mirror of
https://github.com/langhuihui/monibuca.git
synced 2025-12-24 13:48:04 +08:00
73 lines
1.8 KiB
Go
73 lines
1.8 KiB
Go
package box
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import (
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"encoding/binary"
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"io"
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)
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// aligned(8) class SampleToChunkBox extends FullBox(‘stsc’, version = 0, 0) {
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// unsigned int(32) entry_count;
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// for (i=1; i <= entry_count; i++) {
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// unsigned int(32) first_chunk;
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// unsigned int(32) samples_per_chunk;
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// unsigned int(32) sample_description_index;
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// }
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// }
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type SampleToChunkBox []STSCEntry
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func NewSampleToChunkBox() *SampleToChunkBox {
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return &SampleToChunkBox{}
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}
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func (stsc SampleToChunkBox) Size() uint64 {
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return FullBoxLen + 4 + 12*uint64(len(stsc))
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}
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func (stsc *SampleToChunkBox) Decode(r io.Reader) (offset int, err error) {
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var fullbox FullBox
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if _, err = fullbox.Decode(r); err != nil {
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return
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}
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tmp := make([]byte, 4)
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if _, err = io.ReadFull(r, tmp); err != nil {
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return
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}
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l := binary.BigEndian.Uint32(tmp)
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*stsc = make([]STSCEntry, l)
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buf := make([]byte, l*12)
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if _, err = io.ReadFull(r, buf); err != nil {
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return
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}
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offset = 8
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idx := 0
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for i := 0; i < int(l); i++ {
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entry := &(*stsc)[i]
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entry.FirstChunk = binary.BigEndian.Uint32(buf[idx:])
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idx += 4
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entry.SamplesPerChunk = binary.BigEndian.Uint32(buf[idx:])
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idx += 4
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entry.SampleDescriptionIndex = binary.BigEndian.Uint32(buf[idx:])
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idx += 4
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}
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offset += idx
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return
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}
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func (stsc SampleToChunkBox) Encode() (int, []byte) {
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fullbox := NewFullBox(TypeSTSC, 0)
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fullbox.Box.Size = stsc.Size()
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offset, buf := fullbox.Encode()
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binary.BigEndian.PutUint32(buf[offset:], uint32(len(stsc)))
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offset += 4
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for _, entry := range stsc {
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binary.BigEndian.PutUint32(buf[offset:], entry.FirstChunk)
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offset += 4
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binary.BigEndian.PutUint32(buf[offset:], entry.SamplesPerChunk)
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offset += 4
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binary.BigEndian.PutUint32(buf[offset:], entry.SampleDescriptionIndex)
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offset += 4
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}
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return offset, buf
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}
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