Concat demux PTS discontinuity

For the developers that use FFmpeg in their software.
Post Reply
chanof
Posts: 1
Joined: Sat Feb 17, 2018 3:42 am

Concat demux PTS discontinuity

Post by chanof » Sun Feb 25, 2018 5:29 pm

Hi everyone, my goal is to create the closed gop encoding suitable for mpeg-dash live, unfortunately, the concat demux generates a discrepancy of the PTS between videos concatenated:

PTS time stamp:
[...]
382.021016
384.021016
386.021016 the concat demux effect:
388.043047
390.043047
392.043047
[...]

Command line for encoding is

Code: Select all

ffmpeg -y -i "$f" -i ../logo/logo.png -c:a aac -b:a 384k -ar 48000 -ac 2 -async 1 -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -r $FPSC -b:v 4800k -maxrate 4800k -bufsize 3000k -profile:v main -crf 22 -t $DUR -filter_complex "[0:v][1:v]overlay=main_w-overlay_w-10:10,scale=1920:1080,setsar=1" ../buffer/${NAME}-1080.mp4
Command line for concat is

Code: Select all

ffmpeg -f concat -safe 0 -i 1080list.txt -t $TOTDUR -c copy ../output/1080set.mp4
These commands are inserted into a bash script to automate the generation of 3 adaption sets (1080p, 720p, 360p), for full script:
https://stackoverflow.com/questions/487 ... 3#48776153

Videos for input has regular timestamp and starts from 0s
How can I get a regular timestamp after concat demux process without performing another encoding (to avoid a process that is too long)?

Thanks!

Giammy

Post Reply