[FFmpeg-trac] #6326(avfilter:new): FFmpeg 3.3+3.4-dev crash when scaling to same dimensions with scale_npp

[FFmpeg]

#6326: FFmpeg 3.3+3.4-dev crash when scaling to same dimensions with scale_npp
-------------------------------------+-------------------------------------
             Reporter:  Bloof        |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  important    |                Component:  avfilter
              Version:  git-master   |               Resolution:
             Keywords:  crash        |               Blocked By:
  SIGSEGV                            |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by kikobyte):

 Happens to me as well, when source and destination dimensions match for
 scale_npp.

 Debug 3.3.5:
 {{{
 Program received signal SIGSEGV, Segmentation fault.
 nppscale_filter_frame (link=link at entry=0x3b7f8a0, in=0x3b82620) at
 libavfilter/vf_scale_npp.c:496
 496         AVCUDADeviceContext *device_hwctx =
 frames_ctx->device_ctx->hwctx;
 (gdb) where
 #0  nppscale_filter_frame (link=link at entry=0x3b7f8a0, in=0x3b82620) at
 libavfilter/vf_scale_npp.c:496
 #1  0x00000000004c0fb2 in ff_filter_frame_framed (frame=0x3b82620,
 link=0x3b7f8a0) at libavfilter/avfilter.c:1116
 #2  ff_filter_frame_to_filter (link=0x3b7f8a0) at
 libavfilter/avfilter.c:1264
 #3  ff_filter_activate_default (filter=<optimized out>) at
 libavfilter/avfilter.c:1315
 #4  ff_filter_activate (filter=<optimized out>) at
 libavfilter/avfilter.c:1476
 #5  0x00000000004c4604 in ff_filter_graph_run_once
 (graph=graph at entry=0x287b060) at libavfilter/avfiltergraph.c:1449
 #6  0x00000000004c54d0 in push_frame (graph=0x287b060) at
 libavfilter/buffersrc.c:181
 #7  av_buffersrc_add_frame_internal (ctx=ctx at entry=0x3b7fb80,
 frame=frame at entry=0x2797dc0, flags=flags at entry=4) at
 libavfilter/buffersrc.c:262
 #8  0x00000000004c5b6d in av_buffersrc_add_frame_flags (ctx=0x3b7fb80,
 frame=frame at entry=0x2797dc0, flags=flags at entry=4) at
 libavfilter/buffersrc.c:164
 #9  0x00000000004a07a5 in ifilter_send_frame (frame=0x2797dc0,
 ifilter=0x2012e20) at ffmpeg.c:2216
 #10 send_frame_to_filters (ist=ist at entry=0x201c860,
 decoded_frame=decoded_frame at entry=0x2797dc0) at ffmpeg.c:2294
 #11 0x00000000004a11da in decode_video (ist=0x201c860, pkt=<optimized
 out>, got_output=<optimized out>, eof=<optimized out>,
 decode_failed=<optimized out>) at ffmpeg.c:2494
 #12 0x00000000004a3648 in process_input_packet (ist=0x201c860,
 pkt=0x7fffffffd9b0, no_eof=0) at ffmpeg.c:2643
 #13 0x0000000000483e27 in process_input (file_index=<optimized out>) at
 ffmpeg.c:4417
 #14 transcode_step () at ffmpeg.c:4528
 #15 transcode () at ffmpeg.c:4582
 #16 main (argc=2, argv=0x201c860) at ffmpeg.c:4787
 }}}

 Seems that frames_ctx was not properly initialized:

 {{{
 (gdb) info locals
 ctx = 0x3b7e7a0
 s = 0x3b7e8a0
 outlink = 0x3b804e0
 frames_ctx = <error reading variable frames_ctx (Cannot access memory at
 address 0x8)>
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/6326#comment:2>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker