Importing audio streams from videos?

[soul_message]

I'm positively surprised that Reaper features the ability to read audio streams from video files.

I just can't figure out how to deal with video files that have more than one audio stream. Right now Reaper will always insert the audio from the primary stream (or the first that is in line according to VLC) and I can't seem to find an option to insert the second audio stream instead.

Does anyone know a solution for this?

[SonicAxiom]

Originally Posted by soul_message

I'm positively surprised that Reaper features the ability to read audio streams from video files.

I just can't figure out how to deal with video files that have more than one audio stream. Right now Reaper will always insert the audio from the primary stream (or the first that is in line according to VLC) and I can't seem to find an option to insert the second audio stream instead.

Does anyone know a solution for this?

welcome to the Reaper forums, soul_message!

Reaper is not capable of importing more than the first audio stream of a video. If you're on Windows you can use something like Free Audio Video Pack (http://www.pazera-software.com/produ...io-video-pack/) to extract multiple audio streams from a video (via drop-down menu in the audio section on the lower right hand side after choosing "Audio Converter" -> "Audio Extractor/Converter"). You can also choose to convert the extracted audio stream(s) to a desired format. I'd suggest to either select the original stream format or choose PCM Wave to have the least amount of conversion loss while further processing the audio in Reaper. You may then import the extracted second, third, etc. audio stream(s) into Reaper and align them with the first stream Reaper shows.

There are several other free apps that can extract the audio streams from a video.

If you are planning to process the video's audio in Reaper and then re-combine it with the original video stream (maybe including multiple audio streams again), do not render the video in Reaper as this will require video recompression which causes some quality loss. Rather simply render one or more processed audio streams separately (as wave or MP3 audio files) and then use something like AVIDemux to re-mux (=re-combine) one or more processed audio streams with the original video by replacing the former audio streams. This way, the video quality will not be altered at all and the muxing process only takes a few seconds vs. several minutes when choosing to render the video in Reaper.

Hope you can undestand and follow my instructions

.

[soul_message]

Thank you very much! That's a very helpful program. Takes a little time to click through every window but it definitely does the job.

Originally Posted by SonicAxiom

If you are planning to process the video's audio in Reaper and then re-combine it with the original video stream (maybe including multiple audio streams again), do not render the video in Reaper as this will require video recompression which causes some quality loss. Rather simply render one or more processed audio streams separately (as wave or MP3 audio files) and then use something like AVIDemux to re-mux (=re-combine) one or more processed audio streams with the original video by replacing the former audio streams. This way, the video quality will not be altered at all and the muxing process only takes a few seconds vs. several minutes when choosing to render the video in Reaper.

Hope you can undestand and follow my instructions

I'm afraid I can't quite follow. My intention is to sample sounds from movies and so far I achieved this by dropping video files straight into Reaper and then cut/slice the relevant sounds and use the 'Glue' function to save the samples for later use. I never noticed any loss in audio quality but I haven't paid much attention to it to be quite honest. Is glueing parts of the video's audio track considered rendering? Will this result in a quality downgrade?

[DVDdoug]

If you have a DVD, DVDshrink will allow you to eliminate one or more track/stream so your "shrunk" copy will only have one stream. (DVDshrink can also make one-big VOB file, which isn't a standards-compliant DVD but it makes it easier to open/extract the audio.)

but I haven't paid much attention to it to be quite honest. Is glueing parts of the video's audio track considered rendering? Will this result in a quality downgrade?

The audio in most audio/video files is in a lossy-compressed format.* When you open a compressed file in REAPER (or any "normal" audio editor or DAW) it gets decompressed.


If you re-render to a lossy format you are going through another generation of lossy compression and the "damage" can accumulate. Of course, the same is true if you edit lossy video.







* There are exceptions LPCM. (one of the DVD-compatible formats) is lossless, but DOLBY AC3 (lossy) is more common because LPCM on a DVD is 2-channel stereo (no surround). And, there are a couple of lossless Blu-Ray audio formats. A/V files that are not on commercial "shiny discs" can have virtually any audio format, but lossless is rare.