[MPlayer-users] Re: Mplayer Garbled BBC realaudio streams

[Neil Sleightholm]

Bryan Alton wrote:

> I think I know what is causing the garbled audio problem.  The
> realaudio server is dropping packets but only indicates it by jumps
> in the Data packet timestamps and  setting the KeyFrame bit in the
> Flags. If you look at the timestamps of the Real data Packet Headers
> (using ethereal) you will see that whereas normally the delat is aout
> 116 - occassionally there are deltas of about 232 or 348. At the same
> time, the keyframe flag which is normally set once every 32 packet,
> is set at the right point to restart the striping. The striping
> mechanism is explained in a doc in the Mplayer directory.
> 
> The Realaudio stream has the audio striped across multiple packets
> and so if Mplayer doesn't detect the missing packets it starts
> putting the audio stream back toegther in the wrng order. 
> 
> As implemented RTS just takes each packet and  buffers the data and
> ignore the timestamp and key frame data.  What needs to be done is
> when a gap is detected, some packets needs to be inserted to make up
> the loss.
> 
> I am trying to code up a solution but I think I am on the right
> track.

Bryan, that is good news. This is a particularly anoying error for me
and stops me using my SqueezeBox for listening to live streams - you
will make a lot SqeezeBox users happy if you fix this. Let me know if
you want me to test anything.

Thanks

Neil