Lucas RayanandClaude Sonnet 5
6328220c60
CI / Format and clippy (push) Successful in 1m57s
CI / Dependency audit (push) Successful in 13s
CI / Check desktop app (Linux) (push) Successful in 3m54s
CI / Tests (Linux) (push) Failing after 7m25s
Release / Create release (push) Successful in 6s
Release / CLI (linux-aarch64) (push) Successful in 1m48s
Release / CLI (linux-x86_64) (push) Successful in 2m39s
Release / Desktop app (linux-aarch64) (push) Successful in 10m9s
Release / Desktop app (linux-x86_64) (push) Successful in 12m20s
Release / Desktop app (windows) (push) Successful in 7m32s
Release / Build latest.json (push) Successful in 5s
Completes the English-only standardization for code, comments, scripts and CI templates (UI/CLI-facing strings stay bilingual pt-BR/en, untouched). Covers the remaining crates/, apps/gui/ui/ and apps/gui/src-tauri/ comments, .gitea/ workflow and template comments, .githooks/ hooks, and the scripts/ source comments for the files already renamed in a prior commit (check.sh, generate-logo.py, install-hooks.sh). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01VAyr8d7HuAdUGB6aA5xmDD
1284 lines
42 KiB
Rust
1284 lines
42 KiB
Rust
//! Reconstructs MP4/MOV video files missing their `moov` atom (interrupted camera/drone recordings
|
|
//! or truncated files). Video frames sit in `mdat` as length-prefixed NAL units; we rebuild the
|
|
//! `moov` index from them: sample sizes, keyframes, timing, and for H.264, presentation order
|
|
//! (POC) when B-frames are present. Audio tracks are not reconstructed.
|
|
|
|
use crate::source::{read_vec, Source};
|
|
|
|
fn be32(b: &[u8], o: usize) -> u32 {
|
|
b.get(o..o + 4)
|
|
.map(|s| u32::from_be_bytes(s.try_into().unwrap()))
|
|
.unwrap_or(0)
|
|
}
|
|
|
|
// ------------------------------------------------------------------ bits
|
|
|
|
struct Bits<'a> {
|
|
d: &'a [u8],
|
|
pos: usize,
|
|
}
|
|
|
|
impl<'a> Bits<'a> {
|
|
fn new(d: &'a [u8]) -> Self {
|
|
Self { d, pos: 0 }
|
|
}
|
|
fn bit(&mut self) -> Option<u32> {
|
|
let b = *self.d.get(self.pos / 8)?;
|
|
let v = (b >> (7 - self.pos % 8)) & 1;
|
|
self.pos += 1;
|
|
Some(v as u32)
|
|
}
|
|
fn u(&mut self, n: u32) -> Option<u32> {
|
|
let mut v = 0u32;
|
|
for _ in 0..n {
|
|
v = (v << 1) | self.bit()?;
|
|
}
|
|
Some(v)
|
|
}
|
|
fn ue(&mut self) -> Option<u32> {
|
|
let mut z = 0;
|
|
while self.bit()? == 0 {
|
|
z += 1;
|
|
if z > 31 {
|
|
return None;
|
|
}
|
|
}
|
|
Some(((1u64 << z) - 1 + self.u(z)? as u64) as u32)
|
|
}
|
|
fn se(&mut self) -> Option<i32> {
|
|
let k = self.ue()?;
|
|
Some(if k % 2 == 1 {
|
|
(k / 2 + 1) as i32
|
|
} else {
|
|
-((k / 2) as i32)
|
|
})
|
|
}
|
|
fn skip(&mut self, n: usize) {
|
|
self.pos += n;
|
|
}
|
|
}
|
|
|
|
/// Strips H.264/HEVC emulation prevention bytes (`00 00 03` -> `00 00`).
|
|
fn unescape(nal: &[u8]) -> Vec<u8> {
|
|
let mut out = Vec::with_capacity(nal.len());
|
|
let mut z = 0;
|
|
for &b in nal {
|
|
if z >= 2 && b == 3 {
|
|
z = 0;
|
|
continue;
|
|
}
|
|
z = if b == 0 { z + 1 } else { 0 };
|
|
out.push(b);
|
|
}
|
|
out
|
|
}
|
|
|
|
// ------------------------------------------------------------------ H.264
|
|
|
|
#[derive(Clone, Debug, Default)]
|
|
pub struct Sps264 {
|
|
pub profile: u8,
|
|
pub compat: u8,
|
|
pub level: u8,
|
|
pub width: u32,
|
|
pub height: u32,
|
|
pub log2_max_frame_num: u32,
|
|
pub poc_type: u32,
|
|
pub log2_max_poc_lsb: u32,
|
|
pub frame_mbs_only: bool,
|
|
/// `(num_units_in_tick, time_scale)` from VUI timing info.
