mirror of
https://github.com/aler9/gortsplib
synced 2025-10-05 15:16:51 +08:00
729 lines
16 KiB
Go
729 lines
16 KiB
Go
package h264
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import (
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"fmt"
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"github.com/bluenviron/gortsplib/v3/pkg/bits"
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)
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const (
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maxRefFrames = 255
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)
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func readScalingList(buf []byte, pos *int, size int) ([]int32, bool, error) {
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lastScale := int32(8)
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nextScale := int32(8)
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scalingList := make([]int32, size)
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var useDefaultScalingMatrixFlag bool
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for j := 0; j < size; j++ {
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if nextScale != 0 {
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deltaScale, err := bits.ReadGolombSigned(buf, pos)
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if err != nil {
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return nil, false, err
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}
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nextScale = (lastScale + deltaScale + 256) % 256
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useDefaultScalingMatrixFlag = (j == 0 && nextScale == 0)
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}
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if nextScale == 0 {
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scalingList[j] = lastScale
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} else {
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scalingList[j] = nextScale
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}
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lastScale = scalingList[j]
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}
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return scalingList, useDefaultScalingMatrixFlag, nil
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}
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// SPS_HRD is a hypotetical reference decoder.
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type SPS_HRD struct { //nolint:revive
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CpbCntMinus1 uint32
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BitRateScale uint8
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CpbSizeScale uint8
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BitRateValueMinus1 []uint32
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CpbSizeValueMinus1 []uint32
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CbrFlag []bool
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InitialCpbRemovalDelayLengthMinus1 uint8
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CpbRemovalDelayLengthMinus1 uint8
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DpbOutputDelayLengthMinus1 uint8
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TimeOffsetLength uint8
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}
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func (h *SPS_HRD) unmarshal(buf []byte, pos *int) error {
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var err error
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h.CpbCntMinus1, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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err = bits.HasSpace(buf, *pos, 8)
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if err != nil {
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return err
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}
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h.BitRateScale = uint8(bits.ReadBitsUnsafe(buf, pos, 4))
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h.CpbSizeScale = uint8(bits.ReadBitsUnsafe(buf, pos, 4))
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for i := uint32(0); i <= h.CpbCntMinus1; i++ {
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v, err := bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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h.BitRateValueMinus1 = append(h.BitRateValueMinus1, v)
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v, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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h.CpbSizeValueMinus1 = append(h.CpbSizeValueMinus1, v)
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vb, err := bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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h.CbrFlag = append(h.CbrFlag, vb)
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}
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err = bits.HasSpace(buf, *pos, 5+5+5+5)
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if err != nil {
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return err
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}
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h.InitialCpbRemovalDelayLengthMinus1 = uint8(bits.ReadBitsUnsafe(buf, pos, 5))
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h.CpbRemovalDelayLengthMinus1 = uint8(bits.ReadBitsUnsafe(buf, pos, 5))
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h.DpbOutputDelayLengthMinus1 = uint8(bits.ReadBitsUnsafe(buf, pos, 5))
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h.TimeOffsetLength = uint8(bits.ReadBitsUnsafe(buf, pos, 5))
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return nil
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}
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// SPS_TimingInfo is a timing info.
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type SPS_TimingInfo struct { //nolint:revive
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NumUnitsInTick uint32
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TimeScale uint32
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FixedFrameRateFlag bool
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}
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func (t *SPS_TimingInfo) unmarshal(buf []byte, pos *int) error {
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err := bits.HasSpace(buf, *pos, 32+32+1)
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if err != nil {
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return err
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}
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t.NumUnitsInTick = uint32(bits.ReadBitsUnsafe(buf, pos, 32))
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t.TimeScale = uint32(bits.ReadBitsUnsafe(buf, pos, 32))
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t.FixedFrameRateFlag = bits.ReadFlagUnsafe(buf, pos)
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return nil
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}
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// SPS_BitstreamRestriction are bitstream restriction infos.
