#musicbrainz-devel

ogg? maybe

*checks*

yes

m4a, not mp4

from lowest to highest: mp3, mp4, aac, flac?

but what if I want to analyze my music videos?

not yet.

:)

it doesn't prefer one over the other, this is just to see if it should try and open the file

the alternative that I might switch to is try and run it, and see if it chokes

I need to get a version of libav without mp3 support to test this though

how much of the "phrasing" stuff is in the toolkit? I don't have the link to the info handy, but echonest has like measure and etc info?

derwin: this is very low-level

oh great ;)

the idea is you can look at the implementation, see what numbers you have, and go and make phrases yourself

(or wait for someone to do so)

alastairp: my "prefer" comment is on the server side.

ruaok: oh. I guess

meaning, if I have one lossy format, under which conditions do I want to replace it with something that is better than what I have?

e.g. is mp3 320k better than a low quality aac?

thats where it gets tricky. :(

lots of comparing apples to oranges.

and we're trying to compare them by diameter, when we really want to compare them by sugar content.

heh.

"on average, an apple has x sugar per cm³, and an orange has y sugar per cm³, so if we assume both are spherical, we can approximatly compare if we know the diameter"

so I guess it's just a matter of picking good values for x and y :)

(in other words, maybe just assign a bitrate multiplier for each codec, and pick which one has the higher bitrate * multiplier score?)

alastairp: you have a pull request :P

kepstin-laptop: interesting idea.

... where do I actually get a copy of the essentia stuff? google isn't being very helpful

lets see what alastairp comes up with for bit rates

https://github.com/MTG/essentia ?

oh, now I just feel silly for not looking there :)

yeah, I just bashed the readme file out. it needs some care

also, there are linux 64 bit static binaries somewhere

um. ruaok got link?

one sec

found it

also, the readme says it looks in $PATH for a binary. that's a lie, it just looks in .

no

however you do need new libav

(sorry)

ubuntu 14.04 has it

feh. time to dist upgrade this vm

it just uses the example binary right? doesn't need the python bindings?

yep

./waf configure --with-examples

should be all you need

ok, good. to install numpy, I need to rebuild my gcc with fortran support enabled, that could take a while :)

ouch

those better be some pretty yaks

huh, weird. it builds essentia as a static library only? then statically links it into the example tools?

but odd, but I guess it makes it easier to handle since I only need the 1 tool and not extra libs.

don't ask.

woo, filename in output!

:)

hmm. how do you do basename(file) in both posix and windows?

in c++

those were always part of baseline libraries for whatever project I worked on.

yeah

don't think there's one here

are there ways to determine if you're on windows?

using a macro?

#ifdef windoes

and then #if #else #endif

wow, pytaglib is GPL-3

that's a bit limiting on the licenses of projects that use it...

DIR_CONCAT = "/"

or

DIR_CONCAT = "\\"

and then use DIR_CONCAT to join parts.

not the best, but gets 99% of the people you care about

kepstin-laptop: oh, I didn't see that

essentia is agpl-3 :)

alastairp: file_name for the key name ?

AGPLv3 \o/

ruaok: I'm not joining parts - I'm splitting to get the last. but same process. I know

ruaok: in what subkey? metadata->audio_properties

?

I guess under metadata | tags | file_name ?

I think of it more as tag data, not audio.

ok

CODEC long name `MP3 (MPEG audio layer 3)`

winning

alastairp:

I'm planning on making sure those fields exist.

think we need to check for more than that?

alright, looks like abzsubmit is running for me now.

really? that's scary cool. :)

I guess I should try it on some files now and see if it breaks

:)

15 tracks!

ruaok: yeah, those look like the important ones

though kepstin-laptop, pleae stop it for a little while.

yeah, I submitted dark side of the moon

I haven't run it over any tracks yet

ah, ok.

do you realise how long it took me to choose a symbolic first album?

so, hang on with any serious running until we get the latest from alastairp.

.01 seconds?

nah, a good minute or so :)

so, I have filename and codec extracted, but need to wire it into the monster that is essentia to get it into the output

I'll put that one on when its submitted for eal.

+r

alastairp: that gives me a chance to finish the sanity checking.

still debating bitrate. I need to see what I can get from libav - if anyone feels like reading libav docs to help me :)

you're using libav as a library, not the command-line tools?

yes

urg. we're consuming data frame-by-frame though. not sure then how to do it

I mean, I have a commit in ffmpeg, but that was in a completely unrelated area ;)

http://ffmpeg.org/doxygen/trunk/structAVCodecCo... bit_rate

alastairp: my understanding is that's more for encoding, I dunno if it's populated when decoding?

decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.

so, flac set it to 0, mp3 set it to 192000

ok, then :)

let me try ogg and vbr

BIT RATE `112000`

BIT RATE `162284`

well. ruaok, if you're happy with that I'll try and get it into the output

looks like ffprobe gives useful output for opus, vorbis, and vbr mp3 in my testing

I think short name for codec? not long_name

looks good to me, including short name

so, the "annoying" thing is that flac gives 0. I guess that's OK though because of the encoder

yep.

wav -> BIT RATE `1411200`

what?

we wont look at that field if lossless = t

so

alastairp: that's the exactly correct bitrate for a wav with 16bit 44.1kHz audio...

lossless = (decoder == "flac" or decoder == "pcm_s16le") ?

kepstin-laptop: right :)

don't forget alac, ape, musepack, etc.

yeah

so, this depends also on what the persons ffmpeg has

hmm. does ffmpeg do tak decoding yet? I think they added it at some point

if you could do all the hard work and get me a list of lossless ffmeg decoders, that'd be awesome :)

alastairp: is file_name going to be a list or a single string

(everything else in that section is a list)

the list of short names of lossless ffmpeg audio decoders is: alac, ape, flac, pcm_*, shorten, tak, truehd, tta, wavpack (sometimes), wmalossless,

I don't think I missed any

ruaok: that's because taglib did it