Transcoding with fast-forward

[mvallevand]

Afaik the mainconcept was/is installed with the haup-sw, although I don't know if they still use it. I guess sub hasn't updated/tried the trans2mvp.exe for a long time.

Ok, I downgraded to 3.3 25032 and the MainConcept (Hauppauge) MPEG Encoder is now there. It still doesn't work so it could still be a Vista thing, after all the Hauppauge software doesn't work well on Vista.

Martin

[zehd]

There are two different things going on in this thread...

When pBS suggested <MVPTranscodeUsingFFmpeg>false</MVPTranscodeUsingFFmpeg>

That would cause GB-PVR to use Trans2MVP.exe, which indeed doesn't work very well and relies on the MainConcept filter...

The Hauppauge software, is the one that when working on its own provides for on-the-fly transcoding, that also includes Fast Forward seeking.

I'm amazed how it works. I think the transcoder is able to read the AVI and shuttle it forward and then start transcoding from that point. Really cool...

Sync is also bang on.

I don't like the positioning though. That's one thing I like about ZProcess. You can adjust the rectangle to accommodate overscan and older TVs. But even on the newer TVs, the Hauppauge software doesn't use the whole rectangle. It maintains the aspect ratio, but doesn't stretch out some avis to touch the left and right margins...

Now it's a matter of building something that will use the Hauppauge software but be implemented from within GB-PVR.

Most likely it won't be able to use the current technique, with
<MVPTranscodeUsingFFmpeg>true</MVPTranscodeUsingFFmpeg>
and GB-PVR calling ffmpeg or ZProcess, having the transcoder transcode, and GB-PVR streaming the resulting on-the-fly file.

I believe that GB-PVR will have to have two way communication with the Hauppauge Transcoder to tell it to shuttle forward, and wait for the transcoder to shuttle and transcode...

sub and Martin would know this, whether GB-PVR would be able to receive fast forward keystrokes and not just try to move its own temp MPG forward, but also tell the transcoder to move forward...

This is so cool, but it probably has to be sewn into GB-PVR...

I hope we can do something like this. I hope we'll have control over positioning too...

[pBS]

check out this http://www.advansib.com they have a network renderer filter, which is similar to what Haupp. uses to do their magic...
also http://www.asvzzz.com which has similar plus a nice little util called directspy, connect to graphs that are not in ROT table!

in download section there are a couple of filters to try out.. [anrender]
basically it's a net enabled filter you stick in graph as renderer..then set server and port...then on receiver, specify net reader as source, [assuming MVP can do this] and play on 'receiver'....you'll see you can control the encoding graph's process...

this is how they do it, so that the entire file looks like it's completely encoded to the receiver, so skipping to near end isn't problem..it jus moves encoding to that point and it's never behind more than the buffer amount..reconnects well too..

imagine playing a rendering graph in graphedit, now move the pos. slider at top..it just moves encoding to that pos. and continues..same thing..only stick the network in between the graph and player interface..

just a thought, as that's how they do it and very flexible..
not sure what we'd need on MVP end...but the sending shouldn't need any changes.. as long as the MVP file reader is Async i think it will work..

[mvallevand]

I'm amazed how it works. I think the transcoder is able to read the AVI and shuttle it forward and then start transcoding from that point. Really cool...

I had an internal version of mvpmc that worked with GBPVR for the gui stream but allowed a choice of using Hauppauge or GBPVR for the media stream. It was cool but I found that even though they are separate servers they can't be completely independent.

sub and Martin would know this, whether GB-PVR would be able to receive fast forward keystrokes and not just try to move its own temp MPG forward, but also tell the transcoder to move forward...

Since the dongle sends the same keystrokes whether or not it talking to GBPVR or Hauppauge, it is totally controlled by the server. Sub has chosen to do skipping by minutes and Hauppauge likes percentage. For a television program based system I think minutes is more logical.

I hope we can do something like this. I hope we'll have control over positioning too...

Another possibility is how mvpmc talks directly to vlc for streaming and position non-mpeg video files. It is the smoothest method I have found and requires the least system resources.

Martin

[zehd]

I'm a little more meat and potatoes when I program. Might not have all the terminology. Wonder if I'm on the right track.

The current GB-PVR way is:

MVP selects a non-mpg. It calls ZProcess, does some rectangle calculations, calls Mencoder, transcodes to a MPG, GB-PVR plays that MPG...

The proposed way:

MVP selects a non-mpg. ZProcess does the rectangle calculations, calls the renderer, start from the begining, calls Mencoder to read the stream generated from the renderer and transcodes to an MPG

Does the Mencoder output a MPG that GB-PVR sees and displays? Let's say it does...

Then ZProcess skips the renderer forward a minute (eventually GB-PVR will tell ZProcess to skip forward a minute)

The stream changes location, but isn't broken. The output MPG isn't broken, and GB-PVR continues to play the temp MPG.

