forked from 32bitkid/mpeg
/
extension_and_user_data.go
92 lines (79 loc) · 2.08 KB
/
extension_and_user_data.go
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package video
func (br *VideoSequence) extension_and_user_data(i int) error {
for {
if nextbits, err := br.Peek32(32); err != nil {
return err
} else if StartCode(nextbits) != ExtensionStartCode && StartCode(nextbits) != UserDataStartCode {
break
} else if (i != 1) && (StartCode(nextbits) == ExtensionStartCode) {
if err := br.extension_data(i); err != nil {
return err
}
} else if StartCode(nextbits) == UserDataStartCode {
if _, err := br.user_data(); err != nil {
return err
}
}
}
return nil
}
func (br *VideoSequence) extension_data(i int) error {
for {
if nextbits, err := br.Peek32(32); err != nil {
return err
} else if StartCode(nextbits) != ExtensionStartCode {
break
}
br.Skip(32)
switch i {
case 0: /* follows sequence_extension() */
nextbits, err := br.Peek32(4)
if err != nil {
return err
}
switch ExtensionID(nextbits) {
case SequenceDisplayExtensionID:
if _, err := sequence_display_extension(br); err != nil {
return err
}
default:
if _, err := sequence_scalable_extension(br); err != nil {
return err
}
}
case 1: /* NOTE - i never takes the value 1 because extension_data()
never follows a group_of_pictures_header() */
case 2: /* follows picture_coding_extension() */
nextbits, err := br.Peek32(4)
if err != nil {
return err
}
switch ExtensionID(nextbits) {
case QuantMatrixExtensionID:
if err := br.quant_matrix_extension(); err != nil {
return err
}
case CopyrightExtensionID:
copyright_extension()
case PictureDisplayExtensionID:
picture_display_extension()
case PictureSpatialScalableExtensionID:
picture_spatial_scalable_extension()
default:
if _, err := picture_temporal_scalable_extension(br); err != nil {
return err
}
}
}
}
return nil
}
func copyright_extension() {
panic("unsupported: copyright_extension")
}
func picture_display_extension() {
panic("unsupported: picture_display_extension")
}
func picture_spatial_scalable_extension() {
panic("unsupported: picture_spatial_scalable_extension")
}