Video for which extended timestamps fix doesn't work

[Michael J.T. O'Kelly]

After I run flvmeta.exe 1.0.10 on this FLV:

http://videos.highlightcam.com.s3.amazonaws.com/video_759da317c08c40e5b8b12cba7db9ae97.flv

I still get "Invalid timestamp" complaints from ffmpeg:

"[mpeg4 @ 0x1635010]Error, Invalid timestamp=16843080, last=16843080"


Should flvmeta be able to fix this video? Thanks!


Best,
Michael

[Marc]

According to flvdump, this video has some timestamp related oddities,
like :

--- Tag #2287 at 0x41AAD (268973) ---
Tag type: Video
Body length: 51
Timestamp: 54037
* Video codec: Sorensen H.263
* Video frame type: disposable inter frame
Previous tag size: 62
--- Tag #2288 at 0x41AEF (269039) ---
Tag type: Video
Body length: 66
Timestamp: 53809 (should be 16831025)
* Video codec: Sorensen H.263
* Video frame type: inter frame
Previous tag size: 77

which is weird, because it's not really correct for a video to have
decreasing timestamps, unless there's something I'm not aware of in
the FLV format.

As of now, flvmeta is kinda conservative in its timestamp fixing
algorithm as it will consider decreasing timestamps in a stream as the
indication that an overflow occured and the 4th byte should be used
for the following timestamps.

I guess I need to do something smarter than that, because the
difference between 54037 and 53809 is way too small to be taken into
account for such a case.

Regards,
Marc

On Nov 2, 9:15 am, "Michael J.T. O'Kelly" <moke...@hlcam.com> wrote:
> After I run flvmeta.exe 1.0.10 on this FLV:
>

> http://videos.highlightcam.com.s3.amazonaws.com/video_759da317c08c40e...

[Marc]

I committed r136 of FLVmeta into the trunk that fixes the
aforementionned behaviour.

Now, the extended timestamp handling will only be triggered if the
difference between the consecutive tags is > 15728640.

I will probably backport the fix to the 1.0.x branch.

[Michael J.T. O'Kelly]

Thanks for the quick fix.

The FLV was recorded from an RTMP stream by a Wowza Pro server, which
I suspect is the origin of the decreasing timestamps. (FLVs from
Justin.tv can have similar timestamp problems.)

I'd actually like to use flvmeta to correct problems like this in
FLVs, since they cause ffmpeg to choke. Is that a feature you would
consider including?


Thanks,
Michael