[FFmpeg-user] Trying to transcode raw video file from VLC

[no6b at no6b.com]

Doing some screencaps in VLC but its x264 transcoder is apparently broken on  Win8.1 x64 systems, including my own.  No problem, I figure: I'll just save the video in raw format (I'm only capturing a 554x65 area so even with raw video the file isn't too big) & transcode it to x264 using ffmpeg.  But no...

C:\.DATA>ffprobe test1.avi
ffprobe version N-73696-g8250943 Copyright (c) 2007-2015 the FFmpeg developers
  built with gcc 4.9.2 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --
enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm --enable-l
ibilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enab
le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --en
able-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --ena
ble-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc
 --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enabl
e-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --ena
ble-decklink --enable-zlib
  libavutil      54. 28.100 / 54. 28.100
  libavcodec     56. 49.101 / 56. 49.101
  libavformat    56. 40.101 / 56. 40.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 22.101 /  5. 22.101
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.101 /  1.  2.101
  libpostproc    53.  3.100 / 53.  3.100
[avi @ 00000000047d5300] Could not find codec parameters for stream 0 (Video: no
ne (RV32 / 0x32335652), none, 540x65, 34097 kb/s): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
test1.avi: Operation not permitted



So it looks like ffmpeg can't figure out the file format.  I tried forcing "rawvideo" input format with the -f switch & got this:

C:\.DATA>ffprobe -f rawvideo -i test1.avi
ffprobe version N-73696-g8250943 Copyright (c) 2007-2015 the FFmpeg developers
  built with gcc 4.9.2 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --
enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm --enable-l
ibilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enab
le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --en
able-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --ena
ble-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc
 --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enabl
e-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --ena
ble-decklink --enable-zlib
  libavutil      54. 28.100 / 54. 28.100
  libavcodec     56. 49.101 / 56. 49.101
  libavformat    56. 40.101 / 56. 40.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 22.101 /  5. 22.101
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.101 /  1.  2.101
  libpostproc    53.  3.100 / 53.  3.100
[IMGUTILS @ 000000000023fb50] Picture size 0x0 is invalid
[IMGUTILS @ 000000000023f680] Picture size 0x0 is invalid
[rawvideo @ 00000000047053e0] Could not find codec parameters for stream 0 (Vide
o: rawvideo (I420 / 0x30323449), yuv420p, -4 kb/s): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
test1.avi: Operation not permitted

>From this point I tried specifying the video frame size with -s, but that didn't work.  Any ideas as to how to tell ffmpeg how to read this, or am I going down the wrong path?  VLC says the raw format is RV32 & ffmpeg seemed to be able to get the video size correct on that 1st try without the -f switch, so the "-f rawvideo" might be leading ffmpeg astray?

Thanks

Bob