0006198: Auto-conversion / Soundcheck leveling isn't perfectly accurate - MantisBT

ID	Project	Category	View Status	Date Submitted	Last Update

0006198	MMW v4	Synchronization	public	2009-11-26 21:32	2011-05-23 22:47

Reporter	rusty	Assigned To
Priority	urgent	Severity	minor	Reproducibility	always
Status	closed	Resolution	fixed
Product Version	3.1.2
Target Version	4.0	Fixed in Version	4.0

Summary	0006198: Auto-conversion / Soundcheck leveling isn't perfectly accurate
Description	Auto-conversion isn't yielding expected results when syncing to the iPhone, yielding different results depending on whether tracks are converted or auto-converted! Tests carried out with: Track1: Track Gain: +13.2, Album Gain: +4.9 Track2: Track Gain: -10, Album Gain: -7.2 Test 1: a) Add both tracks to playlist 'VolumeTest' and auto-sync 'Volume Test' to iPhone, with auto-conversion enabled (no volume leveling, MP3 VBR V5, Encoding Quality 2, everything else set to defaults) b) Copy the auto-converted tracks from the iPhone back to the PC c) Compare tracks from a), b), and iPhone visually and by playing them in MediaMonkey --> In MM's default config (with Album Gain leveling enabled), listening to the track on the iPhone yielded different results than a) and b) (as expected, I suppose because the iPhone doesn't store Album Gain) --> After setting levelling to 'Track Gain', all three scenarios were equivalent (tested with track leveling enabled) d) re-analyze tracks from a) and b) (first set MM to re-analyze volume even if volume levels are calculated) --> Track level values stay the same Lesson learned: everything works as expected. When testing, make sure to either have volume leveling disabled or set to only track gain, since iPhone doesn't store Album gain! Test 2: e) Manually convert the tracks via Tools > Convert, using identical conversion settings as in b) f) Add tracks from e) to the playlist 'VolumeTest' and auto-sync 'Volume Test' to the iPhone g) Compare volumes of tracks synced to the iPhone -->With Soundcheck off: ---Track1: auto-converted track is louder than manually converted track ---Track2: both tracks are of equivalent loudness -->With Soundcheck on: ---Track1: auto-converted track is quieter than manually converted track ---Track2: auto-converted track is significantly louder than manually converted track
Additional Information	Reported at: http://www.mediamonkey.com/support/staff/index.php?_m=tickets&_a=viewticket&ticketid=7169#
Tags	No tags attached.
Attached Files	bug_6198-incorrect_album_volume_levelling.jpg (29,317 bytes) bug_6198-incorrect_album_volume_levelling.jpg (29,317 bytes)

Fixed in build	1374

jiri 2009-11-26 21:42 administrator ~0019785	Ludek, please review where is the problem exactly supposed to happen, we can discuss then a possible remedy.

Ludek 2009-12-01 13:45 developer ~0019809 Last edited: 2009-12-01 13:47	I tested with MP3 track Track1: [Track: +32.4 dB, Album: +32.4 dB] Track2: Same as Track1, but converted to a lower bitrate [Track: +32.4 dB, Album: +32.4 dB] Auto-conversion set so that only Track1 is auto-converted (note that '[ ] Level volume when synchronizing' left unchecked) Synched the tracks, but both tracks are of equivalent loudness (playback directly in iPhone with phones connected). If souncheck is ON then both tracks are still of equivalent loudness, but both plays louder.

Ludek 2009-12-01 14:54 developer ~0019810	Tested with various tracks and results are always the same. Auto-conversion doesn't change volume adjustment in my case. Rusty, could you ensure that both tracks (the original to be auto-converted and the manually converted track) have both same track volume gain before synchronizing?

rusty 2011-05-10 18:58 administrator ~0025031	It seems that the bug is more general than originally described--it's not specific to auto-conversion but to conversion in general. Here's how to easily reproduce: 1. Take 1 ape/flac track with +10db track vol. coefficient and one with -10db track vol. coefficient 2. Make sure that MM is configured with Tools > Options > Player > Level Playback/Sync volume to use Track volume coefficient (note that there may be another issue here: does the conversion dialog use this setting? it should, but I'm not sure that it does.) 3. Convert the tracks to MP3 (Medium: VBR preset) labeled as <filename>_convert.mp3 4. Convert the tracks to MP3 (Medium: VBR preset) with volume leveling enabled, labeled as <filename>_convert_level.mp3 5. Play back the tracks with volume leveling enabled --> Converted tracks play back at the same volume as the original flac tracks --> Converted_leveled tracks play back at higher lower volumes!!

jiri 2011-05-11 09:04 administrator ~0025073	I don't see any such problem. When you re-analyze the converted tracks' volume, do you see any problem? What value is shown in Track Volume for the converted tracks, and does the value change significantly in case you re-analyze these tracks? (You must enable this in Options, otherwise they won't be re-analyzed).

rusty 2011-05-11 18:46 administrator ~0025089	Further testing reveals that the problem occurs specifically in MM's default configuration, when 'Level Playback / Sync Volume' is set 'per Album'. When 'Level Track Volume' is enabled, MM uses the 'Track Volume Co-efficient' instead of the track's 'Album volume leveling co-efficient'. The net effect is as seen in the attached screen capture: tracks that are converted without levelling enabled play back at a different level than tracks that are converted with levelling enabled, _even_if_the_player_levels_playback_volume_. To fixs this, MM should use the volume leveling co-efficient that the user has configured. In terms of auto-conversion to the iPod, I've found that when the tracks above are synced to the device (with volume leveling disabled), the volumes played on the iPod are similar to above, which implies that MM syncs the Album Leveling co-efficient (if it exists), and otherwise syncs/uses the Track Leveling Co-efficient. Please confirm the logic that MM uses (i.e. which leveling coefficients are synced in which case). Note also: I suspect that if the user syncs with volume leveling enabled, that the bug would occur on sync.

Ludek 2011-05-12 14:02 developer ~0025117 Last edited: 2011-05-12 14:05	It really seems that MediaMonkey has never used album gain when auto-converting or converting audio tracks, but uses it when synchronizing (iPod's Soundcheck). Jiri, is this intended or a bug?

jiri 2011-05-12 14:45 administrator ~0025118	Fixed in build 1374. - Conversions were really always made according to Track Leveling, regardless of settings. It's fixed now.