HD Video Quality setting

[zip]

OK, it sucks that it doesn't clip the bitrate. As you can see from Illico's example, the original file shows bitrate of 192k, which is obviously wrong, so it's not reliable. Using the muxrate only for videos with higher bitrate than the desired limit will not work - I'd have to enforce it for every remuxed file, no matter what original bitrate it has.

Not sure if it should be a setting in the console, across all available renderers and transcode options or just a setting per profile. Probably the former, with the setting turned off by default.

[tombert]

Yeah this sucks - I as well tried to search for a switch to retrieve the average bitrate but couldn't find it - I thought it would work similar to mediainfo ...

I did the same tests with Sintel and it seems that I was to euphoric:

Sintel.mkv (original)
Mediainfo tells Overall bit rate: 8.219 Kbps
File size: 911.918 KB

Sintel.mpeg (copy stream)
Mediainfo tells Overall bit rate: 7.183 Kbps
File size: 796.901 KB

Sintel_10000.mpeg (copy stream, remux with -muxrate 10000k)
Mediainfo tells Overall bit rate: 10.4 Mbps
File size: 1.176.143 KB

Sintel_5000.mpeg (copy stream, remux with -muxrate 5000k)
Mediainfo tells Overall bit rate: 5.013 Kbps
File size: 777.648 KB

Sintel_1000.mpeg (copy stream, remux with -muxrate 1000k)
Mediainfo tells Overall bit rate: 1.003 Kbps
File size: 783.768 KB

The Video quality seems to be the same with all files, Mediainfo clearly is wrong when estimating the bit rate.
It looks as when using the copy statement the bitrate can be only increased and lowering has no effect.

I tried the same with -vcodec mpeg2video one time using -muxrate, the other time -b ... the options are producing different results but reliably reducing the bitrate to the one requested. The drawback: it's slow.

The conclusion: maybe a switch to enforce re-encoding even if the video is already in the correct format - so the already existing option maxVBitrate would get applied.

thx

[zip]

According to this: http://ffmpeg-users.933282.n4.nabble.co ... 23777.html

It looks like setting bitrate too low would cause FFmpeg to crash.

I'm thinking if it's the TV that is the bottleneck or the network. Could you test with playing the file straight to the TV via a cable (no wireless).

[tombert]

No wireless - connected via GBit cable ... I understood that the TV is 100 MBit only ... PS3 measures the speed with ~75MBit.
The problems is a bit weird because the network load towards my TV shows <15MBit - that's about the same load when using PS3 MediaServer (tried with the same file) but there it plays fine ...
Initially I thought that stuttering happens when serviio resyncs the library, then I thought it happens when still an ffmpeg process is running, I increased serviio's priority - but that didn't help ...

Maybe it's the way serviio is streaming the data to the TV? Is there a way of knowing/measuring?
I guess the TV is requesting the data and then serviio sends it?

It as well could be the TV not able to handle such bitrates - I measured the transfer rate with ifstat and that gives me averages only - there could be spikes inside and I don't see them ...

Hmmmm ... I could try to increase the bitrate of Sintel and see when it beginns to stutter ...

This is how PS3 Media server does it, -qmin -qmax . I agree too many people are having problems streaming HD. PS3 Media Server also allows specifying a max bandwidth to use. It would be great if Serviio had similar functionality. This is from PS3 Media server:

"ncoder Tips:

The video is automatically transcoded and muxed to a MPEG-PS / AC3 audio (highly compatible on PS3)
You can play with the vqscale, vqmin and keyint parameters to achieve good, even almost lossless transcoding quality.
Drawback to this is the VBR bitrate who can peaks sometimes above your max network capacity.
That's why you can also set the bandwith if you're on WiFi, CPL, etc. However, the transcoding quality
is a balance between network speed and cpu power: the more quality you will put in a constrained bitrate,"

It would be great if Serviio was the same.

[tombert]

All this is achieved with tsMuxR and zip already said that he won't do this ... which in fact I can understand - the better the TVs getting the more useless those features will be ...

Hi, Hmm... I think regardless of how 'good' TV's come, I think this would still be extremely useful. People have differing networks and TV's and this allows them to tweak Serviio to their specific environments. It would be great were it added (at least the network throttle).

Hi,

I have to agree there needs to be a method of increasing the quality for transcoded media streams. In the simple tests i've done non transcoded video files (on my setup) have a much higher image quality than the transcoded equivalents.

[zip]

If the file is remuxed, the quality will be the same. if it's really transcoded, -sameq parameter of FFmpeg is used. It should deliver the best quality.