VBR used correctly

tyromaniac · Post by **tyromaniac** » Thu Jul 27, 2006 9:59 am

Ok, I was wondering how you successfully create an AMV with VBR audio without any loss in timing or quality. I checked the guide, but I don't think it really explained how to successfully attach it......at least that's what I think....I tried editing directly with the VBR audio in Premiere, but when I saved it, exited out, and came back in, the same timing problem occured where the vid went much faster than the audio. I tried editing with CBR audio and then attaching the VBR audio to the vid through Virtual Dub, but that also created the same problem. It's a shame because VBR is a great method of capturing the mood. Anyone know the right way to make VBR work correctly? Thanks

DeinReich · Post by **DeinReich** » Thu Jul 27, 2006 1:25 pm

Why use VBR audio in the first place? Just rip your CDs as .wav's instead for lossless quality.

(as always, unless I completly missed something in your post)

tyromaniac · Post by **tyromaniac** » Thu Jul 27, 2006 2:37 pm

Have you ever listened to a song that's CBR and then after using BeSweet GUI a VBR version? I think that the VBR version brings out the real feel of the music as it makes the silent parts of the music silent and the loud parts "louder and more powerful". Give it a try. It's deffinetly an improvement in my book.

downwithpants · Post by **downwithpants** » Thu Jul 27, 2006 4:08 pm

tyromaniac wrote:Have you ever listened to a song that's CBR and then after using BeSweet GUI a VBR version? I think that the VBR version brings out the real feel of the music as it makes the silent parts of the music silent and the loud parts "louder and more powerful". Give it a try. It's deffinetly an improvement in my book.

that's not what vbr does.
but use wav while you're editing in premiere. you can compress the wav to vbr mp3 in virtualdub after you've finished editing in premiere. just choose one of the vbr profiles under lame mp3. that way your end product will still have vbr audio, but when you edit, you'll be using uncompressed audio, which shouldn't cause timing problems.

tyromaniac · Post by **tyromaniac** » Thu Jul 27, 2006 4:46 pm

Thank you, but what exactly does VBR do than actually? I thought Variable Bit Rate was self explanitory as it would make silent beats quieter and louder beats louder because more bits are given to it.....???

downwithpants · Post by **downwithpants** » Fri Jul 28, 2006 12:44 am

having a higher bitrate doesn't mean it's louder, but that the waveform is more accurately represented, and more compression artifacts are avoided. as an example the difference between low bitrate and high bitrate audio, compare the sound coming from your phone to the sound coming from your stereo.

tyromaniac · Post by **tyromaniac** » Fri Jul 28, 2006 9:44 am

Oh O.O , thanks for explaining it to me

and thanks for the answer in the first place as well. I'm in your debt

Willen · Post by **Willen** » Sat Jul 29, 2006 5:47 am

tyromaniac wrote:Thank you, but what exactly does VBR do than actually? I thought Variable Bit Rate was self explanitory as it would make silent beats quieter and louder beats louder because more bits are given to it.....???

Having more bits for certain portions of the audio allows the encoder to record that portion with more precision. It also makes the encoding more efficient where parts that don't need many bits won't get them and are instead used to encode the parts that do need the extra bits. If very bit demanding portions of audio are encoded with insufficient bits you will either get compression artifacts (swooshing, frying, or other strange sounds) or the encoder may decide to drop certain sounds, creating a "hollow" or "flat" sound.

This matters more for lower bitrate CBR MP3 (and VBR to a lesser extent) since it doesn't utilize many of the more modern perceptual encoding methods that codecs like AAC do which allow more of the original sound to be faithfully recorded at lower bitrates (< 128kbps). Even at the "nominal" 128kbps bitrate, CBR MP3 may not perform as well as a more modern codec with certain types of music. Above 192kbps, the typical CBR MP3 encode will compare favorably with most other codecs, but will create a generally larger file because of the less efficient encoding.

Then why not use VBR MP3 all the time? I'll link to the EADFAG section on encoding MP3 for an AVI file for explanation: http://www.animemusicvideos.org/guides/ ... audio.html .
Suffice to say, you may get sync issues and seeking while playing back may be problematic

tyromaniac · Post by **tyromaniac** » Sat Jul 29, 2006 6:45 am

Willen wrote:Suffice to say, you may get sync issues and seeking while playing back may be problematic

Buy what if we got around the timing errors and play back problems? Would it not be a better method then?

Willen · Post by **Willen** » Sat Jul 29, 2006 7:24 am

tyromaniac wrote:
Willen wrote:Suffice to say, you may get sync issues and seeking while playing back may be problematic

Buy what if we got around the timing errors and play back problems? Would it not be a better method then?

Technically, yes. But I'd rather waste bits by encoding CBR MP3 at higher bitrates to get better audio quality and not compromise playback/sync. I have a broadband internet connection so another few MBs for the audio is nothing, but for people on dial-up accounts, more bits = longer downloads...