Efficiently convert videos with HE-AAC audio

Sometimes there are MP4 videos with audio tracks encoded by the HE-AAC codec. This format is an extension of AAC. AAC has been the standard for a long time and is therefore widely used and understood by virtually all MP4 hardware processors. Unfortunately, this is not yet the case with HE-AAC.

To make a video playable with HE-AAC, you have to convert at least the audio stream to AAC or AC3. Multimedia Xpert can do this very efficiently by converting just the audio stream and copying the other streams 1:1. Since video conversion of a media is the much bigger task, this is a much faster way and saves a lot of time and energy. The conversion time can easily be reduced by a factor of 10 or more.

To convert only the audio you need to configure an output specification that transfers video and subtitle streams directly without processing. For MP4 there is already a predefined one named "Video MP4 only Audio Conversion to AAC", but for other formats you need to do the following:

1. Switch to the Output Specifications tab.
   
   
2. Select the output specification that is closest to your desired output format.
   
   
3. Enter the name for a new specification under 'Name', e.g. "Video H.264 without video conversion", and press . This will duplicate all previous values to the new specification.
   
   
4. Empty the 'Output Video Codec' field. This is the crucial one.
   
   
   
   
5. Since now the video stream is copied 1:1 to the output, you must clear all option fields that are related to video streams or set them to the default value. Without this a conversion would have to take place, and ffmpeg will report this contradiction with the error message "Filtering and streamcopy cannot be used together".

Having such a specification you can just convert the video selecting this specification as output specification.

If this does not result in a playable video, the video stream or other streams inside are probably the problem. In this case you can try to disable streams other than the video and audio stream in the Stream Selection column and convert again or else doing a full conversion.