Sakuraqwq1/moonflac-encoder/src/encode

README
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StreamEncoder
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encode
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stream_encoder
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stream_finish
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stream_header
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stream_write
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version

Sakuraqwq1/moonflac-encoder/src/encode does not have a README file

EncodeError

pub suberror EncodeError {
  Empty
  BadChannels(Int)
  BadBits(Int)
  BadSampleRate(Int)
  NotWholeFrames(Int, Int)
}

Why an encode request was rejected.

StreamEncoder

source

pub struct StreamEncoder {
  sample_rate : Int
  channels : Int
  bits : Int
  frame_number : Int
  buffer : Array[Int64]
  filled : Int
}

Incremental encoder: feed PCM as it arrives, get FLAC frames back.

The one-shot encode needs the whole signal because STREAMINFO carries the total sample count and the MD5 of the unencoded PCM. A stream does not have either up front, so this encoder writes both fields as zero, which RFC 9639 defines as "unknown". The reference flac tool does the same when its output is not seekable. A decoder still gets a valid stream, it just cannot use the digest to verify the decode.

StreamEncoder::finish

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fn StreamEncoder::finish(self : StreamEncoder) -> Bytes

Flush the final partial block. Call once, after the last [StreamEncoder::write]; further calls return nothing.

StreamEncoder::header

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fn StreamEncoder::header(self : StreamEncoder) -> Bytes

The fLaC marker and the STREAMINFO block, with the sample count and PCM digest left unknown. Emit this once, before the first frame.

StreamEncoder::new

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fn StreamEncoder::new(sample_rate : Int, channels : Int, bits_per_sample : Int) -> StreamEncoder raise EncodeError

Start a stream with the given parameters. Nothing is emitted until [StreamEncoder::header] or [StreamEncoder::write] is called.

StreamEncoder::write

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fn StreamEncoder::write(self : StreamEncoder, samples : Array[Int64]) -> Bytes raise EncodeError

Push interleaved PCM and receive whatever complete frames that produced.

The result is usually empty for small inputs: samples are buffered until a full block is available, because frame size is what the format trades compression against latency for.

encode

source

fn encode(samples : Array[Int64], sample_rate : Int, channels : Int, bits_per_sample : Int) -> Bytes raise EncodeError

Encode interleaved signed PCM as a native FLAC stream.

samples holds channels interleaved values per frame, each already scaled to bits_per_sample two's complement range. The result is a complete .flac file: fLaC marker, a STREAMINFO block carrying the PCM digest, and fixed blocksize frames with per-frame CRC-8 and CRC-16.

Source Files

Install

Download zip

Pure MoonBit FLAC encoder: turn interleaved PCM into a native .flac stream with fixed and LPC prediction, Rice partitioned residuals and stereo decorrelation.

flacaudiocodeclosslessencoderricelpcpcm

Sakuraqwq1

Apache-2.0