[FFmpeg-devel] [PATCH 1/3] avformat/oggparsevp8: fix pts calculation on pages ending with an invisible frame

[James Almer]

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavformat/oggparsevp8.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libavformat/oggparsevp8.c b/libavformat/oggparsevp8.c
index d57419e..3ba5375 100644
--- a/libavformat/oggparsevp8.c
+++ b/libavformat/oggparsevp8.c
@@ -82,7 +82,11 @@ static uint64_t vp8_gptopts(AVFormatContext *s, int idx,
     struct ogg *ogg = s->priv_data;
     struct ogg_stream *os = ogg->streams + idx;
 
-    uint64_t pts  = (granule >> 32);
+    uint32_t invcnt = !((granule >> 30) & 3);
+    // If page granule is that of an invisible vp8 frame, its pts will be
+    // that of the end of the next visible frame. We substract 1 for those
+    // to prevent messing up pts calculations.
+    uint64_t pts  = (granule >> 32) - invcnt;
     uint32_t dist = (granule >>  3) & 0x07ffffff;
 
     if (!dist)
-- 
2.9.0