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type SPS_BitstreamRestriction struct { //nolint:revive
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MotionVectorsOverPicBoundariesFlag bool
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MaxBytesPerPicDenom uint32
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MaxBitsPerMbDenom uint32
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Log2MaxMvLengthHorizontal uint32
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Log2MaxMvLengthVertical uint32
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MaxNumReorderFrames uint32
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MaxDecFrameBuffering uint32
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}
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func (r *SPS_BitstreamRestriction) unmarshal(buf []byte, pos *int) error {
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var err error
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r.MotionVectorsOverPicBoundariesFlag, err = bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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r.MaxBytesPerPicDenom, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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r.MaxBitsPerMbDenom, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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r.Log2MaxMvLengthHorizontal, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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r.Log2MaxMvLengthVertical, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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r.MaxNumReorderFrames, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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r.MaxDecFrameBuffering, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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return nil
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}
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// SPS_VUI is a video usability information.
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type SPS_VUI struct { //nolint:revive
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AspectRatioInfoPresentFlag bool
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// AspectRatioInfoPresentFlag == true
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AspectRatioIdc uint8
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SarWidth uint16
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SarHeight uint16
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OverscanInfoPresentFlag bool
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// OverscanInfoPresentFlag == true
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OverscanAppropriateFlag bool
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VideoSignalTypePresentFlag bool
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// VideoSignalTypePresentFlag == true
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VideoFormat uint8
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VideoFullRangeFlag bool
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ColourDescriptionPresentFlag bool
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// ColourDescriptionPresentFlag == true
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ColourPrimaries uint8
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TransferCharacteristics uint8
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MatrixCoefficients uint8
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ChromaLocInfoPresentFlag bool
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// ChromaLocInfoPresentFlag == true
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ChromaSampleLocTypeTopField uint32
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ChromaSampleLocTypeBottomField uint32
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TimingInfo *SPS_TimingInfo
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NalHRD *SPS_HRD
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VclHRD *SPS_HRD
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LowDelayHrdFlag bool
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PicStructPresentFlag bool
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BitstreamRestriction *SPS_BitstreamRestriction
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}
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func (v *SPS_VUI) unmarshal(buf []byte, pos *int) error {
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var err error
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v.AspectRatioInfoPresentFlag, err = bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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if v.AspectRatioInfoPresentFlag {
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tmp, err := bits.ReadBits(buf, pos, 8)
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if err != nil {
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return err
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}
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v.AspectRatioIdc = uint8(tmp)
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if v.AspectRatioIdc == 255 { // Extended_SAR
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err := bits.HasSpace(buf, *pos, 32)
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if err != nil {
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return err
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}
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v.SarWidth = uint16(bits.ReadBitsUnsafe(buf, pos, 16))
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v.SarHeight = uint16(bits.ReadBitsUnsafe(buf, pos, 16))
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}
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}
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v.OverscanInfoPresentFlag, err = bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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if v.OverscanInfoPresentFlag {
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v.OverscanAppropriateFlag, err = bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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}
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v.VideoSignalTypePresentFlag, err = bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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if v.VideoSignalTypePresentFlag {
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err := bits.HasSpace(buf, *pos, 5)
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if err != nil {
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return err
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}
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v.VideoFormat = uint8(bits.ReadBitsUnsafe(buf, pos, 3))
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v.VideoFullRangeFlag = bits.ReadFlagUnsafe(buf, pos)
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v.ColourDescriptionPresentFlag = bits.ReadFlagUnsafe(buf, pos)
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if v.ColourDescriptionPresentFlag {
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err := bits.HasSpace(buf, *pos, 24)
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if err != nil {
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return err
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}
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v.ColourPrimaries = uint8(bits.ReadBitsUnsafe(buf, pos, 8))
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v.TransferCharacteristics = uint8(bits.ReadBitsUnsafe(buf, pos, 8))
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v.MatrixCoefficients = uint8(bits.ReadBitsUnsafe(buf, pos, 8))
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}
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}
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v.ChromaLocInfoPresentFlag, err = bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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if v.ChromaLocInfoPresentFlag {
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v.ChromaSampleLocTypeTopField, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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v.ChromaSampleLocTypeBottomField, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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}
