[Ffmpeg-devel] WMA encoding and Windows Media Player for Mac OS X

Tyler Loch tylerl82
Wed Mar 7 22:57:37 CET 2007

> a few things you could try:
> * different preroll_time (grep preroll_time asf-enc.c)

Changing this to an absurd value seems to halfway work (as of the  
latest asf-enc.c SVN update):
#define PREROLL_TIME 210000000
Works on:

Does not work on:
WMP Windows

Haven't tested:
Windows Mobile

Obviously, this is a bad edit in the first place, but might add some  
more clues.

> * try to prevent 2 audio packets from being put in the same "chunk"
>   a quick hack to gurantee this is to reduce PACKET_SIZE in asf.h so
>   2 wont fit but 1+headers does

Reducing this to 800 or so plays the first 15ish seconds ok in WMP  
Mac, then the player seems to repeatedly stall as if it were  
downloading while playing.

> * mess with interleaving of packets aka mux a few seconds of audio  
> before
>   any video (for a quick hack simply modifying  
> av_interleave_packet_per_dts()
>   should do) i can provide a patch if the code is too confusing

I couldn't see where/how to edit this (utils.c? globally?)

-Tyler Loch
Techspansion LLC

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