There's a 50-minute long webm video file which stops playing after about 8th minute. As I don't require the beginning of the video, I decided to split it and get last 30 minutes of it.
For that, I have installed ffmpeg and I am using the following command as suggested in here,
ffmpeg -ss 00:20:00 -t 00:50:00 -i a.webm -acodec copy -vcodec copy b.webm
When I do this, however, I am getting the following error messages:
Truncating packet of size 591111 to 13231
[matroska,webm @ 00000225a4ac8c00] Element at 0xb966ccb ending at 0x11ee2070 exceeds containing master element ending at 0xbc386e8
Last message repeated 1 times
[matroska,webm @ 00000225a4ac8c00] Length 5 indicated by an EBML number's first byte 0x09 at pos 200544103 (0xbf40f67) exceeds max length 4.
[matroska,webm @ 00000225a4ac8c00] Element at 0xc4e9b68 ending at 0xc4eb1e3 exceeds containing master element ending at 0xc4e9bb9
Does it mean that I can't split the file until I fix it? And if so, can you guide me in fixing it given the error stack?