optimizing flux ?
optimizing flux ?
Hello,
First, a big thank you for your software, the best video server I have used! GREAT !
I would just like to submit an idea.
UMS has a setting to limit the bandwidth (or an automatic bandwidth detection).
The limit is respected, but with a bitrate much lower than the limit.
What a pity because the quality is not the maximum possible.
On my PC (and my TV 1080p), I thought to solve the problem by changing a line in the TV.conf file :
where a = iw/ih of course.
The scale is limited by 1920 x 1080, the resolution of my 16/9 TV.
The important value of the scale is 1000*sqrt(a) : it allows to manage the number of pixels in each image (before pad instruction).
Here, it's about 1000^2, in other words 1 000 000 pixels :
for a 2.35 video, the scale is 1533:652 (and then the pad 1533:862) ;
for a 16/9 video, the scale is 1333:750 (and then the pad 1333:750) ;
for a 4/3 video, the scale is 1155:866 (and then the pad 1540:866) ;
etc.
The factor 1000 in the formula 1000*sqrt(a) is a good value for my installation PC-TV :
the factor 1000 product a median flux about 60% of the bandwidth (between 20% et 100%);
lower than 1000, the transcoded video is more blur with artefacts on TV (with quite dirty source for instance);
greater than 1000, the bitrate is too high in complex scenes...
With the default configuration of UMS, there is no scale, and the result is not always as good :
for a source 1080p, the transcoded flux is blocking (because too many pixels transcoded, my bandwidth is too low) ;
for a source 320p, the transcoded video is blur with artefacts on TV (because too few pixels transcoded), with a median flux about 10% or 20% of the bandwidth... What a pity.
So, I think the parameter (the number of pixels per transcoded image, before "padding") in the GUI that could make it simply tuning would be useful.
Isn't it ?
Best regards & sorry for my english.
First, a big thank you for your software, the best video server I have used! GREAT !
I would just like to submit an idea.
UMS has a setting to limit the bandwidth (or an automatic bandwidth detection).
The limit is respected, but with a bitrate much lower than the limit.
What a pity because the quality is not the maximum possible.
On my PC (and my TV 1080p), I thought to solve the problem by changing a line in the TV.conf file :
Code: Select all
OverrideFFmpegVideoFilter = scale=min(1000*sqrt(a)\\, min(1920\\,1080*a)):-1, pad=max(iw\\,ih*16/9):max(ih\\,iw/16*9):(ow-iw)/2:(oh-ih)/2The scale is limited by 1920 x 1080, the resolution of my 16/9 TV.
The important value of the scale is 1000*sqrt(a) : it allows to manage the number of pixels in each image (before pad instruction).
Here, it's about 1000^2, in other words 1 000 000 pixels :
for a 2.35 video, the scale is 1533:652 (and then the pad 1533:862) ;
for a 16/9 video, the scale is 1333:750 (and then the pad 1333:750) ;
for a 4/3 video, the scale is 1155:866 (and then the pad 1540:866) ;
etc.
The factor 1000 in the formula 1000*sqrt(a) is a good value for my installation PC-TV :
the factor 1000 product a median flux about 60% of the bandwidth (between 20% et 100%);
lower than 1000, the transcoded video is more blur with artefacts on TV (with quite dirty source for instance);
greater than 1000, the bitrate is too high in complex scenes...
With the default configuration of UMS, there is no scale, and the result is not always as good :
for a source 1080p, the transcoded flux is blocking (because too many pixels transcoded, my bandwidth is too low) ;
for a source 320p, the transcoded video is blur with artefacts on TV (because too few pixels transcoded), with a median flux about 10% or 20% of the bandwidth... What a pity.
So, I think the parameter (the number of pixels per transcoded image, before "padding") in the GUI that could make it simply tuning would be useful.
Isn't it ?
Best regards & sorry for my english.