Best audio codec?

[supercain]

Hi,

i would like to know if there is any audio codec out there that allows you encode an avi with the best sound quality and compression possible. So far i have been using direct stream copy for audio with virtualdub but i wonder if this is making my videos bigger than they should be. I heard AAC codec is the best one out there. What do you think? also, where can i get it from? i googled for it but i cant find the right now.

Thank you.

[hech54]

i would like to know if there is any audio codec out there that allows you encode an avi with the best sound quality and compression possible.

My answer would be "no".
The best quality would be PCM (LPCM) straight from a CD, second would probably be FLAC but FLAC alongside video is quite rare because of the lack of FLAC support in "all things video".
Also you said "avi"....showing your immense lack of knowledge on the subject. "AVI" can range from super high quality uncompressed video to badly compressed, downsized, crap quality(compared to H264) xvid.

[supercain]

Well, sorry for my "immense lack of knowledge" but the thing is that AVI is the name of the format im encoding to. So what else could i call it? Anyway, if you are unable to advice me on what audio codec should i use then i will have to wait for another user to reply. Hope they can give me a more helpful answer. Notice that i said QUALITY AND COMPRESSION so i dont even know why you even mentioned PCM at all.

[Hoser Rob]

avi is the name of the container, not the encoding format per se. You should look up the difference between codecs and containers.

You can't really expect a more helpful answer without saying what encoding you're using, assuming you know what that is. For avi's (when I actually do them) I use xvid and mp3 lame encoding. It's better supported. I wouldn't use aac for avi's.

I don't really see what the point is of worrying about the size of the audio track is anyway. It's going to be dwarfed by the size of the video part of the file anyway, and it'd be a much better use of time and effort to optimize that part of encoding first.

And, frankly, no one who knows what they're doing encodes to avi much anymore anyway. For high quality and better compression h.264 is the way to go. Plus it supports ac3 passthrough much better. Divx and xvid avi's just don't compare.

I think the point hech was trying to make maybe was that the best encoding is no encoding. I'm pretty fussy about music. I don't mind watching xvid encoded video as long as it's reasonably well done, but I have almost no mp3 encoded music. it's virtually all flac files, which is not encoded, just zipped.

[supercain]

What i mean is that the extension of my final encoded files is avi. There is no other name for that. The video codec i am using is x264. I make videos i put on the web to be downloaded so a small size is preferable by the users who download them. Of course i try to keep quality as good as possible, thats why its a hard job. For a 23min long movie i usually end up with videos of almost 700MB in size. The quality is very good but i just think it can be even smaller without compromising video quality if i do something with sound instead. Thats why i am asking about the audio codec.

[jagabo]

If you're using Direct Stream Copy for the audio nobody can tell you how much more compression you can expect unless you say what audio codec is in the source file and what bitrate it is.

What is "best" is subjective. Some people may prefer more compression with more artifacts. Some prefer less compression with fewer artifacts. Different codecs can produce different types of artifacts with different types of audio. Different implementations of a codec can produce different results, both encoding and decoding. And different people respond differently to those artifacts. So there's not clear cut answer to your question, "which is best?" It also depends on what you're listening with. $15 computer speakers will make it harder to tell the difference between a high quality track and a not so high quality track.

In general, aac sounds better than MP3 at the same bitrate, when using low bitrates. But it has far less support when it comes to players.

http://listening-tests.hydrogenaudio.org/igorc/aac-96-a/

And as Hoser Rob said, the audio is usually much smaller than the video in an AVI file so it's usually not worth worrying about. The main exception would be if your audio is uncompressed PCM or losslessy compressed (like Flac) where the audio size is very large. Keep in mind that recompressing audio with a lossy codec will always reduce it's quality so keeping the original track is usually best.

[El Heggunte]

What i mean is that the extension of my final encoded files is avi. There is no other name for that. The video codec i am using is x264. I make videos i put on the web to be downloaded so a small size is preferable by the users who download them. Of course i try to keep quality as good as possible, thats why its a hard job. For a 23min long movie i usually end up with videos of almost 700MB in size. The quality is very good but i just think it can be even smaller without compromising video quality if i do something with sound instead. Thats why i am asking about the audio codec.

Well, if file size + download times are the problem, then stay away from AVI, and switch to either MKV or MP4. These latter do have less muxing overhead than AVI. As for the audio codec, definitely you should choose AAC --- in most cases, 64kbps per channel is sufficient for a very-good quality output. And if you are sure that your target audience has zero audiophiles , you may use HE-AAC and choose even-lower bitrates.

