1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
use ebml_struct::{
Size,
ids::{
EL_ATTACHMENTS, EL_CHAPTERS, EL_CLUSTER, EL_CRC32, EL_CUES, EL_EBML, EL_INFO, EL_SEEKHEAD,
EL_SEGMENT, EL_TAGS, EL_TRACKS, EL_VOID,
},
matroska::{Cluster, Ebml, Info, Tags, Tracks},
read::{EbmlReadExt, TagRead},
write::{EbmlWriteExt, TagWrite},
};
use std::io::{BufReader, BufWriter, ErrorKind, Read, Result, stdin, stdout};
pub trait BitstreamFilter: Sized {
const INPUT_CODEC_ID: &str;
const OUTPUT_CODEC_ID: &str;
fn new(width: u32, height: u32) -> Self;
fn process_block(&mut self, a: Vec<u8>) -> Vec<u8>;
}
pub fn bitstream_filter_main<F: BitstreamFilter>() -> Result<()> {
let mut inp = BufReader::new(stdin());
let mut out = BufWriter::new(stdout());
let (id, inner) = inp.read_tag()?;
assert_eq!(id, EL_EBML);
inner.consume()?;
Ebml {
ebml_version: 1,
ebml_read_version: 1,
ebml_max_id_length: 4,
ebml_max_size_length: 8,
doc_type: "matroska".to_string(),
doc_type_version: 4,
doc_type_read_version: 2,
doc_type_extensions: vec![],
}
.write(&mut out)?;
let (id, mut segment) = inp.read_tag()?;
assert_eq!(id, EL_SEGMENT);
out.write_tag_id(EL_SEGMENT)?;
out.write_size(Size::Unknown)?;
let (mut info, mut tracks) = read_info_and_tracks(&mut segment)?;
info.muxing_app = "ebml-struct".to_string();
info.writing_app = "video-codec-experiments".to_string();
let mut encode_track = None;
for t in &mut tracks.entries {
if t.track_type == 1 && encode_track.is_none() {
assert_eq!(t.codec_id, F::INPUT_CODEC_ID);
t.codec_id = F::OUTPUT_CODEC_ID.to_string();
t.codec_private = None;
t.codec_download_urls =
vec!["https://codeberg.org/metamuffin/video-codec-experiments".to_string()];
encode_track = Some(t.clone());
}
}
let filter_track = encode_track.expect("no video track found");
tracks.write(&mut out)?;
info.write(&mut out)?;
let mut filter = F::new(
filter_track.video.as_ref().unwrap().pixel_width as u32,
filter_track.video.as_ref().unwrap().pixel_height as u32,
);
loop {
let (id, mut element) = match segment.read_tag() {
Ok(x) => x,
Err(e) if e.kind() == ErrorKind::UnexpectedEof => break,
Err(e) => return Err(e),
};
match id {
EL_CUES | EL_ATTACHMENTS | EL_SEEKHEAD | EL_CHAPTERS | EL_CRC32 | EL_VOID => {
element.consume()?;
}
EL_TAGS => {
Tags::read(&mut element)?.write(&mut out)?;
}
EL_CLUSTER => {
let mut cluster = Cluster::read(&mut element)?;
for b in &mut cluster.simple_blocks {
if b.track == filter_track.track_number {
assert_eq!(b.lacing, None);
assert_eq!(b.discardable, false);
assert_eq!(b.keyframe, true);
b.data = filter.process_block(b.data.clone());
}
}
cluster.write(&mut out)?;
}
_ => {
eprintln!("unhandled element {id:x}");
element.consume()?;
}
}
}
Ok(())
}
fn read_info_and_tracks(mut segment: impl Read) -> Result<(Info, Tracks)> {
let mut info = None;
let mut tracks = None;
loop {
let (id, mut element) = segment.read_tag()?;
match id {
EL_CUES | EL_TAGS | EL_ATTACHMENTS | EL_SEEKHEAD | EL_CHAPTERS | EL_CRC32 | EL_VOID => {
element.consume()?;
}
EL_INFO => {
info = Some(Info::read(&mut element)?);
}
EL_TRACKS => {
tracks = Some(Tracks::read(&mut element)?);
}
EL_CLUSTER => {
eprintln!("not ready for clusters yet");
element.consume()?;
}
_ => {
eprintln!("unhandled element {id:x}");
element.consume()?;
}
};
if tracks.is_some() && info.is_some() {
break Ok((info.unwrap(), tracks.unwrap()));
}
}
}
|
