[vlc-devel] libvlc_MediaMetaChanged event being sent too soon

Jason Butler jbutler at hcn-inc.com
Mon Jul 12 20:32:21 CEST 2010

I put the following code inside my libvlc_MediaMeataChanged event handler:

signed long long int time = libvlc_media_player_get_buffered_time(mp);
printf("buffer time: %lli\n", time);

It always returned a buffer time of 0. Is this the expected result or am 
I doing something wrong.
I got the same result if I used an int instead of a signed long long. 
libvlc_time_t is a int64_t which I believe is a singed long long.

On 10-07-10 01:15 AM, Frank Enderle wrote:
> the event is fired as soon as vlc gets the data from the streaming
> server. however it does not take in account that the audio data will be
> buffered and thus delayed. that's why there's a gap between the event
> and the actual data being valid for the current stream position.
> i solved this for me by applying a patch to vlc which gives me the
> ability to see how much streamtime is buffered. when i get the event i
> calculate when it becomes valid by adding the time left in the buffer to
> the current (monotonic) timestamp and put the result in a ring buffer
> which is frequently checked. when the title change gets valid it is
> shown to the user and removed from the ring.
> i played with the thought to add this as a patch to vlc itself so the
> event is fired timecorrected, but i didn't do it because i think it is
> the applications responsibility to deal with the delay since there might
> be cases when it is a good idea to have the data early, for example if
> you want to do some artwork prefetch. so i only added the ability to get
> the time left in the buffers.
> i sent the patch a while ago to the list, but i don't think it has been
> incorporated to the git master (i might be wrong). i added you the patch
> against vlc 1.1.0. it gives you a new function to get the buffered time
> in ms.
> libvlc_time_t
> libvlc_media_player_get_buffered_time(libvlc_media_player_t *p_mi);
> hope this helps
> frank
> Am 10.07.2010 01:17, schrieb Jason Butler:
>> I am using libvlc 1.1.0 to play an audio steam on Linux. I want to get
>> the title, album, and artist every time the track changes so I am
>> hooking up a callback function to the libvlc_MediaMetaChanged event. The
>> problem is when the stream starts playing the libvlc_MediaMetaChanged
>> event is sent serveral times before all the track meta data is valid. If
>> I call  libvlc_media_get_meta(m,libvlc_meta_Artist), or
>> libvlc_media_get_meta(m,libvlc_meta_Album) too soon then I get a segment
>> fault.  I thought about waiting for the libvlc_MediaPlayerPlaying event
>> but libvlc_MediaMetaChanged event is still sent several times before the
>> album and artist data is valid.
>> Is there a way to check if the artist and album data is valid before
>> calling  libvlc_media_get_meta?
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