FLV File Conversion Issues

[vaylie]

So, I have a few FLV files of a streaming TV show that I was hoping to convert to either mkv or mp4. But everything I've tried doesn't work. I can only play it using VLC Player.

VLC Player View/Attempt
1. 6 seconds of blank screen with only audio playing and filename.flv in the title
2. THEN the video starts playing with audio, title changes to MPEG_TS.

1. The blank screen's codec info:

[Attachment 54242 - Click to enlarge]

2. The MPEG_TS codec info:

[Attachment 54241 - Click to enlarge]

When I try to convert this file using VLC, it only converts the blank 6 seconds at the start of the video.

FFMPEG attempt:
When I try to convert it using ffmpeg, using -analyzeduration and -probesize of up to 100M, nothing works. I keep getting this error.

C:\ffmpeg\bin\ffmpeg.exe -analyzeduration 100
M -probesize 100M -i filename.flv -c copy test.mp4
ffmpeg version git-2020-06-20-29ea4e1 Copyright (c) 2000-2020 the FFmpeg develop
ers
  built with gcc 9.3.1 (GCC) 20200523
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfi
g --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libb
luray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enab
le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --e
nable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-lib
twolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --
enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --e
nable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo
-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom
--enable-libgsm --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable
-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enabl
e-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 55.100 / 56. 55.100
  libavcodec     58. 93.100 / 58. 93.100
  libavformat    58. 47.100 / 58. 47.100
  libavdevice    58. 11.100 / 58. 11.100
  libavfilter     7. 86.100 /  7. 86.100
  libswscale      5.  8.100 /  5.  8.100
  libswresample   3.  8.100 /  3.  8.100
  libpostproc    55.  8.100 / 55.  8.100
[flv @ 00000000004a3000] Packet mismatch -1256851446 15257199 15257199
filename.flv: could not find codec parameters

Handbrake Attempt:

It doesn't even allow me to click 'Start.' Nothing in the file scans.

FLV Extract:

It pops up an error saying video does not exist, mp3 does not exist.

FLV Meta:

0x0000000d: error E30013: unknown tag type 174
0x0000000e: warning W20017: tag body length (15257188 bytes) is abnormally large

0x00000011: error E40019: first timestamp should be zero, 524747008 found instea
d
0x00000015: error E20025: tag stream id must be zero, 3011495 found instead
0x00e8ce80: error E12051: previous tag size should be 15257199, 3038115850 found
 instead
0x00e8ce80: error E30013: unknown tag type 44
0x00e8ce80: fatal F30084: consecutive tags with unknown type found, aborting
6 error(s), 1 warning(s)

Unfortunately I can't open this file in any video editor, and it's 400MB large, so I can't upload a sample. Hopefully somebody here recognizes what this file is and has some tips on how to convert it.

Thanks in advance!

[blud7]

ffmpeg -i "input.flv" -c copy "output.mkv"

Try that then try manipulating it.

[vaylie]

I get the same packet mismatch error as I do when I try to convert to mp4 unfortunately.

[ProWo]

Try to remux your flv to mkv with MkvToolNix.
Try also to rename the file extention from flv to ts.