[MPlayer-users] Encoding from DVB-T mpeg-ts recordings

Nico Sabbi nsabbi at tiscali.it
Sun Oct 3 14:46:46 CEST 2004


Samson Lee wrote:

> Nico Sabbi wrote:
>
>> Samson Lee wrote:
>>
>>> I want to convert my DVB-T mpeg-ts recordings to mpeg4/divx video 
>>> with direct copy audio (mp3). The command I tried is this:
>>>
>>> mencoder -ovc lavc -lavcopts vcodec=mpeg4 -oac copy -o output.avi 
>>> input.ts
>>>
>> DVB contains almost always mp2, sometimes ac3
>
>
> This is the mencoder output showing it selected [mp3] audio codec:
>
> ========================================================================== 
>
> Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
> MP3lib: init layer2&3 finished, tables done
> AUDIO: 48000 Hz, 2 ch, 16 bit (0x10), ratio: 32000->192000 (256.0 kbit)
> Selected audio codec: [mp3] afm:mp3lib (mp3lib MPEG layer-2, layer-3)
> ========================================================================== 
>
>
> Does that mean mp3 or mp2?


neither mp3lib (the other decoder that is faster but sometimes sounds 
metallic when decoding mp2)
not libmad report what layer they are decoding.
The only clue is the tag they use: 0x50 identifies mp2, 0x55 is mp3


>
>>> When I play the output.avi file in Windows Media Player (yeh i know 
>>> .. it's for someone else!) or Zoomplayer, the video works but there 
>>> is no audio. The file plays properly with both video and audio in 
>>> mplayer of course. I also tried playing it with the DivX Player, 
>>> which tells me, "This file contains unknown audio data .. Tag 80".
>>
>>
>> 80==0x50 is mp2. If you want to keep audio unmodified you should 
>> install the latest ffdshow
>> (available here: 
>> http://ffdshow.sourceforge.net/tikiwiki/tiki-view_articles.php) and 
>> configure
>> its audio decoder to handle mp2 (I suggest libmad as codec)
>
>
> Cool, I have ffdshow already .. just gotta figure out how to configure 
> libmad ..


ffdshow->audio configuration -> codecs -> MP2 by and select libmad in 
the list

>
> Also, is it possible to do a perfect mp2 to mp3 transcode? If so, how? 
> If not, what's the closest?
>
> Thanks heaps ..
>

if by perfect you mean lossless then it's not possible (unless you use a 
lossless codec, that takes a lot of space),
otherwise converting to lame with a decent bitrate will sound quite good.
I always use lame at 128 kb/s cbr, and only in scenes with explotions I  
hear distortions.

        Nico




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