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mirror of https://github.com/wader/fq.git synced 2024-11-28 03:02:55 +03:00
fq/format/mpeg/mpeg_pes_packet.go
2022-07-19 18:33:50 +02:00

206 lines
6.6 KiB
Go

package mpeg
// http://dvdnav.mplayerhq.hu/dvdinfo/mpeghdrs.html
// http://stnsoft.com/DVD/sys_hdr.html))
import (
"github.com/wader/fq/format"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/interp"
"github.com/wader/fq/pkg/scalar"
)
func init() {
interp.RegisterFormat(decode.Format{
Name: format.MPEG_PES_PACKET,
Description: "MPEG Packetized elementary stream packet",
DecodeFn: pesPacketDecode,
})
}
const (
sequenceHeader = 0xb3
packHeader = 0xba
systemHeader = 0xbb
privateStream1 = 0xbd
)
type subStreamPacket struct {
number int
buf []byte
}
var startAndStreamNames = scalar.URangeToScalar{
{Range: [2]uint64{0x00, 0x00}, S: scalar.S{Sym: "picture"}},
{Range: [2]uint64{0x01, 0xaf}, S: scalar.S{Sym: "slice"}},
{Range: [2]uint64{0xb0, 0xb1}, S: scalar.S{Sym: "reserved"}},
{Range: [2]uint64{0xb2, 0xb2}, S: scalar.S{Sym: "user_data"}},
{Range: [2]uint64{0xb3, 0xb3}, S: scalar.S{Sym: "sequence_header"}},
{Range: [2]uint64{0xb4, 0xb4}, S: scalar.S{Sym: "sequence_error"}},
{Range: [2]uint64{0xb5, 0xb5}, S: scalar.S{Sym: "extension"}},
{Range: [2]uint64{0xb6, 0xb6}, S: scalar.S{Sym: "reserved"}},
{Range: [2]uint64{0xb7, 0xb7}, S: scalar.S{Sym: "sequence_end"}},
{Range: [2]uint64{0xb8, 0xb8}, S: scalar.S{Sym: "group_of_pictures"}},
{Range: [2]uint64{0xb9, 0xb9}, S: scalar.S{Sym: "program_end"}},
{Range: [2]uint64{0xba, 0xba}, S: scalar.S{Sym: "pack_header"}},
{Range: [2]uint64{0xbb, 0xbb}, S: scalar.S{Sym: "system_header"}},
{Range: [2]uint64{0xbc, 0xbc}, S: scalar.S{Sym: "program_stream_map"}},
{Range: [2]uint64{0xbd, 0xbd}, S: scalar.S{Sym: "private_stream1"}},
{Range: [2]uint64{0xbe, 0xbe}, S: scalar.S{Sym: "padding_stream"}},
{Range: [2]uint64{0xbf, 0xbf}, S: scalar.S{Sym: "private_stream2"}},
{Range: [2]uint64{0xc0, 0xdf}, S: scalar.S{Sym: "audio_stream"}},
{Range: [2]uint64{0xe0, 0xef}, S: scalar.S{Sym: "video_stream"}},
{Range: [2]uint64{0xf0, 0xf0}, S: scalar.S{Sym: "ecm_stream"}},
{Range: [2]uint64{0xf1, 0xf1}, S: scalar.S{Sym: "emm_stream"}},
{Range: [2]uint64{0xf2, 0xf2}, S: scalar.S{Sym: "itu_t_rec_h_222_0"}},
{Range: [2]uint64{0xf3, 0xf3}, S: scalar.S{Sym: "iso_iec_13522_stream"}},
{Range: [2]uint64{0xf4, 0xf4}, S: scalar.S{Sym: "itu_t_rec_h_222_1_type_a"}},
{Range: [2]uint64{0xf5, 0xf5}, S: scalar.S{Sym: "itu_t_rec_h_222_1_type_b"}},
{Range: [2]uint64{0xf6, 0xf6}, S: scalar.S{Sym: "itu_t_rec_h_222_1_type_c"}},
{Range: [2]uint64{0xf7, 0xf7}, S: scalar.S{Sym: "itu_t_rec_h_222_1_type_d"}},
{Range: [2]uint64{0xf8, 0xf8}, S: scalar.S{Sym: "itu_t_rec_h_222_1_type_e"}},
{Range: [2]uint64{0xf9, 0xf9}, S: scalar.S{Sym: "ancillary_stream"}},
{Range: [2]uint64{0xfa, 0xfe}, S: scalar.S{Sym: "reserved"}},
{Range: [2]uint64{0xff, 0xff}, S: scalar.S{Sym: "program_stream_directory"}},
}
var mpegVersion = scalar.UToDescription{
0b01: "MPEG2",
0b10: "MPEG1",
}
func pesPacketDecode(d *decode.D, _ any) any {
var v any
d.FieldU24("prefix", d.AssertU(0b0000_0000_0000_0000_0000_0001), scalar.ActualBin)
startCode := d.FieldU8("start_code", startAndStreamNames, scalar.ActualHex)
switch {
case startCode == sequenceHeader:
