]> git.sesse.net Git - ffmpeg/blob - libavcodec/dvbsub_parser.c
ivi_common: Initialize a variable at declaration in ff_ivi_decode_blocks().
[ffmpeg] / libavcodec / dvbsub_parser.c
1 /*
2  * DVB subtitle parser for Libav
3  * Copyright (c) 2005 Ian Caulfield
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 #include "avcodec.h"
22 #include "dsputil.h"
23 #include "get_bits.h"
24
25 /* Parser (mostly) copied from dvdsub.c */
26
27 #define PARSE_BUF_SIZE  (65536)
28
29
30 /* parser definition */
31 typedef struct DVBSubParseContext {
32     uint8_t *packet_buf;
33     int packet_start;
34     int packet_index;
35     int in_packet;
36 } DVBSubParseContext;
37
38 static av_cold int dvbsub_parse_init(AVCodecParserContext *s)
39 {
40     DVBSubParseContext *pc = s->priv_data;
41     pc->packet_buf = av_malloc(PARSE_BUF_SIZE);
42
43     return 0;
44 }
45
46 static int dvbsub_parse(AVCodecParserContext *s,
47                         AVCodecContext *avctx,
48                         const uint8_t **poutbuf, int *poutbuf_size,
49                         const uint8_t *buf, int buf_size)
50 {
51     DVBSubParseContext *pc = s->priv_data;
52     uint8_t *p, *p_end;
53     int i, len, buf_pos = 0;
54
55     av_dlog(avctx, "DVB parse packet pts=%"PRIx64", lpts=%"PRIx64", cpts=%"PRIx64":\n",
56             s->pts, s->last_pts, s->cur_frame_pts[s->cur_frame_start_index]);
57
58     for (i=0; i < buf_size; i++)
59     {
60         av_dlog(avctx, "%02x ", buf[i]);
61         if (i % 16 == 15)
62             av_dlog(avctx, "\n");
63     }
64
65     if (i % 16 != 0)
66         av_dlog(avctx, "\n");
67
68     *poutbuf = NULL;
69     *poutbuf_size = 0;
70
71     s->fetch_timestamp = 1;
72
73     if (s->last_pts != s->pts && s->pts != AV_NOPTS_VALUE) /* Start of a new packet */
74     {
75         if (pc->packet_index != pc->packet_start)
76         {
77             av_dlog(avctx, "Discarding %d bytes\n",
78                     pc->packet_index - pc->packet_start);
79         }
80
81         pc->packet_start = 0;
82         pc->packet_index = 0;
83
84         if (buf_size < 2 || buf[0] != 0x20 || buf[1] != 0x00) {
85             av_dlog(avctx, "Bad packet header\n");
86             return -1;
87         }
88
89         buf_pos = 2;
90
91         pc->in_packet = 1;
92     } else {
93         if (pc->packet_start != 0)
94         {
95             if (pc->packet_index != pc->packet_start)
96             {
97                 memmove(pc->packet_buf, pc->packet_buf + pc->packet_start,
98                             pc->packet_index - pc->packet_start);
99
100                 pc->packet_index -= pc->packet_start;
101                 pc->packet_start = 0;
102             } else {
103                 pc->packet_start = 0;
104                 pc->packet_index = 0;
105             }
106         }
107     }
108
109     if (buf_size - buf_pos + pc->packet_index > PARSE_BUF_SIZE)
110         return -1;
111
112 /* if not currently in a packet, discard data */
113     if (pc->in_packet == 0)
114         return buf_size;
115
116     memcpy(pc->packet_buf + pc->packet_index, buf + buf_pos, buf_size - buf_pos);
117     pc->packet_index += buf_size - buf_pos;
118
119     p = pc->packet_buf;
120     p_end = pc->packet_buf + pc->packet_index;
121
122     while (p < p_end)
123     {
124         if (*p == 0x0f)
125         {
126             if (p + 6 <= p_end)
127             {
128                 len = AV_RB16(p + 4);
129
130                 if (p + len + 6 <= p_end)
131                 {
132                     *poutbuf_size += len + 6;
133
134                     p += len + 6;
135                 } else
136                     break;
137             } else
138                 break;
139         } else if (*p == 0xff) {
140             if (p + 1 < p_end)
141             {
142                 av_dlog(avctx, "Junk at end of packet\n");
143             }
144             pc->packet_index = p - pc->packet_buf;
145             pc->in_packet = 0;
146             break;
147         } else {
148             av_log(avctx, AV_LOG_ERROR, "Junk in packet\n");
149
150             pc->packet_index = p - pc->packet_buf;
151             pc->in_packet = 0;
152             break;
153         }
154     }
155
156     if (*poutbuf_size > 0)
157     {
158         *poutbuf = pc->packet_buf;
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 static av_cold void dvbsub_parse_close(AVCodecParserContext *s)
169 {
170     DVBSubParseContext *pc = s->priv_data;
171     av_freep(&pc->packet_buf);
172 }
173
174 AVCodecParser ff_dvbsub_parser = {
175     .codec_ids      = { CODEC_ID_DVB_SUBTITLE },
176     .priv_data_size = sizeof(DVBSubParseContext),
177     .parser_init    = dvbsub_parse_init,
178     .parser_parse   = dvbsub_parse,
179     .parser_close   = dvbsub_parse_close,
180 };