mirror of
https://github.com/wader/fq.git
synced 2024-12-23 13:22:58 +03:00
8e0dde03d0
This will allow passing both cli options and format options to sub decoder. Ex: pass keylog option to a tls decoder when decoding a pcap. Ex: pass decode options to a format inside a http body inside a pcap. Add ArgAs method to lookup argument based on type. This also makes the format decode function have same signature as sub decoders in the decode API. This change decode.Format a bit: DecodeFn is now just func(d *D) any DecodeInArg renamed to DefaultInArg
106 lines
3.7 KiB
Go
106 lines
3.7 KiB
Go
package mpeg
|
|
|
|
// https://github.com/mstorsjo/fdk-aac/blob/f285813ec15e7c6f8e4839c9eb4f6b0cd2da1990/libMpegTPEnc/src/tpenc_asc.cpp
|
|
// https://www.iis.fraunhofer.de/content/dam/iis/de/doc/ame/wp/FraunhoferIIS_Application-Bulletin_AAC-Transport-Formats.pdf
|
|
// https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/aac_adtstoasc_bsf.c
|
|
|
|
import (
|
|
"github.com/wader/fq/format"
|
|
"github.com/wader/fq/pkg/decode"
|
|
"github.com/wader/fq/pkg/interp"
|
|
"github.com/wader/fq/pkg/scalar"
|
|
)
|
|
|
|
var aacFrameFormat decode.Group
|
|
|
|
func init() {
|
|
interp.RegisterFormat(decode.Format{
|
|
Name: format.ADTS_FRAME,
|
|
Description: "Audio Data Transport Stream frame",
|
|
DecodeFn: adtsFrameDecoder,
|
|
Dependencies: []decode.Dependency{
|
|
{Names: []string{format.AAC_FRAME}, Group: &aacFrameFormat},
|
|
},
|
|
})
|
|
}
|
|
|
|
var protectionAbsentNames = scalar.BoolMapDescription{
|
|
true: "No CRC",
|
|
false: "Has CRC",
|
|
}
|
|
|
|
func adtsFrameDecoder(d *decode.D) any {
|
|
|
|
/*
|
|
adts_frame() {
|
|
adts_fixed_header();
|
|
adts_variable_header();
|
|
if (number_of_raw_data_blocks_in_frame == 0) {
|
|
adts_error_check();
|
|
raw_data_block();
|
|
} else {
|
|
adts_header_error_check();
|
|
for( i = 0; i <= number_of_raw_data_blocks_in_frame; i++ ) {
|
|
raw_data_block();
|
|
adts_raw_data_block_error_check();
|
|
}
|
|
}
|
|
}
|
|
*/
|
|
|
|
// A 12 syncword 0xFFF, all bits must be 1
|
|
// B 1 MPEG Version: 0 for MPEG-4, 1 for MPEG-2
|
|
// C 2 Layer: always 0
|
|
// D 1 protection absent, Warning, set to 1 if there is no CRC and 0 if there is CRC
|
|
// E 2 profile, the MPEG-4 Audio Object Type minus 1
|
|
// F 4 MPEG-4 Sampling Frequency Index (15 is forbidden)
|
|
// G 1 private bit, guaranteed never to be used by MPEG, set to 0 when encoding, ignore when decoding
|
|
// H 3 MPEG-4 Channel Configuration (in the case of 0, the channel configuration is sent via an inband PCE)
|
|
// I 1 originality, set to 0 when encoding, ignore when decoding
|
|
// J 1 home, set to 0 when encoding, ignore when decoding
|
|
// K 1 copyrighted id bit, the next bit of a centrally registered copyright identifier, set to 0 when encoding, ignore when decoding
|
|
// L 1 copyright id start, signals that this frame's copyright id bit is the first bit of the copyright id, set to 0 when encoding, ignore when decoding
|
|
// M 13 frame length, this value must include 7 or 9 bytes of header length: FrameLength = (ProtectionAbsent == 1 ? 7 : 9) + size(AACFrame)
|
|
// O 11 Buffer fullness
|
|
// P 2 Number of AAC frames (RDBs) in ADTS frame minus 1, for maximum compatibility always use 1 AAC frame per ADTS frame
|
|
// Q 16 CRC if protection absent is 0
|
|
|
|
d.FieldU12("syncword", d.UintAssert(0b1111_1111_1111), scalar.UintBin)
|
|
d.FieldU1("mpeg_version", scalar.UintMapSymStr{0: "mpeg4", 1: "mpeg2_aac"})
|
|
d.FieldU2("layer", d.UintAssert(0))
|
|
protectionAbsent := d.FieldBool("protection_absent", protectionAbsentNames)
|
|
|
|
objectType := d.FieldU2("profile", scalar.UintActualAdd(1), format.MPEGAudioObjectTypeNames)
|
|
d.FieldUintFn("sampling_frequency", decodeEscapeValueAbsFn(4, 24, 0), frequencyIndexHzMap)
|
|
d.FieldU1("private_bit")
|
|
d.FieldU3("channel_configuration", channelConfigurationNames)
|
|
d.FieldU1("originality")
|
|
d.FieldU1("home")
|
|
d.FieldU1("copyrighted")
|
|
d.FieldU1("copyright")
|
|
frameLength := d.FieldU13("frame_length")
|
|
dataLength := int64(frameLength - 7)
|
|
if !protectionAbsent {
|
|
// TODO: multuple RDBs CRCs
|
|
dataLength -= 2
|
|
}
|
|
|
|
d.FieldU11("buffer_fullness")
|
|
numberOfRDBs := d.FieldU2("number_of_rdbs", scalar.UintActualAdd(1))
|
|
if !protectionAbsent {
|
|
d.FieldU16("crc")
|
|
}
|
|
|
|
if dataLength < 0 {
|
|
d.Fatalf("dataLength < 0")
|
|
}
|
|
|
|
d.FieldArray("raw_data_blocks", func(d *decode.D) {
|
|
for i := uint64(0); i < numberOfRDBs; i++ {
|
|
d.FieldFormatLen("raw_data_block", dataLength*8, aacFrameFormat, format.AACFrameIn{ObjectType: int(objectType)})
|
|
}
|
|
})
|
|
|
|
return nil
|
|
}
|