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https://github.com/wader/fq.git
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7c5215347d
Remove bitio.Buffer layer. bitio.Buffer was a kitchen sink layer with helpers now it's just a buffer and most functions have been moved to decode instead. bitio package now only have primitive types and functions simialar to standard library io and bytes packages. Make nearly eveything internally use bitio.Bit* interfaces so that slicing work correctly this will also make it possible to start experimenting with more complicated silcing helpers, ex things like: breplace(.header.bitrate; 123) to get a new buffer with bitrate changed.
84 lines
1.6 KiB
Go
84 lines
1.6 KiB
Go
package mpeg
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// TODO: probeable?
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// http://dvdnav.mplayerhq.hu/dvdinfo/mpeghdrs.html
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import (
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"log"
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"github.com/wader/fq/format"
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"github.com/wader/fq/format/registry"
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"github.com/wader/fq/pkg/bitio"
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"github.com/wader/fq/pkg/decode"
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)
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var pesPacketFormat decode.Group
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var spuFormat decode.Group
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func init() {
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registry.MustRegister(decode.Format{
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Name: format.MPEG_PES,
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Description: "MPEG Packetized elementary stream",
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DecodeFn: pesDecode,
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RootArray: true,
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RootName: "packets",
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Dependencies: []decode.Dependency{
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{Names: []string{format.MPEG_PES_PACKET}, Group: &pesPacketFormat},
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{Names: []string{format.MPEG_SPU}, Group: &spuFormat},
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},
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})
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}
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type subStream struct {
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b []byte
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l int
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}
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func pesDecode(d *decode.D, in interface{}) interface{} {
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substreams := map[int]*subStream{}
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prefix := d.PeekBits(24)
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if prefix != 0b0000_0000_0000_0000_0000_0001 {
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d.Errorf("no pes prefix found")
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}
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i := 0
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spuD := d.FieldArrayValue("spus")
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for d.NotEnd() {
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dv, v, err := d.TryFieldFormat("packet", pesPacketFormat, nil)
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if dv == nil || err != nil {
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log.Printf("errs[0]: %#+v\n", err)
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break
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}
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switch dvv := v.(type) {
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case subStreamPacket:
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s, ok := substreams[dvv.number]
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if !ok {
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s = &subStream{}
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substreams[dvv.number] = s
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}
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s.b = append(s.b, dvv.buf...)
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if s.l == 0 && len(s.b) >= 2 {
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s.l = int(s.b[0])<<8 | int(s.b[1])
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// TODO: zero l?
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}
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// TODO: is this how spu end is signalled?
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if s.l == len(s.b) {
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spuD.FieldFormatBitBuf("spu", bitio.NewBitReader(s.b, -1), spuFormat, nil)
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s.b = nil
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s.l = 0
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}
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}
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i++
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}
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return nil
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}
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