asf file fails to play

[compn]

file found in wild has data before asf header. this prevents it from being demuxed. removing the first 12 bytes or so of the file allows it to be played.

w:\>ffmpeg -i test1.wmv
ffmpeg version N-83243-g2080bc3 Copyright (c) 2000-2017 the FFmpeg developers

built with gcc 5.4.0 (GCC)
configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx

--enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-l
ibass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libi
lbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enab
le-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --e
nable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-
libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink
--enable-zlib

libavutil 55. 45.100 / 55. 45.100
libavcodec 57. 75.100 / 57. 75.100
libavformat 57. 63.100 / 57. 63.100
libavdevice 57. 2.100 / 57. 2.100
libavfilter 6. 70.100 / 6. 70.100
libswscale 4. 3.101 / 4. 3.101
libswresample 2. 4.100 / 2. 4.100
libpostproc 54. 2.100 / 54. 2.100

test1.wmv: Invalid data found when processing input

also does not work with -f asf_o

mplayer and vlc fail to play file. even older wmplayer fails to play original file.

is it possible to increase asf probing?

[compn]

file header indicates it was created by TMPGEnc Video Mastering Works 6