Hello,
sometimes I capture THE SIMPSONS, and then I need a good audio-codec for verylow bitrates (perhaps 40 or 50kbits). I tested Ogg (64kbits), but it sounds very bad! MP3pro (VBR, about 45kbits) sound a lot better, but there is no directshow-filter for movies, I think. Is there a AAC+-DirectshowFilter? Or should I use AAC? Or is there another codec which work for movies? Ths sound file has 44100khz, but I can resample it to 22050khz, I don't hear a big difference (that means that the difference is not so important for movies and not that I have bad ears...).

Thanx
Big_Berny

Use t3h Speex!!!

If MP3Pro at 45kbps sounded a lot better than 64 kbps Vorbis, you did something wrong.

What are you looking for? I think most codecs won't preserve dolby pro-logic information.
If you don't care about stereo either you can encode in mono.

Did you encode to Ogg Vorbis using 64kbps CBR?

This is strange, because ogg is probably on of the best codec for this bitrate ?
What options sid you use ? I would suggest
oggenc -q 0 (or even oggenc -q -1)

But, be sure to use a >= 1.0 libVorbis release. Previous release aren't tuned very good for low bitrate !
Maybe you used a (very very) old version ?


I really don't understand that... mp3pro should be way behind ogg at this bitrate !

I think you'll find HE AAC will beat Ogg at this bitrate, but anyway, back to the man's questions.

1. Codec I'd use would the HE AAC codec inside Nero. It uses similar (but better implemented) technology to mp3Pro and there is a directshow filter...
2. Called CoreAAC (found here under the AAC section). You'll also need the 3ivX spliter (found here). Finally, you'll need to mux the AAC and video in a Matroska cntainer.

I am using aac without 3ivX. Only CoreAAC and matroska

If you're using MPEG-4 for video and AAC for audio, consider using MP4 for the container format. That's what it's made for

The MP4 conttainer is not recomended as it has serious issues. It has no way to hold subtitles and doesn't sync well on playback.

I agree. If hardware support for MPEG4 video + AAC audio ever happens (on, EG, DVD players), it will surely be for the MP4 container, and not for Matroska.

That's an issue of the 3ivX splitter.

I never experienced sync issues with QuickTime, Envivio, Philips Platform4...

and what are the tools to use to mux heacc with mp4 video

It already comes inside the MP4 container if you use Nero to encode it.

Then, you can add a video stream to the container using MP4ui or MPEG4ip MP4creator.

MP4ui is more user-friendly. I recommend it.

I used HeadAC3he and set the quality to VBR 0.00!
Here are 3 examples:
AAC+ 38kbits (Nero: Lowest - Tape)
OggVorbis about 59kbits (q 0.00)
MP3pro about 58kbits (Nero: EncQuali:Highest, VarBitr: Lowest

Lossless (Monkey)
Lossless

The ogg-file sounds very bad, isn't it? Does AAC+ work with Matroska? I think, that AAC+ is the best, because it uses a veryverylow bitrate with the same quality. For the video I use the Real/Helix-Codec, so I have to use the Matroska-container.

Thanx
Big_Berny

Oh yeah! Something is screwy here... I listened to the mp3-pro sample with just an mp3 player (so effectively it was an mp3 at half the bit rate, right?) and it sounded better than the Ogg.

edit: just for yucks, can you put up a flac file of the sample you used?

More edit: xmms showed the mp3 pro (played as mp3) to be sampled at 22 khz compared to
the ogg file sampled at 44 khz.

I know! The ogg sounds ok over 112kbits! I tried the newest OggDropXP too, but the same problem.

It sounds so bad - it's hard to believe it's really ogg -q0. Could it be transcoded? Can you upload the original sample, please (lossless compressed)?

It shouldn't be transcoded.
Here the original file:

Lossless (Monkey)
Lossless

Yes, download the latest mkvmerge from here:
http://www.bunkus.org/videotools/mkvtoolnix/

When you use AAC+ you have to use the special: "--aac-is-sbr" -switch with mkvmerge.
Also make sure you have the latest CoreAAC 1.0b7 installed which supports AAC HE/+ (download from rarewares).

The Ogg sounds really bad. This must be a HeadAC3he error. I would try Besweet instead.

Actually it is not.
But after listening to the original APE file, I thing that the sound test as a serious phase problem.
I things the channels may have 180-degree phase problem.
It would explain why ogg sounds so lame.

I am at work, I can't edit the wav and invert one of the sound channel phase (right or left, this has no importance). Anybody can do that ?

Sorry, but I don't know how to do that...

You hit the nail on the head. Here is the ogg file after inverting the right channel:

http://www.xiph.org/~carsten/simpsons2.ogg

Much better!

Carsten Haese
Ogg Traffic Editor, Xiph.org Foundation

How did you sample the sound ? Using a cable from you VCR to your computer ?

In this case, I think that the out-of-phase problem is due to the cable. (or maybe cheap VCR or cheap sound card). On way you may try is to unplug the left or right RCA plug, unscrew it, and invert the + and the - wires.

I may be out of subject, if the phase is not the problem, but it seems to me very clearly that your original APE file, had serious out-of-phase problem. I listenned it to with headphone.

A MP3pro played in a normal MP3-Player is NOT a MP3 with half bitrate! It has only the half frequences (normally 22'050khz)!
But anyway...

My TV-Card (Hauppauge with BT848) is connected via cable directly from the tv-plug-socket. The audio goes over the TV-Card to the Soundcard (Soundblaster 4.1 digital) an then I capture with Virtualdub.

Since the problem is provably due to channel inversion, you should check your connections. Either the cable from the TV to the TV-Card or the connection between TV-Card to soundcard has its wires on one channel crossed.

Good luck,

Carsten.

P.S.: Just to clarify, I did mean "provably" as in "can be proven," not "probably."

Check model of your card. If it has a stereo receiver, could it be some fancy procesing at the tv station to make it sound more "stereo" like? How about signal quality? Maybe the MTS decoding process (assuming NTSC) screws phase when the reception is not optimal?

In any case, should an encoder be able to compensate for these out of phase problems?

Well, other encoders are doing well here, so I reckon Vorbis is partially to blame, and not only Big Bernie's hardware.