[Libav-user] Decoding only on specific slice using FFmpeg.

[s.yamashita]

I have a hevc all-intra bitstream in which each frame has 4(2x2)
tiles(slices). My program can
decode it using ffmpeg and render it using OpenGL. The decoding
process is almost the same
as this example.
http://ffmpeg.org/doxygen/4.0/decode__video_8c_source.html

What I want is only one specific tile in each frame (for example, the
second tile). In order
 to reduce  the decoder load, I don't want to decode the other 3
tiles. If it is possible to decode
 only one specific tile(slice), please teach me how to do it.

(I posted this question to StackOverFlow before, but received no
answer. Someone advised me
 to post to this mailing list.)

Thank you.