indeo: Do not reference mismatched tiles
[ffmpeg.git] / libavcodec / tak_parser.c
1 /*
2  * TAK parser
3  * Copyright (c) 2012 Michael Niedermayer
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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
30 typedef struct TAKParseContext {
31     ParseContext  pc;
32     TAKStreamInfo ti;
33     int           index;
34 } TAKParseContext;
35
36 static av_cold int tak_init(AVCodecParserContext *s)
37 {
38     ff_tak_init_crc();
39     return 0;
40 }
41
42 static int tak_parse(AVCodecParserContext *s, AVCodecContext *avctx,
43                      const uint8_t **poutbuf, int *poutbuf_size,
44                      const uint8_t *buf, int buf_size)
45 {
46     TAKParseContext *t = s->priv_data;
47     ParseContext *pc   = &t->pc;
48     int next           = END_NOT_FOUND;
49     GetBitContext gb;
50     int consumed = 0;
51     int needed   = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
52
53     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
54         TAKStreamInfo ti;
55         init_get_bits(&gb, buf, 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         *poutbuf      = buf;
60         *poutbuf_size = buf_size;
61         return buf_size;
62     }
63
64     while (buf_size || t->index + needed <= pc->index) {
65         if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
66             int tmp_buf_size       = FFMIN(2 * TAK_MAX_FRAME_HEADER_BYTES,
67                                            buf_size);
68             const uint8_t *tmp_buf = buf;
69
70             ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size);
71             consumed += tmp_buf_size;
72             buf      += tmp_buf_size;
73             buf_size -= tmp_buf_size;
74         }
75
76         for (; t->index + needed <= pc->index; t->index++)
77             if (pc->buffer[t->index]     == 0xFF &&
78                 pc->buffer[t->index + 1] == 0xA0) {
79                 TAKStreamInfo ti;
80
81                 init_get_bits(&gb, pc->buffer + t->index,
82                               8 * (pc->index - t->index));
83                 if (!ff_tak_decode_frame_header(avctx, &gb,
84                                                 pc->frame_start_found ? &ti
85                                                                       : &t->ti,
86                                                 127) &&
87                     !ff_tak_check_crc(pc->buffer + t->index,
88                                       get_bits_count(&gb) / 8)) {
89                     if (!pc->frame_start_found) {
90                         pc->frame_start_found = 1;
91                         s->duration           = t->ti.last_frame_samples ?
92                                                 t->ti.last_frame_samples :
93                                                 t->ti.frame_samples;
94                     } else {
95                         pc->frame_start_found = 0;
96                         next                  = t->index - pc->index;
97                         t->index              = 0;
98                         goto found;
99                     }
100                 }
101             }
102     }
103
104 found:
105     if (consumed && !buf_size && next == END_NOT_FOUND ||
106         ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
107         *poutbuf      = NULL;
108         *poutbuf_size = 0;
109         return buf_size + consumed;
110     }
111
112     if (next != END_NOT_FOUND) {
113         next        += consumed;
114         pc->overread = FFMAX(0, -next);
115     }
116
117     *poutbuf      = buf;
118     *poutbuf_size = buf_size;
119     return next;
120 }
121
122 AVCodecParser ff_tak_parser = {
123     .codec_ids      = { AV_CODEC_ID_TAK },
124     .priv_data_size = sizeof(TAKParseContext),
125     .parser_init    = tak_init,
126     .parser_parse   = tak_parse,
127     .parser_close   = ff_parse_close,
128 };