mirror of https://git.ffmpeg.org/ffmpeg.git
224 lines
7.6 KiB
C
224 lines
7.6 KiB
C
/*
|
|
* 3GPP TS 26.245 Timed Text decoder
|
|
* Copyright (c) 2012 Philip Langdale <philipl@overt.org>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "avcodec.h"
|
|
#include "ass.h"
|
|
#include "libavutil/avstring.h"
|
|
#include "libavutil/common.h"
|
|
#include "libavutil/bprint.h"
|
|
#include "libavutil/intreadwrite.h"
|
|
#include "libavutil/mem.h"
|
|
|
|
#define STYLE_FLAG_BOLD 1
|
|
#define STYLE_FLAG_ITALIC 2
|
|
#define STYLE_FLAG_UNDERLINE 4
|
|
|
|
static int text_to_ass(AVBPrint *buf, const char *text, const char *text_end,
|
|
char **style_start, char **style_end,
|
|
uint8_t **style_flags, int style_entries)
|
|
{
|
|
int i = 0;
|
|
while (text < text_end) {
|
|
for (i = 0; i < style_entries; i++) {
|
|
if (*style_flags[i] && text == style_start[i]) {
|
|
if (*style_flags[i] & STYLE_FLAG_BOLD)
|
|
av_bprintf(buf, "{\\b1}");
|
|
if (*style_flags[i] & STYLE_FLAG_ITALIC)
|
|
av_bprintf(buf, "{\\i1}");
|
|
if (*style_flags[i] & STYLE_FLAG_UNDERLINE)
|
|
av_bprintf(buf, "{\\u1}");
|
|
}
|
|
}
|
|
|
|
switch (*text) {
|
|
case '\r':
|
|
break;
|
|
case '\n':
|
|
av_bprintf(buf, "\\N");
|
|
break;
|
|
default:
|
|
av_bprint_chars(buf, *text, 1);
|
|
break;
|
|
}
|
|
|
|
for (i = 0; i < style_entries; i++) {
|
|
if (*style_flags[i] && text == style_end[i]) {
|
|
if (*style_flags[i] & STYLE_FLAG_BOLD)
|
|
av_bprintf(buf, "{\\b0}");
|
|
if (*style_flags[i] & STYLE_FLAG_ITALIC)
|
|
av_bprintf(buf, "{\\i0}");
|
|
if (*style_flags[i] & STYLE_FLAG_UNDERLINE)
|
|
av_bprintf(buf, "{\\u0}");
|
|
}
|
|
}
|
|
text++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mov_text_init(AVCodecContext *avctx) {
|
|
/*
|
|
* TODO: Handle the default text style.
|
|
* NB: Most players ignore styles completely, with the result that
|
|
* it's very common to find files where the default style is broken
|
|
* and respecting it results in a worse experience than ignoring it.
|
|
*/
|
|
return ff_ass_subtitle_header_default(avctx);
|
|
}
|
|
|
|
static int mov_text_decode_frame(AVCodecContext *avctx,
|
|
void *data, int *got_sub_ptr, AVPacket *avpkt)
|
|
{
|
|
AVSubtitle *sub = data;
|
|
int ret, ts_start, ts_end;
|
|
AVBPrint buf;
|
|
char *ptr = avpkt->data;
|
|
char *end;
|
|
//char *ptr_temp;
|
|
int text_length, tsmb_type, style_entries;
|
|
uint64_t tsmb_size, tracksize;
|
|
char **style_start = { 0, };
|
|
char **style_end = { 0, };
|
|
uint8_t **style_flags = { 0, };
|
|
const uint8_t *tsmb;
|
|
int index, i, size_var;
|
|
uint8_t *flag;
|
|
char *style_pos;
|
|
|
|
if (!ptr || avpkt->size < 2)
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
/*
|
|
* A packet of size two with value zero is an empty subtitle
|
|
* used to mark the end of the previous non-empty subtitle.
|
|
* We can just drop them here as we have duration information
|
|
* already. If the value is non-zero, then it's technically a
|
|
* bad packet.
|
|
*/
|
|
if (avpkt->size == 2)
|
|
return AV_RB16(ptr) == 0 ? 0 : AVERROR_INVALIDDATA;
|
|
|
|
/*
|
|
* The first two bytes of the packet are the length of the text string
|
|
* In complex cases, there are style descriptors appended to the string
|
|
* so we can't just assume the packet size is the string size.