(Eventually ZProcess could tell GB-PVR to update it's location in the OSD and ZProcess would actually tell GB-PVR the end time...

This all hinges on an unbroken MPG Temp file.

Or GB-PVR could be writen to read the output stream of the renderer directly rather than the output MPG.

In theory is any of this possible? I'm going to start on a test

[mvallevand]

I'm a little more meat and potatoes when I program. Might not have all the terminology. Wonder if I'm on the right track.

I don't think you are on the right track. You can either make a transcoder to replace ffmpeg/mencode, or you can make a new media server that virtualizes the files using the kind of process that Hauppauge does and that pBS mentioned. I don't see where your solution fits in at all.

This all hinges on an unbroken MPG Temp file.

Actually this isn't as important as you might think. When you change channels on livetv the mpg is broken but in the vast majority of changes the mvp recovers, the key is not to starve either the audio or video portions of the demux.

Or GB-PVR could be writen to read the output stream of the renderer directly rather than the output MPG.

In reality a file and a stream can be considered equal so this isn't really a problem on modern hardware unless you are writing to a slow drive, especially on an network and even more so on a wireless network. However reading a stream is what mvpmc does with vlc, it reads the http output from transcoding but after the file is opened the code doesn't differentiate that the mpeg data is coming from http and not from a file share.

Martin

[sub]

Is there some way to emulate the on-the-fly conversion used by MediaMVP software? Perhaps a way to use the Hauppauge transcoding dlls instead of ffmpeg?

The MediaMVP software is better at playing non-MPEG movies. The difference is that GBPVR converts the file on the fly to disk which means that you cannot jump past where it has got to transcoding the file. MediaMVP also converts on the fly, but streams it so you can jump straight to the end of the movie and back again, and also remembers where you were for each movie.

GBPVR is fine for watching movies, but not having fast-forward/skipping is limiting.

I'm using:

MediaMVP 2.5.0.3362
PVRX 1.0.0.0

Sorry, its unlikely I'll ever implement support for this. The Hauppauge MVP server software has always been better than GB-PVR in this respect, but its not really practical for me to take a similiar approach. Unfortunately the licensed mainconcept components they use in this method arent reusable in GB-PVR.

I'll just continue to recommend MVP users stick to MPEG2.

[fvfv]

I did not know of the VLC solution using mvpmc until I tried it.

It works really good, as far as resources and Skip, FFWD, REW.

The only issue I have is with subtitles. I have been on the VLC forums, the mvpmc forums and cannot find anything to help me with the problem.

VLC 0.8.6 supports the telnet interface and the "Auto Discovering" of srt subtitles.

IF I give vlc a file name such as "c:\movies\avis\test.avi" and there is an srt file in the same folder with the same name, then VLC plays fine the subs.

However, when doing it from mvpmc a share must be used so the file then becomes /movies/avis/test.avi. The autodiscovery does not work in this case. No subs are displayed.

Other than that, vlc is a really great way to get avis into the mvp with full rew, ff, skip support.

[mvallevand]

However, when doing it from mvpmc a share must be used so the file then becomes /movies/avis/test.avi. The autodiscovery does not work in this case. No subs are displayed.

I would be very surprised if this would work. vlc would have to be able to either mux the text from the srt into the mpeg stream or convert it into a DVD style graphic subtitle and not simple overlay an OSD image as it probably does as a standalone player for this to happen.

Martin

[zehd]

I would be very surprised if this would work. vlc would have to be able to either mux the text from the srt into the mpeg stream or convert it into a DVD style graphic subtitle and not simple overlay an OSD image as it probably does as a standalone player for this to happen.

Martin

I've had ZProcess v1 using subtitles with VLC almost from the when I brought VLC in (ZProcess 2 still doesn't use VLC)

Same name same directory, but I did have to explicitly add to the command line...

Code:

"C:\Program Files\VideoLAN\VLC\vlc.exe" "C:\TV\Video\Stargate.SG-1-S10E14-The.Shroud.avi" :sout=#transcode{vcodec=mp2v,vb=2400,scale=1,acodec=mpga,ab=192,channels=2}:standard{access=file,mux=ps,dst="C:\TV\Override\Stargate.SG-1-S10E14-The.Shroud.mpg"} :aspect-ratio="4:3" :sout-transcode-width=640 :sout-transcode-height=480 :sout-transcode-paddtop=0 :sout-transcode-paddbottom=0 :sout-transcode-paddleft=0 :sout-transcode-paddright=0 :sout-transcode-fps=29.97 :sout-ffmpeg-keyint=12 :sout-ffmpeg-strict-rc :sout-transcode-soverlay :sub-margin=22.5 :freetype-font=C:\WINDOWS\fonts\trebuc.TTF :freetype-fontsize=20 :freetype-opacity=200 :freetype-effect=2 vlc:quit