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Multi-stream Quicktime files from separate WAV sources – streams disabled in Quicktime Player
So I’m using ffmpeg to take separate WAV audio files and combine them into a single multi-stream Quicktime file (specifically, 6 wavs are used to create 6 mono audio tracks in the QT file via “-map”, while the 7th and 8th wav files are combined into a single stereo stream using “amerge.”)
The process works great, except for one issue – when ffmpeg creates the quicktime file, only the first stream (“Sound Track 1”) is enabled, and the rest of the streams are all disabled in QT Player. The reason they’re being disabled is because for every stream, ffmpeg is setting the “Alternate” specification in the metadata (in QT Player, this is under “Movie Properties/Other Settings”) for each stream to the name of one of the other streams (i.e. “Sound Track 2″‘s “Alternate” is “Sound Track 3.) The only way I can save a version of the QT file where all 7 streams play back properly is by manually switching all of the “Alternate” tags to “None,” manually clicking each checkbox to re-enable the streams, and saving out of QT Pro.
I’ve tried setting “-map_metadata” to -1 to clear all the metadata, but that does nothing. And there doesn’t appear to be an ffmpeg equivalent for this particular piece of the metadata. Any ideas for how I can get ffmpeg to ignore this and leave the “Alternate” as none so that each of the streams works by default?
Here’s an example of how I’m running this:
ffmpeg -i 1.wav -i 2.wav -i 3.wav -i 4.wav -i 5.wav -i 6.wav -i 7.wav -i 8.wav -filter_complex "[6:a][7:a]amerge=inputs=2[aout]" -acodec pcm_s24le -map_metadata -1 -map 0 -map 1 -map 2 -map 3 -map 4 -map 5 -map "[aout]" output.movThanks!
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2 Replies
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This doesn’t make much sense. Are you perhaps confusing multiple audio streams with a single audio stream that has multiple channels?
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No, I’m talking about multiple individual streams, not a single multi-channel stream. Here’s a screenshot of the output I’m getting from FFMpeg:
This is exactly what I need, but I want each of the individual streams to be enabled (Checkbox checked) by default when FFMpeg makes the file. Instead, FFMpeg is turning off each stream except the very first during the transcode. I believe the reason might be because FFMpeg is assigning an “Alternate” for each stream, which it should not be doing. The only way to enable the streams and save the file properly is to change the “Alternate” to “None.” If the Alternate is not set to “None,” then the saved file will not have the streams enabled when reopened.
So my question is if anyone knows a way to make sure that FFMpeg has each of the individual streams enabled when the file completes transcode?
Thanks!
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