|
|
*/
|
|
text_length = AV_RB16(ptr);
|
|
end = ptr + FFMIN(2 + text_length, avpkt->size);
|
|
ptr += 2;
|
|
|
|
ts_start = av_rescale_q(avpkt->pts,
|
|
avctx->time_base,
|
|
(AVRational){1,100});
|
|
ts_end = av_rescale_q(avpkt->pts + avpkt->duration,
|
|
avctx->time_base,
|
|
(AVRational){1,100});
|
|
|
|
tsmb_size = 0;
|
|
tracksize = 2 + text_length;
|
|
// Note that the spec recommends lines be no longer than 2048 characters.
|
|
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
|
|
if (text_length + 2 != avpkt->size) {
|
|
while (tracksize + 8 <= avpkt->size) {
|
|
// A box is a minimum of 8 bytes.
|
|
tsmb = ptr + tracksize - 2;
|
|
tsmb_size = AV_RB32(tsmb);
|
|
tsmb += 4;
|
|
tsmb_type = AV_RB32(tsmb);
|
|
tsmb += 4;
|
|
|
|
if (tsmb_size == 1) {
|
|
if (tracksize + 16 > avpkt->size)
|
|
break;
|
|
tsmb_size = AV_RB64(tsmb);
|
|
tsmb += 8;
|
|
size_var = 18;
|
|
} else
|
|
size_var = 10;
|
|
//size_var is equal to 10 or 18 depending on the size of box
|
|
|
|
if (tracksize + tsmb_size > avpkt->size)
|
|
break;
|
|
|
|
if (tsmb_type == MKBETAG('s','t','y','l')) {
|
|
if (tracksize + size_var > avpkt->size)
|
|
break;
|
|
style_entries = AV_RB16(tsmb);
|
|
tsmb += 2;
|
|
|
|
// A single style record is of length 12 bytes.
|
|
if (tracksize + size_var + style_entries * 12 > avpkt->size)
|
|
break;
|
|
|
|
for(i = 0; i < style_entries; i++) {
|
|
style_pos = ptr + AV_RB16(tsmb);
|
|
index = i;
|
|
av_dynarray_add(&style_start, &index, style_pos);
|
|
tsmb += 2;
|
|
style_pos = ptr + AV_RB16(tsmb);
|
|
index = i;
|
|
av_dynarray_add(&style_end, &index, style_pos);
|
|
tsmb += 2;
|
|
// fontID = AV_RB16(tsmb);
|
|
tsmb += 2;
|
|
flag = av_malloc(1);
|
|
if (!flag)
|
|
return AVERROR(ENOMEM);
|
|
*flag = AV_RB8(tsmb);
|
|
index = i;
|
|
av_dynarray_add(&style_flags, &index, flag);
|
|
//fontsize=AV_RB8(tsmb);
|
|
tsmb += 2;
|
|
// text-color-rgba
|
|
tsmb += 4;
|
|
}
|
|
text_to_ass(&buf, ptr, end, style_start, style_end, style_flags, style_entries);
|
|
|
|
for(i = 0; i < style_entries; i++) {
|
|
av_freep(&style_flags[i]);
|
|
}
|
|
av_freep(&style_start);
|
|
av_freep(&style_end);
|
|
av_freep(&style_flags);
|
|
}
|
|
tracksize = tracksize + tsmb_size;
|
|
}
|
|
} else
|
|
text_to_ass(&buf, ptr, end, NULL, NULL, 0, 0);
|
|
|
|
ret = ff_ass_add_rect_bprint(sub, &buf, ts_start, ts_end - ts_start);
|
|
av_bprint_finalize(&buf, NULL);
|
|
if (ret < 0)
|
|
return ret;
|
|
*got_sub_ptr = sub->num_rects > 0;
|
|
return avpkt->size;
|
|
}
|
|
|
|
AVCodec ff_movtext_decoder = {
|
|
.name = "mov_text",
|
|
.long_name = NULL_IF_CONFIG_SMALL("3GPP Timed Text subtitle"),
|
|
.type = AVMEDIA_TYPE_SUBTITLE,
|
|
.id = AV_CODEC_ID_MOV_TEXT,
|
|
.init = mov_text_init,
|
|
.decode = mov_text_decode_frame,
|
|
};
|