FFmpeg Archives - blog.travisrunyard.us

April 25 2022

FFmpeg [aac @ ] Using a PCE to encode channel layout “5.1(side)”

Travis BSD, Jellyfin, Linux, Media, Operating Systems, Shell, Windows 5.1, 5.1(side), AAC, FFmpeg 0

If the source file signals a layout of 5.1(side) instead of 5.1, the AAC encoder will throw the error because the AAC spec only supports 5.1 (rear channels instead of side). The general cause of the problem is while transcoding to the AAC codec (Advanced Audio Coding) from various other high quality codecs such as AC3 (Dolby Digital/DD), E-AC-3 (Dolby Digital Plus/DDP/DD+), DTS, TrueHD (24-bit hd audio), it does not auto-select the standard 5.1 channel layout (called 5.1) if the original source has a channel layout of 5.1(side). While the AAC encoder may be able to automatically determine the amount of audio channels, FFmpeg has a hard time determining correct channel layout.

February 26 2022

FFmpeg Map English Subtitles or Audio Stream Only

Travis Media FFmpeg 0

Dynamic FFmpeg Subtitle Stream Mapping by Language You can map English subs only by using -map 0:s:m:language:eng. With FFmpeg you can dynamically map streams which match certain criteria such as language that you specify. If you’re looking for the 3-letter language codes go to https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes. This is very handy within script loops when calling the FFmpeg binary in case some streams within media containers differ. For additional example scripts for FFmpeg batch transcoding/remuxing check out this post blog.travisrunyard.us/ffmpeg-batch-transcode-audio. This is the syntax: <stream #>:<video/audio/subtitle>:<metadata>:<property>:<value> Map all subtitle streams where language is English: 0:s:m:language:eng # full cli example: for f in

zoidbert-your-encoding-is-bad-and-you-should-feel-bad

March 29 2020

FFmpeg Batch Transcode Audio

Travis Linux, Operating Systems, Shell Bash, FFmpeg 0

Recently I have been dealing with transcoding media files for my streaming site travisflix and performing ad-hoc media conversions is no longer realistic. I strongly recommend checking out my FFmpeg Examples to give you a head start if you’re not familiar with deep diving in FFmpeg details. Before you choose to batch transcode the audio for your entire library, the following will stdout anything not using the AAC codec: find . -mount -depth -maxdepth 2 -regextype posix-extended -regex ‘.*mkv$|.*mp4$’ -type f -exec bash -c ‘echo “{}” $(ffprobe -loglevel error -select_streams a:0 -show_entries stream=codec_name -of default=noprint_wrappers=1:nokey=1 “{}”)’ 2>/dev/null \; | grep