mirror of
https://github.com/wader/fq.git
synced 2024-12-27 07:24:48 +03:00
1b32b42f93
Generate more code More generic and comfortable API Improve and Update format decoder to new API Add some more format tests
73 lines
1.8 KiB
Go
73 lines
1.8 KiB
Go
package mpeg
|
|
|
|
// https://wiki.multimedia.cx/index.php/MPEG-4_Audio
|
|
|
|
import (
|
|
"github.com/wader/fq/format"
|
|
"github.com/wader/fq/format/registry"
|
|
"github.com/wader/fq/pkg/decode"
|
|
)
|
|
|
|
func init() {
|
|
registry.MustRegister(&decode.Format{
|
|
Name: format.MPEG_ASC,
|
|
Description: "MPEG-4 Audio Specific Config",
|
|
DecodeFn: ascDecoder,
|
|
})
|
|
}
|
|
|
|
var frequencyIndexHz = map[uint64]int{
|
|
0x0: 96000,
|
|
0x1: 88200,
|
|
0x2: 64000,
|
|
0x3: 48000,
|
|
0x4: 44100,
|
|
0x5: 32000,
|
|
0x6: 24000,
|
|
0x7: 22050,
|
|
0x8: 16000,
|
|
0x9: 12000,
|
|
0xa: 11025,
|
|
0xb: 8000,
|
|
0xc: 7350,
|
|
0xd: -1,
|
|
0xe: -1,
|
|
0xf: -1,
|
|
}
|
|
|
|
var channelConfigurationNames = decode.UToStr{
|
|
0: "defined in AOT Specifc Config",
|
|
1: "front-center",
|
|
2: "front-left, front-right",
|
|
3: "front-center, front-left, front-right",
|
|
4: "front-center, front-left, front-right, back-center",
|
|
5: "front-center, front-left, front-right, back-left, back-right",
|
|
6: "front-center, front-left, front-right, back-left, back-right, LFE-channel",
|
|
7: "front-center, front-left, front-right, side-left, side-right, back-left, back-right, LFE-channel",
|
|
}
|
|
|
|
func ascDecoder(d *decode.D, in interface{}) interface{} {
|
|
objectType := d.FieldUFn("object_type", func(d *decode.D) uint64 {
|
|
n := d.U5()
|
|
if n == 31 {
|
|
n = 32 + d.U6()
|
|
}
|
|
return n
|
|
}, d.MapUToStr(format.MPEGAudioObjectTypeNames))
|
|
d.FieldUScalarFn("sampling_frequency", func(d *decode.D) decode.Scalar {
|
|
v := d.U4()
|
|
if v == 15 {
|
|
return decode.Scalar{Actual: d.U24()}
|
|
}
|
|
if f, ok := frequencyIndexHz[v]; ok {
|
|
return decode.Scalar{Actual: v, Sym: f}
|
|
}
|
|
return decode.Scalar{Description: "invalid"}
|
|
})
|
|
d.FieldU4("channel_configuration", d.MapUToStr(channelConfigurationNames))
|
|
// TODO: GASpecificConfig etc
|
|
d.FieldRawLen("var_aot_or_byte_align", d.BitsLeft())
|
|
|
|
return format.MPEGASCOut{ObjectType: int(objectType)}
|
|
}
|