Serato Video General Discussion

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 Serato Video General Discussion
iTunes tag compatibility/possible bug
Talk about Serato Video and Video-SL.

iTunes tag compatibility/possible bug

DJ Czar 4:58 AM - 2 January, 2008
First of all, congratulations and thank you for VIDEO-SL! It leaves VirtualDJ/Vinyl in the dust. It's been a long wait, but well worth it, this product shines with the same quality and ingenuity as we've all come to expect from Serato, the best! And now for some of my findings and suggestions :)

For all of my testing, I am using QuickTime encoded MPEG-4 video and AAC audio inside the MP4 container. I'm running on 2.4GHz MacBook Pro, 2Gb of ram. All media is on the internal 250Gb 5400rpm hard drive.

If you have videos in your iTunes library, and "Read iTunes Library" is enabled in SL, importing these videos to the SL library treats them as audio files and NOT video! Upon removing these videos from the iTunes library or disabling "Read iTunes Library" in SL, the videos are recognized as video, with the correct red filmstrip icon (before they would have the iTunes icon).

I have a lot of MP4 videos with proper metadata. While SL does correctly parse the artist, title, album, genre, track#, comment, etc, fields, it fails to parse the BPM field. Dropping these videos into iTunes, does display the BPM values. I read a reply from Nathan H in a different thread saying that it's a lot more complicated to store metadata in video than audio, and while that may be true for things like cuepoints, overviews and loops, the BPM values should work, if iTunes supports them. While I am able to retrieve the cuepoints, overviews, etc upon restarting SL, if the files are moved to a different system, the metadata does disappear. I noticed that SL stores the metadata for videos in external files, inside the .ScratchLIVE hidden folder. While this does work for the time being, I really hope storing the metadata inside the actual video files can be implemented, especially for robust containers such as MP4. Currently, some record pools serve MP3s with cuepoints inserted and overviews built. If the metadata were stored externally, this would not be possible...

It would also be nice to be able to use "Read iTunes Library" for video as well. Since Serato has always embraced iTunes as a great organizational tool for music, it would be only logical to use it for videos as well, as it already supports it.

Lastly, more of an observation, upon first downloading and installing 1.8.0+Video-SL, the performance was horrible, with constant lockups. I knew something was wrong, since my 2.4 MacBook Pro is within the specs. I noticed I was still running 2.something firmware and upon upgrading to 3.03, the performance improved dramatically. While I'm still experiencing occasional crashes when stacking up on filters, the response time is fantastic. Scratches, backspins, etc are very fluid. I wonder, how the firmware had something to do with it, since the 57 is primarily just used as a controller, and all the processing is done in software...

Thanks!
DJ Czar 4:59 AM - 2 January, 2008
And how could I forget, HAPPY NEW YEAR!
DJ Czar 11:29 PM - 2 January, 2008
bump?
Serato
Nathan H 11:59 PM - 2 January, 2008
Hi,
Quote:
If you have videos in your iTunes library, and "Read iTunes Library" is enabled in SL, importing these videos to the SL library treats them as audio files and NOT video!

We could indeed have a separate iTunes Video icon which we hadn't really considered. This would at least allow us to show the differentiation

MP4 tag reading has not been implemented in favour of our external system for the time being. It would be a nice feature but given the wide range of containers that are supported an external method would be necessary regardless...

And I have no idea why upgrading the firmware would make it significantly faster ;-)

N
DJ Czar 3:44 AM - 3 January, 2008
Thanks for the reply, Nathan! I Believe you misunderstood me, as the icon is the least of my worries. What I meant was, importing a video file into SL that already exists in the iTunes library behaves as an AUDIO file. That is, loading it onto the decks does not show video, and only the audio portion plays back. Upon deleting the reference to this video file from the iTunes Library, the video portion starts working. Furthermore, SL does not properly read the iTunes video library. For example, clicking on iTunes playlists containing video does not show anything, they're simply blank.

I understand about the MP4 tag reading. However, if it has not been implemented, why do most of the tracks work regardless? Just not the bpm tag... ;)


Thanks again!
Serato
Nathan H 4:29 AM - 3 January, 2008
Ah - sorry! That is definitely a more worrying problem. I think that iTunes interaction may have been overlooked when video support was added to ScratchLIVE so we didn't realise that they were implicitly being treated as audio regardless. I've logged this and hopefully we can get this sorted in a future version of ScratchLIVE.

It seems from playing around a little with setting tags in iTunes that we are accurately reading the information from the iTunes library including BPM but that iTunes itself doesn't store any information in the file as tags (duplicating the file and adding it to iTunes loses tag information).

That said we do read some MPEG-4 container atoms as part of our AAC support (sorry for the misinformation in my previous post, I just talked to our AAC guy who set me straight ;-). This is why you are finding artist/album information is coming up.

For BPM we use a Serato specific atom type as we could only find one standard BPM related atom, which is the one iTunes supports. This is an integer only atom however so we couldn't store the precision necessary.

How are you setting your tag information? If we can find out what are regarded as 'standard' tags then we can add support for them later...