[supercain]

Thank you. Then i will switch to AAC. The problem is, where can i download it from? Also, i use avi because thats the format virtualdub converts to. Im really not familiar with other video editing programs. Otherwise i would use mp4.

[Cauptain]

Thank you. Then i will switch to AAC. The problem is, where can i download it from? Also, i use avi because thats the format virtualdub converts to. Im really not familiar with other video editing programs. Otherwise i would use mp4.

You don't.

But Virtualdub have a very nice feature - External encoders.

Look here: http://forums.virtualdub.org/index.php?act=ST&f=3&t=18840&st=0

Using EE u can edit all in Virtualdub and encode to MP4.


Edit: You can use VIRTUALDUB FRAMESERVER and encode in RIPBOT or MEGUI or HIBRYD...



Claudio

[El Heggunte]

@ supercain:

the x264vfw config applet has an "Extra Options" textbox, where you can specify a different output filename
(e.g., -o C:\Path-To\MyMP4File.mp4). As for the AAC output, you'd better demux the audio stream out of the original source, decompress it to WAV, encode to AAC, and then combine this latter with the previous video-only MP4/MKV. I know, this is "too-much complication", but sometimes it's the only viable way to do some things --- remember, VirtualDub itself does not contain other multiplexers than the .AVI one, and so far there is no AAC encoder suitable for the ACM interface (required by VirtualDub).

OTOH, you have the right to prefer the "easier" ways suggested by Cauptain, of course.
Fortunately he didn't mention Avidemux, whose interface I dislike very-much

Hope this helps.

[budwzr]

Keep in mind play-ability. AVC-AAC in an .mp4 is the most universal combination.

[supercain]

Thanks for your advices. I decided to try with virtualdub and megui by using the frameserver option virtualdub has. However i just dont get it right. Virtualdub created a vdr file megui cant read. It has to be an Avisynth script. I followed this tutorial:

This is a basic guide on how to use .vdf (VirtualDub Frameserver) files as input for MeGUI.

1. Go to your Vdub, or VdubMod directory and run AuxSetup.exe. Choose "Install handler"
2. Setup Vdub or VDubMod as you always do except you will not need any compression. Just use video defaults
3. File > Start Frame Server
4. Press "start" leaving name as is
5. A save dialog will come up. Name can be anything.vdr, but I prefer "signpost.vdr" - make a habit of saving it in the same place like C:\My_VDR_Files or such
6. Verify all is working by opening another instance of VDub and dragging or opening "signpost.vdr". You should see video
7. Create a simple Avisynth script using - Avisource ("C:\My_VDR_Files\signpost.vdr").converttoyv12( ) - Save this script as signpost.avs and make sure if using notepad there is no .txt added on to it
8. Verify signpost.avs plays in VDub, WMP, or similar
9. Open this script as your source with MeGUI
10. Proceed with encoding as normal
11. After finishing, It was always recommended to run auxsetup again and select uninstall handler

but i dont understand what he means with "Create a simple Avisynth script". Where do i do that?

Thank you.

[Hoser Rob]

What i mean is that the extension of my final encoded files is avi. There is no other name for that. The video codec i am using is x264...

Not a good idea. The avi container doesn't support all x.264/h.264 features. Try mp4 instead.

[yoda313]

To supercain:

If these have surround sound I would reconsider the option of using aac.

The reason being aac surround sound files don't play well with settop surround receivers. I have an older amp (pre hdmi) and I can't play 5.1 aac files. I can play ac3 and dts just fine (non hd audio though).

If everything is just stereo than yes aac is just fine as anything will play it back. Just take note if they are surround sound or not.

----------

Please note this is for file playback in a home theater. If these are intended just for a desktop environment with computer speakers hooked up directly to the computer than that will play these back just fine. Its just that amps with 5.1 aac playback are rare or virtually unheard of so far as I know.

Again if they are stereo or mainly for desktop playback aac is fine. If they are surround sound consider sticking with ac3 at no lower bitrate than 384. 448 is max for dolby digital standard def audio and is the bitrate is use most - unless the source is 384 than stay with the source bitrate as changing the bitrate higher won't do you any good and will take up more space.

[supercain]

Please somebody help me with my last question. I want to try mp4 but i need to do all my edits on virtualdub first.

[jagabo]

i dont understand what he means with "Create a simple Avisynth script". Where do i do that?

