MKV Audio track stop playing

Question

I have a show with two sources, Blu-Ray and DVD. Blu-Ray doesn't contain the correct audio language but DVD does. I want to add the DVD audio track to the Blu-Ray. So I have decided to rip them.

Using ffmpeg I have extracted the audio track from the DVD and converted it to have the correct length:

ffmpeg -i "dvd source"  -map 0:a:1 -af "atempo=0.95904096" "audio track"

Then I add the audio track to the Blu-Ray file:

ffmpeg -i "blu ray source"  -i "audio track" -map 0 -map 1 -c:v copy -c:s copy -c:a copy "merged mkv"

The episode plays correctly with the right audio track then, after a few minutes, the audio stops playing.

I have checked the audio track alone after the DVD rip, it works. I have also re-extracted the audio from the merged MKV and it works too. Duration of tracks are good.

I am wondering if I am doing something incorrectly.

Answer 1

I think I found something to make it works on my first two episodes. Instead of adding audio to the blu ray source, I have extracted audio from both source, I have also extracted subs from the blu ray only (as I don't expect to use subs for my languages ;) ) and create a new file by copying video from the blu ray, audio tracs from the two sources and the subs.

So here's what I'm doing that works so far :

• ffmpeg -i "dvd source" -map 0:a:1 -af "atempo=0.95904096" "audio track 1"
• ffmpeg -i "blu ray source" -map 0:a -c copy "audio tracks 2"
• ffmpeg -i "blu ray source" -map 0:s -c copy "subs"
• ffmpeg -i "blu ray source" -i "audio track 1" -i "audio tracks 2" -i "subs" -map 0:v -map 1:a -map 2:a -map 3:s -c copy "merged file"

I don't really understand why this work and the previous didn't since I am theorically doing the same thing. Maybe it doesn't like haved tracks IDs not in order ?