avfilter/vf_v360: add octahedron format
[ffmpeg.git] / libavcodec / dvbsub_parser.c
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
22 #include <inttypes.h>
23 #include <string.h>
24
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/mem.h"
27
28 #include "avcodec.h"
29 #include "internal.h"
30
31 /* Parser (mostly) copied from dvdsub.c */
32
33 #define PARSE_BUF_SIZE  (65536)
34
35
36 /* parser definition */
37 typedef struct DVBSubParseContext {
38     int packet_start;
39     int packet_index;
40     int in_packet;
41     uint8_t packet_buf[PARSE_BUF_SIZE];
42 } DVBSubParseContext;
43
44 static int dvbsub_parse(AVCodecParserContext *s,
45                         AVCodecContext *avctx,
46                         const uint8_t **poutbuf, int *poutbuf_size,
47                         const uint8_t *buf, int buf_size)
48 {
49     DVBSubParseContext *pc = s->priv_data;
50     uint8_t *p, *p_end;
51     int i, len, buf_pos = 0;
52     int out_size = 0;
53
54     ff_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         ff_dlog(avctx, "%02x ", buf[i]);
60         if (i % 16 == 15)
61             ff_dlog(avctx, "\n");
62     }
63
64     if (i % 16 != 0)
65         ff_dlog(avctx, "\n");
66
67     *poutbuf      = buf;
68     *poutbuf_size = buf_size;
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             ff_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             ff_dlog(avctx, "Bad packet header\n");
85             return buf_size;
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 buf_size;
110
111 /* if not currently in a packet, pass 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 (6 <= p_end - p)
126             {
127                 len = AV_RB16(p + 4);
128
129                 if (len + 6 <= p_end - p)
130                 {
131                     out_size += len + 6;
132
133                     p += len + 6;
134                 } else
135                     break;
136             } else
137                 break;
138         } else if (*p == 0xff) {
139             if (1 < p_end - p)
140             {
141                 ff_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 (out_size > 0)
156     {
157         *poutbuf = pc->packet_buf;
158         *poutbuf_size = out_size;
159         pc->packet_start = *poutbuf_size;
160     }
161
162     if (s->pts == AV_NOPTS_VALUE)
163         s->pts = s->last_pts;
164
165     return buf_size;
166 }
167
168 AVCodecParser ff_dvbsub_parser = {
169     .codec_ids      = { AV_CODEC_ID_DVB_SUBTITLE },
170     .priv_data_size = sizeof(DVBSubParseContext),
171     .parser_parse   = dvbsub_parse,
172 };