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85 lines
1.7 KiB
Go
85 lines
1.7 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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b, _ := dvv.bb.BytesRange(0, int(dvv.bb.Len()/8))
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s.b = append(s.b, b...)
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if s.l == 0 && len(b) >= 2 {
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s.l = int(b[0])<<8 | int(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.NewBufferFromBytes(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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