recording quality

[sasha]

While watching program wih DVBViewer 3.2.6 the picture quality is pretty good (with CyberlinkDVD 6.0 mpeg codec, ATI9250 graphic card and using only TVOUT)

 

Unfortunally recorded video doesn't seem to have the same quality.

It looks more like low bitrate encoded divx. An there are some lines on the edges (for example near the eyes of the actors) noticable during faster motion scenes.

 

Could anybody recomend me the recording setup. Which codec to use, overlay or vmr7/vmr9 and do I need to setup something in the Filters menu. Also, I've heard somewere that the GE version is better for recording. Is this true?

 

Thanks for your answers,

Sasha

[Guest Lars_MQ]

Unfortunally recorded video doesn't seem to have the same quality.

Nonsense. It's the mpeg2 stream you saw while recording as a file.

 

How do you playback? with the DVBViewer?

[sasha]

Nope I transfer it to another computer over my home LAN. Then open it with BSPlayer, Cyberlink PowerDVD6, RadLight4.0. Every single one produce a picture with at some scenes smudgy color or with litle blocks(if fast motion) and with sharp edges on smaller objects.

Maybe the video on LCD monitor looks worse then when reprodued on TV (using tvout)

 

Lars I do not have a reason to talk nonsense. Just wonna setup my hometheatre corectly. Sorry if something in my previous post have iritated you but if you look closely, you will se that it was in a form of question. I wasn't claiming that there is something wrong with DVBViewer!

 

Anyway thanks for trying to help.

[Guest Lars_MQ]

How does it look if you play back the files with the DVBViewer?

 

And yes the sentence I quoted was nonsense, so I stated the obvious There is no recompression, no recoding nothing. Heck if we would do such things with the cpu use of the DVBViewer, we could make a fortune

 

So you see is what you receive. But if the playback computer has bad oder bad setup mpeg2 videodecoders the playback can look the way you describe it.

 

I think the normal way would be to test it on the DVBViewer computer (where it should play the same quality like live watching) before you go and say the DVBViewer does a bad job recording.

 

And one more thing: It's just a ugly rumour that you go blind if you use the search function of the forum

[sasha]

I think the normal way would be to test it on the DVBViewer computer (where it should play the same quality like live watching) before you go and say the DVBViewer does a bad job recording.

 

Ok, now you are insulting me.

Maybe you have problems reading my post?

There is no line in my post that would lead to the conclusion that I think DVBViewer have done a bad job. So you are clearly puting words in my mouth.

I am pretty pleased with DVBViewer. In fact by mine opinion it is shurely on of the best dvbplayer available (if not the best). If I didn't like it I would just erase it from mine computer and never look back, but as you see it is not the case.

 

I was asking a question about codecs, filters and other setups!

And where have you read that I've stated DVBViewer is using recompression ?

Again maybe you should read posts carefuly because you go and insult people by puting word in their mouth.

 

Afcore I do know how to use search but I do not know how to read German. And meny post regarding my question are written in German language. The other ones are not so helpfull, hence my post.

 

I know that this post is now way off the subject but before you go and blame it on me please read your posts (and mine if you will).

 

Thanks,

Sasa

[Griga]

Could anybody recomend me the recording setup. Which codec to use, overlay or vmr7/vmr9

 

And where have you read that I've stated DVBViewer is using recompression ?

 

If you ask which codec to use for recording, it implies recompression.

 

Lars and other supportes have to deal with so many complaints and bug reports based on totally wrong assumptions about digital TV... sometimes one really gets fed up with it.

 

Let's have a look at the whole data path:

 

- A bad *broadcasted* quality is caused by DVB-T bandwidth limitations or broadcasters saving money by saving bitrate.

 

- There may be lost data packets due to reception problems, bad signal quality, wrong antenna type etc.

 

- The driver may lose data, because it is faulty or subject to ressource conflicts.

 

Lost data packets result in jerky playback, audio dropouts and different kinds of *randomly* occuring artefacts.

 

Now the stream reaches DVBViewer. If you want to check the input quality, go to View -> Filters -> DVBSource. The property page shows the video bitrate and resolution, the audio format and bitrate and the number of discontinuities (= missing packets) since you switched over to the channel.

 

When recording, DVBViewer does the following:

 

- In case of pure audio recording, it unpacks the MPEG audio elementary stream from the transportstream container and writes it to disk.

 

- In case of MPG it unpacks the video and audio elementary streams from the transportstream container, re-packs it as MPEG2 program stream and writes it to disk.

 

The program stream created by DVBViewer has been checked very carefully for syntax errors and such - there are none. DVBViewer is known for its MPEG2 compliance in this respect.

 

- In case of TS DVBViewer writes a subset of the original transportstream to disk - the data packets that belong to the channel that shall be recorded.

 

As you can see, no codecs involved. No change of the received content. When recording, DVBViewer only deals with the packet layer, nothing else.

 

Now, when writing the data to disk, again parts of it may get lost in rare cases, due to heavy processor or disk usage. For cases like this, DVBViewer provides additional buffering capacities -> see options.

 

That's all - everything that happens afterwards is a different matter: *playback* quality.

[sasha]

Hi Griga, first of all thank you for your detailed answer.

Many things are much clearer now. Afcourse I do not understand much about dvb-mpeg, stream recording or the way DVBViewer is programmed. That is why my questions are mainly posted i Newbies section.

 

Lars and other supportes have to deal with so many complaints and bug reports based on totally wrong assumptions about digital TV... sometimes one really gets fed up with it.

I am not complaining neither I will ever do something like that in a forum or any other public place. If I had some complaints about quality of purchased product I would probably email or post a private messege to it's programmers.

If you ask which codec to use for recording, it implies recompression.

If I haven't posted my question in Newbies section I would agree with you. But in here I think nobody should be resoning by implications, modus ponens or any other kind of deduction.

 

That's all - everything that happens afterwards is a different matter: *playback* quality.

Ok, I must admit that I was wrong when nameing Topic for my question, because it could be interpreted in a wrong way. Everything else, I think is in place.

Maybe some moderator should change the word "record" with the word "playback" in the topic name. I really dont mind.

 

Again, thanks for answering my question, and I promise I will be more carefull when nameing my topics in the future.

 

Sasa