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
31 typedef struct TAKParseContext {
32 ParseContext pc;
33 TAKStreamInfo ti;
34 int index;
35 } TAKParseContext;
36
tak_parse(AVCodecParserContext * s,AVCodecContext * avctx,const uint8_t ** poutbuf,int * poutbuf_size,const uint8_t * buf,int buf_size)37 static 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 }
103 found:
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
119 fail:
120 *poutbuf = NULL;
121 *poutbuf_size = 0;
122 return buf_size + consumed;
123 }
124
125 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