Resize & add subtitles to video (using ffmpeg).
recode-vid.sh is a wrapper around ffmpeg that simplifies recoding video files for viewing on tablet computers. Typically it performs the next tasks:
- resize video while keeping correct aspect,
- normalize SAR to 1:1 (necessary for viewing on some tablet computers, e.g. Amazon Kindle Fire),
- search for matching external audio files in input subdirectories,
- select audio track by language id (e.g. "jpn"), description or pathname,
- normalize audio volume (when downmixing from 5.1 or more channels, resulting audio is often too quiet),
- detect buffer drops due to large audio timestamps jitter,
- search for matching external subtitle files in input subdirectories,
- select subtitles by language, description or pathname,
- render subtitles over video (hardsub).
The script is most useful for recoding anime tv series, when each video file has several audio tracks and external fansubs in various languages ("jpn", "rus", "eng" etc).
Its most useful feature is ability to search for external audio and subtitle files in subdirectories near main video files. For example, if main video file is called "[Yousei-raws] Kuuchuu Buranko 07 [BDrip 1920x1080 x264 FLAC].mkv", the script is able to find matching fandub file:
- "RUS Sound [Vulpes Vulpes]/[Yousei-raws] Kuuchuu Buranko 07 [BDrip 1920x1080 x264 FLAC].mka"
and matching fansubs:
- "RUS Subs [NWP]/[Yousei-raws] Kuuchuu Buranko 07 [BDrip 1920x1080 x264 FLAC].ass"
- "RUS Subs [NWP]/[Yousei-raws] Kuuchuu Buranko 07 [BDrip 1920x1080 x264 FLAC].censored version.ass"
If neither -aid nor -alang option is specified the script picks up the default audio stream. If no default stream is found, it picks up the 1st audio stream (internal streams are considered first, external streams next). If -alang is specified while -aid is not, -alang's value is used as audio stream "selector". If -aid option is specified, its value overrides -alang's one and is used as a "selector" instead.
Subtitles are selected in a similar way except there's no -slang option, only -sid one.
Video stream selectors are not supported at the moment.
Audio and subtitles "selectors" may be composed of several positive and/or negative case-sensitive patterns, separated/prefixed by ':' and '!', and for a selector to match a stream, all of its patterns must match the stream's description. Negative patterns start with '!', positive start with ':'. If first pattern in selector isn't prefixed, it's assumed to be positive. For example, -sid 'rus!default:srt' is split into 3 patterns - ':rus', '!default' and ':srt' and it matches non-default russian srt subtitle streams. If there's more than one matching stream, 1st one is selected unless selector contains a number. For example, 'rus:0' matches 1st russian stream, '1' matches 2nd stream, '-1:eng' matches last english stream and 'jap:-2' matches last but one japanese.
Logical ORing or grouping of patterns isn't supported in stream selectors.
Special value "none" in place of an -aid selector produces video without audio track. "-sid none" turns off subtitle rendering. If you want to use "none" as a selector, prefix it with ':'. The same trick works if selector looks like ffmpeg-style stream_id:
- input_file_index:stream_index, e.g. 0:1
- [input_file_index:]stream_type[:stream_index], e.g. '
0:a:1', '0:a', 'a:1', 'a' - [input_file_index:]p:program_id[:stream_index], e.g. '0:p:1:0', '0:p:1', 'p:1:0', 'p:1'
- [input_file_index:]#stream_id, e.g. '0:#0x1100', '#0x1100'
- [input_file_index:]i:stream_id, e.g. '0:i:0x1100', 'i:0x1100'
- [input_file_index:]m:key[:value], e.g. '
0:m:LANGUAGE:eng', '0:m:LANGUAGE', 'm:LANGUAGE:eng', 'm:LANGUAGE'