[gst-devel] otem-gstreamer-video-thumbnailer sometimes fails to generate the thumbnail of ASF file

[Stefan Kost]

Bastien Nocera schrieb:
> On Tue, 2009-01-06 at 15:20 +0200, Stefan Kost wrote:
>> hi,
>>
>> Lin Raffel schrieb:
>>> I found totem-gstreamer-video-thumbnailer sometimes fails to generate
>>> the thumbnail of ASF file,
>>> the output message is.
>>>
>>> Reason: Took too much time to process.
>>>
>>> Is this the problem with the ASF file itself ?
>> Its also happens with AVI files for me. IMHO its because for most files demuxers
>> always scan the index and if that files has a very finegrained index it takes
>> long. Its fixable, but requires quite some work.
> 
> As Stefan mentioned, it usually happens with broken files.
> 
> You can use the "--no-limit" command-line option, but right now the
> thumbnailer limits itself to using 30 seconds of wall-clock time at the
> maximum, so as to avoid hanging indefinitely.
> 
> If the file isn't broken,  and plays straight away in Totem, you might
> have found a bug though.

The files are actually valid, they are either very long or have insanely dense
index entries. One easy way to check if that is the case if
  filesrc ! avidemux ! ...
va.
  filesrc ! queue ! avidemux
The later switches to streaming mode where the index is not scanned.

One way to solve this could be to build the index while playing. Then one can
easily seek back. If one seeks forward, the demuxer would scan. The current
behaviour of pre-scanning the index in not very smart as people do not always
seek. There might be some issues with such a change as well. From looking at
avidemux:
- the reported duration is adjusted to the duration from index if it diferes
from the values in the header
- the index is sorted, in theory entries in a avi might come in a random order
(can they?)

Stefan

> 
> Cheers
> 
> 
> ------------------------------------------------------------------------------
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel