FFmpeg/libavcodec/assenc.c
Clément Bœsch 36e61e24e7 lavc: add ff_bprint_to_extradata() helper and use it.
This commit also makes sure the extradata and subtitle_header are NUL
terminated, without taking into account the trailing '\0' in account in
the size.

At the same time, it should fix 'warning: dereferencing type-punned
pointer will break strict-aliasing rules' warning for compilers who
don't consider uint8_t** and char** compatibles.
2012-12-30 22:19:04 +01:00

73 lines
2.3 KiB
C

/*
* SSA/ASS encoder
* Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.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 <string.h>
#include "avcodec.h"
#include "libavutil/avstring.h"
#include "libavutil/internal.h"
#include "libavutil/mem.h"
static av_cold int ass_encode_init(AVCodecContext *avctx)
{
avctx->extradata = av_malloc(avctx->subtitle_header_size + 1);
if (!avctx->extradata)
return AVERROR(ENOMEM);
memcpy(avctx->extradata, avctx->subtitle_header, avctx->subtitle_header_size);
avctx->extradata_size = avctx->subtitle_header_size;
avctx->extradata[avctx->extradata_size] = 0;
return 0;
}
static int ass_encode_frame(AVCodecContext *avctx,
unsigned char *buf, int bufsize,
const AVSubtitle *sub)
{
int i, len, total_len = 0;
for (i=0; i<sub->num_rects; i++) {
if (sub->rects[i]->type != SUBTITLE_ASS) {
av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");
return -1;
}
len = av_strlcpy(buf+total_len, sub->rects[i]->ass, bufsize-total_len);
if (len > bufsize-total_len-1) {
av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");
return -1;
}
total_len += len;
}
return total_len;
}
AVCodec ff_ass_encoder = {
.name = "ass",
.long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
.type = AVMEDIA_TYPE_SUBTITLE,
.id = AV_CODEC_ID_SSA,
.init = ass_encode_init,
.encode_sub = ass_encode_frame,
};