[vlc-devel] Re: MP4 Movies that stop before they are finished

[James MacLean]

On Mon, 26 Apr 2004, James MacLean wrote:

> On Mon, 26 Apr 2004, Gildas Bazin wrote:
> 
> > On Monday 26 April 2004 19:30, James MacLean wrote:
> > > Still doing more tests, but AVI streams are running again here,
> > > JES
> > Nice catch :)
> > I just committed the patch.
> > --
> > Gildas
> Mind suggesting how to find a similar problem with mp4s? This time they
> play locally properly in 0.7.1 and latest CVS so I can not play "The Price
> is Right"(higher, higher, lower lower ;)) game with svn :(.
> They seem to only work over an http link if the link speed very fast... 
> Tried all sorts of mp4s with no luck. Looked at modules/demux/mp4/mp4.c, 
> but again, nothing jumps out at me :(.

Proved it doesn't work as far back 0.6.2. If I modify 
modules/demux/mp4/mp4.c so that what reads :

   /* we will read 100ms for each stream so ...*/
    p_sys->i_time += __MAX( p_sys->i_timescale / 10 , 1 );

becomes:

   /* we will read 100ms for each stream so ...*/
    p_sys->i_time += __MAX( p_sys->i_timescale , 1 );

It will play a bit more aggressively at the start but still stall out. 
Also, when set like this, the timeline that feeds across the viewer is 
skewed as if it is going too fast.. Until it stops :(.

On the sessions that fail I see :

[00000424] access_http input debug: protocol 'HTTP' answer code 206
[00000424] access_http input debug: stream size=4677245
[00000424] access_http input debug: Content-Type: video/mp4
[00000424] access_http input debug: trying to seek to 99927
[00000424] main input debug: net: connecting to 'lrt.ednet.ns.ca:80'
[00000424] main input debug: looking for network module
[00000424] main input debug: probing 4 candidates
[00000424] ipv4 input debug: connection in progress
[00000047] main module debug: using network module "ipv4"
[00000047] main module debug: unlocking module "ipv4"
[00000430] alsa audio output warning: recovered from buffer underrun
[00000424] access_http input debug: protocol 'HTTP' answer code 206
[00000424] access_http input debug: stream size=4677245
[00000424] access_http input debug: Content-Type: video/mp4
[00000430] main audio output warning: computed PTS is out of range (4992), clearing out
[00000430] main audio output warning: PTS is out of range (4994), dropping buffer
[00000430] main audio output warning: output PTS is out of range (5004), clearing out
[00000430] main audio output warning: PTS is out of range (-18126), dropping buffer
[00000424] access_http input debug: trying to seek to 94322

You can see it if you try :

vlc http://www.ednet.ns.ca/~macleajb/MP4/yard2-320x240-200-ac3-128.mp4

I notice that the avi's don't seek, and mp4.c seems to seek quite a bit. 

Is there something in how http feeds mp4.c during demux that I should be 
looking at? I saw a note in one of the header files that mp4 expects a 
seekable feed... Would that be relavent for this? 

I remember that it also was stalling when getting it's feed from
mp4live once in a while... So maybe it's not http specific.

Appreciate any direction on where to look.

thanks,
JES
-- 
James B. MacLean        macleajb at ednet.ns.ca
Department of Education 
Nova Scotia, Canada
     

-- 
This is the vlc-devel mailing-list, see http://www.videolan.org/vlc/
To unsubscribe, please read http://developers.videolan.org/lists.html
If you are in trouble, please contact <postmaster at videolan.org>