Re: Having trouble extracting ac3 from dvd

Mishehu Mashehu <[email protected]>
Newsgroups gmane.comp.video.transcode.user
Message-ID <[email protected]>
It's fairly explanatory.  You first off did not use the same syntax as 
was provided to you.  the -x and -y params are a pair.  First is video, 
second is audio codec.  So transcode -x null,ac3 -y null,ac3 is more 
likely your candidate there.  Plus read the man page for the params for 
-N.  You are specifically telling it what type of audio is in the audio.

I wish I could provide more specific examples myself, however I am 
having difficulty building transcode...  having a problem linking tcmodinfo.

-Mishehu

andrew wrote:
> On Wed, Feb 11, 2009 at 12:17:56PM +0100, Maik Holtkamp wrote:
>   
>> 0n 09/02/09@22:28 andrew told me:
>>
>>     
>>> Using transcode 1.1.0 with no great skill I am attempting to extract
>>> an ac3 stream directly from title 1, chapter 1 of a DVD. 
>>>       
>
>   
>>> andrew@skamandros~$ transcode -x null,ac3 -i /dev/dvd -T1,1,1 \
>>> -a 1 -A -y ac3 -o test.ac3
>>>       
>> The syntax of -y is vmod[,amod]. Did you try -y null,ac3?
>>     
>
> Thanks for that, and I apologise or misunderstanding the basics.
> However for ac3 Transcode 1.1.0 does not like that syntax:
>
> transcode -x dvd -i /dev/dvd -T 1,3,1 -a 0 -y null,ac3 \
> -E 48000 -m $HOME/Desktop/test.ac3
>
> with the error message:
>
> [import_dvd.so] waiting...
> [import_dvd.so] waiting...
> [export_ac3.so] warning: *** This module is non-optimal ***
> [export_ac3.so] warning: *** Use -N 0x2000 instead of -y ...,ac3
> (faster) ***
> [export_ac3.so] ffmpeg -y -f s16le -ac 2 -ar 48000 -i - -ab 128
> -acodec ac3 /home/andrew/Desktop/test.ac3 >/dev/null 2>&1
>
> Leaving a zero byte file. I experimented with the suggested syntax a
> little:
>
> transcode -x null,dvd -i /dev/dvd -T 1,3,1 -a 0 -N 0x2000 \
> -E 48000 -m $HOME/Desktop/test.ac3
>
> But while this imported well enough it did not export:
>
> [transcode] V: auto-probing     | /dev/dvd (OK)
> [transcode] V: import format    | MPEG 2 program stream in DVD PAL
> (module=null)
> [transcode] A: auto-probing     | /dev/dvd (OK)
> [transcode] A: import format    | AC3 in DVD PAL (module=dvd)
> [transcode] V: AV demux/sync    | (1) sync AV at initial MPEG sequence
> [transcode] V: import frame     | disabled
> [transcode] V: bits/pixel       | 0.000 (unknown)
> [transcode] V: decoding fps,frc | 25.000,3
> [transcode] V: video format     | YUV420 (4:2:0) aka I420
> [transcode] A: import format    | 0x2000  AC3          [48000,16,2]
> [transcode] A: export           | disabled
> [transcode] V: encoding fps,frc | 25.000,3
> [transcode] A: language         | en
> [transcode] A: bytes per frame  | 7680 (7680.000000)
> [transcode] A: adjustment       | 0@1000
> [transcode] V: IA32/AMD64 accel | sse3 sse2 sse mmx cmove asm 
> [transcode] V: video buffer     | 10 @ 0x0 [0x2]
> [transcode] A: audio buffer     | 10 @ 48000x2x16
> [import_dvd.so] v0.4.1 (2007-07-15) (video) DVD | (audio) MPEG/AC3/PCM
> [import_null.so] v0.2.0 (2002-01-19) (video) null | (audio) null
> [export_null.so] v0.1.2 (2001-08-17) (video) null | (audio) null
>
> so obviously I have this all upside down. I was tossing up whether to
> recompile and enable deprecated syntax but I am keen to learn the
> correct, newer syntax.
>
> Andrew
>
>
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