Draft: HOWTO convert audio file formats

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Re: Draft: HOWTO convert audio file formats

Post by bgravato » Wed Feb 09, 2011 3:08 pm

giampaolo44 wrote:hi steve,

a) thank you for this tutorial! it was needed :)

b) could you put an example for converting files to specific format and compressions?
i would like to be able to run a batch that converts all my lossless m4a into lower definition m4a, so that i can fit my music library in my ipod touch, but could not figure out the appropriate options in SoX....

cheers
Which distribution do you use? Is pacpl available for your distro? If so give it a try. pacpl syntax is simpler than sox and it also supports m4a.
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Re: Draft: HOWTO convert audio file formats

Post by giampaolo44 » Thu Feb 10, 2011 1:34 pm

:)
i'm on fedora 14. i searched for pacpl in the standard repositories but it does not seem to be there.

even when trying to load an m4a file into audacity i can't. :(
it says that it recognized that the m4a should use ffmpeg based importers, but that none of them does recognize it. digging further it shows a "wma-proprietary" issue. is it possible that ripping my cd in m4a from iTunes it was saved with DRM blockage?
(i have Audacity 1.3.12-beta (Unicode), which should handle m4a, and ffmpeg installed)

thanks!

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Re: Draft: HOWTO convert audio file formats

Post by bgravato » Thu Feb 10, 2011 3:06 pm

Apparently there's no fedora package for pacpl.

Were the m4a encoded as lossless aac?

There's a nice tool called mediainfo which gives a lot of information about media files. You can get it for fedora here: http://mediainfo.sourceforge.net/pt-PT/Download/Fedora

Meanwhile I'll try to have a look at sox syntax and provide some examples.
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Re: Draft: HOWTO convert audio file formats

Post by steve » Thu Feb 10, 2011 8:29 pm

giampaolo44 wrote:hope this thread is not built to be a discussion between the two of you,
Not at all - this is a public forum.
giampaolo44 wrote:a) thank you for this tutorial! it was needed :)
b) also the scripting part is greatly appreciated, in particular applied to this kind of tools. i have been searching manuals and forums all around, but found that examples are very rare.
That's exactly why we started the topic. I think that we eventually need to transfer the main content from the forum to the Audacity wiki as a more permanent reource.
giampaolo44 wrote:sox FAIL formats: no handler for file extension `m4a'
Looks like SoX has been built without m4a support. This happens quite a lot on Linux as many of the major Linux distributions wish to comply with some form of GPL licensing which means they need to be careful about conflicting with licensing terms when dealing with closed proprietary formats.

I'm intrigued how and why you are running iTunes on Linux. There are plenty of excellent CD rippers for Linux that don't use proprietary formats.
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Re: Draft: HOWTO convert audio file formats

Post by giampaolo44 » Fri Feb 11, 2011 10:49 am

bgravato wrote:Apparently there's no fedora package for pacpl.
Were the m4a encoded as lossless aac?
yes
bgravato wrote: There's a nice tool called mediainfo which gives a lot of information about media files. You can get it for fedora here: http://mediainfo.sourceforge.net/pt-PT/Download/Fedora
they have a host of versions, but the dependency libzen0 is compiled only through fedora 13
bgravato wrote: Meanwhile I'll try to have a look at sox syntax and provide some examples.
thank you!
steve wrote: Looks like SoX has been built without m4a support. This happens quite a lot on Linux as many of the major Linux distributions wish to comply with some form of GPL licensing which means they need to be careful about conflicting with licensing terms when dealing with closed proprietary formats.
I kind of figured it out by now. :cry: Unfortunately that makes life such a mess for newbies or dumbies like me.
I've been on Linux for two years now, and still can't figure out how to run my scanner, or my ipod touch without windows. i can't even see all my disks at all times :lol:
steve wrote: I'm intrigued how and why you are running iTunes on Linux. There are plenty of excellent CD rippers for Linux that don't use proprietary formats.
I assume if I had a decent level of understanding of all this, probably I would have hacked my Touch on linux by now, or would have been able to run some Banshee or Rhythmbox or else with it, but couldn't (i did try everything but the hack :mrgreen: ). In fact my Ipod has not been updated in... two years :oops:
i know i'm just not cut for computers, but the number of hours spent with so little results make me a depressed lover of linux :?

two people helping out at the same time... i never got that much attention, it's a great surprise. probably my questions are sometimes so dumb... :D

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Re: Draft: HOWTO convert audio file formats

Post by bgravato » Fri Feb 11, 2011 11:56 am

giampaolo44 wrote:
bgravato wrote:Apparently there's no fedora package for pacpl.
Were the m4a encoded as lossless aac?
yes
On pacpl FAQ they say:
When converting a .m4a file, I get an error saying: "Unable to find correct AAC sound track in the MP4 file."

