Missing 2nd Track Audio Using MTS Files


#1

Hi All,
This will be my first post since beginning to using shotcut since around August 2016, I cannot even express how grateful I am to Dan, and all who help to make shotcut the great program that it is! Typically I can find any answer I need to any question I have in the forums, but so far the answer to this one question I have recently, seems to be evading me!
I recently received MTS. files from one of my new videographers (I am a manager at an event planning company) I have never received MTS files from any videographer that worked for us before. The issue is, when I place the MTS. files into shotcut and look for the 2nd audio track that would normally be there when I receive any other video files, it is not there, only 2 ch 48KHz pcm_Bluray Track 1. (The way my videographers usually shoot for us that allows me to have 2 track audio is, using one mic directly connected to there video camera which would be track 1, and another track which comes from receiving audio wirelessly and directly from the DJs board to the video camera, so we can get the cleanest audio of the music and the Emcee on the Microphone.) This new guy shot the same way as all the other guys, (I know this for sure, because i was there as the coordinator to check on everything throughout the event) but I do not get a 2nd audio track. I was just wondering if its possible that shotcut doesn’t find the 2nd audio track when using MTS files, or if im missing something? Anyone that could help me out that may have any ideas, it would be much appreciated!! Thanks in advance!

Im sure some of this next info will be useful, even necessary for some people to help me solve my problem.
I am using shotcut version 18.10
I am using a dell inspirion 15 with a intel core i7 3632qm and 8 gb ddr3 ram 1TB HDD only 50% used


#2

I’m not exactly sure how mts files work, but with an multi-audio track on an MP4

Shotcut only uses audio track, and track 1 by default, unless you set it to a different track, If you want to edit all audio tracks, you can either detatch the track 1 audio, then set properties for track 2 audio, or just have two video tracks, same video, just blind/hide one track.

Properties tab, Audio tab
shotcut_2018-11-22_15-37-22

shotcut_2018-11-22_15-37-34


#3

Exactly! I should have shown screen shots in my first post, so ill put them here,

Untitled

So just as your pictures show, in my first screenshot, using our usual MXF files or even our MP4 files we get multiple tracks we can choose from, but than in the 2nd screen shot (in my 2nd post, because as a new user I am only allowed to post 1 picture per post) as you can see, were only getting 1 track to pick from. That is where my issue lies, and I just was wondering if this is a shotcut problem or something I am possibly doing wrong? Or maybe for these types of files I need to do something before putting it into shotcut so, it can read or find the 2nd track?


#4

Untitled1


#5

This is more than likely a bug in FFmpeg. Shotcut v18.11.18 is using v4.0.2 of FFmpeg. You can verify it using ffprobe that comes with Shotcut: path/Shotcut/ffprobe filename


#6

Thank you for the information, and I’m sorry its taken me so long to respond! Upon trying what you suggested, (downloading Shotcut version 18.11.18 and checking that FFmpeg v4.0.2 is indeed being used in the Shotcut folder), it still did not produce a 2nd audio track for the MTS file. Just to make sure that these files did indeed have a 2nd track, I asked my videographer to tell me which program he uses to view these. He had me download SONY CATALYST BROWSE. Here is what the audio tracks look like inside Catalyst Browse with the MTS files…

To be completely fair, after I took your advice about upgrading Shotcut versions and trying the files again as well as trying the MTS files on Sony Catalyst Browse, I did try putting these MTS files into other programs as well, such as, VideoLAN (VLC Media Player), Aiseesoft Ultimate video converter and also Aiseesoft MTS video Converter. None of these programs were able to see the MTS files 2nd audio track either. I use Shotcut for my editing though, so while I don’t really care that those programs cant find track 2 I was hoping it be possible to find a solution as to why Shotcut cant. If any of this new information and screenshot helps to find a solution I would be very grateful!!


#7

I would second this. If you can give us the output of ffprobe, we would be able to tell you if it is possible to support in Shotcut.


#8

I think this is what your looking for…?


#9

The output from ffprobe indicates that ffmpeg only sees a single stereo audio stream. The Catalyst Browse screenshot shows that there are two channels and one is mapped to left and the other is mapped to right. So it looks like your file contains a single audio stream. The audio stream is stereo (2 channel). Perhaps the left channel contains one track and the right channel contains the other track. You could try playing the file in VLC and use the balance control to listen to the left and right channels and see if they contain what you expect. If that turns out to be the case, you can use the Audio Pan filter to balance between the two channels.


#10

I apologize, I should have realized that only showing one picture with the checks that way might not have been enough, I had set the checks that way before I took the screenshot, but I can check off none, or all the checks. a few examples below…

I understand that you said the output from ffprobe shows a single stereo audio stream, but maybe these 3 pictures tell you something else? When I check different boxes, the sound does change, for instance, if we only look at the “Left side”, if I select “track 1” and then “track 2” and deselect '“track 1” there is a difference in the audios sound quality. Of course there is also a difference if I select “track 1” “Left” and than “track 1” “right”, but I know that doesn’t count because in that instance I am adding sound from another side to make the “mono” sound become “stereo”. Please let me know if showing these new pictures changes your idea of the problem/solution or not. Thanks in advance!


#11

The pictures reinforce my suspicion. Shotcut is showing you all of the audio tracks in the file (only one). That one audio track has two channels. You should use the “Pan” filter in Shotcut to route the channel you want to the output channels (just like Catalyst is letting you do with the check boxes).


#12

It’s been my experience you have to select which audio track to play outside of track 1, which is by default. I haven’t done this in a many months and perhaps this has changed.

In this example, I have Application & Mic audio on Track 1, App audio on Track 2, and Mic audio on Track 3.
shotcut_2018-11-28_05-43-08

If I wanted V1’s audio Track2 I have to select.

If I wanted to have V1 audio Track2 & Track3 audio tracks independent, I would either have to detach audio from V1, or simply add another video track, select the audio track from the properties.


#13

Yes. That is the more common way to put multiple audio “things” in a file. But OP’s file does not do it that way.

A file can have multiple audio tracks (some programs call them streams). Each track can have multiple channels. If it has 1 channel, it is a mono track. If it has 2 channels, it is a stereo track. etc. The more common way to carry two audio “things” for the OP’s use case would be to have one mono track for the local mic and another mono track for the house sound. That would be two tracks with one channel each for a total of two channels. But in this specific case, the device has one stereo track - with local mic in one channel and house sound in the other. Both methods result in two channels. In this case those two channels are in the same track.


#14

Look at his recent screen shots, I mistaken them that he had two audio tracks, and after look at his original screen shot he clearly has just one track.


#15

Did you load the video file from a folder or folder tree containing other files from the camera into that Sony app?

Often cameras write extra files for metadata or so-called “sidecar” data. If you are loading the file from a folder structure that looks like camera storage, then I expect the Sony app to read and understand others files in there to provide more data. The point I am getting to is that there might be an audio file elsewhere or alongside the video file that it finds and makes it appear together with the video. It might also be that it reads additional data in the MTS file that was written in a non-standard manner. Many media and photo management apps have a lot of extensions to read things from various cameras while Shotcut does not yet.