avcodec/aacdec_fixed: fix invalid shift in predict()
[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     uint8_t *packet_buf;
39     int packet_start;
40     int packet_index;
41     int in_packet;
42 } DVBSubParseContext;
43
44 static av_cold int dvbsub_parse_init(AVCodecParserContext *s)
45 {
46     DVBSubParseContext *pc = s->priv_data;
47     pc->packet_buf = av_malloc(PARSE_BUF_SIZE);
48
49     return 0;
50 }
51
52 static int dvbsub_parse(AVCodecParserContext *s,
53                         AVCodecContext *avctx,
54                         const uint8_t **poutbuf, int *poutbuf_size,
55                         const uint8_t *buf, int buf_size)
56 {
57     DVBSubParseContext *pc = s->priv_data;
58     uint8_t *p, *p_end;
59     int i, len, buf_pos = 0;
60
61     ff_dlog(avctx, "DVB parse packet pts=%"PRIx64", lpts=%"PRIx64", cpts=%"PRIx64":\n",
62             s->pts, s->last_pts, s->cur_frame_pts[s->cur_frame_start_index]);
63
64     for (i=0; i < buf_size; i++)
65     {
66         ff_dlog(avctx, "%02x ", buf[i]);
67         if (i % 16 == 15)
68             ff_dlog(avctx, "\n");
69     }
70
71     if (i % 16 != 0)
72         ff_dlog(avctx, "\n");
73
74     *poutbuf = NULL;
75     *poutbuf_size = 0;
76
77     s->fetch_timestamp = 1;
78
79     if (s->last_pts != s->pts && s->pts != AV_NOPTS_VALUE) /* Start of a new packet */
80     {
81         if (pc->packet_index != pc->packet_start)
82         {
83             ff_dlog(avctx, "Discarding %d bytes\n",
84                     pc->packet_index - pc->packet_start);
85         }
86
87         pc->packet_start = 0;
88         pc->packet_index = 0;
89
90         if (buf_size < 2 || buf[0] != 0x20 || buf[1] != 0x00) {
91             ff_dlog(avctx, "Bad packet header\n");
92             return -1;
93         }
94
95         buf_pos = 2;
96
97         pc->in_packet = 1;
98     } else {
99         if (pc->packet_start != 0)
100         {
101             if (pc->packet_index != pc->packet_start)
102             {
103                 memmove(pc->packet_buf, pc->packet_buf + pc->packet_start,
104                             pc->packet_index - pc->packet_start);
105
106                 pc->packet_index -= pc->packet_start;
107                 pc->packet_start = 0;
108             } else {
109                 pc->packet_start = 0;
110                 pc->packet_index = 0;
111             }
112         }
113     }
114
115     if (buf_size - buf_pos + pc->packet_index > PARSE_BUF_SIZE)
116         return -1;
117
118 /* if not currently in a packet, discard data */
119     if (pc->in_packet == 0)
120         return buf_size;
121
122     memcpy(pc->packet_buf + pc->packet_index, buf + buf_pos, buf_size - buf_pos);
123     pc->packet_index += buf_size - buf_pos;
124
125     p = pc->packet_buf;
126     p_end = pc->packet_buf + pc->packet_index;
127
128     while (p < p_end)
129     {
130         if (*p == 0x0f)
131         {
132             if (6 <= p_end - p)
133             {
134                 len = AV_RB16(p + 4);
135
136                 if (len + 6 <= p_end - p)
137                 {
138                     *poutbuf_size += len + 6;
139
140                     p += len + 6;
141                 } else
142                     break;
143             } else
144                 break;
145         } else if (*p == 0xff) {
146             if (1 < p_end - p)
147             {
148                 ff_dlog(avctx, "Junk at end of packet\n");
149             }
150             pc->packet_index = p - pc->packet_buf;
151             pc->in_packet = 0;
152             break;
153         } else {
154             av_log(avctx, AV_LOG_ERROR, "Junk in packet\n");
155
156             pc->packet_index = p - pc->packet_buf;
157             pc->in_packet = 0;
158             break;
159         }
160     }
161
162     if (*poutbuf_size > 0)
163     {
164         *poutbuf = pc->packet_buf;
165         pc->packet_start = *poutbuf_size;
166     }
167
168     if (s->pts == AV_NOPTS_VALUE)
169         s->pts = s->last_pts;
170
171     return buf_size;
172 }
173
174 static av_cold void dvbsub_parse_close(AVCodecParserContext *s)
175 {
176     DVBSubParseContext *pc = s->priv_data;
177     av_freep(&pc->packet_buf);
178 }
179
180 AVCodecParser ff_dvbsub_parser = {
181     .codec_ids      = { AV_CODEC_ID_DVB_SUBTITLE },
182     .priv_data_size = sizeof(DVBSubParseContext),
183     .parser_init    = dvbsub_parse_init,
184     .parser_parse   = dvbsub_parse,
185     .parser_close   = dvbsub_parse_close,
186 };