|
|
pub timing: Option<(u32, u32)>,
|
|
}
|
|
|
|
fn skip_scaling_list(b: &mut Bits, n: usize) -> Option<()> {
|
|
let (mut last, mut next) = (8i32, 8i32);
|
|
for _ in 0..n {
|
|
if next != 0 {
|
|
next = (last + b.se()? + 256) % 256;
|
|
}
|
|
last = if next == 0 { last } else { next };
|
|
}
|
|
Some(())
|
|
}
|
|
|
|
pub fn parse_sps264(nal: &[u8]) -> Option<Sps264> {
|
|
if nal.len() < 5 || nal[0] & 0x1F != 7 {
|
|
return None;
|
|
}
|
|
let rbsp = unescape(&nal[1..]);
|
|
let mut b = Bits::new(&rbsp);
|
|
let mut s = Sps264 {
|
|
profile: b.u(8)? as u8,
|
|
compat: b.u(8)? as u8,
|
|
level: b.u(8)? as u8,
|
|
..Default::default()
|
|
};
|
|
b.ue()?; // sps_id
|
|
let mut chroma = 1;
|
|
if matches!(
|
|
s.profile,
|
|
100 | 110 | 122 | 244 | 44 | 83 | 86 | 118 | 128 | 138 | 139 | 134 | 135
|
|
) {
|
|
chroma = b.ue()?;
|
|
if chroma == 3 {
|
|
b.bit()?;
|
|
}
|
|
b.ue()?;
|
|
b.ue()?;
|
|
b.bit()?;
|
|
if b.bit()? == 1 {
|
|
for i in 0..(if chroma != 3 { 8 } else { 12 }) {
|
|
if b.bit()? == 1 {
|
|
skip_scaling_list(&mut b, if i < 6 { 16 } else { 64 })?;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
s.log2_max_frame_num = b.ue()? + 4;
|
|
s.poc_type = b.ue()?;
|
|
match s.poc_type {
|
|
0 => s.log2_max_poc_lsb = b.ue()? + 4,
|
|
1 => {
|
|
b.bit()?;
|
|
b.se()?;
|
|
b.se()?;
|
|
let n = b.ue()?;
|
|
for _ in 0..n.min(255) {
|
|
b.se()?;
|
|
}
|
|
}
|
|
_ => {}
|
|
}
|
|
b.ue()?; // max_num_ref_frames
|
|
b.bit()?;
|
|
let w = b.ue()? + 1;
|
|
let h = b.ue()? + 1;
|
|
s.frame_mbs_only = b.bit()? == 1;
|
|
if !s.frame_mbs_only {
|
|
b.bit()?;
|
|
}
|
|
b.bit()?;
|
|
let (mut cl, mut cr, mut ct, mut cb) = (0, 0, 0, 0);
|
|
if b.bit()? == 1 {
|
|
cl = b.ue()?;
|
|
cr = b.ue()?;
|
|
ct = b.ue()?;
|
|
cb = b.ue()?;
|
|
}
|
|
let (sub_w, sub_h) = match chroma {
|
|
0 => (1, 2 - s.frame_mbs_only as u32),
|
|
1 => (2, 2 * (2 - s.frame_mbs_only as u32)),
|
|
2 => (2, 2 - s.frame_mbs_only as u32),
|
|
_ => (1, 2 - s.frame_mbs_only as u32),
|
|
};
|
|
s.width = (w * 16).checked_sub((cl + cr) * sub_w)?;
|
|
s.height = ((2 - s.frame_mbs_only as u32) * h * 16).checked_sub((ct + cb) * sub_h)?;
|
|
// Parse VUI parameters up to `timing_info_present_flag`.
|
|
if b.bit()? == 1 {
|
|
if b.bit()? == 1 && b.u(8)? == 255 {
|
|
b.skip(32);
|
|
}
|
|
if b.bit()? == 1 {
|
|
b.bit()?;
|
|
}
|
|
if b.bit()? == 1 {
|
|
b.skip(4);
|
|
if b.bit()? == 1 {
|
|
b.skip(24);
|
|
}
|
|
}
|
|
if b.bit()? == 1 {
|
|
b.ue()?;
|
|
b.ue()?;
|
|
}
|
|
if b.bit()? == 1 {
|
|
let units = b.u(32)?;
|
|
let scale = b.u(32)?;
|
|
if units > 0 && scale > 0 {
|
|
s.timing = Some((units, scale));
|
|
}
|
|
}
|
|
}
|
|
Some(s)
|
|
}
|
|
|
|
/// Parses `(first_mb == 0, slice_type, pps_id, frame_num, is_idr, poc_lsb)` from an H.264 slice header.
|
|
struct SliceInfo {
|
|
frame_num: u32,
|
|
first_mb0: bool,
|
|
idr: bool,
|
|
poc_lsb: Option<u32>,
|
|
bottom: bool,
|
|
}
|
|
|
|
fn slice264(nal: &[u8], sps: &Sps264, pic_order_present: bool) -> Option<SliceInfo> {
|
|
let rbsp = unescape(&nal[1..nal.len().min(48)]);
|
|
let mut b = Bits::new(&rbsp);
|
|
let first = b.ue()?;
|
|
b.ue()?; // slice_type
|
|
b.ue()?; // pps_id
|
|
let frame_num = b.u(sps.log2_max_frame_num)?;
|
|
let mut bottom = false;
|
|
if !sps.frame_mbs_only && b.bit()? == 1 {
|
|
bottom = b.bit()? == 1;
|
|
}
|
|
let idr = nal[0] & 0x1F == 5;
|
|
if idr {
|
|
b.ue()?;
|
|
}
|
|
let mut poc_lsb = None;
|
|
if sps.poc_type == 0 {
|
|
poc_lsb = Some(b.u(sps.log2_max_poc_lsb)?);
|
|
let _ = pic_order_present;
|
|
}
|
|
Some(SliceInfo {
|
|
frame_num,
|
|
first_mb0: first == 0,
|
|
idr,
|
|
poc_lsb,
|
|
bottom,
|
|
})
|
|
}
|
|
|
|
/// Extracts `bottom_field_pic_order_in_frame_present_flag` from an H.264 PPS.
