && rice->sum1 < ff_tta_shift_16[rice->k1])
295                rice->k1--;
296            else if(rice->sum1 > ff_tta_shift_16[rice->k1 + 1])
297                rice->k1++;
298            value += ff_tta_shift_1[rice->k0];
299        default:
300            rice->sum0 += value - (rice->sum0 >> 4);
301            if (rice->k0 > 0 && rice->sum0 < ff_tta_shift_16[rice->k0])
302                rice->k0--;
303            else if(rice->sum0 > ff_tta_shift_16[rice->k0 + 1])
304                rice->k0++;
305        }
306
307        // extract coded value
308        *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
309
310        // run hybrid filter
311        s->dsp.ttafilter_process_dec(filter->qm, filter->dx, filter->dl, &filter->error, p,
312                                     filter->shift, filter->round);
313
314        // fixed order prediction
315#define PRED(x, k) (int32_t)((((uint64_t)(x) << (k)) - (x)) >> (k))
316        switch (s->bps) {
317        case 1: *p += PRED(*predictor, 4); break;
318        case 2:
319        case 3: *p += PRED(*predictor, 5); break;
320        case 4: *p +=      *predictor;     break;
321        }
322        *predictor = *p;
323
324        // flip channels
325        if (cur_chan < (s->channels-1))
326            cur_chan++;
327        else {
328            // decorrelate in case of multiple channels
329            if (s->channels > 1) {
330                int32_t *r = p - 1;
331                for (*p += *r / 2; r > p - s->channels; r--)
332                    *r = *(r + 1) - *r;
333            }
334            cur_chan = 0;
335            i++;
336            // check for last frame
337            if (i == s->last_frame_length && get_bits_left(&gb) / 8 == 4) {
338                frame->nb_samples = framelen = s->last_frame_length;
339                break;
340            }
341        }
342    }
343
344    align_get_bits(&gb);
345    if (get_bits_left(&gb) < 32) {
346        ret = AVERROR_INVALIDDATA;
347        goto error;
348    }
349    skip_bits_long(&gb, 32); // frame crc
350
351    // convert to output buffer
352    switch (s->bps) {
353    case 1: {
354        uint8_t *samples = (uint8_t *)frame->data[0];
355        for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
356            *samples++ = *p + 0x80;
357        break;
358        }
359    case 2: {
360        int16_t *samples = (int16_t *)frame->data[0];
361        for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
362            *samples++ = *p;
363        break;
364        }
365    case 3: {
366        // shift samples for 24-bit sample format
367        int32_t *samples = (int32_t *)frame->data[0];
368        for (i = 0; i < framelen * s->channels; i++)
369            *samples++ <<= 8;
370        // reset decode buffer
371        s->decode_buffer = NULL;
372        break;
373        }
374    }
375
376    *got_frame_ptr = 1;
377
378    return buf_size;
379error:
380    // reset decode buffer
381    if (s->bps == 3)
382        s->decode_buffer = NULL;
383    return ret;
384}
385
386static int init_thread_copy(AVCodecContext *avctx)
387{
388    TTAContext *s = avctx->priv_data;
389    s->avctx = avctx;
390    return allocate_buffers(avctx);
391}
392
393static av_cold int tta_decode_close(AVCodecContext *avctx) {
394    TTAContext *s = avctx->priv_data;
395
396    if (s->bps < 3)
397        av_free(s->decode_buffer);
398    s->decode_buffer = NULL;
399    av_freep(&s->ch_ctx);
400
401    return 0;
402}
403
404#define OFFSET(x) offsetof(TTAContext, x)
405#define DEC (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM)
406static const AVOption options[] = {
407    { "password", "Set decoding password", OFFSET(pass), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
408    { NULL },
409};
410
411static const AVClass tta_decoder_class = {
412    .class_name = "TTA Decoder",
413    .item_name  = av_default_item_name,
414    .option     = options,
415    .version    = LIBAVUTIL_VERSION_INT,
416};
417
418AVCodec ff_tta_decoder = {
419    .name           = "tta",
420    .long_name      = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
421    .type           = AVMEDIA_TYPE_AUDIO,
422    .id             = AV_CODEC_ID_TTA,
423    .priv_data_size = sizeof(TTAContext),
424    .init           = tta_decode_init,
425    .close          = tta_decode_close,
426    .decode         = tta_decode_frame,
427    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
428    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
429    .priv_class     = &tta_decoder_class,
430};
431