[FFmpeg-devel] [PATCH] libavformat/mov.c: use calculated dts offset when seeking in streams

[Peter Große]

From: Jonas Licht <jonas.licht at fem.tu-ilmenau.de>

Subtract the calculated dts offset from the requested timestamp before
seeking. This fixes an error "Error while filtering: Operation not
permitted" observed with a short file which contains only one key frame
and starts with negative timestamps.

Then, av_index_search_timestamp() returns a valid negative timestamp,
but mov_seek_stream bails out with AVERROR_INVALIDDATA.

Fixes ticket #6139.

Signed-off-by: Jonas Licht <jonas.licht at fem.tu-ilmenau.de>
Signed-off-by: Peter Große <pegro at friiks.de>
---

Compared to the other seek results in this test, the values are not
that far off.

 libavformat/mov.c        |  6 ++++--
 tests/ref/seek/extra-mp4 | 16 ++++++++--------
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 2ee67561e4..60a0f4ccf4 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -6882,10 +6882,12 @@ static int mov_seek_fragment(AVFormatContext *s, AVStream *st, int64_t timestamp
 static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp, int flags)
 {
     MOVStreamContext *sc = st->priv_data;
-    int sample, time_sample;
+    int sample, time_sample, ret;
     unsigned int i;
 
-    int ret = mov_seek_fragment(s, st, timestamp);
+    timestamp -= sc->time_offset;
+
+    ret = mov_seek_fragment(s, st, timestamp);
     if (ret < 0)
         return ret;
 
diff --git a/tests/ref/seek/extra-mp4 b/tests/ref/seek/extra-mp4
index c25544c095..c17ce4003c 100644
--- a/tests/ref/seek/extra-mp4
+++ b/tests/ref/seek/extra-mp4
@@ -28,10 +28,10 @@ ret: 0         st: 0 flags:0 dts: 50.633333 pts: 50.733333 pos:5926157 size:  13
 ret: 0         st: 0 flags:0 dts: 50.666667 pts: 50.666667 pos:5927464 size:   150
 ret: 0         st: 0 flags:0 dts: 50.700000 pts: 50.700000 pos:5927614 size:   176
 ret: 0         st:-1 flags:1  ts: 153.470835
-ret: 0         st: 0 flags:1 dts: 153.466667 pts: 153.500000 pos:15867700 size: 96169
-ret: 0         st: 0 flags:0 dts: 153.500000 pts: 153.533333 pos:15963869 size:   785
-ret: 0         st: 0 flags:0 dts: 153.533333 pts: 153.633333 pos:15964654 size:  3135
-ret: 0         st: 0 flags:0 dts: 153.566667 pts: 153.566667 pos:15967789 size:   859
+ret: 0         st: 0 flags:1 dts: 151.966667 pts: 152.000000 pos:15705355 size:146924
+ret: 0         st: 0 flags:0 dts: 152.000000 pts: 152.100000 pos:15852279 size:  1355
+ret: 0         st: 0 flags:0 dts: 152.033333 pts: 152.033333 pos:15853634 size:   211
+ret: 0         st: 0 flags:0 dts: 152.066667 pts: 152.066667 pos:15853845 size:   217
 ret: 0         st: 0 flags:0  ts: 76.365000
 ret: 0         st: 0 flags:1 dts: 77.833333 pts: 77.866667 pos:8659657 size: 41182
 ret: 0         st: 0 flags:0 dts: 77.866667 pts: 77.966667 pos:8700839 size:  4197
@@ -83,10 +83,10 @@ ret: 0         st: 0 flags:0 dts: 101.333333 pts: 101.433333 pos:11049548 size:
 ret: 0         st: 0 flags:0 dts: 101.366667 pts: 101.366667 pos:11053072 size:   562
 ret: 0         st: 0 flags:0 dts: 101.400000 pts: 101.400000 pos:11053634 size:   599
 ret: 0         st:-1 flags:0  ts: 25.306672
-ret: 0         st: 0 flags:1 dts: 27.400000 pts: 27.433333 pos:2674605 size:127383
-ret: 0         st: 0 flags:0 dts: 27.433333 pts: 27.466667 pos:2801988 size:    68
-ret: 0         st: 0 flags:0 dts: 27.466667 pts: 27.500000 pos:2802268 size:  1754
-ret: 0         st: 0 flags:0 dts: 27.500000 pts: 27.533333 pos:2804022 size:  4071
+ret: 0         st: 0 flags:1 dts: 25.300000 pts: 25.333333 pos:2607246 size: 40273
+ret: 0         st: 0 flags:0 dts: 25.333333 pts: 25.433333 pos:2647519 size:  2959
+ret: 0         st: 0 flags:0 dts: 25.366667 pts: 25.366667 pos:2650478 size:   197
+ret: 0         st: 0 flags:0 dts: 25.400000 pts: 25.400000 pos:2650675 size:   230
 ret: 0         st:-1 flags:1  ts: 128.200839
 ret: 0         st: 0 flags:1 dts: 127.833333 pts: 127.866667 pos:13514072 size: 67382
 ret: 0         st: 0 flags:0 dts: 127.866667 pts: 127.966667 pos:13581454 size:  2936
-- 
2.13.6