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timingInfoPresentFlag, err := bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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if timingInfoPresentFlag {
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v.TimingInfo = &SPS_TimingInfo{}
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err := v.TimingInfo.unmarshal(buf, pos)
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if err != nil {
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return err
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}
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}
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nalHrdParametersPresentFlag, err := bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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if nalHrdParametersPresentFlag {
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v.NalHRD = &SPS_HRD{}
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err := v.NalHRD.unmarshal(buf, pos)
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if err != nil {
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return err
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}
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}
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vclHrdParametersPresentFlag, err := bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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if vclHrdParametersPresentFlag {
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v.VclHRD = &SPS_HRD{}
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err := v.VclHRD.unmarshal(buf, pos)
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if err != nil {
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return err
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}
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}
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if nalHrdParametersPresentFlag || vclHrdParametersPresentFlag {
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v.LowDelayHrdFlag, err = bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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}
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v.PicStructPresentFlag, err = bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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bitstreamRestrictionFlag, err := bits.ReadFlag(buf, pos)
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if err != nil {
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return err
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}
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if bitstreamRestrictionFlag {
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v.BitstreamRestriction = &SPS_BitstreamRestriction{}
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err := v.BitstreamRestriction.unmarshal(buf, pos)
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if err != nil {
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return err
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}
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}
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return nil
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}
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// SPS_FrameCropping is the frame cropping part of a SPS.
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type SPS_FrameCropping struct { //nolint:revive
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LeftOffset uint32
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RightOffset uint32
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TopOffset uint32
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BottomOffset uint32
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}
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func (c *SPS_FrameCropping) unmarshal(buf []byte, pos *int) error {
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var err error
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c.LeftOffset, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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c.RightOffset, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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c.TopOffset, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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c.BottomOffset, err = bits.ReadGolombUnsigned(buf, pos)
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if err != nil {
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return err
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}
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return nil
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}
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// SPS is a H264 sequence parameter set.
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type SPS struct {
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ProfileIdc uint8
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ConstraintSet0Flag bool
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ConstraintSet1Flag bool
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ConstraintSet2Flag bool
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ConstraintSet3Flag bool
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ConstraintSet4Flag bool
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ConstraintSet5Flag bool
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LevelIdc uint8
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ID uint32
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// only for selected ProfileIdcs
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ChromeFormatIdc uint32
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SeparateColourPlaneFlag bool
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BitDepthLumaMinus8 uint32
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BitDepthChromaMinus8 uint32
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QpprimeYZeroTransformBypassFlag bool
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// seqScalingListPresentFlag == true
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ScalingList4x4 [][]int32
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UseDefaultScalingMatrix4x4Flag []bool
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ScalingList8x8 [][]int32
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UseDefaultScalingMatrix8x8Flag []bool
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Log2MaxFrameNumMinus4 uint32
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PicOrderCntType uint32
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// PicOrderCntType == 0
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Log2MaxPicOrderCntLsbMinus4 uint32
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// PicOrderCntType == 1
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DeltaPicOrderAlwaysZeroFlag bool
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OffsetForNonRefPic int32
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OffsetForTopToBottomField int32
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OffsetForRefFrames []int32
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MaxNumRefFrames uint32
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GapsInFrameNumValueAllowedFlag bool
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PicWidthInMbsMinus1 uint32
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PicHeightInMapUnitsMinus1 uint32
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FrameMbsOnlyFlag bool
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// FrameMbsOnlyFlag == false
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MbAdaptiveFrameFieldFlag bool
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Direct8x8InferenceFlag bool
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FrameCropping *SPS_FrameCropping
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VUI *SPS_VUI
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}
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// Unmarshal decodes a SPS from bytes.