|
|
fn pps_pic_order_present(nal: &[u8]) -> bool {
|
|
let rbsp = unescape(&nal[1..]);
|
|
let mut b = Bits::new(&rbsp);
|
|
let (Some(_), Some(_), Some(_)) = (b.ue(), b.ue(), b.bit()) else {
|
|
return false;
|
|
};
|
|
b.bit() == Some(1)
|
|
}
|
|
|
|
// ------------------------------------------------------------------ HEVC
|
|
|
|
#[derive(Clone, Debug, Default)]
|
|
pub struct SpsHevc {
|
|
pub width: u32,
|
|
pub height: u32,
|
|
pub ptl: [u8; 12],
|
|
pub chroma: u32,
|
|
pub bit_depth_luma: u32,
|
|
pub bit_depth_chroma: u32,
|
|
pub timing: Option<(u32, u32)>,
|
|
}
|
|
|
|
pub fn parse_sps_hevc(nal: &[u8]) -> Option<SpsHevc> {
|
|
if nal.len() < 8 || (nal[0] >> 1) & 0x3F != 33 {
|
|
return None;
|
|
}
|
|
let rbsp = unescape(&nal[2..]);
|
|
let mut b = Bits::new(&rbsp);
|
|
b.u(4)?; // vps id
|
|
let max_sub = b.u(3)? as usize;
|
|
b.bit()?;
|
|
// profile_tier_level
|
|
let mut s = SpsHevc::default();
|
|
for (i, v) in s.ptl.iter_mut().enumerate() {
|
|
*v = b.u(8)? as u8;
|
|
let _ = i;
|
|
}
|
|
// general profile/tier/level: 2+1+5 bits, 32 compat, 48 constraint flags, 8 level => 12 bytes (1+4+6+1)
|
|
let mut sub_profile = vec![];
|
|
let mut sub_level = vec![];
|
|
for _ in 0..max_sub {
|
|
sub_profile.push(b.bit()?);
|
|
sub_level.push(b.bit()?);
|
|
}
|
|
if max_sub > 0 {
|
|
for _ in max_sub..8 {
|
|
b.u(2)?;
|
|
}
|
|
}
|
|
for i in 0..max_sub {
|
|
if sub_profile[i] == 1 {
|
|
b.skip(88);
|
|
}
|
|
if sub_level[i] == 1 {
|
|
b.skip(8);
|
|
}
|
|
}
|
|
b.ue()?; // sps id
|
|
s.chroma = b.ue()?;
|
|
if s.chroma == 3 {
|
|
b.bit()?;
|
|
}
|
|
s.width = b.ue()?;
|
|
s.height = b.ue()?;
|
|
if b.bit()? == 1 {
|
|
let (l, r, t, bt) = (b.ue()?, b.ue()?, b.ue()?, b.ue()?);
|
|
let (sw, sh) = match s.chroma {
|
|
1 => (2, 2),
|
|
2 => (2, 1),
|
|
_ => (1, 1),
|
|
};
|
|
s.width = s.width.checked_sub((l + r) * sw)?;
|
|
s.height = s.height.checked_sub((t + bt) * sh)?;
|
|
}
|
|
s.bit_depth_luma = b.ue()? + 8;
|
|
s.bit_depth_chroma = b.ue()? + 8;
|
|
Some(s)
|
|
}
|
|
|
|
// -------------------------------------------------------------- samples
|
|
|
|
/// Codec parameter sets (SPS/PPS/VPS) extracted from a donor video recorded by the same camera.
|
|
#[derive(Clone, Debug)]
|
|
pub struct MediaConfig {
|
|
pub codec: Codec,
|
|
pub sps: Vec<Vec<u8>>,
|
|
pub pps: Vec<Vec<u8>>,
|
|
pub vps: Vec<Vec<u8>>,
|
|
}
|
|
|
|
/// Extracts `avcC`/`hvcC` codec configuration from an intact MP4 (reading up to `max` bytes from `off`).
|
|
pub fn config_from_mp4(src: &dyn Source, off: u64, max: u64) -> Option<MediaConfig> {
|
|
// The `moov` atom is typically near the beginning or the end of the file: check both.
|
|
let size = src.size();
|
|
let head = read_vec(src, off, max.min(4 << 20) as usize).ok()?;
|
|
let mut hay: Vec<Vec<u8>> = vec![head];
|
|
if max > (4 << 20) && off + max <= size {
|
|
let tail_off = off + max - (4 << 20).min(max);
|
|
hay.push(read_vec(src, tail_off, (off + max - tail_off) as usize).ok()?);
|
|
}
|
|
for h in hay {
|
|
for i in 4..h.len().saturating_sub(12) {
|
|
let tag = &h[i..i + 4];
|
|
if tag == b"avcC" {
|
|
let c = &h[i + 4..];
|
|
if c.len() > 8 && c[0] == 1 {
|
|
let mut p = 6;
|
|
let mut sps = vec![];
|
|
for _ in 0..(c[5] & 0x1F) {
|
|
let l = u16::from_be_bytes([*c.get(p)?, *c.get(p + 1)?]) as usize;
|
|
sps.push(c.get(p + 2..p + 2 + l)?.to_vec());
|
|
p += 2 + l;
|
|
}
|
|
let np = *c.get(p)? as usize;
|
|
p += 1;
|
|
let mut pps = vec![];
|
|
for _ in 0..np {
|
|
let l = u16::from_be_bytes([*c.get(p)?, *c.get(p + 1)?]) as usize;
|
|
pps.push(c.get(p + 2..p + 2 + l)?.to_vec());
|
|
p += 2 + l;
|
|
}
|
|
if !sps.is_empty() && !pps.is_empty() {
|
|
return Some(MediaConfig {
|
|
codec: Codec::Avc,
|
|
sps,
|
|
pps,
|
|
vps: vec![],
|
|
});
|
|
}
|
|
}
|
|
} else if tag == b"hvcC" {
|
|
let c = &h[i + 4..];
|
|
if c.len() > 23 && c[0] == 1 {
|
|
let n = c[22] as usize;
|
|
let mut p = 23;
|
|
let (mut vps, mut sps, mut pps) = (vec![], vec![], vec![]);
|
|
for _ in 0..n {
|
|
let t = c.get(p)? & 0x3F;
|
|
let cnt = u16::from_be_bytes([*c.get(p + 1)?, *c.get(p + 2)?]) as usize;
|
|
p += 3;
|
|
for _ in 0..cnt {
|
|
let l = u16::from_be_bytes([*c.get(p)?, *c.get(p + 1)?]) as usize;
|
|
let nal = c.get(p + 2..p + 2 + l)?.to_vec();
|
|
match t {
|
|
32 => vps.push(nal),
|
|
33 => sps.push(nal),
|
|
34 => pps.push(nal),
|
|
_ => {}
|
|
}
|
|
p += 2 + l;
|
|
}
|
|
}
|
|
if !sps.is_empty() && !pps.is_empty() {
|
|
return Some(MediaConfig {
|
|
codec: Codec::Hevc,
|
|
sps,
|
|
pps,
|
|
vps,
|
|
});
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
None
|
|
}
|
|
|
|
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
|
|
pub enum Codec {
|
|
Avc,
|
|
Hevc,
|
|
}
|
|
|
|
#[derive(Clone, Debug)]
|
|
struct Sample {
|
|
/// Absolute source offset of the first byte of the sample (including the 4-byte length prefix).
