Re: Downmixing Surround Flac to Stereo.
The Blaze ET still choked on the stereo.flac produced by the ffmpeg example, but I was at least able to get it to play on my desktop without it sounding like most of the audio was missing, though I'm starting to think my original problem was mkvextract not knowing how to deal with audio streams in surround flac(I've previously only used mkvextract on files using Ac3 as far as I know). In this case, I only needed the first audio track from the mkv, but for future reference, is there a way to specify ffmpeg should extract the second or third audio track? Most of the mkvs I encounter are at least dual audio and English isn't always the first track. -- Sincerely, Jeffery Wright President Emeritus, Nu Nu Chapter, Phi Theta Kappa. Former Secretary, Student Government Association, College of the Albemarle. ___ Blinux-list mailing list Blinux-list@redhat.com https://www.redhat.com/mailman/listinfo/blinux-list
Re: Downmixing Surround Flac to Stereo.
Yes, this is what I do all the time with mkv files. I have created a couple scripts, e.g. #!/bin/bash #Use ffmpeg to extract 16bit to audio.wav #One argument is input file ffmpeg -i "$1" -acodec pcm_s16le -ac 2 audio.wav From there I can "flac -best" or "oggenc -q 10" or whatever. I generally play via mplayer, which will handle mkv perfectly well, by the way. Janina Linux for blind general discussion writes: > Since the first two channels of a 5.1 audio stream are front-left > and front-right[1] all you need is to extract those channels. > > Ffmpeg can do this. Here's what I concoct (untested) based > on some web advice.[2] > > ffmpeg -i input.mkv -vn -c:a copy -ac 2 stereo.flac > > -vn means don't take the video, -c:a copy means copy the > audio stream without decoding/re-encoding, -ac 2 means > take two audio channels. > > It's possible you might have to move the '-ac 2' earlier > in the command. Depending on position, options affect > either the input or output stream. > > Let us know how it goes! > > 1. https://en.wikipedia.org/wiki/5.1_surround_sound > 2. > https://superuser.com/questions/1041858/converting-5-1-audio-to-stereo-and-keeping-both-tracks > > joel > > On Mon, Oct 16, 2017 at 11:18:05PM +, Linux for blind general discussion > wrote: > > I recently downloaded a .mkv file with 5.1 audio encoded to flac and > > as I inteneded to listen to it on my Blaze ET, which doesn't support > > mkv files, I used mkvextract to extract the audio, producing a 1.1GB > > file with roughly a 90 minute runtime. Unfortunately, My Blaze ET > > apparently can't handle surround files and trying to play the flac in > > ogg123 seems to only be producing sound effects. > > > > Can anyone suggest either a means of converting the surround flac file > > to stereo from the command line or suggest a lightweight command line > > flac player that can properly playback surround sound files through > > earphones? > > > > -- > > Sincerely, > > > > Jeffery Wright > > President Emeritus, Nu Nu Chapter, Phi Theta Kappa. > > Former Secretary, Student Government Association, College of the Albemarle. > > > > ___ > > Blinux-list mailing list > > Blinux-list@redhat.com > > https://www.redhat.com/mailman/listinfo/blinux-list > > -- > Joel Roth > > > ___ > Blinux-list mailing list > Blinux-list@redhat.com > https://www.redhat.com/mailman/listinfo/blinux-list -- Janina Sajka, Phone: +1.443.300.2200 sip:jan...@asterisk.rednote.net Email: jan...@rednote.net Linux Foundation Fellow Executive Chair, Accessibility Workgroup: http://a11y.org The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI) Chair, Accessible Platform Architectureshttp://www.w3.org/wai/apa ___ Blinux-list mailing list Blinux-list@redhat.com https://www.redhat.com/mailman/listinfo/blinux-list
Re: Downmixing Surround Flac to Stereo.
You could get a stereo .wav using something like mplayer -noconsolecontrols -novideo -really-quiet -vc null -vo null -ao pcm:file=stereo_filename.wav downloaded.mkv You do not need all the flags above, but it should work. HTH, Willem On Mon, 16 Oct 2017, Linux for blind general discussion wrote: I recently downloaded a .mkv file with 5.1 audio encoded to flac and as I inteneded to listen to it on my Blaze ET, which doesn't support mkv files, I used mkvextract to extract the audio, producing a 1.1GB file with roughly a 90 minute runtime. Unfortunately, My Blaze ET apparently can't handle surround files and trying to play the flac in ogg123 seems to only be producing sound effects. Can anyone suggest either a means of converting the surround flac file to stereo from the command line or suggest a lightweight command line flac player that can properly playback surround sound files through earphones? -- Sincerely, Jeffery Wright President Emeritus, Nu Nu Chapter, Phi Theta Kappa. Former Secretary, Student Government Association, College of the Albemarle. ___ Blinux-list mailing list Blinux-list@redhat.com https://www.redhat.com/mailman/listinfo/blinux-list ___ Blinux-list mailing list Blinux-list@redhat.com https://www.redhat.com/mailman/listinfo/blinux-list
Re: Downmixing Surround Flac to Stereo.
Since the first two channels of a 5.1 audio stream are front-left and front-right[1] all you need is to extract those channels. Ffmpeg can do this. Here's what I concoct (untested) based on some web advice.[2] ffmpeg -i input.mkv -vn -c:a copy -ac 2 stereo.flac -vn means don't take the video, -c:a copy means copy the audio stream without decoding/re-encoding, -ac 2 means take two audio channels. It's possible you might have to move the '-ac 2' earlier in the command. Depending on position, options affect either the input or output stream. Let us know how it goes! 1. https://en.wikipedia.org/wiki/5.1_surround_sound 2. https://superuser.com/questions/1041858/converting-5-1-audio-to-stereo-and-keeping-both-tracks joel On Mon, Oct 16, 2017 at 11:18:05PM +, Linux for blind general discussion wrote: > I recently downloaded a .mkv file with 5.1 audio encoded to flac and > as I inteneded to listen to it on my Blaze ET, which doesn't support > mkv files, I used mkvextract to extract the audio, producing a 1.1GB > file with roughly a 90 minute runtime. Unfortunately, My Blaze ET > apparently can't handle surround files and trying to play the flac in > ogg123 seems to only be producing sound effects. > > Can anyone suggest either a means of converting the surround flac file > to stereo from the command line or suggest a lightweight command line > flac player that can properly playback surround sound files through > earphones? > > -- > Sincerely, > > Jeffery Wright > President Emeritus, Nu Nu Chapter, Phi Theta Kappa. > Former Secretary, Student Government Association, College of the Albemarle. > > ___ > Blinux-list mailing list > Blinux-list@redhat.com > https://www.redhat.com/mailman/listinfo/blinux-list -- Joel Roth ___ Blinux-list mailing list Blinux-list@redhat.com https://www.redhat.com/mailman/listinfo/blinux-list