The file you are trying to convert is a lossless .m4a file. The format is not yet supported by FAAC/FAAD.
I'm not sure if this also applies to sox, ffmpeg, etc...

Can you play the files in linux with any player? You could also have a look at mplayer/mencoder...

I'm sorry I didn't have time to look further into this and I'll be out of town for the next days. Steve can you please have a look at this? Thanks.

I shall be back monday.
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Re: Draft: HOWTO convert audio file formats

Post by giampaolo44 » Fri Feb 11, 2011 3:54 pm

bgravato wrote: On pacpl FAQ they say:
When converting a .m4a file, I get an error saying: "Unable to find correct AAC sound track in the MP4 file."
The file you are trying to convert is a lossless .m4a file. The format is not yet supported by FAAC/FAAD.
I'm not sure if this also applies to sox, ffmpeg, etc...
Can you play the files in linux with any player? You could also have a look at mplayer/mencoder...
yes, i can, it plays normally in most players: i have now installed rhythmbox & banshee, and am sure i tried at least one or two more. audacity and SoX seem to have problems.
bgravato wrote: I'm sorry I didn't have time to look further into this and I'll be out of town for the next days. Steve can you please have a look at this? Thanks.
I shall be back monday.
don't be, i'll be out probably too.
actually thanks for the help so far.

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Re: Draft: HOWTO convert audio file formats

Post by giampaolo44 » Fri Feb 11, 2011 4:06 pm

btw:
in this help page of audacity it says it should be able to handle them, although no specific mention of the lossless...
http://audacityteam.org/help/faq?s=file ... ry&lang=en

i found also strange that it refers you to super: it runs only on windows but states clearly that it does so because it is a GUI for linux libraries, and that in linux there are several GUIs that already do the job. which ones?

anyway: have both a nice weekend

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Re: Draft: HOWTO convert audio file formats

Post by steve » Fri Feb 11, 2011 5:53 pm

As you have access to a Windows computer, I'd go for the easy option and use iTunes to either, convert the m4a files to a different format (such as WAV), or re-rip the CDs to WAV. Both Microsoft and Apple purposefully make it as difficult as possible to convert their proprietary formats to open standards so as to tie users into their products. The Linux community has risen to the challenge and now has at least partial support for most of these formats, but support is not yet complete, and in some countries is not legal. In my opinion the best solution is to not use these formats. From my own tests and the most recent published double blind tests that I can find, FLAC (open standard) is as good as any other lossless compression, and Ogg Vorbis is (at least) as good as any lossy compressed audio format.
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Re: Draft: HOWTO convert audio file formats

Post by giampaolo44 » Mon Feb 14, 2011 2:44 pm

steve wrote:As you have access to a Windows computer, I'd go for the easy option and use iTunes to either, convert the m4a files to a different format (such as WAV), or re-rip the CDs to WAV.
the 250-300cds make for a few days of work... so i better plan properly:
- did you suggest WAV because it's a lossless format from which it is easier to convert to other formats?
- before your suggestion i was actually planning to have at some point lossless music in Flac and then loss AAC, say at 192k, to be able to transfer the music into the ipod, but i didn't know i'd have to go through quite a bit of work to convert.... would that imply ripping the cds twice?
steve wrote: Both Microsoft and Apple purposefully make it as difficult as possible to convert their proprietary formats to open standards so as to tie users into their products. The Linux community has risen to the challenge and now has at least partial support for most of these formats, but support is not yet complete, and in some countries is not legal. In my opinion the best solution is to not use these formats. From my own tests and the most recent published double blind tests that I can find, FLAC (open standard) is as good as any other lossless compression, and Ogg Vorbis is (at least) as good as any lossy compressed audio format.
i know, but that ipod touch got me stuck to have stuff in proprietary formats :roll:

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