[FFmpeg-user] Audio issue while streaming

[Laszlo Szabo]

Hi everyone,
We are using FFMPEG for streaming to video.ibm.com through rtmp.

The script we used worked just fine for days, then today we ran into a
severe audio issue.
The audio got super distorted, it this artifact only appeared in the
network stream (the local recording (same script but saves file to drive
instead of streaming ig) did not have these problems.

The log is 100 megs big and consists of a lot of
"dshow passing through packet of type audio size     3840 timestamp
951639930000 orig timestamp 951639930000 graph timestamp 951639440000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951640130000 orig timestamp 951640130000 graph timestamp 951639640000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951640330000 orig timestamp 951640330000 graph timestamp 951639840000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951640530000 orig timestamp 951640530000 graph timestamp 951640040000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951640730000 orig timestamp 951640730000 graph timestamp 951640240000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951640930000 orig timestamp 951640930000 graph timestamp 951640440000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951641130000 orig timestamp 951641130000 graph timestamp 951640640000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951641330000 orig timestamp 951641330000 graph timestamp 951640840000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951641530000 orig timestamp 951641530000 graph timestamp 951641040000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951641730000 orig timestamp 951641730000 graph timestamp 951641240000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951641930000 orig timestamp 951641930000 graph timestamp 951641440000 diff
-490000 vMix Audio - Bus E
dshow passing through packet of type audio size     3840 timestamp
951642130000 orig timestamp 951642130000 graph timestamp 951641630000 diff
-500000 vMix Audio - Bus E"
lines.

Here is the script:

"@ECHO Off

:: %1 = Stream URL
:: %2 = Language name (window title)
:: %3 = Language code

START "(MAIN) %2 Streaming" "C:\\Program Files
(x86)\\vMix\\streaming\\ffmpeg.exe"^
-report^
-y^
-f dshow^
-rtbufsize 800M^
-i video="vMix Video":audio="vMix Audio"^
-acodec aac^
-strict -2^
-b:a 192k^
-r 25^
-force_key_frames "expr:gte(t,n_forced*1)"^
-vcodec libx264^
-pix_fmt:v yuv420p^
-preset:v superfast^
-b:v 5000k^
-maxrate 5500k^
-bufsize 22000k^
-f flv^
"%11|language=%3""

What could be the problem?

Thanks!