From 70c6a1bcf021b396c9186c4a46dd6c96cc9f59f8 Mon Sep 17 00:00:00 2001 From: James Almer Date: Sat, 5 Nov 2016 17:46:52 -0300 Subject: [PATCH] avformat/matroskadec: fix DiscardPadding element parsing If the value is negative then it means padding at the start of the packet instead of at the end. Based on a patch by Hendrik Leppkes. Reviewed-by: James Zern Signed-off-by: James Almer --- libavformat/matroskadec.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index 32f5e49f0c..d2a691bc06 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -3082,10 +3082,14 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska, av_free(pkt); return AVERROR(ENOMEM); } - AV_WL32(side_data, 0); - AV_WL32(side_data + 4, av_rescale_q(discard_padding, + discard_padding = av_rescale_q(discard_padding, (AVRational){1, 1000000000}, - (AVRational){1, st->codecpar->sample_rate})); + (AVRational){1, st->codecpar->sample_rate}); + if (discard_padding > 0) { + AV_WL32(side_data + 4, discard_padding); + } else { + AV_WL32(side_data, -discard_padding); + } } if (track->ms_compat)