N
DJ Czar 6:34 AM - 3 January, 2008
I set my tag information in iTunes. In my case, the files ARE modified when tags are changed and written inside the file. Editing the tags in iTunes and then copying the file to another system retains all of the tags. Also, dropping this file into SL properly parses all of the tags except the BPM, provided of course SL is not set to 'Read iTunes Library.' Perhaps you are expriencing problems due to non QuickTime-encoded MP4 files, as we all know how quirky Apple can sometimes be ;) Tags can also be edited within QuickTime, but not all iTunes-specific ones are supported.

Quote:
That said we do read some MPEG-4 container atoms as part of our AAC support (sorry for the misinformation in my previous post, I just talked to our AAC guy who set me straight ;-). This is why you are finding artist/album information is coming up.

I'm a bit confused, as I thought BPM information was stored in external .xml files for each video? As far as I understand, atoms are pieces of data within the mp4 stream, so does this mean the data IS in fact written to the file?

Quote:
For BPM we use a Serato specific atom type as we could only find one standard BPM related atom, which is the one iTunes supports. This is an integer only atom however so we couldn't store the precision necessary.

Perhaps we could duplicate the BPM value rounded off to the nearest integer in the iTunes compatible BPM atom? And vice versa, read the iTunes compatible BPM atom and store it within the Serato one, until modified for extra precision? Integer only BPM values should still be quite good for most tasks.

Thanks!
Serato
Nathan H 9:46 PM - 3 January, 2008
Quote:
Perhaps you are expriencing problems due to non QuickTime-encoded MP4 files, as we all know how quirky Apple can sometimes be ;) Tags can also be edited within QuickTime, but not all iTunes-specific ones are supported.

Probably ;-)

Quote:
I'm a bit confused, as I thought BPM information was stored in external .xml files for each video? As far as I understand, atoms are pieces of data within the mp4 stream, so does this mean the data IS in fact written to the file?

Sorry for the confusion. The .xml metadata storage is used for ALL video files. However our AAC audio support also uses Quicktime and proper atom based metadata.

This seems to mean that if you have a proper MP4 container (i.e. uses atoms) then it will still be parsed/read for atom metadata (because it is an MPEG-4 container same as all AAC files) BUT ScratchLIVE will use the .xml files to write metadata (because it is a movie).

Quote:
Perhaps we could duplicate the BPM value rounded off to the nearest integer in the iTunes compatible BPM atom? And vice versa, read the iTunes compatible BPM atom and store it within the Serato one, until modified for extra precision? Integer only BPM values should still be quite good for most tasks.

I think that is a pretty good idea and have forwarded it to the aforementioned AAC guy who agrees :-)
DJ Czar 12:27 AM - 4 January, 2008
Great news Nathan! It's developer/user interaction like this that has made Serato what it is today and above all the competition! I'm glad I was able to help and looking forward to the new version!
Serato
Nathan H 3:34 AM - 10 January, 2008
Hi,
Can I ask what OS & version of iTunes you are running? I've started working on the 'iTunes treating videos as audio/not showing in playlists bug' and am having trouble replicating it.

Thanks,

N
DJ Czar 11:52 AM - 10 January, 2008
I'm running OS X 10.5 Leopard and iTunes 7.4.2. These aren't the latest versions of either, so perhaps a newer version of iTunes may behave differently, although I doubt it.

It's great that you started working on this, Nathan, again I am very impressed with the kind of personal responses I've been getting here :) But mind if I ask, you mentioned you were a "graphics guy," and video formats aren't reality your background. Are you then relaying our conversations to the developers? I never did understand if the moderators on this forum are just moderators or actual developers within the company. Would be nice to know :)

On a different note, I've been meaning to ask where video-sl stores video+audio link information. That is, when you assign an audio file to a video file, the link stays even upon restarting SL. While we know that the metadata/overviews are stored within the .ScratchLIVE directory, I could not find any files that relate to the A/V linking... And it doesn't seem like the mp3 gets modified either, as the file modified date stays the same. Although I haven't further looked into that.

Thanks again and good to hear from you!
Serato
Nathan H 9:32 PM - 10 January, 2008
Quote:
I'm running OS X 10.5 Leopard and iTunes 7.4.2. These aren't the latest versions of either, so perhaps a newer version of iTunes may behave differently, although I doubt it.

I'm testing on Tiger so Leopard is a likely candidate as a source of the problem. I'll investigate and get back to you...

Quote:
It's great that you started working on this, Nathan, again I am very impressed with the kind of personal responses I've been getting here :) But mind if I ask, you mentioned you were a "graphics guy," and video formats aren't reality your background. Are you then relaying our conversations to the developers? I never did understand if the moderators on this forum are just moderators or actual developers within the company. Would be nice to know :)

I am the Video-SL developer (don't tell anyone) and by 'graphics' I meant the maths/programming side so it is all the effects/other features which are my area ;-).
Many of the developers post on the forum although we usually restrict it to specific stuff and every 'Moderator' is an employee of either Rane or Serato.

Quote:
On a different note, I've been meaning to ask where video-sl stores video+audio link information. That is, when you assign an audio file to a video file, the link stays even upon restarting SL. While we know that the metadata/overviews are stored within the .ScratchLIVE directory, I could not find any files that relate to the A/V linking... And it doesn't seem like the mp3 gets modified either, as the file modified date stays the same. Although I haven't further looked into that.

We store that in the ScratchLIVE database, so if you move the .mp3 it will break the link until you use 'relocate lost files'. I'm not sure how much more I should say ;-)