@@ -2118,17 +2118,19 @@ static int mkv_write_vtt_blocks(AVFormatContext *s, AVIOContext *pb, const AVPac
mkv_track *track = &mkv->tracks[pkt->stream_index];
ebml_master blockgroup;
int id_size, settings_size, size;
- uint8_t *id, *settings;
+ const char *id, *settings;
int64_t ts = track->write_dts ? pkt->dts : pkt->pts;
const int flags = 0;
id_size = 0;
id = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_IDENTIFIER,
&id_size);
+ id = id ? id : "";
settings_size = 0;
settings = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_SETTINGS,
&settings_size);
+ settings = settings ? settings : "";
size = id_size + 1 + settings_size + 1 + pkt->size;
The argument pertaining to a printf %s conversion specifier must not be NULL, even if the precision (i.e. the number of characters to write) is zero. If it is NULL, it is undefined behaviour. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> --- libavformat/matroskaenc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)