mirror of
https://github.com/kemko/icecast-ripper.git
synced 2026-01-01 15:55:42 +03:00
Dmitry Andreev
b5f23a50b7
* feat: integrate MP3 duration extraction and silence handling - Added a new dependency on github.com/tcolgate/mp3 for MP3 frame decoding. - Implemented actual MP3 duration retrieval in the scanRecordings function, falling back to an estimation if retrieval fails. - Introduced a silent frame asset for generating silence in audio streams. - Created a silence reader to provide a continuous stream of silent frames. - Added necessary documentation and licensing for the new MP3 package. - Updated .gitignore to exclude MP3 files except for the internal data directory. * feat: update README and improve application configuration and logging * refactor: remove unused GenerateFileHash function and improve resource cleanup in MP3 and recorder modules
84 lines
2.1 KiB
Go
84 lines
2.1 KiB
Go
package mp3
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/*
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func (this *FrameHeader) Parse(bs []byte) error {
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this.Size = 0
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this.Samples = 0
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this.Duration = 0
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if len(bs) < 4 {
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return fmt.Errorf("not enough bytes")
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}
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if bs[0] != 0xFF || (bs[1]&0xE0) != 0xE0 {
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return fmt.Errorf("missing sync word, got: %x, %x", bs[0], bs[1])
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}
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this.Version = Version((bs[1] >> 3) & 0x03)
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if this.Version == MPEGReserved {
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return fmt.Errorf("reserved mpeg version")
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}
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this.Layer = Layer(((bs[1] >> 1) & 0x03))
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if this.Layer == LayerReserved {
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return fmt.Errorf("reserved layer")
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}
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this.Protection = (bs[1] & 0x01) != 0x01
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bitrateIdx := (bs[2] >> 4) & 0x0F
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if bitrateIdx == 0x0F {
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return fmt.Errorf("invalid bitrate: %v", bitrateIdx)
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}
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this.Bitrate = bitrates[this.Version][this.Layer][bitrateIdx] * 1000
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if this.Bitrate == 0 {
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return fmt.Errorf("invalid bitrate: %v", bitrateIdx)
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}
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sampleRateIdx := (bs[2] >> 2) & 0x03
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if sampleRateIdx == 0x03 {
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return fmt.Errorf("invalid sample rate: %v", sampleRateIdx)
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}
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this.SampleRate = sampleRates[this.Version][sampleRateIdx]
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this.Pad = ((bs[2] >> 1) & 0x01) == 0x01
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this.Private = (bs[2] & 0x01) == 0x01
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this.ChannelMode = ChannelMode(bs[3]>>6) & 0x03
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// todo: mode extension
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this.CopyRight = (bs[3]>>3)&0x01 == 0x01
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this.Original = (bs[3]>>2)&0x01 == 0x01
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this.Emphasis = Emphasis(bs[3] & 0x03)
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if this.Emphasis == EmphReserved {
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return fmt.Errorf("reserved emphasis")
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}
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this.Size = this.size()
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this.Samples = this.samples()
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this.Duration = this.duration()
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return nil
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}
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func (this *FrameHeader) samples() int {
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return samplesPerFrame[this.Version][this.Layer]
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}
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func (this *FrameHeader) size() int64 {
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bps := float64(this.samples()) / 8
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fsize := (bps * float64(this.Bitrate)) / float64(this.SampleRate)
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if this.Pad {
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fsize += float64(slotSize[this.Layer])
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}
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return int64(fsize)
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}
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func (this *FrameHeader) duration() time.Duration {
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ms := (1000 / float64(this.SampleRate)) * float64(this.samples())
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return time.Duration(time.Duration(float64(time.Millisecond) * ms))
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}
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*/
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