|
|
off: u64,
|
|
size: u32,
|
|
sync: bool,
|
|
poc: Option<i64>,
|
|
idr: bool,
|
|
}
|
|
|
|
pub struct Rebuilt {
|
|
/// Leading atoms from the original file before `mdat` (`ftyp`, etc.).
|
|
pub pre_len: u64,
|
|
/// Start and end offsets of the video sample payload in the source.
|
|
pub payload: (u64, u64),
|
|
pub moov: Vec<u8>,
|
|
pub frames: usize,
|
|
pub width: u32,
|
|
pub height: u32,
|
|
pub codec: Codec,
|
|
pub fps: f64,
|
|
pub skipped_bytes: u64,
|
|
}
|
|
|
|
impl Rebuilt {
|
|
/// 16-byte 64-bit `mdat` atom header covering the sample payload.
|
|
pub fn mdat_header(&self) -> Vec<u8> {
|
|
let size = 16 + (self.payload.1 - self.payload.0);
|
|
let mut v = Vec::with_capacity(16);
|
|
v.extend_from_slice(&1u32.to_be_bytes());
|
|
v.extend_from_slice(b"mdat");
|
|
v.extend_from_slice(&size.to_be_bytes());
|
|
v
|
|
}
|
|
}
|
|
|
|
fn avc_nal_ok(b: u8) -> bool {
|
|
b & 0x80 == 0 && matches!(b & 0x1F, 1 | 5..=12)
|
|
}
|
|
fn hevc_nal_ok(b0: u8, b1: u8) -> bool {
|
|
b0 & 0x81 == 0 && ((b0 >> 1) & 0x3F) <= 40 && b1 & 0x07 != 0 && (b1 >> 3) == 0
|
|
}
|
|
|
|
/// Parses the `mdat` header at `at`: returns `(payload_start, declared_end_or_0)`.
|
|
fn mdat_at(src: &dyn Source, at: u64) -> Option<(u64, u64)> {
|
|
let h = read_vec(src, at, 16).ok()?;
|
|
if h.len() < 8 || &h[4..8] != b"mdat" {
|
|
return None;
|
|
}
|
|
let sz = be32(&h, 0) as u64;
|
|
if sz == 1 && h.len() >= 16 {
|
|
Some((at + 16, u64::from_be_bytes(h[8..16].try_into().unwrap())))
|
|
} else {
|
|
Some((at + 8, sz))
|
|
}
|
|
}
|
|
|
|
/// Rebuilds the `moov` index for a headerless/truncated MP4 starting at `off` (reading at most `avail` bytes).
|
|
pub fn rebuild(src: &dyn Source, off: u64, avail: u64, refs: &[MediaConfig]) -> Option<Rebuilt> {
|
|
if let Some(r) = rebuild_with(src, off, avail, None) {
|
|
return Some(r);
|
|
}
|
|
refs.iter()
|
|
.find_map(|c| rebuild_with(src, off, avail, Some(c)))
|
|
}
|
|
|
|
fn rebuild_with(
|
|
src: &dyn Source,
|
|
off: u64,
|
|
avail: u64,
|
|
preset: Option<&MediaConfig>,
|
|
) -> Option<Rebuilt> {
|
|
// Parse leading atoms before `mdat`.
|
|
let mut p = 0u64;
|
|
let mut pre_end = None;
|
|
for _ in 0..16 {
|
|
let h = read_vec(src, off + p, 16).ok()?;
|
|
if h.len() < 8 {
|
|
return None;
|
|
}
|
|
let ty = &h[4..8];
|
|
if ty == b"mdat" {
|
|
pre_end = Some(p);
|
|
break;
|
|
}
|
|
if !matches!(
|
|
ty,
|
|
b"ftyp" | b"free" | b"skip" | b"wide" | b"uuid" | b"pnot" | b"junk" | b"styp"
|
|
) {
|
|
return None;
|
|
}
|
|
let sz = be32(&h, 0) as u64;
|
|
if sz < 8 {
|
|
return None;
|
|
}
|
|
p += sz;
|
|
}
|
|
let pre_len = pre_end?;
|
|
let (data_start, declared) = mdat_at(src, off + pre_len)?;
|
|
let hard_end = off + avail.min(src.size() - off);
|
|
let data_end_decl = if declared == 0 {
|
|
hard_end
|
|
} else {
|
|
(off + pre_len + declared).min(hard_end)
|
|
};
|
|
|
|
// Scan the `mdat` payload in chunks, parsing length-prefixed NAL units.
