[Ffmpeg-devel] [BUG] MPEG 2 Division By Zero

[Brian Brice]

Hello.

Something quite strange is happening when I'm encoding MPEG 2.  I'm
encoding clips that are just noise and I get "division by 0" crashes.
Unforunately, I can't produce a call stack (using DLLs in Windows from
VC++), but I did narrow down where the division is occurring:

     lavc/h263.c:565
     ff_mpeg4_init_direct_mv

Here's my "call stack" I did make with av_logs though (it's not really a
stack, but more of a sequence of what is called):

    bbrice: lavc/utils.c - avcodec_encode_video()
    bbrice: lavc/mpegvideo.c - MPV_encode_picture()
    bbrice: lavc/mpegvideo.c - load_input_picture()
    bbrice: lavc/mpegvideo.c - select_input_picture()
    bbrice: lavc/mpegvideo.c - MPV_frame_start()
    bbrice: lavc/mpegvideo.c - encode_picture()
    bbrice: lavc/mpegvideo.c - encode_picture() | ff_set_mpeg4_time()
    bbrice: lavc/h263.c - ff_set_mpeg4_time() | pict_type=B
    bbrice: lavc/h263.c - ff_mpeg4_init_direct_mv() | pp_time=0

These are the settings I'm using for the video codec context:
   codec:        mpeg2video
   bit_rate:     18300000
   width:        1280
   height:       720
   aspect_ratio: 16:9
   rate:         ntsc (30/1.001)
   gop_size:     6
   max_b_frames: 2
   profile:      4 (MP)
   level:        6 (HL 1440)
   rc_min_rate:  18300000
   rc_max_rate:  18300000
   rc_buffer_size: 3670016 (448 KiB * 1024 * 8)

-- 
Brian Brice