[FFmpeg-user] Continuation problem after video concatenation

[Marco Baumgartl]

Well, I didn't solve the problem, but I found at least an explanation.

The video stream (duration=3176.106267) is shorter than the audio stream 
(duration=3221.490068). While the source video is in sync, the 
synchronization is lost during concatenation.

Is there any way to keep synchronization while concatenating videos?

ffprobe input.mp4 -show_streams

[STREAM]
index=0
codec_name=h264
codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
profile=Main
codec_type=video
codec_time_base=1001/60000
codec_tag_string=avc1
codec_tag=0x31637661
width=1280
height=720
has_b_frames=2
sample_aspect_ratio=0:1
display_aspect_ratio=0:1
pix_fmt=yuv420p
level=40
color_range=tv
color_space=bt709
timecode=N/A
id=N/A
r_frame_rate=30000/1001
avg_frame_rate=30000/1001
time_base=1/90000
start_pts=0
start_time=0.000000
duration_ts=285849564
duration=3176.106267
bit_rate=69901
max_bit_rate=N/A
nb_frames=95188
nb_read_frames=N/A
nb_read_packets=N/A
DISPOSITION:default=1
DISPOSITION:dub=0
DISPOSITION:original=0
DISPOSITION:comment=0
DISPOSITION:lyrics=0
DISPOSITION:karaoke=0
DISPOSITION:forced=0
DISPOSITION:hearing_impaired=0
DISPOSITION:visual_impaired=0
DISPOSITION:clean_effects=0
DISPOSITION:attached_pic=0
TAG:creation_time=2014-08-13 19:11:44
TAG:language=und
TAG:encoder=JVT/AVC Coding
[/STREAM]
[STREAM]
index=1
codec_name=aac
codec_long_name=AAC (Advanced Audio Coding)
profile=unknown
codec_type=audio
codec_time_base=1/44100
codec_tag_string=mp4a
codec_tag=0x6134706d
sample_fmt=fltp
sample_rate=44100
channels=1
channel_layout=mono
bits_per_sample=0
id=N/A
r_frame_rate=0/0
avg_frame_rate=0/0
time_base=1/44100
start_pts=0
start_time=0.000000
duration_ts=142067712
duration=3221.490068
bit_rate=95966
max_bit_rate=N/A
nb_frames=138738
nb_read_frames=N/A
nb_read_packets=N/A
DISPOSITION:default=1
DISPOSITION:dub=0
DISPOSITION:original=0
DISPOSITION:comment=0
DISPOSITION:lyrics=0
DISPOSITION:karaoke=0
DISPOSITION:forced=0
DISPOSITION:hearing_impaired=0
DISPOSITION:visual_impaired=0
DISPOSITION:clean_effects=0
DISPOSITION:attached_pic=0
TAG:creation_time=2014-08-13 19:11:44
TAG:language=und
[/STREAM]


Cheers,
Marco