ffmpeg - Parse mkv file to get duration -

ffmpeg - Parse mkv file to get duration -

i have 1 mkv file doesn't have valid duration. want alter duration parameter manually. gone through matroska specification defined @ http://www.matroska.org/technical/specs/index.html

looking @ specification matroska contains identification magic numbers, doesn't specify length data.

so, question how parse matroska header duration field , alter field?

any help or advice? give thanks in advance.

the type of duration field float. according documentation can either 4 or 8 octets. know size is, have @ info size part of field. info size part uses utf-8 system. it's explained here.

ffmpeg mkv matroska