|
|
let mut samples: Vec<Sample> = vec![];
|
|
let mut cache: Vec<u8> = vec![];
|
|
let mut cache_off = data_start;
|
|
let read_at = |o: u64, n: usize, cache: &mut Vec<u8>, cache_off: &mut u64| -> Option<Vec<u8>> {
|
|
if o < *cache_off || o + n as u64 > *cache_off + cache.len() as u64 {
|
|
let want = (data_end_decl.saturating_sub(o) as usize)
|
|
.min(8 << 20)
|
|
.max(n)
|
|
.min((hard_end - o) as usize);
|
|
*cache = read_vec(src, o, want).ok()?;
|
|
*cache_off = o;
|
|
}
|
|
let s = (o - *cache_off) as usize;
|
|
cache.get(s..s + n).map(|x| x.to_vec())
|
|
};
|
|
// Detect the codec (H.264 vs HEVC) that yields the longest initial chain of valid NAL units.
|
|
let chain = |c: Codec| -> usize {
|
|
let Ok(head) = read_vec(src, data_start, 64 << 10) else {
|
|
return 0;
|
|
};
|
|
let mut p = 0usize;
|
|
let mut n = 0;
|
|
while p + 6 <= head.len() {
|
|
let l = be32(&head, p) as usize;
|
|
let ok = (1..=8 << 20).contains(&l)
|
|
&& match c {
|
|
Codec::Avc => avc_nal_ok(head[p + 4]),
|
|
Codec::Hevc => hevc_nal_ok(head[p + 4], head[p + 5]),
|
|
};
|
|
if !ok {
|
|
break;
|
|
}
|
|
n += 1;
|
|
p += 4 + l;
|
|
}
|
|
n
|
|
};
|
|
let codec = match preset {
|
|
Some(c) => Some(c.codec),
|
|
None => {
|
|
let (a, h) = (chain(Codec::Avc), chain(Codec::Hevc));
|
|
if a == 0 && h == 0 {
|
|
None
|
|
} else if a >= h {
|
|
Some(Codec::Avc)
|
|
} else {
|
|
Some(Codec::Hevc)
|
|
}
|
|
}
|
|
};
|
|
let codec = codec?;
|
|
let mut pos = data_start;
|
|
let mut payload_end = data_start;
|
|
let mut sps_nals: Vec<Vec<u8>> = vec![];
|
|
let mut pps_nals: Vec<Vec<u8>> = vec![];
|
|
let mut vps_nals: Vec<Vec<u8>> = vec![];
|
|
let mut sps264: Option<Sps264> = None;
|
|
let mut sps265: Option<SpsHevc> = None;
|
|
let mut pic_order_present = false;
|
|
if let Some(c) = preset {
|
|
sps_nals = c.sps.clone();
|
|
pps_nals = c.pps.clone();
|
|
vps_nals = c.vps.clone();
|
|
match codec {
|
|
Codec::Avc => {
|
|
sps264 = c.sps.iter().find_map(|n| parse_sps264(n));
|
|
pic_order_present = c
|
|
.pps
|
|
.first()
|
|
.map(|p| pps_pic_order_present(p))
|
|
.unwrap_or(false);
|
|
}
|
|
Codec::Hevc => sps265 = c.sps.iter().find_map(|n| parse_sps_hevc(n)),
|
|
}
|
|
}
|
|
let mut idr_total = 0usize;
|
|
let mut idr_bad = 0usize;
|
|
let mut cur: Option<Sample> = None;
|
|
let mut group_start: Option<u64> = None; // start offset of the non-VCL NAL group preceding a frame
|
|
let mut nal_count = 0usize;
|
|
let mut max_len = 0u64;
|
|
// POC (H.264 pic_order_cnt_type 0)
|
|
let mut prev_msb: i64 = 0;
|
|
let mut prev_lsb: i64 = 0;
|
|
|
|
'outer: while pos + 6 <= data_end_decl {
|
|
let hdr = read_at(pos, 6, &mut cache, &mut cache_off)?;
|
|
let len = be32(&hdr, 0) as u64;
|
|
let ok = (1..=16 << 20).contains(&len)
|
|
&& pos + 4 + len <= data_end_decl
|
|
&& match codec {
|
|
Codec::Avc => avc_nal_ok(hdr[4]),
|
|
Codec::Hevc => hevc_nal_ok(hdr[4], hdr[5]),
|
|
};
|
|
let mut ok = ok;
|
|
if ok && nal_count >= 3 && len > (max_len * 6).max(1 << 20) {
|
|
// A declared NAL length far larger than valid range is interleaved audio or garbage.
|
|
ok = false;
|
|
}
|
|
if ok {
|
|
let head = read_at(pos + 4, (len as usize).min(48), &mut cache, &mut cache_off)?;
|
|
ok = nal_plausible(codec, &head, len, sps264.as_ref(), pps_nals.len());
|
|
}
|
|
let valid = ok;
|
|
if valid {
|
|
max_len = max_len.max(len);
|
|
}
|
|
if !valid {
|
|
// Likely an interleaved audio chunk: scan ahead for the next plausible video NAL sequence.
|
|
let found = scan_nal(
|
|
src,
|
|
codec,
|
|
pos + 1,
|
|
(pos + (2 << 20)).min(data_end_decl),
|
|
data_end_decl,
|
|
sps264.as_ref(),
|
|
pps_nals.len(),
|
|
(max_len * 6).max(1 << 20),
|
|
);
|
|
match found {
|
|
Some(q) if nal_count > 0 => {
|
|
// Flush the current frame before starting the next one.
