about vMix2PortsdownH264ExtendedSR.bat

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
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F1SSF
Posts: 93
Joined: Sat Nov 25, 2017 5:14 pm

about vMix2PortsdownH264ExtendedSR.bat

Post by F1SSF » Thu Apr 11, 2019 7:27 pm

Hi alls,
Someone can explain to me the formula for biterate calculation?
if %SR%==333 (
if %FEC%==1/2 set VIDRATE=428571
if %FEC%==2/3 set VIDRATE=571429
.......
I don't find consistency with the informations I have.
I think these values are total biterate ?? (video BR+sound BR+tables+null packets) please can you confirm.
Super 73 Franck

M0DHP
Posts: 92
Joined: Sun Sep 24, 2017 3:25 pm

Re: about vMix2PortsdownH264ExtendedSR.bat

Post by M0DHP » Thu Apr 11, 2019 8:37 pm

Hi Franck

I submitted that batch file after the tests described here: viewtopic.php?f=103&t=5282

The bitrates were found by trial and error, starting with the original MPEG-2 settings and adjusting them to get the fewest ffmpeg errors and best stream quality on my setup.

73
Ray M0DHP

F1SSF
Posts: 93
Joined: Sat Nov 25, 2017 5:14 pm

Re: about vMix2PortsdownH264ExtendedSR.bat

Post by F1SSF » Thu Apr 11, 2019 9:15 pm

Hi Ray,
I understood now the differences between the theory and values in this file, but I'm not surprised because it is also the approach of Jean Pierre F6DZP to do these adjustements by trial test.
Good information for speed preset, I did not know .
73 Franck F1SSF

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