From b096f160957bbb598a0fa00947b98393f3158e23 Mon Sep 17 00:00:00 2001 From: Simon Thelen Date: Fri, 11 Sep 2015 21:49:07 +0200 Subject: [PATCH] lavf/webvttenc: Require webvtt file to contain exactly one WebVTT stream. Not requiring this can end up producing hilariously broken files together with -c:s copy (e.g. a webvtt file containing binary subtitle data). Signed-off-by: Simon Thelen Signed-off-by: Michael Niedermayer (cherry picked from commit b84232694ef0c6897e82b52326c9ea4027c69ec4) Signed-off-by: Michael Niedermayer --- libavformat/webvttenc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/libavformat/webvttenc.c b/libavformat/webvttenc.c index b93993d55c..c386538718 100644 --- a/libavformat/webvttenc.c +++ b/libavformat/webvttenc.c @@ -46,8 +46,14 @@ static void webvtt_write_time(AVIOContext *pb, int64_t millisec) static int webvtt_write_header(AVFormatContext *ctx) { AVStream *s = ctx->streams[0]; + AVCodecContext *avctx = ctx->streams[0]->codec; AVIOContext *pb = ctx->pb; + if (ctx->nb_streams != 1 || avctx->codec_id != AV_CODEC_ID_WEBVTT) { + av_log(ctx, AV_LOG_ERROR, "Exactly one WebVTT stream is needed.\n"); + return AVERROR(EINVAL); + } + avpriv_set_pts_info(s, 64, 1, 1000); avio_printf(pb, "WEBVTT\n");