FFmpeg
libavcodec
dvbsub_parser.c
Go to the documentation of this file.
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/*
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* DVB subtitle parser for FFmpeg
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* Copyright (c) 2005 Ian Caulfield
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <inttypes.h>
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#include <string.h>
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#include "
libavutil/intreadwrite.h
"
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#include "
avcodec.h
"
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/* Parser (mostly) copied from dvdsub.c */
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#define PARSE_BUF_SIZE (65536)
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/* parser definition */
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typedef
struct
DVBSubParseContext
{
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int
packet_start
;
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int
packet_index
;
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int
in_packet
;
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uint8_t
packet_buf
[
PARSE_BUF_SIZE
];
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}
DVBSubParseContext
;
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static
int
dvbsub_parse
(
AVCodecParserContext
*
s
,
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AVCodecContext
*avctx,
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const
uint8_t **poutbuf,
int
*poutbuf_size,
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const
uint8_t *buf,
int
buf_size)
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{
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DVBSubParseContext
*pc =
s
->priv_data;
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uint8_t *p, *p_end;
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int
i
,
len
, buf_pos = 0;
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int
out_size
= 0;
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ff_dlog
(avctx,
"DVB parse packet pts=%"
PRIx64
", lpts=%"
PRIx64
", cpts=%"
PRIx64
":\n"
,
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s
->pts,
s
->last_pts,
s
->cur_frame_pts[
s
->cur_frame_start_index]);
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for
(
i
=0;
i
< buf_size;
i
++)
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{
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ff_dlog
(avctx,
"%02x "
, buf[
i
]);
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if
(
i
% 16 == 15)
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ff_dlog
(avctx,
"\n"
);
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}
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if
(
i
% 16 != 0)
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ff_dlog
(avctx,
"\n"
);
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*poutbuf = buf;
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*poutbuf_size = buf_size;
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s
->fetch_timestamp = 1;
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if
(
s
->last_pts !=
s
->pts &&
s
->pts !=
AV_NOPTS_VALUE
)
/* Start of a new packet */
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{
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if
(pc->
packet_index
!= pc->
packet_start
)
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{
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ff_dlog
(avctx,
"Discarding %d bytes\n"
,
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pc->
packet_index
- pc->
packet_start
);
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}
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pc->
packet_start
= 0;
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pc->
packet_index
= 0;
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if
(buf_size < 2 || buf[0] != 0x20 || buf[1] != 0x00) {
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ff_dlog
(avctx,
"Bad packet header\n"
);
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return
buf_size;
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}
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buf_pos = 2;
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pc->
in_packet
= 1;
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}
else
{
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if
(pc->
packet_start
!= 0)
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{
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if
(pc->
packet_index
!= pc->
packet_start
)
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{
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memmove(pc->
packet_buf
, pc->
packet_buf
+ pc->
packet_start
,
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pc->
packet_index
- pc->
packet_start
);
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pc->
packet_index
-= pc->
packet_start
;
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pc->
packet_start
= 0;
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}
else
{
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pc->
packet_start
= 0;
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pc->
packet_index
= 0;
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}
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}
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}
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if
(buf_size - buf_pos + pc->
packet_index
>
PARSE_BUF_SIZE
)
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return
buf_size;
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/* if not currently in a packet, pass data */
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if
(pc->
in_packet
== 0)
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return
buf_size;
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memcpy(pc->
packet_buf
+ pc->
packet_index
, buf + buf_pos, buf_size - buf_pos);
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pc->
packet_index
+= buf_size - buf_pos;
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p = pc->
packet_buf
;
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p_end = pc->
packet_buf
+ pc->
packet_index
;
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while
(p < p_end)
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{
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if
(*p == 0x0f)
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{
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if
(6 <= p_end - p)
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{
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len
=
AV_RB16
(p + 4);
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if
(
len
+ 6 <= p_end - p)
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{
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out_size
+=
len
+ 6;
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p +=
len
+ 6;
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}
else
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break
;
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}
else
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break
;
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}
else
if
(*p == 0xff) {
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if
(1 < p_end - p)
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{
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ff_dlog
(avctx,
"Junk at end of packet\n"
);
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}
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pc->
packet_index
= p - pc->
packet_buf
;
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pc->
in_packet
= 0;
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break
;
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}
else
{
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av_log
(avctx,
AV_LOG_ERROR
,
"Junk in packet\n"
);
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pc->
packet_index
= p - pc->
packet_buf
;
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pc->
in_packet
= 0;
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break
;
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}
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}
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if
(
out_size
> 0)
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{
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*poutbuf = pc->
packet_buf
;
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*poutbuf_size =
out_size
;
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pc->
packet_start
= *poutbuf_size;
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}
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if
(
s
->pts ==
AV_NOPTS_VALUE
)
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s
->pts =
s
->last_pts;
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return
buf_size;
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}
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const
AVCodecParser
ff_dvbsub_parser
= {
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.
codec_ids
= {
AV_CODEC_ID_DVB_SUBTITLE
},
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.priv_data_size =
sizeof
(
DVBSubParseContext
),
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.parser_parse =
dvbsub_parse
,
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};
DVBSubParseContext::packet_start
int packet_start
Definition:
dvbsub_parser.c:36
out_size
int out_size
Definition:
movenc.c:55
DVBSubParseContext::packet_index
int packet_index
Definition:
dvbsub_parser.c:37
AV_CODEC_ID_DVB_SUBTITLE
@ AV_CODEC_ID_DVB_SUBTITLE
Definition:
codec_id.h:545
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition:
log.h:180
intreadwrite.h
s
#define s(width, name)
Definition:
cbs_vp9.c:256
DVBSubParseContext::packet_buf
uint8_t packet_buf[PARSE_BUF_SIZE]
Definition:
dvbsub_parser.c:39
ff_dlog
#define ff_dlog(a,...)
Definition:
tableprint_vlc.h:28
AVCodecParser::codec_ids
int codec_ids[7]
Definition:
avcodec.h:2972
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition:
avutil.h:248
PARSE_BUF_SIZE
#define PARSE_BUF_SIZE
Definition:
dvbsub_parser.c:31
DVBSubParseContext
Definition:
dvbsub_parser.c:35
i
#define i(width, name, range_min, range_max)
Definition:
cbs_h2645.c:269
len
int len
Definition:
vorbis_enc_data.h:426
avcodec.h
AVCodecParserContext
Definition:
avcodec.h:2812
DVBSubParseContext::in_packet
int in_packet
Definition:
dvbsub_parser.c:38
AVCodecContext
main external API structure.
Definition:
avcodec.h:426
ff_dvbsub_parser
const AVCodecParser ff_dvbsub_parser
Definition:
dvbsub_parser.c:166
AVCodecParser
Definition:
avcodec.h:2971
av_log
#define av_log(a,...)
Definition:
tableprint_vlc.h:27
dvbsub_parse
static int dvbsub_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition:
dvbsub_parser.c:42
AV_RB16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition:
bytestream.h:98
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