You make an AviSynth script by creating a plain text file with the commands you need. You can use Notepad for this, just change the extension from .TXT to .AVS.

http://avisynth.org/mediawiki/Main_Page#New_to_AviSynth_-_start_here

[budwzr]

Jagabo, can you help me with a basic script for the fisheye removal thingy? I can't figure it out. I installed AviSynth, but I can't find the program file anywhere, it's weird.

[jagabo]

Jagabo, can you help me with a basic script for the fisheye removal thingy? I can't figure it out. I installed AviSynth, but I can't find the program file anywhere, it's weird.

AviSynth works in the background. There is no "program" to run. You create a plain text script then open that script with an editor or encoder that supports AviSynth scripts. I don't know what this "fisheye removal" filter is but you will be doing something like:

AviSource("filename.avi")
FishEyeRemoval()

Start NotePad. Type that text into the document. Save As -> filename.AVS. Then open that AVS file an editor/encoder like VirtualDub, and encode.

[budwzr]

Jagabo, can you help me with a basic script for the fisheye removal thingy? I can't figure it out. I installed AviSynth, but I can't find the program file anywhere, it's weird.

AviSynth works in the background. There is no "program" to run. You create a plain text script then open that script with an editor or encoder that supports AviSynth scripts.

OK, I'm starting to get it.

I was able to get the 60p interpolation filter to work in MeGUI from the very detailed step-by-step directions at http://www.spirton.com/convert-videos-to-60fps/ that somebody here kindly posted (PDR I think). But that's as far as I got with it. Just the one tool, although it's extremely a good tool.

If you could just cook me up a simple basic script maybe I can figure out how to use it. Right now I'm stuck. The author's site is too technical, not for noobs.

[jagabo]

I added more to my previous reply.

Do you have a sample of your fish eye video? What filter will you be using to remove it?

[Cauptain]

but i dont understand what he means with "Create a simple Avisynth script". Where do i do that?

Thank you.

Are you have install AVISYNTH??

IF yes, make it.

- Edit your file in Virtualdub.
- Select uncompress codec to VIDEO and AUDIO
- Run Frameserve feature and save this using: "frameserve.AVI, no VDR.
- In desktop, click mouse button 2, New, Avisynth Script
- Open new Avisynth document, and type:

AVISource("frameserve.avi")
ConverttoYV12()

- Save this.
- Go to MEGUI and load created avs file.
- Encode


Try and reply.


Claudio

[budwzr]

I added more to my previous reply.

Do you have a sample of your fish eye video? What filter will you be using to remove it?

This is the filter: http://avisynth.org/vcmohan/DeBarrel/DeBarrel.html

And the sample: Fisheye.mp4

[supercain]

Hmm, i followed the instructions to the letter but i get this error when i try to open the avs file on megui:

Could not locate video stream. (C:\Users\cain\Desktop\test.avs, line 1)


These are the contents of my avs file:

Avisource ("C:\Users\cain\Desktop\test.avi").converttoyv1 2( )

Why doesnt it work?

Thank you.

[Cauptain]

Could not locate video stream. (C:\Users\cain\Desktop\test.avs, line 1)

Avisource ("test.avi").converttoyv12( )

Remember, the AVS and VIDEO on Desktop.



Claudio

[jagabo]

Is your source file really an AVI file? The error message hints that it's not.

If the AVS file is in the same folder as the video file you don't need to give the full pathname. For example, with the AVI and AVS files on your desktop all you need is:

AviSource("test.avi")
ConvertToYV12() # if necessary

[Cauptain]

Is your source file really an AVI file?

jagabo, look the path in AVS...


Claudio

[supercain]

I swear that both the avi file and the avs file are on my desktop but still i get the error saying it cant locate the file. Cauptain said something about installing avisynth. I did install a handler with the virtualdub aux application. Maybe that was not enough?

[jagabo]

Are you using VirtualDub to frame serve to the AVS script? Is VirtualDub's frame server still running? You should see VirtualDub's little frame server dialog. You have to leave it running until you are down with the script.



Also, if you didn't specify .AVI as the frame server file the default is .VDR, not .AVI.

[supercain]

Yes, i select start frameserver on virtualdub, save as avi and then i leave it running. Then i open the avs file on megui but i get the error i posted. Also, im sure its frame serving right because if i open the avs file with WMP or other player it plays. Its just megui that doesnt work.

[jagabo]

You did run auxsetup.exe from the VirtualDub folder, right? That has to be run once after installing VirtualDub to set up the registry.

I recommend you start with something simple. Put a real AVI file on your desktop. Try to open that with AviSource(). That will tell you if AviSynth is working correctly.