flac: add Encoder API to encode audio samples and metadata blocks #32
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golangci
reviewed
Aug 18, 2018
encode_meta.go
Outdated
| // --- [ Padding ] ------------------------------------------------------------- | ||
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| // encodePadding encodes the Padding metadata block, writing to bw. | ||
| func encodePadding(bw bitio.Writer, length int64, last bool) error { |
This was referenced Aug 18, 2018
Encode has been removed in favour of using NewEncoder. The Encode function was temporarily added to support re-encoding FLAC streams to update the metadata, but it had no support for encoding audio samples. The added flac.Encoder has support for encoding both metadata and audio samples. It also does not require that you first decode a FLAC file to later re-encode it by calling Encode (as was the previous behaviour).
Reported by golangci
frame/utf8.go:57:6: `decodeUTF8Int` is unused (deadcode)
func decodeUTF8Int(r io.Reader) (n uint64, err error) {
^
internal/utf8/encode.go:32:16: unnecessary conversion (unconvert)
bits = uint64(t2 | (x>>6)&mask2)
^
internal/utf8/encode.go:37:16: unnecessary conversion (unconvert)
bits = uint64(t3 | (x>>(6*2))&mask3)
^
internal/utf8/encode.go:42:16: unnecessary conversion (unconvert)
bits = uint64(t4 | (x>>(6*3))&mask4)
^
encode_frame.go:89:1: cyclomatic complexity 52 of func `(*Encoder).encodeFrameHeader` is high (> 30) (gocyclo)
func (enc *Encoder) encodeFrameHeader(w io.Writer, hdr frame.Header) error {
^
internal/utf8/encode.go:66:17: unnecessary conversion (unconvert)
bits := uint64(tx | (x>>uint(6*i))&maskx)
^
encode_subframe.go:105:46: unnecessary conversion (unconvert)
if err := bw.WriteBits(uint64(sample), byte(hdr.BitsPerSample)); err != nil {
^
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For the LPC stuff, just wanted to note and zc lpc So one possible way to approach flac LPC (the fixed LPC shouldn't require this BTW) would be If that is of interest to you, I'm happy to collaborate. |
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Thanks for the writeup William! That information will definitely be useful for implementing LPC encoding in the future. When this future arrives depends on when there will be a good time slot to do some hobby hacking on this. For now, I'm quite involved with courses at Uni so will be some time till next long hack session on the flac lib. That being said, if you are eager to get started, feel free and my brother and I will do our best to get you up to speed with the code base. |
This was referenced Sep 13, 2018
mewmew
added a commit
that referenced
this pull request
Dec 13, 2021
This change adds enc.go, which was removed in #32. To fix the build, a single change is made to enc.go, namely, updating the type of bw in the encoder struct from bitio.Writer to *bitio.Writer. Note: encoding metadata with mewkiz/flac is unsupported (for now), so maintenance of the metadata encoding feature will be governed by the Go community at large, when such need arrise. Furthermore, the metadata encoding as implemented by enc.go has not been tested locally. It is quite possible that is has broken, but if not, feel free to use! To use FLAC metadta encoding, pin the "unsupported-metadata-encoding" branch of mewkiz/flac in your go.mod. ref: #40 (comment)
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This pull request deprecates the
flac.EncodeAPI which is now superseded byflac.NewEncoder. The rationale is explained in ca2e405:This PR adds support for Verbatim encoding of audio samples. Future pull requests can implement the remaining prediction methods for audio sample encoding (e.g. LPC).
Fixes #15.