[FFmpeg-user] converting to AAC audio duration changes

[Jeanne Rich]

----- Original Message -----
> So the big issue is doing the concatination.  The 2 h.264 movie segments used
> in the concatenation have audio synced.  When I concat the 2 movies with the
> demux, the audio is late by about 1/2 a frame.  I tried using -async 0 this
> did nothing.  This time the audio start is at 0, and the video start is > 0.
> Here is the ffprobe result:


Woops gave you the wrong ffprobe output before, the output before was the first segment, here is the output of the concat h.264

[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=1/48
codec_tag_string=avc1
codec_tag=0x31637661
width=1920
height=1080
has_b_frames=0
sample_aspect_ratio=0:1
display_aspect_ratio=0:1
pix_fmt=yuv420p
level=50
timecode=N/A
id=N/A
r_frame_rate=24/1
avg_frame_rate=24/1
time_base=1/12288
start_pts=258
start_time=0.020996
duration_ts=24576
duration=2.000000
bit_rate=51777968
nb_frames=48
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:language=eng
TAG:handler_name=DataHandler
[/STREAM]
[STREAM]
index=1
codec_name=aac
codec_long_name=AAC (Advanced Audio Coding)
profile=unknown
codec_type=audio
codec_time_base=1/48000
codec_tag_string=mp4a
codec_tag=0x6134706d
sample_fmt=fltp
sample_rate=48000
channels=2
bits_per_sample=0
id=N/A
r_frame_rate=0/0
avg_frame_rate=0/0
time_base=1/48000
start_pts=0
start_time=0.000000
duration_ts=98048
duration=2.042667
bit_rate=127613
nb_frames=96
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:language=eng
TAG:handler_name=DataHandler
[/STREAM]
[FORMAT]
filename=/laika/tmp/jrich/trans/outConcat.mov
nb_streams=2
format_name=mov,mp4,m4a,3gp,3g2,mj2
format_long_name=QuickTime / MOV
start_time=0.000000
duration=2.043000
size=12979561
bit_rate=50825495
TAG:major_brand=qt  
TAG:minor_version=512
TAG:compatible_brands=qt  
TAG:encoder=Lavf55.16.103
[/FORMAT]

----- Original Message -----
> So the big issue is doing the concatination.  The 2 h.264 movie segments used
> in the concatenation have audio synced.  When I concat the 2 movies with the
> demux, the audio is late by about 1/2 a frame.  I tried using -async 0 this
> did nothing.  This time the audio start is at 0, and the video start is > 0.
> Here is the ffprobe result:
>