Missing Quick Time Audio - solved!

For months many FCP users including myself have been plagued with ?missing audio? when rendering quicktime movies from FCP sequences. I personally can?t begin to list the number of wasted productivity hours I have racked up re-exporting or fixing a faulty client viewing tape, OMF tracker or the likes. After some experimentation. I have finally figured out that the bug lies in the way FCP keeps track of renders and particularly RE-renders of audio. When I first posted my problem, a number of forum users suggested that there was ?no bug? and that one only needed to ?RENDER all audio? prior to any exports to avoid the problem. I did this before each QT export and still randomly had missing audio on my exports. These sequences were part of a long form project that had received numerous revisions. Those areas that were dropping out had been tweaked and re-tweaked again and again. It wasn?t until by chance that I stumbled on a solution to the problem. When working on a revision, one of the problem sequences required an overall level boost, so I executed a global audio adjust of a few db to the ENTIRE sequence audio, and re-rendered the audio. Voila? I exported a perfect QT movie. This global adjustment seems to fool FCP into thinking the sequence is a new sequence ready for a FULL re-render. I noticed a similar and possibly related bug in the FCP 3 and I believe 4 software, where after repeatedly massaging transitions on video tracks, the system would stop executing the changes. I would have to drop a bogus piece of video on the track above the problem transition, then delete it, and re-render ? thus fooling a FULL re-render. Note: This bug may also relate to the problem some users have been posting in the last month relating to missing audio when nesting?
So here is the work-around for at least the QT audio bug: Prior to exporting a QT movie, click in the sequence, go to the Edit pull down, Select All, go to the Modify pull down, click Levels, Relative, adjust + or ? 1 db, hit ok. Click in the sequence again and render audio (Ctrl,Optn,R), and then export QT movie. Hopefully Apple can make some improvements on there render software in FCP5.


MG

Sorry - The key stroking is (Optn,Apple,R) and yes, it is technically called a mixdown.

MG

Sorry for the earlier typos. Here is the thread cleaned-up and clarified.

For months many FCP users including myself have been plagued with ?missing audio? when exporting QuickTime movies from FCP sequences. I personally can?t begin to list the number of wasted productivity hours I have racked up re-exporting or fixing a faulty client viewing tape, OMF tracker or the likes. After some experimentation. I have finally figured out that the bug lies in the way FCP keeps track of mixdowns and particularly RE-mixdowns of audio. When I first posted my problem, a number of forum users suggested that there was ?no bug? and that one only needed to ?MIXDOWN ALL AUDIO? prior to any exports to avoid the problem. I have always done this before each QT export and still randomly have had missing audio on certain exports. These problem sequences were usually part of long form projects that had received numerous revisions - those areas that were dropping out had been tweaked and re-tweaked again and again. It wasn?t until by chance that I stumbled on a solution to the problem. When working on a revision, one of the problem sequences (one that continuously exported to QT with missing audio) required an overall level boost, so I executed a global audio adjust of a few db to the ENTIRE sequence audio, and did a mixdown of the audio. Voila?I exported the QT movie for the first time with perfect audio. This global level adjustment seemed to force FCP into dumping the incomplete or corrupt mixdown files, and to replace them with a full clean mixdown. I noticed a similar and possibly related bug in the FCP 3 and I believe 4 software, where after repeatedly massaging transitions on video tracks, the system would stop executing the changes. I would have to drop a bogus piece of video on the track above the problem transition, then delete it, and re-render ? thus fooling a FULL re-render. Note: This bug may also somehow relate to the problem some users have been posting in the last month relating to missing audio when nesting? So here is the work-around for at least the QT audio bug: Prior to exporting a QT movie, click in the sequence, go to the Edit pull down, Select All, go to the Modify pull down, click Levels, Relative, adjust + or ? 1 db, hit ok. (note: keep track and alternate the + or - 1 db change over successive exports so as not to radically effect the overall levels of the sequence) Click in the sequence again and mix down the audio (Optn,Apple,R), and then export the QT movie.

FCP 4.1.1 Dual 867 mhz, 2 gig RAM, QT 6.5, OSX 10.2.8

MG

Thanks for the report MG

mike

I have waisted so much time with this as well. Your a great man for releasing this information into the world

Wow - mystery solved! Thanks...Andy