Tools for extracting audio from avi

[Yukimura]

Before downloading every shareware program with "avi to xxx" I can find I was wondering if anyone had any suggestions about what programs are good for pulling the audio out of an avi. I'd prefer to go straight from the avi to an mp3 but I have a wav to mp3 converter if the best tools only do avi to wav.

[Kraco]

I once tried to drag'n'drop, almost by accident, an avi file to Goldwave, and it worked perfectly. Though it was a while ago, and before an XP reinstallation (or two), so I can't tell exactly what my codec situation was back then. Right now I don't have Goldwave installed (haven't yet reinstalled after my latest XP reinstall), so I can't run a retest. But it's worth a shot. Goldwave is a jolly good program in any case.

Well, you could also of course use a program like BeLight (a GUI for BeSweet). It would be a program exactly for the purpose you described, unlike Goldwave which is, after all, a sound editing program, not a ripping program.

[darkshadow]

Xilisoft Video Converter, not only is it one hell of a video converter, it should also be able to save just the audio of the file, you can even set the start time, and duration of recording, for if you want a specific part.
I've never used it for audio myself ( i use creative wavestudio or mediasource player for audio stuff, but that came with my audio card), but it gets the job done for video, should work fine with audio too.

[Deadfire]

I personally use Audacity (http://audacity.sourceforge.net/). set it to what ever my soundcard is outputting and press record. After save as MP3. It's not as feature-full as what DS is suggesting but it's simple.

[complich8]

for an avi? Use virtualdubmod. Load the avi, hit streams->stream list. Pick the stream. Click "Demux". Save it. You're done.

[Kraco]

When I tried for the first time to extract the audio from an avi container, I tried virtualdubmod, but unfortunately I didn't possess the wits to use it for the process... Well, it's not like I'm totally computer illiterate and I've used a variety of programs, some of them quite special and amazingly poorly documented. Based on that experience virtualdubmod certainly wasn't the most intuitive.

Although for my own defence I have to say terms like "demux" wouldn't have meant anything for me back then. All the better to hear how it's done with it, though, now.

[Yukimura]

Yeah...so 20 min after posting my question I remembered that I had Vdubmod and it could do this for me.
I'll walk through the steps I used in case anyone has the same question later.

Step 0: Be lucky and find the Tut I found and follow its superior instructions that
I'm just plagiarizing from memory

Step 1: Fire up Vdubmod

Step 2: Open the video you want the stream from (I'd recommend it be an avi since I don't know what effect the file being an mpg or something else might have).

Step 2A: If a yes or no box pops up saying something about the VBR being impropre, just hit no.

Step 3: Open the Stream List (Under the Streams Menu)

Step 4: Right click on the thing in the box (there should only be one) and select Full Processing Mode, Direct Stream Copy Is the default but it doesn't work sometimes (not sure why)

Step 5: Hit the Save WAV (after clicking the check box to put the job on queue if you want to do several at once).

NOTE: The WAV file will likely be larger than the original video file as it will be uncompressed.
Once you have it use your favorite WAV->MP3 converter. I used Sony's Sound Forge 9 since I like using professional software I'm completely not qualified to operate. You just open the wav and then save it as an mp3, you can choose the bitrate and even the id3 settings in the Save as dialog (you can also trim silence at the beginning or end as well, great program)

[complich8]

No, seriously, there's a "demux" button. Don't reprocess your stream, just yank it out.

Step 1: fire up vdubmod.
Step 2: load video file.
Step 3: streams -> stream list.
Step 4: select the audio stream you want to demux. In a single-audio avi, it's already selected.
Step 5: press "demux". Tell it where to save and what to save as.

No full processing, no saving as a wav and reconverting. It just rips your stream directly out.

If you really, REALLY want to rip the stream as a wav, you can, but ... why?

[Yukimura]

Ask whoever wrote the tut I found, I think it said something about there being issues sometimes because of something with the audio but it didn't sound like it was common enough to make direct stream bad in the general case.

Anyway I doubt it's a big deal, either shold work and I didn't really care either way. Also going from wav to mp3 with my SoundForge let me set id3 tags without having to open the file in a player, saving me a step.

[complich8]

ehh, I dunno, waiting for a file to reencode to set id3 info, versus just setting it ... seems sorta roundabout to me >_>

[Kraco]

Isn't taking an mp3 and uncompressing it to wav and then compressing back to mp3 a bit like taking a jpeg, uncompressing to plain bitmap and then back to jpeg?

[Board of Command]

Ask whoever wrote the tut I found, I think it said something about there being issues sometimes because of something with the audio but it didn't sound like it was common enough to make direct stream bad in the general case.
Whoever wrote the tutorial is a noob. If there's something wrong with the audio stream, demux it and work on it in another sound editor, not inside Virtualdub.


Isn't taking an mp3 and uncompressing it to wav and then compressing back to mp3 a bit like taking a jpeg, uncompressing to plain bitmap and then back to jpeg?
Not really. When you do that to JPEG you lose quality each time you save it. MP3 will remain the same no matter how many times you convert it back and forth (assuming you're not changing the bitrate).

[complich8]

That's not quite true. Even without changing the bitrate, you may change the codec being used, or the codec profile, or the minor version number, or the motion search quality, or the lowpass/highpass used, and since the data won't be the same as the input wav, you're going to have differences in the input signal analysis that become further differences in the output. Marginal errors accumulate across lossy reencodes.

The only possible justification for pulling out to wav is if it's already got a recompress in its future. If you're just trying to copy the audio stream, then regardless of any other arguments, you're wasting time and degrading signal by decompressing and recompressing it.