|
|
if let Some(mut s) = cur.take() {
|
|
s.size = (group_start.unwrap_or(pos) - s.off) as u32;
|
|
samples.push(s);
|
|
}
|
|
group_start = None;
|
|
pos = q;
|
|
continue 'outer;
|
|
}
|
|
_ => break 'outer,
|
|
}
|
|
}
|
|
let nal_start = pos + 4;
|
|
let nal = read_at(
|
|
nal_start,
|
|
len.min(64 << 10) as usize,
|
|
&mut cache,
|
|
&mut cache_off,
|
|
)?;
|
|
let (is_vcl, first_of_pic, is_idr, ty) = match codec {
|
|
Codec::Avc => {
|
|
let t = nal[0] & 0x1F;
|
|
match t {
|
|
1 | 2 | 5 => {
|
|
let first = sps264
|
|
.as_ref()
|
|
.and_then(|s| slice264(&nal, s, pic_order_present));
|
|
(
|
|
true,
|
|
first.as_ref().map(|f| f.first_mb0).unwrap_or(true),
|
|
t == 5,
|
|
t,
|
|
)
|
|
}
|
|
7 => {
|
|
if sps264.is_none() {
|
|
sps264 = parse_sps264(&nal);
|
|
}
|
|
if !sps_nals.contains(&nal) && sps_nals.len() < 4 {
|
|
sps_nals.push(nal.clone());
|
|
}
|
|
(false, false, false, t)
|
|
}
|
|
8 => {
|
|
if pps_nals.is_empty() {
|
|
pic_order_present = pps_pic_order_present(&nal);
|
|
}
|
|
if !pps_nals.contains(&nal) && pps_nals.len() < 4 {
|
|
pps_nals.push(nal.clone());
|
|
}
|
|
(false, false, false, t)
|
|
}
|
|
_ => (false, false, false, t),
|
|
}
|
|
}
|
|
Codec::Hevc => {
|
|
let t = (nal[0] >> 1) & 0x3F;
|
|
match t {
|
|
0..=9 | 16..=21 => (
|
|
true,
|
|
nal.get(2).map(|b| b & 0x80 != 0).unwrap_or(true),
|
|
(16..=21).contains(&t),
|
|
t,
|
|
),
|
|
32 => {
|
|
if !vps_nals.contains(&nal) && vps_nals.len() < 2 {
|
|
vps_nals.push(nal.clone());
|
|
}
|
|
(false, false, false, t)
|
|
}
|
|
33 => {
|
|
if sps265.is_none() {
|
|
sps265 = parse_sps_hevc(&nal);
|
|
}
|
|
if !sps_nals.contains(&nal) && sps_nals.len() < 4 {
|
|
sps_nals.push(nal.clone());
|
|
}
|
|
(false, false, false, t)
|
|
}
|
|
34 => {
|
|
if !pps_nals.contains(&nal) && pps_nals.len() < 4 {
|
|
pps_nals.push(nal.clone());
|
|
}
|
|
(false, false, false, t)
|
|
}
|
|
_ => (false, false, false, t),
|
|
}
|
|
}
|
|
};
|
|
let _ = ty;
|
|
if is_vcl {
|
|
if first_of_pic {
|
|
// flush previous frame
|
|
if let Some(mut s) = cur.take() {
|
|
// frame size up to the start of the current non-VCL group (or this VCL NAL)
|
|
let end = group_start.unwrap_or(pos);
|
|
s.size = (end - s.off) as u32;
|
|
samples.push(s);
|
|
}
|
|
let start = group_start.take().unwrap_or(pos);
|
|
let mut poc = None;
|
|
if codec == Codec::Avc {
|
|
if let Some(sp) = &sps264 {
|
|
if let Some(si) = slice264(&nal, sp, pic_order_present) {
|
|
if si.idr {
|
|
prev_msb = 0;
|
|
prev_lsb = 0;
|
|
idr_total += 1;
|
|
if si.frame_num != 0 {
|
|
idr_bad += 1;
|
|
}
|
|
}
|
|
if let Some(lsb) = si.poc_lsb {
|
|
let max = 1i64 << sp.log2_max_poc_lsb;
|
|
let lsb = lsb as i64;
|
|
let msb = if lsb < prev_lsb && prev_lsb - lsb >= max / 2 {
|
|
prev_msb + max
|
|
} else if lsb > prev_lsb && lsb - prev_lsb > max / 2 {
|
|
prev_msb - max
|
|
} else {
|
|
prev_msb
|
|
};
|
|
poc = Some(msb + lsb);
|
|
if nal[0] & 0x60 != 0 {
|
|
prev_msb = msb;
|
|
prev_lsb = lsb;
|
|
}
|
|
let _ = si.bottom;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
cur = Some(Sample {
|
|
off: start,
|
|
size: 0,
|
|
sync: is_idr,
|
|
poc,
|
|
idr: is_idr,
|
|
});
|
|
}
|
|
if !first_of_pic {
|
|
group_start = None;
|
|
}
|
|
} else if cur.is_some() && group_start.is_none() {
|
|
group_start = Some(pos);
|
|
} else if cur.is_none() && group_start.is_none() {
|
|
group_start = Some(pos);
|
|
}
|
|
pos = nal_start + len;
|
|
nal_count += 1;
|
|
payload_end = pos;
|
|
}
|
|
if let Some(mut s) = cur.take() {
|
|
s.size = (payload_end - s.off) as u32;
|
|
samples.push(s);
|
|
}
|
|
samples.retain(|s| s.size > 4);
|
|
if samples.len() < 2 || (idr_total > 0 && idr_bad * 4 > idr_total) {
|
|
return None;
|
|
}
|
|
let (width, height, timing, profile_info) = match codec {
|
|
Codec::Avc => {
|
|
let s = sps264.clone()?;
|
|
(s.width, s.height, s.timing, None::<SpsHevc>)
|
|
}
|
|
Codec::Hevc => {
|
|
let s = sps265.clone()?;
|
|
(s.width, s.height, s.timing, Some(s))
|
|
}
|
|
};
|
|
if width == 0 || height == 0 || sps_nals.is_empty() || pps_nals.is_empty() {
|
|
return None;
|
|
}
|
|
let (num, den) = match timing {
|
|
Some((units, scale)) if codec == Codec::Avc => (scale, 2 * units), // fps = time_scale / (2 * num_units_in_tick)
|
|
Some((units, scale)) => (scale, units),
|
|
None => (30, 1),
|
|
};
|
|
let fps = num as f64 / den as f64;
|
|
let (num, den) = if !(1.0..=240.0).contains(&fps) {
|
|
(30, 1)
|
|
} else {
|
|
(num, den)
|
|
};
|
|
let fps = num as f64 / den as f64;
|
|
// Timescale: frame tick = den, timescale = num.
