[mythtv-users] Fwd: Video encoding and ffmpeg

Jonathan Larson jtlarson at u.washington.edu
Tue Oct 12 17:02:59 UTC 2010

-----Original Message-----
From: mythtv-users-bounces at mythtv.org [mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Justin Bracken
Sent: Tuesday, October 12, 2010 9:31 AM
To: mythtv-users at mythtv.org
Subject: [mythtv-users] Fwd: Video encoding and ffmpeg


I believe audio bitrate would cause a sync problem since the sample rate control the max frequencies and bitrate controls how many bits per sample are used. So it would cause a cumulative error since the data is not being used up at the rate intended.

Thanks for the help so far!


The bit rate is defined as bits per second--the unit of time (seconds) never changes, and neither will it affect the timing of your output. 
Sample rate on the other hand can affect timing--I convert many audio tracks from 44.1 kHz to 22.05 kHz, but once I forgot the 50 and just output at 22Khz even, which introduced a gradual creep in the audio track over the span of the video. I mention this because it sounds similar to your description, so you might want to check that you are outputting at the same sample rate that you are inputting.


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