If you work as an audio editor or mixer on projects that has been through a video edit, how many times have you been frustrated by what OMF, AFF and video files you have been sent from the video editor. In this article we share our recommendations as to what a video editor can do to make life easier for sound editors and mixers. You might want to share this with any video editors that you work with, if you have problems with the resources you receive from them.
Field Recorders And Metadata
More and more audio is being recorded on location using digital audio field recorders, and with the introduction of low cost recorders like the Zoom F4 and F8 and the use of DSLR cameras, the use of field recorders has increased significantly even on lower cost projects. The audio files created by field recorders can contain useful metadata, including the project name, scene, take, shoot date, sample rate, bit depth, timecode, tape ID, and channel name.
To make sure as much of this useful metadata makes its way through the video edit to the audio post production stage, we have some specific advice for video editors and their assistants when it comes to ingesting the rushes.
We recommend that you ingest field recorder audio files straight into your NLE and not into any other 3rd party software utilities during the transcode. Although these tools can be useful for making “review” dailies, as a rule they do not pass the original sound metadata into the synced clips, making our job in audio post production very much harder.
Avid Media Composer AutoSync - Avid’s Media Composer has an AutoSync tool, which enables the editor to keep the metadata intact throughout the edit process and gives the audio team the option to work with the separate tracks that were recorded on the field recorder, even if the video editor cut to a guide of mixed track.
Premiere Multiclip Not Merge - When it comes to Adobe Premiere Pro please, please do not use the Merge command, if you do, most of the metadata is stripped out, making our life in audio post-production very difficult. Adobe. Rather than use the Merge command, we recommend using the Multiclip functionality in Premiere instead.
Laying Out Audio Tracks In The Video Edit
There are key differences between the way video and audio editors lay out audio tracks on the timeline. As audio editors we prefer to have separate audio tracks for individual characters as well as multiple FXs and music tracks. We don’t mind that there are lots of audio tracks, in fact we very much prefer it.
When it comes to video editors, we are well aware that you prefer as few audio tracks as possible so you can see as much as possible in the Edit window without having to scroll down.
These 2 different requirements come up against each other when it comes to transfer the audio tracks out of the NLE ready to be imported into a DAW like Pro Tools. So here are some tips for video editors to try and make things work well for both the video and audio editors…
Make sure that when you use stereo tracks please put the left track on odd numbered tracks and the right track on even numbered tracks.
Please don’t mix mono and stereo content on the same tracks. Keep mono content on dedicated mono tracks and stereo content on stereo tracks.
Please be consistent in your track laying. If you have a number of interviews, if at all possible consider putting each interviewee on their own track. This is especially useful if the interviewee makes multiple appearances within a programme. if this possible please make sure the clip names include the interviewee’s name, to help us split them out onto individual tracks.
Put music on a dedicated pair of tracks and if you need more than one pair then have a second pair of music tracks but please don’t put other stuff on the music tracks, or music on other tracks.
Above all label everything so if there are tracks with mixed content, it is easy for us to pick out the different elements to put them on separate dedicated tracks in the audio edit. Labels like Temp VO, contributors names, music and sound effects all make our job in the audio post-production so much easier.
Please include the sync sound for any cutaway shots or B roll and if possible put the cutaway stuff on a dedicated pair of tracks. It really looks bad if we can see activity on a cutaway shot but we have no sound for it.
Be aware that muted tracks don’t always stay muted by the time they work through the AAF process. It is safer to turn the volume down to zero, and do the same with B roll content too if you don’t want to hear it in the video edit.
Make sure there are no muted audio clips on your timeline. If you want to keep a clip on the timeline but you don’t want it audible, pull the volume on the clip all the way down. Muted audio has been known to cause errors when exporting the AAF.
If you are editing in Premiere Pro please avoid using Adaptive Tracks as they can create duplicate tracks when exporting the AAF.
Use the highest audio quality audio. If you are adding other audio like sound effects and music then please avoid using low quality audio formats like mp3 and AAC. Although you may not hear the difference in the edit suite, when it comes to the audio post stages, it will be possible to hear the difference.
When it comes to Temp VOs, please record them as well as possible, please don’t record them on a smartphone in a noisy edit suite. The problem for us is that sometimes the temp VO can become the actual VO, and then we have huge challenges trying to make it sound as if it had been recorded professionally. The same can happen with temp music tracks becoming the finished track because the director has got to comfortable with the temp music. When recording Temp Vos, please record with a decent mic in a quiet space as you could well save the day later on down the production process.
Although keyframe volume information does tend to come through the OMF or AAF process, we prefer fades at the beginning and end of clips to be transitions and not created with volume keyframe data.
One final tool that is incredibly helpful to make sure if anything slips on the timeline is what is called a ‘2 Plop’. This is a one frame clip of 1K audio tone placed exactly 2 seconds before the start of the content. Then also do a similar process at the end of the content. That way if anything slips in the transfer process we can see and hear if a track is out of sync, and quickly and easily sync it back up.
Creating The AAF and Reference Video Files From The NLE
Once the video edit is complete, the video editor will need to export an AAF and reference video to pass on to the audio post-production team. Here are some tips when producing the AAF…
Duplicate your sequence and then delete all the video tracks.
Duplicate any audio clips that have effects on them to another track and render them, as most audio effects don’t make it across the AAF process. Please leave the original clips as they give us an unprocessed version, should we need to redo the effect in the DAW. Turn the volume for the original clips down to zero and label the processed version appropriately.
Create an audio-only AAF using consolidated WAV files with at least 6 second handles.
Mike prefers to have an embedded AAF as it drastically reduces the chances of losing an audio files in the transfer process. However embedding can strip out the precious metadata, so maybe run a test AAF to check what happens with the combination of the NLE and DAW.
You will also need you to export a reference video file, here are some tips to help get the most suitable reference video file for the audio edit and mix…
Make sure there is a timecode burn-in window matching your sequence timecode. Yes we know it takes time but it is a reliable check that there aren’t any problems like dropped frames.
Please do not use codecs like H264 codecs to create the video reference file. For Pro Tools please use the Avid DNxHD or if you are in an Apple world a ProRes Proxy codec will be OK. There is no need for it to be any bigger than 1920×1080 resolution.
Please include the audio mix from your NLE in the reference video. This is useful for us to be to check sync against the AAF. Also it helps to be able to hear your’s and the director’s intent for the mix.
Once you done the AAF and reference video exports, put them all together into a folder clearly labelled. If the AAF in non-embedded make sure that there is a dedicated folder with all the media files. Other useful items can include a list of the director and/or the editor’s notes, a list of character names and the actor’s names that played them, and an up-to-date lined script.