96 replies to this topic

[sjlouis]

Hi,

 

When the cursor moved on one of my movies in MoviePlayer, the box jammed. As I could read the .ts file on the PC, I deleted all the complementaries files on the box. Then the cursor can move on the file without any problem and I can read it. Then it generated a .meta and a.cuts files which I think are used to know where I stop the reading. I can copy the .eit file which contains informations about the movie. It misses .sc and .ap files. I think I can create them with the software tool, but what is their utility?

 

As it's not the first time I have this problem, I'm surprised that one of theses files can jam the box. Somebody have an explanation?

 

Thank you .

[MiLo]

Next time, send me the .sc file, then I can analyze it.

You can reconstruct it from within E2, there's a plugin to make the call (the actual routine is part of E2 itself) for you from within the movielist.

[sjlouis]

Yes I know I can reconstruct them but I ask myself what is the utility of theses files .

 

I've kept the original sc file but I can't upload it, I have the message "You aren't permitted to upload this kind of file".

[betacentauri]

Files are there for faster seeking/skipping and I also think for fast forward/rewind.

 

Rename file (add .txt) or better zip the files.

[Erik Slagter]

MPEG transport streams don't have an index like avi/mkv/mov/mp4 files have. Seeking is very cumbersome without index. .Sc and .ap files are on-the-fly created out-of-band index files.

[sjlouis]

Thank you for the explanations.

 

I've tried to upload a zip file but it doesn't want. it accepts .txt files but as the .sc file is big, I've zipped it and changed it from .7z to .txt file.

 

This MiLo, you can examine it but change the extension from .txt to .7z .

 

Thank you.

Attached Files

•  20110825 2030 - FRANCE 3 - Meurs un autre jour.ts.txt   764.94KB   7 downloads

[sjlouis]

I've reconstructed the .sc and .ap files and the box crashes again .

 

I think I'm going to delete the movie and wait for another broadcasting but I'm surprised that it's necessary to reboot the box, which is not convenient if the box is recording.

 

Thank you .

[Erik Slagter]

You might try converting the movie using mkvmerge, then you won't need the .ap and .sc files.

[sjlouis]

I also can see it without these files .

[Erik Slagter]

Interesting little fact: an mpeg transport stream is quite inefficient for purposes of storage, it's designed to be used for TV transmission, not storage. So if it's on disk, it lacks proper seeking and also it's bulky. If you take the contents of the transport stream and wrap them into another container (like mkv or mp4), which is quite a "light" process (no re-encoding necessary) you will get proper seeking and as a bonus 10-20% less disk usage and as extra bonus the possibility to add own subtitles (srt).

[sjlouis]

Ok I didn't know it (I'm not technician in this domain). Then what is the interest of a .ts file if it's so bulky?

[Erik Slagter]

Exactly what I said, it's perfect for over-the-air transmission because (a.o.) allows the stream to be "picked" up from any position and directly start showing, as there is no index and the relevant metadata is repeated over and over again. Also the small packet size (188 bytes) helps recovering quicker from transmission errors (which, normally, you won't have on a harddisk).

 

So a transport steam is for unreliable streaming, real time, whilst mkv and mp4 are for disk storage. A little side note, technically mp4 can be streamed using rtp and a suitable streamer/hinter, but it's not that common. It needs to be "hinted" and gets properties comparable to transport streams, making it also less storage-efficient.

[sjlouis]

Ok but OpenPli records movies on the disk in .ts files. Why doesn't it use another format?

[Erik Slagter]

Little correction: Enigma records, not OpenPLi

 

The provider puts a number of services into one transport stream (a strong point of the transport stream, it's very well suited for that), which is called multiplexing (muxing, for short). The complete transport stream goes as-is towards the transponder (okay, with some modulation of course). So one transponder = one frequency = one transport stream. Your enigma2 receiver (or any other set-top-box) tunes the tuner to a certain frequency (= transponder) and the tuner starts receiving the complete transport stream from the tuner, with all of the services on that transponder in it. Enigma2 "programs" the demultiplexer (a piece of hardware in the SoC) to sieve out only the requested service (well, the streams belonging to the service: video, audio, text, etc). Enigma2 then reads this data from the demuxer and stores it on disk, nothing more. So what you have on disk, is what the provider broadcasts, 1:1, without the "other" services. This can be done with little effort by enigma2 (= low power CPU). Storing the stream in another format, would require to do a conversion on the fly, which in theory is possible, but rather complex. Conversion from transport stream to mkv/mp4 is easier to do when the stream is complete. You can use mkvmerge for that.

[sjlouis]

Sorry but I don't know exactly what is Enigma, what is OpenPli. There is also Linux .

 

With my precedent hard disk recorder, a DVD player with hard disk in fact, the record format was DVD format but don't ask me what that was exactly, I only know there was several files which do a continuation.

[Erik Slagter]

That was probably an analog device. That means you have to do all sorts of conversions anyway.

[sjlouis]

Thank you Erik for all these explanations. I understand better why there is this "exotic" format for the files.

 

If I want to do a conversion with my PC, with FormatFactory or VSDC Free Video Converter , it's take a long time, 75~90 minutes for a 90 minutes movie. Ok, my PC is old but sufficient for what I use it. Thus, I avoid to do conversions.

 

Can you explain quickly how works the box? There is the kernel, Linux perhaps, Enigma (what did it does?) and at the "top" OpenPli (which gives us all the functionalities we use dayly, that's right?)?

 

Thank you .

[Rob van der Does]

Don't overcomplicate things:
Your STB has Linux as (embedded) OS (Operating System) and Enigma2 as application.
An image (like PLi) = Linux + Enigma2 + a skin + some plugins

You can compare the situation of your STB with a PC running Windows and one single program (like Word) that runs full screen.

[sjlouis]

Ok, thank you. What does exactly Enigma? The main menu to access the timer, the plugins, the parameters... are in Enigma or is it a plugin? MoviePlayer is in standard Enigma or is it a plugin? When OpenPli does all night improvements, it's only on the plugins?

 

And who works on Enigma?

 

Thank you .

[Rob van der Does]

All interactions you have as user with your box are done via E2. It's the application that takes care of all the STB's functionality, such as watching TV, recording and playback. Also the GUI (Graphical User Interface) is an E2-functionality.

Apart from keeping Linux up-to-date an image building team like PLi is mainly busy with the development of E2.
Some basic functionality is there via a plugin (like AutoTimer); some plugins are installed by default, because the builder thinks them to be required,