d.FieldU12("horizontal_size")
d.FieldU12("vertical_size")
d.FieldU4("aspect_ratio")
d.FieldU4("frame_rate_code")
// TODO: bit rate * 400, rounded upwards. Use 0x3FFFF for variable bit rate
d.FieldU18("bit_rate")
d.FieldU1("marker_bit")
d.FieldU10("vbv_buf_size")
d.FieldU1("constrained_parameters_flag")
loadIntraQuantizerMatrix := d.FieldBool("load_intra_quantizer_matrix")
if loadIntraQuantizerMatrix {
d.FieldRawLen("intra_quantizer_matrix", 8*64)
}
loadNonIntraQuantizerMatrix := d.FieldBool("load_non_intra_quantizer_matrix")
if loadNonIntraQuantizerMatrix {
d.FieldRawLen("non_intra_quantizer_matrix", 8*64)
}
case startCode == packHeader:
isMPEG2 := d.PeekBits(2) == 0b01
if isMPEG2 {
d.FieldU2("marker_bits0", mpegVersion)
} else {
d.FieldU4("marker_bits0", mpegVersion)
}
scr0 := d.FieldU3("system_clock0")
d.FieldU1("marker_bits1")
scr1 := d.FieldU15("system_clock1")
d.FieldU1("marker_bits2")
scr2 := d.FieldU15("system_clock2")
d.FieldU1("marker_bits3")
if isMPEG2 {
d.FieldU9("scr_ext")
}
d.FieldU1("marker_bits4")
scr := scr0<<30 | scr1<<15 | scr2
d.FieldValueU("scr", scr)
d.FieldU22("mux_rate")
d.FieldU1("marker_bits5")
if isMPEG2 {
d.FieldU1("marker_bits6")
d.FieldU5("reserved")
packStuffingLength := d.FieldU3("pack_stuffing_length")
if packStuffingLength > 0 {
d.FieldRawLen("stuffing", int64(packStuffingLength*8))
}
}
case startCode == systemHeader:
d.FieldU16("length")
d.FieldU1("skip0")
d.FieldU22("rate_bound")
d.FieldU1("skip1")
d.FieldU6("audio_bound")
d.FieldU1("fixed_flag")
d.FieldU1("csps_flag")
d.FieldU1("system_audio_lock_flag")
d.FieldU1("system_video_lock_flag")
d.FieldU1("skip2")
d.FieldU5("video_bound")
d.FieldU1("packet_rate_restriction_flag")
d.FieldU7("reserved")
d.FieldArray("stream_bound_entries", func(d *decode.D) {
for d.PeekBits(1) == 1 {
d.FieldStruct("stream_bound_entry", func(d *decode.D) {
d.FieldU8("stream_id")
d.FieldU2("skip0")
d.FieldU1("pstd_buffer_bound_scale")
d.FieldU13("pstd_buffer_size_bound")
})
}
})
case startCode >= 0xbd:
length := d.FieldU16("length")
// 0xbd-0xbd // Privatestream1
// 0xc0-0xdf // MPEG1OrMPEG2AudioStream
// 0xe0-0xef // MPEG1OrMPEG2VideoStream
hasExtension := startCode == 0xbd || (startCode >= 0xc0 && startCode <= 0xef)
var headerDataLength uint64
var extensionLength uint64
if hasExtension {
extensionLength = 3
d.FieldStruct("extension", func(d *decode.D) {
d.FieldU2("skip0")
d.FieldU2("scramble_control")
d.FieldU1("priority")
d.FieldU1("data_alignment_indicator")
d.FieldU1("copyright")
d.FieldU1("original")
d.FieldU2("pts_dts_flags")
d.FieldU1("escr_flag")
d.FieldU1("es_rate_flag")
d.FieldU1("dsm_trick_mode_flag")
d.FieldU1("additional_copy_info_flag")
d.FieldU1("pes_crc_flag")
d.FieldU1("pes_ext_flag")
headerDataLength = d.FieldU8("header_data_length")
})
// TODO:
d.FieldRawLen("header_data", int64(headerDataLength)*8)
}
dataLen := int64(length-headerDataLength-extensionLength) * 8
switch startCode {
case privateStream1:
d.FieldStruct("data", func(d *decode.D) {
d.FramedFn(dataLen, func(d *decode.D) {
substreamNumber := d.FieldU8("substream")
substreamBR := d.FieldRawLen("data", dataLen-8)
v = subStreamPacket{
number: int(substreamNumber),
buf: d.ReadAllBits(substreamBR),
}
})
})
default:
d.FieldRawLen("data", dataLen)
}
default:
d.FieldRawLen("data", d.BitsLeft())
}
return v
}