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libavcodec
movtextenc.c
Go to the documentation of this file.
1
/*
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* 3GPP TS 26.245 Timed Text encoder
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* Copyright (c) 2012 Philip Langdale <philipl@overt.org>
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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
8
* modify it under the terms of the GNU Lesser General Public
9
* 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,
13
* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15
* 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
19
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <stdarg.h>
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#include "
avcodec.h
"
24
#include "
libavutil/avassert.h
"
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#include "
libavutil/avstring.h
"
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#include "
libavutil/intreadwrite.h
"
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#include "
ass_split.h
"
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#include "
ass.h
"
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typedef
struct
{
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ASSSplitContext
*
ass_ctx
;
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char
buffer
[2048];
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char
*
ptr
;
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char
*
end
;
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}
MovTextContext
;
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38
static
av_cold
int
mov_text_encode_init
(
AVCodecContext
*avctx)
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{
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/*
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* For now, we'll use a fixed default style. When we add styling
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* support, this will be generated from the ASS style.
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*/
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static
uint8_t
text_sample_entry[] = {
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0x00, 0x00, 0x00, 0x00,
// uint32_t displayFlags
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0x01,
// int8_t horizontal-justification
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0xFF,
// int8_t vertical-justification
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0x00, 0x00, 0x00, 0x00,
// uint8_t background-color-rgba[4]
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// BoxRecord {
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0x00, 0x00,
// int16_t top
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0x00, 0x00,
// int16_t left
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0x00, 0x00,
// int16_t bottom
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0x00, 0x00,
// int16_t right
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// };
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// StyleRecord {
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0x00, 0x00,
// uint16_t startChar
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0x00, 0x00,
// uint16_t endChar
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0x00, 0x01,
// uint16_t font-ID
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0x00,
// uint8_t face-style-flags
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0x12,
// uint8_t font-size
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0xFF, 0xFF, 0xFF, 0xFF,
// uint8_t text-color-rgba[4]
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// };
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// FontTableBox {
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0x00, 0x00, 0x00, 0x12,
// uint32_t size
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'f'
,
't'
,
'a'
,
'b'
,
// uint8_t name[4]
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0x00, 0x01,
// uint16_t entry-count
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// FontRecord {
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0x00, 0x01,
// uint16_t font-ID
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0x05,
// uint8_t font-name-length
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'S'
,
'e'
,
'r'
,
'i'
,
'f'
,
// uint8_t font[font-name-length]
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// };
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// };
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};
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MovTextContext
*s = avctx->
priv_data
;
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avctx->
extradata_size
=
sizeof
text_sample_entry;
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avctx->
extradata
=
av_mallocz
(avctx->
extradata_size
);
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if
(!avctx->
extradata
)
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return
AVERROR
(ENOMEM);
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memcpy(avctx->
extradata
, text_sample_entry, avctx->
extradata_size
);
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s->
ass_ctx
=
ff_ass_split
(avctx->
subtitle_header
);
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return
s->
ass_ctx
? 0 :
AVERROR_INVALIDDATA
;
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}
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static
void
mov_text_text_cb
(
void
*priv,
const
char
*text,
int
len
)
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{
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MovTextContext
*s = priv;
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av_assert0
(s->
end
>= s->
ptr
);
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av_strlcpy
(s->
ptr
, text,
FFMIN
(s->
end
- s->
ptr
, len + 1));
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s->
ptr
+=
FFMIN
(s->
end
- s->
ptr
, len);
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}
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static
void
mov_text_new_line_cb
(
void
*priv,
int
forced)
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{
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MovTextContext
*s = priv;
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av_assert0
(s->
end
>= s->
ptr
);
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av_strlcpy
(s->
ptr
,
"\n"
,
FFMIN
(s->
end
- s->
ptr
, 2));
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if
(s->
end
> s->
ptr
)
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s->
ptr
++;
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}
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static
const
ASSCodesCallbacks
mov_text_callbacks
= {
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.
text
=
mov_text_text_cb
,
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.new_line =
mov_text_new_line_cb
,
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};
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static
int
mov_text_encode_frame
(
AVCodecContext
*avctx,
unsigned
char
*buf,
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int
bufsize,
const
AVSubtitle
*sub)
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{
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MovTextContext
*s = avctx->
priv_data
;
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ASSDialog
*dialog;
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int
i,
len
, num;
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s->
ptr
= s->
buffer
;
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s->
end
= s->
ptr
+
sizeof
(s->
buffer
);
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for
(i = 0; i < sub->
num_rects
; i++) {
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if
(sub->
rects
[i]->
type
!=
SUBTITLE_ASS
) {
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av_log
(avctx,
AV_LOG_ERROR
,
"Only SUBTITLE_ASS type supported.\n"
);
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return
AVERROR
(ENOSYS);
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}
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dialog =
ff_ass_split_dialog
(s->
ass_ctx
, sub->
rects
[i]->
ass
, 0, &num);
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for
(; dialog && num--; dialog++) {
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ff_ass_split_override_codes
(&mov_text_callbacks, s, dialog->
text
);
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}
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}
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if
(s->
ptr
== s->
buffer
)
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return
0;
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AV_WB16
(buf, strlen(s->
buffer
));
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buf += 2;
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len =
av_strlcpy
(buf, s->
buffer
, bufsize - 2);
140
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if
(len > bufsize-3) {
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av_log
(avctx,
AV_LOG_ERROR
,
"Buffer too small for ASS event.\n"
);
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return
AVERROR
(EINVAL);
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}
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return
len + 2;
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}
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static
int
mov_text_encode_close
(
AVCodecContext
*avctx)
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{
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MovTextContext
*s = avctx->
priv_data
;
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ff_ass_split_free
(s->
ass_ctx
);
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return
0;
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}
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AVCodec
ff_movtext_encoder
= {
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.
name
=
"mov_text"
,
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.long_name =
NULL_IF_CONFIG_SMALL
(
"3GPP Timed Text subtitle"
),
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.type =
AVMEDIA_TYPE_SUBTITLE
,
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.id =
AV_CODEC_ID_MOV_TEXT
,
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.priv_data_size =
sizeof
(
MovTextContext
),
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.
init
=
mov_text_encode_init
,
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.encode_sub =
mov_text_encode_frame
,
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.
close
=
mov_text_encode_close
,
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};
Generated on Sat May 25 2013 04:01:07 for FFmpeg by
1.8.2