[Libav-user] ffmpeg version 3.4 (Cantor) behaviour

Francesco, Cuzzocrea francesco at bltitalia.com
Mon Nov 20 18:59:45 EET 2017

inserting latest library version (ffmpg 3.4 "Cantor") in my code, I 
noticed a significant change in encoding behavior mainly in using MPEG2 
at 50 Mbit. The same code that works fine with previous versions, in 
these latest didn't work as before.
Fist change:
In previous version assigning a buffer to the packet the encoded frame 
was put in it avoiding to allocate packet buffer. In latest versions
the packet is allocated regardless of pkt->data field.  Reading the code 
I didn't find any flag that restore previous behavior.
There is a way to restore it ?

Another great change is that allocated packet is of constant size 
excluding first 2  times the got_packet flag is set ( I'm using
gop_size=12 and max_b_frame = 2) and the buffer is mainly zero. Like if 
the pkt->size now indicate buffer size and not
output size.   Again: there is away to restore previous behavior ? How 
can I detect effective compressed frame size ?


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