balrogg
balrogg losslessly recompresses Ogg Vorbis and Opus files. Archives are typically 8-12% smaller than.ogg files and 3-8% smaller than .opus files.Releases are not backwards or forwards compatible until v2.0 is reached.
balrogg is licensed under GNU GPL version 3. See COPYING. Report issues to Kamila Szewczyk k@iczelia.net. The project is hosted at https://github.com/iczelia/balrogg.
Quick start
balrogg e music.ogg music.blrbalrogg d music.blr music.ogg
balrogg -b e *.ogg *.opus
balrogg --progress -9 e music.ogg music.blr
e compresses and d expands. balrogg detects the codec. With -b, every remaining path is processed using the available cores and memory. Encoding appends .blr; decoding removes it. Larger inputs run first.-p or --progress displays a progress bar on stderr for encoding and decoding, with each Vorbis tuning trial identified separately. Use --progress-lines for logs. Batch progress uses separate lines labeled with the input filename.-1 through -9 select effort; the default is -9. Through -4, each level adds a residue-model stage and affects decoding. Higher levels only expand the parameter search, so -4 through -9 decode at the same speed. Vorbis tuning evaluates the complete file at each selected setting. The best candidate is retained in the destination file, with at most the best and current candidate present during a trial.Results for a five-megabyte music file follow.
| Level | Vorbis | Opus |
|---|---|---|
-1 | 8.3 percent smaller at 6.4 MB/s | 4.0 percent smaller at 4.2 MB/s |
-9 | 9.8 percent smaller at 2.9 MB/s | 4.8 percent smaller at 2.4 MB/s |
Caveats
The encoder refuses files it cannot reproduce exactly, including files with bad checksums, invalid page sequences, unsupported Vorbis features, or no final end-of-stream page.Vorbis packets with extra padding or alternative floor subclass choices retain normal floor and residue compression. Classword corrections and padding are modeled separately. Shortened packets (packet peeling) use an adaptive byte model.
Opus support is limited to one mono or stereo logical stream with channel mapping family 0. Packets, including OpusHead and OpusTags, are limited to 61,440 bytes; extended frame headers and padding are supported within that limit. Chained and multichannel Opus files are refused. Refusals produce a diagnostic and exit status 1.
Exit status
| Code | Meaning |
|---|---|
| 0 | Success |
| 1 | Malformed, unsupported, or unrecognized input |
| 2 | Usage error |
| 3 | File access error |
| 4 | Internal error |
Batch mode returns the highest nonzero status reported by any file.
Исходники - https://github.com/iczelia/balrogg