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func (s *SPS) Unmarshal(buf []byte) error {
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buf = EmulationPreventionRemove(buf)
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if len(buf) < 4 {
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return fmt.Errorf("not enough bits")
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}
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s.ProfileIdc = buf[1]
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s.ConstraintSet0Flag = (buf[2] >> 7) == 1
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s.ConstraintSet1Flag = (buf[2] >> 6 & 0x01) == 1
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s.ConstraintSet2Flag = (buf[2] >> 5 & 0x01) == 1
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s.ConstraintSet3Flag = (buf[2] >> 4 & 0x01) == 1
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s.ConstraintSet4Flag = (buf[2] >> 3 & 0x01) == 1
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s.ConstraintSet5Flag = (buf[2] >> 2 & 0x01) == 1
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s.LevelIdc = buf[3]
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buf = buf[4:]
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pos := 0
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var err error
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s.ID, err = bits.ReadGolombUnsigned(buf, &pos)
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if err != nil {
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return err
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}
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switch s.ProfileIdc {
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case 100, 110, 122, 244, 44, 83, 86, 118, 128, 138, 139, 134, 135:
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s.ChromeFormatIdc, err = bits.ReadGolombUnsigned(buf, &pos)
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if err != nil {
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return err
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}
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if s.ChromeFormatIdc == 3 {
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s.SeparateColourPlaneFlag, err = bits.ReadFlag(buf, &pos)
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if err != nil {
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return err
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}
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} else {
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s.SeparateColourPlaneFlag = false
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}
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s.BitDepthLumaMinus8, err = bits.ReadGolombUnsigned(buf, &pos)
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if err != nil {
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return err
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}
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s.BitDepthChromaMinus8, err = bits.ReadGolombUnsigned(buf, &pos)
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if err != nil {
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return err
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}
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s.QpprimeYZeroTransformBypassFlag, err = bits.ReadFlag(buf, &pos)
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if err != nil {
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return err
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}
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seqScalingMatrixPresentFlag, err := bits.ReadFlag(buf, &pos)
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if err != nil {
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return err
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}
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if seqScalingMatrixPresentFlag {
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var lim int
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if s.ChromeFormatIdc != 3 {
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lim = 8
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} else {
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lim = 12
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}
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for i := 0; i < lim; i++ {
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seqScalingListPresentFlag, err := bits.ReadFlag(buf, &pos)
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if err != nil {
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return err
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}
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if seqScalingListPresentFlag {
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if i < 6 {
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scalingList, useDefaultScalingMatrixFlag, err := readScalingList(buf, &pos, 16)
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if err != nil {
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return err
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}
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s.ScalingList4x4 = append(s.ScalingList4x4, scalingList)
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s.UseDefaultScalingMatrix4x4Flag = append(s.UseDefaultScalingMatrix4x4Flag,
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useDefaultScalingMatrixFlag)
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} else {
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scalingList, useDefaultScalingMatrixFlag, err := readScalingList(buf, &pos, 64)