|
|
let (timescale, dur) = (num, den);
|
|
|
|
// Compute presentation order (ctts composition offsets) from POC within each IDR GOP.
|
|
let mut ctts: Option<Vec<i64>> = None;
|
|
if samples.iter().all(|s| s.poc.is_some()) {
|
|
let mut offs = vec![0i64; samples.len()];
|
|
let mut seg_start = 0;
|
|
let mut any = false;
|
|
let mut i = 0;
|
|
while i <= samples.len() {
|
|
if i == samples.len() || (i > seg_start && samples[i].idr) {
|
|
let mut order: Vec<usize> = (seg_start..i).collect();
|
|
order.sort_by_key(|&k| samples[k].poc.unwrap());
|
|
for (rank, &k) in order.iter().enumerate() {
|
|
let d = rank as i64 - (k - seg_start) as i64;
|
|
offs[k] = d;
|
|
any |= d != 0;
|
|
}
|
|
seg_start = i;
|
|
}
|
|
i += 1;
|
|
}
|
|
if any {
|
|
let depth = offs.iter().map(|&d| -d).max().unwrap_or(0).max(0);
|
|
ctts = Some(offs.iter().map(|&d| (d + depth) * dur as i64).collect());
|
|
}
|
|
}
|
|
let reorder_delay: i64 = ctts
|
|
.as_ref()
|
|
.map(|c| c.iter().copied().min().unwrap_or(0))
|
|
.unwrap_or(0);
|
|
|
|
let payload = (data_start, payload_end);
|
|
let out_payload_start = pre_len + 16;
|
|
let map_off = |abs: u64| -> u64 { out_payload_start + (abs - data_start) };
|
|
let moov = build_moov(
|
|
codec,
|
|
width,
|
|
height,
|
|
&sps_nals,
|
|
&pps_nals,
|
|
&vps_nals,
|
|
profile_info.as_ref(),
|
|
&sps264,
|
|
&samples,
|
|
timescale,
|
|
dur,
|
|
ctts.as_deref(),
|
|
reorder_delay,
|
|
&map_off,
|
|
);
|
|
let used: u64 = samples.iter().map(|s| s.size as u64).sum();
|
|
Some(Rebuilt {
|
|
pre_len,
|
|
payload,
|
|
moov,
|
|
frames: samples.len(),
|
|
width,
|
|
height,
|
|
codec,
|
|
fps,
|
|
skipped_bytes: (payload_end - data_start).saturating_sub(used),
|
|
})
|
|
}
|
|
|
|
// -------------------------------------------------------------------- boxes
|
|
|
|
fn bx(ty: &[u8; 4], body: &[u8]) -> Vec<u8> {
|
|
let mut v = Vec::with_capacity(8 + body.len());
|
|
v.extend_from_slice(&((8 + body.len()) as u32).to_be_bytes());
|
|
v.extend_from_slice(ty);
|
|
v.extend_from_slice(body);
|
|
v
|
|
}
|
|
|
|
fn full(ty: &[u8; 4], version: u8, flags: u32, body: &[u8]) -> Vec<u8> {
|
|
let mut b = vec![version];
|
|
b.extend_from_slice(&flags.to_be_bytes()[1..]);
|
|
b.extend_from_slice(body);
|
|
bx(ty, &b)
|
|
}
|
|
|
|
fn u32b(v: u32) -> [u8; 4] {
|
|
v.to_be_bytes()
|
|
}
|
|
|
|
#[allow(clippy::too_many_arguments)]
|
|
fn build_moov(
|
|
codec: Codec,
|
|
width: u32,
|
|
height: u32,
|
|
sps: &[Vec<u8>],
|
|
pps: &[Vec<u8>],
|
|
vps: &[Vec<u8>],
|
|
hevc: Option<&SpsHevc>,
|
|
avc: &Option<Sps264>,
|
|
samples: &[Sample],
|
|
timescale: u32,
|
|
dur: u32,
|
|
ctts: Option<&[i64]>,
|
|
reorder_delay: i64,
|
|
map_off: &dyn Fn(u64) -> u64,
|
|
) -> Vec<u8> {
|
|
let n = samples.len();
|
|
let media_dur = n as u64 * dur as u64;
|
|
let movie_ts = 1000u32;
|
|
let movie_dur = media_dur * movie_ts as u64 / timescale as u64;
|
|
|
|
// Visual sample entry (`avc1` / `hvc1`)
|
|
let mut entry = vec![];
|
|
entry.extend_from_slice(&[0; 6]);
|
|
entry.extend_from_slice(&1u16.to_be_bytes());
|
|
entry.extend_from_slice(&[0; 16]);
|
|
entry.extend_from_slice(&(width as u16).to_be_bytes());
|
|
entry.extend_from_slice(&(height as u16).to_be_bytes());
|
|
entry.extend_from_slice(&0x0048_0000u32.to_be_bytes());
|
|
entry.extend_from_slice(&0x0048_0000u32.to_be_bytes());
|
|
entry.extend_from_slice(&0u32.to_be_bytes());
|
|
entry.extend_from_slice(&1u16.to_be_bytes());
|
|
