AC3 vs AAC-HE VBR 200-250 kbps

[Raboo]

AC3 ==> AAC-HE VBR 200-250 kbps

Is there really a big loss in this?

Cause I've ripped a few DVD movies to x264 + AAC.
Perhaps it's better to have it x264 + Original AC3 if it's a to big of a loss in the converting process.

The difference in size is for example with the Godfather Part II
AC3: 615
AAC: 384

i.e. 62% smaller in size (231 Mb).. I wonder how big of a quality drop there is, maybe it's hard to measure quality.. but let's say in a 1-10 scale or 1-100 scale?

perhaps it's not even possible to give a good answer to this question... but I had to ask cause of my intentions.. I'm trying to find the best way to "computerize" my DVD's without loosing to much quality and to much disk space, simpler said: finding a good balance between size & quality.

[tebasuna51]

If you use VBR don't force to HE, let the encoder select if need Spectral Band Replication (HE) or can encode full high frequencies (LC).

"Is there really a big loss in this?"

Only you can answer your question. You can also downmix from 5.1 to stereo Dolby ProLogic II and use 128 kb/s

[Ranguvar]

I remember seeing something either here or on HydrogenAudio about AAC @ 128kb/s VBR sounding identical to DVD 448kb/s AC3 source (both 5.1).

Encode a few, each with lower and lower bitrate, mix them up, and see if you can identify them.

[Raboo]

The audiostream according to MediaInfo is:
278 Kbps, 48 KHz, 6ch, AAC v4 (LC)

But the audioprofile in StaxRip is called "AAC HE VBR 5.1 200-250 kbps" and the command is (uses BeSweet):
"%application:BeSweet%" -core( -input "%input%" -output "%output%" ) -azid( -c normal ) -ota( -d %delay% -g max ) -bsn( -vbr 0.3 -6chnew )

So I guess the end result is LC..
But according to you guys professional opinion, should I stick with this or change to AC3?

[tebasuna51]

The audiostream according to MediaInfo is:
278 Kbps, 48 KHz, 6ch, AAC v4 (LC)

But the audioprofile in StaxRip is called "AAC HE VBR 5.1 200-250 kbps" and the command is (uses BeSweet):
"%application:BeSweet%" -core( -input "%input%" -output "%output%" ) -azid( -c normal ) -ota( -d %delay% -g max ) -bsn( -vbr 0.3 -6chnew )

So I guess the end result is LC..
But according to you guys professional opinion, should I stick with this or change to AC3?

The encoder command part is correct (without -aacprofile_hc or -aacprofile_lc) to let the automatic encoder select. Only the audioprofile name "AAC HE VBR 5.1..." must be corrected.

The decoder command part -azid( -c normal ) say apply Dynamic Range Compression (DRC). This option is only for low quality audio equipment (laptops, ...) and maybe is enough a -vbr 0.2 to encode this output.

My option is preserve the original audio AC3 without reencode, if I need less space -vbr 0.3 without DRC

[Raboo]

So this line is better if I want to use AAC and save some disk space
"%application:BeSweet%" -core( -input "%input%" -output "%output%" ) -ota( -d %delay% -g max ) -bsn( -vbr 0.2 -6chnew )

And if I intend to do a high quality rip I should use the existing AC3 from the DVD instead.

(btw I tried to find the switches for -bsn but didn't find any, whats the diffrence between -vbr 0.2 and -vbr 0.3)

[tebasuna51]

Is the quality parameter for NeroAacEnc from 0 to 1 (max).
Then 0.2 is less quality than 0.3, the range to use is between 0.2-0.4 with more quality the aac may be bigger than the ac3.