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if err != nil {
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return err
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}
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s.ScalingList8x8 = append(s.ScalingList8x8, scalingList)
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s.UseDefaultScalingMatrix8x8Flag = append(s.UseDefaultScalingMatrix8x8Flag,
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useDefaultScalingMatrixFlag)
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}
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}
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}
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}
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default:
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s.ChromeFormatIdc = 0
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s.SeparateColourPlaneFlag = false
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s.BitDepthLumaMinus8 = 0
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s.BitDepthChromaMinus8 = 0
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s.QpprimeYZeroTransformBypassFlag = false
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}
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s.Log2MaxFrameNumMinus4, err = bits.ReadGolombUnsigned(buf, &pos)
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if err != nil {
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return err
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}
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s.PicOrderCntType, err = bits.ReadGolombUnsigned(buf, &pos)
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if err != nil {
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return err
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}
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|
|
switch s.PicOrderCntType {
|
|
case 0:
|
|
s.Log2MaxPicOrderCntLsbMinus4, err = bits.ReadGolombUnsigned(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
s.DeltaPicOrderAlwaysZeroFlag = false
|
|
s.OffsetForNonRefPic = 0
|
|
s.OffsetForTopToBottomField = 0
|
|
s.OffsetForRefFrames = nil
|
|
|
|
case 1:
|
|
s.Log2MaxPicOrderCntLsbMinus4 = 0
|
|
|
|
s.DeltaPicOrderAlwaysZeroFlag, err = bits.ReadFlag(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
s.OffsetForNonRefPic, err = bits.ReadGolombSigned(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
s.OffsetForTopToBottomField, err = bits.ReadGolombSigned(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
numRefFramesInPicOrderCntCycle, err := bits.ReadGolombUnsigned(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if numRefFramesInPicOrderCntCycle > maxRefFrames {
|
|
return fmt.Errorf("num_ref_frames_in_pic_order_cnt_cycle exceeds %d", maxRefFrames)
|
|
}
|
|
|
|
s.OffsetForRefFrames = make([]int32, numRefFramesInPicOrderCntCycle)
|
|
for i := uint32(0); i < numRefFramesInPicOrderCntCycle; i++ {
|
|
v, err := bits.ReadGolombSigned(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
s.OffsetForRefFrames[i] = v
|
|
}
|
|
|
|
case 2:
|
|
s.Log2MaxPicOrderCntLsbMinus4 = 0
|
|
s.DeltaPicOrderAlwaysZeroFlag = false
|
|
s.OffsetForNonRefPic = 0
|
|
s.OffsetForTopToBottomField = 0
|
|
s.OffsetForRefFrames = nil
|
|
|
|
default:
|
|
return fmt.Errorf("invalid pic_order_cnt_type: %d", s.PicOrderCntType)
|
|
}
|
|
|
|
s.MaxNumRefFrames, err = bits.ReadGolombUnsigned(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
s.GapsInFrameNumValueAllowedFlag, err = bits.ReadFlag(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
s.PicWidthInMbsMinus1, err = bits.ReadGolombUnsigned(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
s.PicHeightInMapUnitsMinus1, err = bits.ReadGolombUnsigned(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
s.FrameMbsOnlyFlag, err = bits.ReadFlag(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if !s.FrameMbsOnlyFlag {
|
|
s.MbAdaptiveFrameFieldFlag, err = bits.ReadFlag(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
} else {
|
|
s.MbAdaptiveFrameFieldFlag = false
|
|
}
|
|
|
|
s.Direct8x8InferenceFlag, err = bits.ReadFlag(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
frameCroppingFlag, err := bits.ReadFlag(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if frameCroppingFlag {
|
|
s.FrameCropping = &SPS_FrameCropping{}
|
|
err := s.FrameCropping.unmarshal(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
} else {
|
|
s.FrameCropping = nil
|
|
}
|
|
|
|
vuiParametersPresentFlag, err := bits.ReadFlag(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if vuiParametersPresentFlag {
|
|
s.VUI = &SPS_VUI{}
|
|
err := s.VUI.unmarshal(buf, &pos)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
} else {
|
|
s.VUI = nil
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Width returns the video width.
|
|
func (s SPS) Width() int {
|
|
if s.FrameCropping != nil {
|
|
return int(((s.PicWidthInMbsMinus1 + 1) * 16) - (s.FrameCropping.LeftOffset+s.FrameCropping.RightOffset)*2)
|
|
}
|
|
|
|
return int((s.PicWidthInMbsMinus1 + 1) * 16)
|
|
}
|
|
|
|
// Height returns the video height.
|
|
func (s SPS) Height() int {
|
|
f := uint32(0)
|
|
if s.FrameMbsOnlyFlag {
|
|
f = 1
|
|
}
|
|
|
|
if s.FrameCropping != nil {
|
|
return int(((2 - f) * (s.PicHeightInMapUnitsMinus1 + 1) * 16) -
|
|
(s.FrameCropping.TopOffset+s.FrameCropping.BottomOffset)*2)
|
|
}
|
|
|
|
return int((2 - f) * (s.PicHeightInMapUnitsMinus1 + 1) * 16)
|
|
}
|
|
|
|
// FPS returns the frames per second of the video.
|
|
func (s SPS) FPS() float64 {
|
|
if s.VUI == nil || s.VUI.TimingInfo == nil {
|
|
return 0
|
|
}
|
|
|
|
return float64(s.VUI.TimingInfo.TimeScale) / (2 * float64(s.VUI.TimingInfo.NumUnitsInTick))
|
|
}
|