1/*
2 * TAK parser
3 * Copyright (c) 2012 Michael Niedermayer
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 * TAK parser
25 **/
26
27#define BITSTREAM_READER_LE
28#include "parser.h"
29#include "tak.h"
30
31typedef struct TAKParseContext {
32    ParseContext  pc;
33    TAKStreamInfo ti;
34    int           index;
35} TAKParseContext;
36
37static int tak_parse(AVCodecParserContext *s, AVCodecContext *avctx,
38                     const uint8_t **poutbuf, int *poutbuf_size,
39                     const uint8_t *buf, int buf_size)
40{
41    TAKParseContext *t = s->priv_data;
42    ParseContext *pc   = &t->pc;
43    int next           = END_NOT_FOUND;
44    GetBitContext gb;
45    int consumed = 0;
46    int needed   = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
47    int ret;
48
49    *poutbuf      = buf;
50    *poutbuf_size = buf_size;
51
52    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
53        TAKStreamInfo ti;
54        if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
55            return buf_size;
56        if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))
57            s->duration = t->ti.last_frame_samples ? t->ti.last_frame_samples
58                                                   : t->ti.frame_samples;
59        return buf_size;
60    }
61
62    while (buf_size || t->index + needed <= pc->index) {
63        if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
64            int tmp_buf_size       = FFMIN(TAK_MAX_FRAME_HEADER_BYTES,
65                                           buf_size);
66            const uint8_t *tmp_buf = buf;
67
68            if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1)
69                goto fail;
70            consumed += tmp_buf_size;
71            buf      += tmp_buf_size;
72            buf_size -= tmp_buf_size;
73        }
74
75        for (; t->index + needed <= pc->index; t->index++) {
76            if (pc->buffer[ t->index     ] == 0xFF &&
77                pc->buffer[ t->index + 1 ] == 0xA0) {
78                TAKStreamInfo ti;
79
80                if ((ret = init_get_bits8(&gb, pc->buffer + t->index,
81                                          pc->index - t->index)) < 0)
82                    goto fail;
83                if (!ff_tak_decode_frame_header(avctx, &gb,
84                        pc->frame_start_found ? &ti : &t->ti, 127) &&
85                    !ff_tak_check_crc(pc->buffer + t->index,
86                                      get_bits_count(&gb) / 8)) {
87                    if (!pc->frame_start_found) {
88                        pc->frame_start_found = 1;
89                        s->duration           = t->ti.last_frame_samples ?
90                                                t->ti.last_frame_samples :
91                                                t->ti.frame_samples;
92                        s->key_frame          = !!(t->ti.flags & TAK_FRAME_FLAG_HAS_INFO);
93                    } else {
94                        pc->frame_start_found = 0;
95                        next                  = t->index - pc->index;
96                        t->index              = 0;
97                        goto found;
98                    }
99                }
100            }
101        }
102    }
103found:
104
105    if (consumed && !buf_size && next == END_NOT_FOUND ||
106        ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
107        goto fail;
108    }
109
110    if (next != END_NOT_FOUND) {
111        next        += consumed;
112        pc->overread = FFMAX(0, -next);
113    }
114
115    *poutbuf      = buf;
116    *poutbuf_size = buf_size;
117    return next;
118
119fail:
120    *poutbuf      = NULL;
121    *poutbuf_size = 0;
122    return buf_size + consumed;
123}
124
125const AVCodecParser ff_tak_parser = {
126    .codec_ids      = { AV_CODEC_ID_TAK },
127    .priv_data_size = sizeof(TAKParseContext),
128    .parser_parse   = tak_parse,
129    .parser_close   = ff_parse_close,
130};
131