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