mp2 audio to dolby ac3

[badri]

hi
i would like to know whether it is possible to encode mp2 audio (in divx movies) to dvd compliant ac3 audio stream.



Thanks;)

[erwan]

corretc me if i wrong but audio tracks in divx movies are mostly MP3 not MP2.
they sometimes are AC3 too.

mp3 has 2 channels.
ac3 has 5 channels.
so i dont think there is much point in reencoding it to ac3.

do you have a special reason for that?
like re encoding the whole thing to a dvd for example?

nethertheless, there are software that will do this :
Digigram.Multichanel.Dolby.Encoder.Decoder or sonic softencode.

erwan

[mlar]

There is a perfectly valid reason for encoding your audio as AC-3. Even though it is very unlikely that you will ever run into a DVD player that cannot play MPEG-2 audio, this is what the DVD Video specification says:

Dolby AC-3 used mandatory for 525/60 (NTSC) players and MPEG-2 is mandatory for 625/50 (PAL) players, but optional on discs themselves.

and

A 525/60 disc must contain either Dolby AC-3 or LPCM.

A 625/50 disc must contain either MPEG-2 audio or LPCM. Due to bandwidth efficiency, most titles will use the more compact Dolby AC-3 or MPEG-2 audio.

Since I'm in NTSC land, I *always* encode my audio as AC-3 to ensure it is playable in every (NTSC) player.

Personally I use Soft Encode to encode my AC-3 tracks. Just because your audio is AC-3 encoded it doesnt necessarily mean it has to have 5.1 channels, 2 channel AC-3 audio is not unheard of.

I think it is obvious that the original poster is talking about DVD's, since he is posting in the DVD Encoding forum - and - mentioned "dvd compliant ac3 audio stream".

[erwan]

oki this was a pretty clear explanation you gave ! :)

i was unfamiliar with ntsc (i live in a pal country) and did not realise one could have only 2 channels in an ac3 audio track.

at least, we both came to quote the same software so badri got his answer !

well once again, this forum taught me something,
thx !

[badri]

I tried to find sonic foundry softencode but i could get only a demo version and sonic foundry has stopped selling this version.
pls tell me where i can get a full version.

thx:p

[dvd_master]

Please no one flame me for this one:
Kazaa.

Or email me. warrior_no_yami@yahoo.com

[orbit-r]

attention guys,this is dangerous....:eek: :eek: :eek:


orbit-r

[badri]

thanks i found it on kazaa

[DSPguru]

please read the forum rules (http://forum.doom9.org/forum-rules.htm) :6) No warez, cracks or serials! Links to content of a questionable nature, asking or offering in any way or form is not tolerated.although AC3Enc's quality isn't as good as SFSE, you might wanna try encoding your mp2 to ac3 in one-step using BeSweet v1.4RC7 (http://DSPguru.doom9.org).
commandline should look like :
BeSweet.exe -core( -input infile.mp2 -output outfile.ac3 -logfile BeSweet.txt ) -ac3enc( -b 384 ) -shibatch( --rate 48000 ) -ota( -g max )

[Arky]

You might find the following thread relevant:

http://forum.doom9.org/showthread.php?s=&threadid=30773&highlight=Cooledit+arky


Arky ;o)

[dvd_master]

I think SoftEncode is the best program out there for AC3 encoding, but make sure you set the smapling rate to the kz (I'll get the right one when I find it)

CoolEdit is an awesome program for editing audio, changing sampling rate, adding effects, and converting IMO. It's really easy to use and works the best for this type of thing. I made the music for my first-play DVD logo's using this.

CoolEdit and Soft Encode are great ! Though Soft Encode makes the volume kinda low.... but I probably can fix that I just haven't tried.

[dvd_maniac]

can somebody tell me how to encode a ac3 2 channel audio file from a 5.1 ac3 file in soft encode? Or any other program for that matter

[dvd_master]

Well it should by itself encode it to 5.1 unless there is settings I didn't know about, so once you start it up, open a new project and load your audio file. If it doesn't load, convert it to WAV and then it will load. SoftEncode is incredibly simple and easy to work, so it should be too much trouble.

[asalpopat]

Hi
I tried besweet and used the settings mentioned above but the quality of the ac3 file was very bad and it was hardly audible even at the higest volume settings.
I also tried softencode and the quality was much much better than besweet but still not as good as the original ac3 track.


Thanks

[DSPguru]

that's correct!
cons for BeSweet :
- SFSE is much better that ac3enc.dll.
pro for BeSweet :
- BeSweet's mp2 decoder is HQ (floating-point HIP)
- sample-rate-convertor is the best you can get (SSRC).
- unlike SFSE, you can transcode a 5.1 stream into 2.0 ac3 (stereo/dpl/dpl2) .

[ronnylov]

Perhaps decode it to 2-channel wav in Besweet and encode it to ac3 in SFSE is the best way to do it then?

[DSPguru]

yea.. :)