Hot answers tagged ac3
Make sure you run the latest version of FFmpeg. For Windows and Linux, static builds are availabe from the homepage. For OS X, you can install FFmpeg through Homebrew. Then, in the simplest case run: ffmpeg -i input.mkv -c:v libx264 -c:a libfaac out.mp4 For controlling video quality, set the crf parameter, which defaults to 23. Lower means better ...
Assuming you have it in an MP4 container... the following should output an MP4 with six different audio streams, each one a mono rip of one of the audio channels: ffmpeg -i input.mp4 -vn -filter_complex channelsplit output.mp4 This more complicated ffmpeg command will split the AC3 file into several different files: ffmpeg -i input.mp4 -vn ...
The following works (sort of) with Audition 1.5... In "Edit View", select File/Open Append. From here you can select multiple files by control-clicking, and when you press Append, all will be concatenated. Cue points will indicate which part of the result came from which file. The trick is getting the sounds in the right order. I've found I have to ...
Audacity has an Export Multiple feature that does exactly that.
You can do it with ffmpeg. Try a command line like this: ffmpeg -i <input_filename> -f <container> -vcodec copy -acodec libmp3lame -ar 44100 -ab 128k -ac 2 <output_filename> Replace the <> stuff with whatever filenames and containers you are using. Do note that this will downmix surround to 2 channel audio.
MKV is just a container. You can have an mpeg-4 video inside of a .mkv container. My suggestion is this: push the file to a .mkv container: mkvmerge -o newfile.mkv inputfile.m4v Get the script available here: https://github.com/JakeWharton/mkvdts2ac3 Run this: mkvdts2ac3.sh newfile.mkv Done! My TV supports AC3, but not DTS so this setup does wonders ...
Ignoring standards Oh, that awful, misleading thread. The ATSC A/52A (AC-3) standard (refer to sections 6.1.12 & 7.8, and also this post by pandy) provides detailed info about how proper downmixing should occur for AC-3. Note that the Low Frequency Effects (LFE) channel may be omitted when downmixing, and I believe that's what ffmpeg does. Changing ...
Normalizing with FFmpeg is a two-step process. First, you need to use the volumedetect filter which will tell you exactly how much dB you're allowed to crank up : ffmpeg.exe -i "D:\Project\AC3.ac3" -ac 2 -af volumedetect -y NUL This will show you the maximum volume of the stereo (downmixed) track along with additional information : ...
Handbrake has a Mac OSX version. It might work for you.
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