ffmpeg vs. SoX for resampling Options

[jkauff]

I just found out that TAudioConverter, although it has SoX support, uses ffmpeg for bitdepth changes, resampling, and dither. I don't use those functions very much, but I'm curious if anyone has done a quality comparison between the two.

[db1989]

I’m no authority, but there’s always good old http://src.infinitewave.ca/

SoX 14.4.0:

FFmpeg 0.10.4:

Let’s, er, let’s hope FFmpeg has evolved by leaps and bounds since that version was released only about half a year ago.

[jkauff]

I’m no authority, but there’s always good old http://src.infinitewave.ca/

SoX 14.4.0:

FFmpeg 0.10.4:

Let’s, er, let’s hope FFmpeg has evolved by leaps and bounds since that version was released only about half a year ago.

Well, FFmpeg is now up to version 1.1.1, and Peter has incorporated it into fb2k, so I think we can assume the program's improved. Whether it's improved for this functionality is another question. Of course, there's a 14.4.1 version of SoX just out, too.

[bandpass]

Well, FFmpeg is now up to version 1.1.1, and Peter has incorporated it into fb2k, so I think we can assume the program's improved. Whether it's improved for this functionality is another question. Of course, there's a 14.4.1 version of SoX just out, too.

Oddly, SoX itself is a little behind the curve: 14.4.1 contains the same (slow, by comparison) version of the resampler that's been there for some years, so until SoX 14.5 is released (couple of months I think), the ffmpeg route will give better performance (about 2-3 x faster).

Don't know if it made it into 1.1.1 or not, but I saw that ffmpeg has also recently ported (most of) SoX's dither code.

[phofman]

... (slow, by comparison) ...
the ffmpeg route will give better performance (about 2-3 x faster).

I am not sure speed is the correct measure of quality.

[bandpass]

I am not sure speed is the correct measure of quality.

The conversion quality is the same (graphs for the newer version are @ infinitewave under Audacity 2.0.3); the performance is higher cos it's faster than before.

And this build wasn't compiled with --enable-libsoxr option

Zeranoe takes ffmpeg build requests at: http://ffmpeg.zeranoe.com/forum/viewforum.php?f=10

[phofman]

The conversion quality is the same (graphs for the newer version are @ infinitewave under Audacity 2.0.3); the performance is higher cos it's faster than before.

Do I understand correctly Audacity 2.0.3 is using new ffmpeg through which it uses libsoxr for the resampling? I would like to add a new resampling option to linux alsa rate plugin. Until recently I thought sox implementation was the best from the quality/speed POW. Using a library compatible with libsamplerate API would make the addition simple as libsamplerate is already supported by the plugin.

Thanks for the info.

[2012]

The conversion quality is the same (graphs for the newer version are @ infinitewave under Audacity 2.0.3); the performance is higher cos it's faster than before.

I would like to add a new resampling option to linux alsa rate plugin.

I already did this. Replicating the libsamplerate code in alsa-plugins with some gluing just works (with some quality modes).

Here is a patch that implements soxr_lsr_{HQ,MQ,LQ} :
http://ompldr.org/vaGc3Ng/Initial-soxr-lsr-support.patch

I shared more info here:
http://www.hydrogenaudio.org/forums/index....st&p=817595