No Audio after converting AVCHD to DNxHD

Up until now I have been using Hitfilm 4 Pro to edit short clips and getting my feet wet in composting, VFX, 3D etc. So I  have been been using PowerDirector for my usual  uncomplicated montages, Music festivals  and slide shows since PD does not have an issue with AVCHD.   Now I want to use HF4 for those task as well.   My problem is that after I convert the file to DNxHD using cliptooz 2 or 3.  Both Hitfilm and Quick time will not play audio, only video.  Windows Media Player will output the audio so I know it's still there.




  • Your source file(s) might have 5 channel AC-3 audio. Can we see a MediaInfo report of the converted file. A report on the source file as well could help.

    I'm not sure what Cliptoolz does with the 5-channel audio in such a transcode since I have no AVCHD files to test. I know Hitfilm will take one channel and ignore the others with separated PCM channels. If Cliptoolz passes the AC-3 through to the MOV file I don't know what Quicktime would do with that.

  •  @NormanPCN   I dowloaded Mediainfo and here is the following:

    Container and General information

    MPEG-4 (Quicktime) (DNxHD 220) 394 MiB, 15s 40ms    Overal Bitrate 220 Mbs

    1 Video Stream VC-3      Writing Application Lavf56.0.100

    1 Audio Stream AC-3

    1: Quick Time TC

    First Video Stream 

    English 220 Mbps, 1980*1080 (16:9) at 29.970 (30000/1001)fps,VC3 (DNxHD) (Version 1) (DNxHD 220)

    First  Audio Stream

    English 256 Kbps,48.0 KHz 16 bits, 21 Channels,AC-3


    So, no five channel

  • Oh, so the problem is AC-3 audio. I have the camera set on 2 channel and media info stated 2 channel.  Hmm the original MTS file will play in Hitfilm 4 pro.

  • I think you have a typo. You typed in 21 channels. I'll assume you meant 2. It is easier and generally best to just copy and paste the MediaInfo report. Plain text or HTML format.

    Not knowing about AVCHD and since it might be asked again I created a 6 channel AVCHD via Sony Vegas. I converted that via Cliptoolz. By default it is keeping the AC-3 audio of the source. The AC-3 audio seems to marked okay in the file header but VLC does not like the AC-3 either. Who knows what the exact issue is.

    So I tried the transcode converting the audio to PCM. Cliptoolz creates a single audio stream which Hitfilm wants. In my case a 6 channel audio stream. Hitfilm ingested this just fine. Conversion to PCM is always lossless.

    To do this in Cliptools you enable the PCM audio button and choose your desired channel format. 48K 16-bit is what you want. Here is a screenshot of Cliptoolz 3. The blue button, 48k 16-bit, is the one. Blue means the feature is enabled. When you click the button you will be presented with a popup menu to select the desired audio setting.

  • edited April 2016


     Thanks Norman that did solve the problem.  Changing the Audio to 44.1K 24-bit did the trick.  Thanks again,


  • @BobDiMarzio Why are you using a 44.1K 24-bit setting when your source audio is 48K 16-bit?

  • @NormanPCN  how much larger does cliptools convert your files to? the program I am using adds about 2/5ths to the file size when transcoding .mts to dnxhd. 

    I understand this one is free, but I like being able to batch convert everything in pavtube. however - a few files are rather large and was wondering how comparable cliptools is?

  • @johnnyjelko File size is completely dependent on the bitrate of the encode. It does not matter what codecs are being used.

    A standard common bitrate for 1080p30 DNxHD is 8-bit 145Mbps.  All programs that convert something to DNxHD 145 will have the same file size. If you convert to DNxHD 8-bit 220Mbps then those files will be 1.5x bigger than the 145 conversion. DNxHD has limited options for choosing a bitrate.

    So if your AVCHD mts file is 28Mbps, then a 145Mbps DNxHD transcode will be 5x bigger than the original mts.

    So the result file size is dependent on the DNxHD encode setting you choose. Not the software used to perform the transcode.

    For simplicity sake I am ignoring audio in the above statements.

  • Aladdin4dAladdin4d Moderator
    edited April 2016

    @johnnyjelko With DNxHD there won't be  much difference, if any, in file sizes between Pavtube and ClipToolz. First they're both based on FFMpeg and second DNxHD has very specific bitrate settings based on resolution and frame rate so different programs transcoding the same clip to the same bitrate setting will produce virtually identical file sizes

  • @NormanPCN   

    Why are you using a 44.1K 24-bit setting when your source audio is 48K 16-bit?

    To be brutally honest.   I was running out of time since I had to leave the house  in 5 min so I arbitrarily snagged one of the two listed PCM values.  

    Although Cliptooz is powerful it's GUI is far from well laid out and intuitive.    

    Thanks again!


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