Hello Ari,
I have some difficulties understanding your problem completly.
Also sprach Ari Huttunen zu "30.11.2003 17:29" Anno Domini:
> I finally got this plugin installed (*), but I find the output is not
> quite ok. There's too much
> blockiness in the picture on the TV. My test case is (almost by
> accident) the closing
> credits of David Attenborough's Life of Mammals. The original quality is
> pretty excellent.
> In case you haven't seen it, there's a video playing on the background
> and credits rolling
> at the same time.
>
Ok, you have a unique scene, which you can use for testing. That
eleminates problems reproducing and comparing the effects.
> What I mean by 'blockiness' is that when there's a lot of movement on
> the screen
> and there is an area of a particular color, I can seen that the area has
> very easily
> seen 'blocks'.
>
Maybe you can specify this 'blockiness' in some more detail. Are there
blocks with distorsions (e.g. black&white patterns) or are these blocks
someway not sharp or blury.
> I encoded this the video with ffmpeg using 1500, 1800 and 2500 kbit/s video
> rate, MPEG-4, hq mode, two passes. I took the mplayer.sh from net.
>
1500kbit/s and higher are quiet high bitrates for MPEG4. FFMpeg supports
three different MPEG4 codecs: mpeg4, msmpeg4, msmpeg4v2. The last two
are not really MPEG4 but incomplete M$-MPEG4 codec. I hope you used the
first one.
Also the quality of the output at a given bitrate depends on the
resolution. So it would be helpful, if you could tell us which
resolution you used.
I use the (propritary & non-free) DivX libraries from divx.com for
encoding to MPEG4, as I made the experience, that they produce a better
quality at the same bitrate as ffmpeg. With a bitrate of about
1500kbit/s and a resolution of up to 1024x576 I never had any block
artefacts in the MPEG4 files.
You only stated that you took mplayer.sh "from the net". Maybe tell us
which one you use, where you find it, which version it is.
> Results:
> (Only blockiness mentioned, of course the smaller kbit/s had other
> effects as well.)
What are the "other effects", shortly?
> - Viewing any quality .AVI file with the mplayer-plugin had almost the same
> amount of blockiness on the TV. I also tried playing with deblocking
> and automatic
> postprocessing filters in mplayer command line: same effect.
Maybe you could post the commandline(s) you used to call mplayer, so we
can see exactly what's happening. The "debug" output from mplayer could
also be interesting as mplayer normally is quiet verbose in telling,
what it's doing. But do not post a complete log, as normally only the
startup outputs (and not the contiues information about currently
presented frame, AV-Sync, ...) are interesting.
> - For comparison I viewed the files with Xine on a computer monitor.
How about using mplayer (the exactly same binary as you use for DVB
output, if possible) to play the files on a computer monitor. I'm not
sure if the decoders, post-processors and their implementation in xine
and mplayer are the same.
> When I played any file with full postprocessing, there was no blockines.
> When I played the 1500/1800 kbit/s versions, with no postprocessing,
> they had
> blockiness in them, 2500 had almost no blockiness.
So you see artefacts in the "low bitrate" files as well on your desktop.
This indicates, that the quality of the encoded video is not perfect.
That's strange as I never had artifacts in something I encoded with such
_high_ bitrates. Maybe you should consider using the DivX libs as I
mentioned above.
>
> Comments, suggestions? My hypothesis is that the MPEG-1 transfer rate of
> my TT DVB-C 2.1
> is not sufficient for playback You see, I tried setting the 5000kbit/s
> rate to 10000kbit/s, and
> the video started playing, hmm.. unevenly at those closing credits.
As far as I know, a bitrate of 10000kbit/sec and above is not possible
as the DVB hardware is to limited to play it smooth.
Maybe try 9000kbit/sec!
> Maybe the video
> should be converted to MPEG-2 for playback?
Of course, that would be possible in theory. But you need a fast _and_
good MPEG2 endocer which can encode at least 25Frames/sec in a bitrate
below 10000kBit/sec. As far as I know, there exists only one MPEG2
encoder for linux at all: mpeg2enc, which is not as fast as required.
The last time I tested this, I used a 2.4GHz Pentium 4 with SMP _and_
hyperthreading and mpeg2enc made only 10-15fps. Ok, the output
resolution was 720x576 but you don't what much less as long as you want
a sharp picture.
>
> (*) There's more trapholes in the installation of this plugin than in
> Swiss cheese.. and I fell in quite many of them. And the installation
> instructions
> are lousy. But still, it's in. :)
>
Maybe you could describe your problems and how you fixed them, so that
others can benifit of. I did not have much problems installing it, as
fas as I remember, but I use mplayer (selfcompiled) for a long time know.
Ok, I know, this will not help you to much, but maybe this will help you
to explain the problem in more detail to us.
CU/all
--
Patrick Cernko | mailto:errror@errror.de | http://www.errror.de
Quote of the Week: "/vmlinuz does not exist.
Installing from scratch, eh?"
(Debian Kernel Installation)
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