On Sat, 2 Feb 2019, Charles Liu wrote:
Binary searching would hang if the fragment items do NOT have timestamp for the
specified stream.
For example, a fmp4 consists of separated 'moof' boxes for each track, and
separated 'sidx' for each segment, but no 'mfra' box.
Then every fragment item only have the timestamp for one of its tracks.
I don't see why you are changing the search to be linear. Is it possible
the some of the stream fragmens have NOPTS_VALUE but other don't? In this
case you should keep the binary search and only fall back to linear search
if binary search finds an AV_NOPTS_VALUE. See similar code in function
mxf_absolute_bodysid_offset of libavformat/mxfdec.c.
On the other hand, if either all stream segments have AV_NOPTS_VALUE, or
none of them do, then why don't you simply break out of the loop with error?
Thanks,
Marton
Signed-off-by: Charles Liu <liuch...@gmail.com>
---
libavformat/mov.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 9b9739f788..ce1130ad07 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1266,9 +1266,8 @@ static int64_t get_frag_time(MOVFragmentIndex *frag_index,
static int search_frag_timestamp(MOVFragmentIndex *frag_index,
AVStream *st, int64_t timestamp)
{
- int a, b, m;
int64_t frag_time;
- int id = -1;
+ int i, frag = 0, id = -1;
if (st) {
// If the stream is referenced by any sidx, limit the search
@@ -1278,20 +1277,18 @@ static int search_frag_timestamp(MOVFragmentIndex
*frag_index,
id = st->id;
}
- a = -1;
- b = frag_index->nb_items;
-
- while (b - a > 1) {
- m = (a + b) >> 1;
- frag_time = get_frag_time(frag_index, m, id);
+ for (i = 0; i < frag_index->nb_items; i++) {
+ frag_time = get_frag_time(frag_index, i, id);
if (frag_time != AV_NOPTS_VALUE) {
- if (frag_time >= timestamp)
- b = m;
if (frag_time <= timestamp)
- a = m;
+ frag = i;
+ else {
+ break;
+ }
}
}
- return a;
+
+ return frag;
}
static int update_frag_index(MOVContext *c, int64_t offset)
--
2.20.1
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