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2ba45a60 DM |
1 | /* |
2 | * DVB subtitle parser for FFmpeg | |
3 | * Copyright (c) 2005 Ian Caulfield | |
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 | #include "avcodec.h" | |
22 | #include "get_bits.h" | |
23 | ||
24 | /* Parser (mostly) copied from dvdsub.c */ | |
25 | ||
26 | #define PARSE_BUF_SIZE (65536) | |
27 | ||
28 | ||
29 | /* parser definition */ | |
30 | typedef struct DVBSubParseContext { | |
31 | uint8_t *packet_buf; | |
32 | int packet_start; | |
33 | int packet_index; | |
34 | int in_packet; | |
35 | } DVBSubParseContext; | |
36 | ||
37 | static av_cold int dvbsub_parse_init(AVCodecParserContext *s) | |
38 | { | |
39 | DVBSubParseContext *pc = s->priv_data; | |
40 | pc->packet_buf = av_malloc(PARSE_BUF_SIZE); | |
41 | ||
42 | return 0; | |
43 | } | |
44 | ||
45 | static int dvbsub_parse(AVCodecParserContext *s, | |
46 | AVCodecContext *avctx, | |
47 | const uint8_t **poutbuf, int *poutbuf_size, | |
48 | const uint8_t *buf, int buf_size) | |
49 | { | |
50 | DVBSubParseContext *pc = s->priv_data; | |
51 | uint8_t *p, *p_end; | |
52 | int i, len, buf_pos = 0; | |
53 | ||
54 | av_dlog(avctx, "DVB parse packet pts=%"PRIx64", lpts=%"PRIx64", cpts=%"PRIx64":\n", | |
55 | s->pts, s->last_pts, s->cur_frame_pts[s->cur_frame_start_index]); | |
56 | ||
57 | for (i=0; i < buf_size; i++) | |
58 | { | |
59 | av_dlog(avctx, "%02x ", buf[i]); | |
60 | if (i % 16 == 15) | |
61 | av_dlog(avctx, "\n"); | |
62 | } | |
63 | ||
64 | if (i % 16 != 0) | |
65 | av_dlog(avctx, "\n"); | |
66 | ||
67 | *poutbuf = NULL; | |
68 | *poutbuf_size = 0; | |
69 | ||
70 | s->fetch_timestamp = 1; | |
71 | ||
72 | if (s->last_pts != s->pts && s->pts != AV_NOPTS_VALUE) /* Start of a new packet */ | |
73 | { | |
74 | if (pc->packet_index != pc->packet_start) | |
75 | { | |
76 | av_dlog(avctx, "Discarding %d bytes\n", | |
77 | pc->packet_index - pc->packet_start); | |
78 | } | |
79 | ||
80 | pc->packet_start = 0; | |
81 | pc->packet_index = 0; | |
82 | ||
83 | if (buf_size < 2 || buf[0] != 0x20 || buf[1] != 0x00) { | |
84 | av_dlog(avctx, "Bad packet header\n"); | |
85 | return -1; | |
86 | } | |
87 | ||
88 | buf_pos = 2; | |
89 | ||
90 | pc->in_packet = 1; | |
91 | } else { | |
92 | if (pc->packet_start != 0) | |
93 | { | |
94 | if (pc->packet_index != pc->packet_start) | |
95 | { | |
96 | memmove(pc->packet_buf, pc->packet_buf + pc->packet_start, | |
97 | pc->packet_index - pc->packet_start); | |
98 | ||
99 | pc->packet_index -= pc->packet_start; | |
100 | pc->packet_start = 0; | |
101 | } else { | |
102 | pc->packet_start = 0; | |
103 | pc->packet_index = 0; | |
104 | } | |
105 | } | |
106 | } | |
107 | ||
108 | if (buf_size - buf_pos + pc->packet_index > PARSE_BUF_SIZE) | |
109 | return -1; | |
110 | ||
111 | /* if not currently in a packet, discard data */ | |
112 | if (pc->in_packet == 0) | |
113 | return buf_size; | |
114 | ||
115 | memcpy(pc->packet_buf + pc->packet_index, buf + buf_pos, buf_size - buf_pos); | |
116 | pc->packet_index += buf_size - buf_pos; | |
117 | ||
118 | p = pc->packet_buf; | |
119 | p_end = pc->packet_buf + pc->packet_index; | |
120 | ||
121 | while (p < p_end) | |
122 | { | |
123 | if (*p == 0x0f) | |
124 | { | |
125 | if (p + 6 <= p_end) | |
126 | { | |
127 | len = AV_RB16(p + 4); | |
128 | ||
129 | if (p + len + 6 <= p_end) | |
130 | { | |
131 | *poutbuf_size += len + 6; | |
132 | ||
133 | p += len + 6; | |
134 | } else | |
135 | break; | |
136 | } else | |
137 | break; | |
138 | } else if (*p == 0xff) { | |
139 | if (p + 1 < p_end) | |
140 | { | |
141 | av_dlog(avctx, "Junk at end of packet\n"); | |
142 | } | |
143 | pc->packet_index = p - pc->packet_buf; | |
144 | pc->in_packet = 0; | |
145 | break; | |
146 | } else { | |
147 | av_log(avctx, AV_LOG_ERROR, "Junk in packet\n"); | |
148 | ||
149 | pc->packet_index = p - pc->packet_buf; | |
150 | pc->in_packet = 0; | |
151 | break; | |
152 | } | |
153 | } | |
154 | ||
155 | if (*poutbuf_size > 0) | |
156 | { | |
157 | *poutbuf = pc->packet_buf; | |
158 | pc->packet_start = *poutbuf_size; | |
159 | } | |
160 | ||
161 | if (s->pts == AV_NOPTS_VALUE) | |
162 | s->pts = s->last_pts; | |
163 | ||
164 | return buf_size; | |
165 | } | |
166 | ||
167 | static av_cold void dvbsub_parse_close(AVCodecParserContext *s) | |
168 | { | |
169 | DVBSubParseContext *pc = s->priv_data; | |
170 | av_freep(&pc->packet_buf); | |
171 | } | |
172 | ||
173 | AVCodecParser ff_dvbsub_parser = { | |
174 | .codec_ids = { AV_CODEC_ID_DVB_SUBTITLE }, | |
175 | .priv_data_size = sizeof(DVBSubParseContext), | |
176 | .parser_init = dvbsub_parse_init, | |
177 | .parser_parse = dvbsub_parse, | |
178 | .parser_close = dvbsub_parse_close, | |
179 | }; |