entry.extend_from_slice(&[0; 32]);
|
|
entry.extend_from_slice(&0x0018u16.to_be_bytes());
|
|
entry.extend_from_slice(&0xFFFFu16.to_be_bytes());
|
|
let (fourcc, cfg) = match codec {
|
|
Codec::Avc => {
|
|
let s = avc.as_ref().unwrap();
|
|
let mut c = vec![
|
|
1,
|
|
s.profile,
|
|
s.compat,
|
|
s.level,
|
|
0xFF,
|
|
0xE0 | sps.len() as u8,
|
|
];
|
|
for x in sps {
|
|
c.extend_from_slice(&(x.len() as u16).to_be_bytes());
|
|
c.extend_from_slice(x);
|
|
}
|
|
c.push(pps.len() as u8);
|
|
for x in pps {
|
|
c.extend_from_slice(&(x.len() as u16).to_be_bytes());
|
|
c.extend_from_slice(x);
|
|
}
|
|
(*b"avc1", bx(b"avcC", &c))
|
|
}
|
|
Codec::Hevc => {
|
|
let h = hevc.unwrap();
|
|
let mut c = vec![1];
|
|
c.extend_from_slice(&h.ptl[..12.min(h.ptl.len())]); // profile_space/tier/profile_idc, profile_compatibility, constraint_indicator, level_idc
|
|
c.truncate(13);
|
|
while c.len() < 13 {
|
|
c.push(0);
|
|
}
|
|
c.extend_from_slice(&0xF000u16.to_be_bytes()); // min_spatial_segmentation_idc
|
|
c.push(0xFC); // parallelismType
|
|
c.push(0xFC | h.chroma as u8);
|
|
c.push(0xF8 | (h.bit_depth_luma - 8) as u8);
|
|
c.push(0xF8 | (h.bit_depth_chroma - 8) as u8);
|
|
c.extend_from_slice(&0u16.to_be_bytes()); // avgFrameRate
|
|
c.push(0x0B); // constantFrameRate=0, numTemporalLayers=1, lengthSizeMinusOne=3
|
|
let arrays: [(u8, &[Vec<u8>]); 3] = [(32, vps), (33, sps), (34, pps)];
|
|
let present: Vec<_> = arrays.iter().filter(|(_, v)| !v.is_empty()).collect();
|
|
c.push(present.len() as u8);
|
|
for (t, v) in present {
|
|
c.push(0x80 | t);
|
|
c.extend_from_slice(&(v.len() as u16).to_be_bytes());
|
|
for x in v.iter() {
|
|
c.extend_from_slice(&(x.len() as u16).to_be_bytes());
|
|
c.extend_from_slice(x);
|
|
}
|
|
}
|
|
(*b"hvc1", bx(b"hvcC", &c))
|
|
}
|
|
};
|
|
entry.extend_from_slice(&cfg);
|
|
let sample_entry = bx(&fourcc, &entry);
|
|
let mut stsd_body = u32b(1).to_vec();
|
|
stsd_body.extend_from_slice(&sample_entry);
|
|
let stsd = full(b"stsd", 0, 0, &stsd_body);
|
|
|
|
let stts = full(
|
|
b"stts",
|
|
0,
|
|
0,
|
|
&[u32b(1).as_slice(), &u32b(n as u32), &u32b(dur)].concat(),
|
|
);
|
|
let mut stsz_body = u32b(0).to_vec();
|
|
stsz_body.extend_from_slice(&u32b(n as u32));
|
|
for s in samples {
|
|
stsz_body.extend_from_slice(&u32b(s.size));
|
|
}
|
|
let stsz = full(b"stsz", 0, 0, &stsz_body);
|
|
let stsc = full(
|
|
b"stsc",
|
|
0,
|
|
0,
|
|
&[u32b(1).as_slice(), &u32b(1), &u32b(1), &u32b(1)].concat(),
|
|
);
|
|
let need64 = samples.iter().any(|s| map_off(s.off) > u32::MAX as u64);
|
|
let stco = if need64 {
|
|
let mut b = u32b(n as u32).to_vec();
|
|
for s in samples {
|
|
b.extend_from_slice(&map_off(s.off).to_be_bytes());
|
|
}
|
|
full(b"co64", 0, 0, &b)
|
|
} else {
|
|
let mut b = u32b(n as u32).to_vec();
|
|
for s in samples {
|
|
b.extend_from_slice(&u32b(map_off(s.off) as u32));
|
|
}
|
|
full(b"stco", 0, 0, &b)
|
|
};
|
|
let syncs: Vec<u32> = samples
|
|
.iter()
|
|
.enumerate()
|
|
.filter(|(_, s)| s.sync)
|
|
.map(|(i, _)| i as u32 + 1)
|
|
.collect();
|
|
let mut stbl_parts = vec![stsd, stts];
|
|
if let Some(c) = ctts {
|
|
// run-length encoded entries
|
|
let mut runs: Vec<(u32, u32)> = vec![];
|
|
for &v in c {
|
|
match runs.last_mut() {
|
|
Some(l) if l.1 == v as u32 => l.0 += 1,
|
|
_ => runs.push((1, v as u32)),
|
|
}
|
|
}
|
|
let mut b = u32b(runs.len() as u32).to_vec();
|
|
for (cnt, v) in runs {
|
|
b.extend_from_slice(&u32b(cnt));
|
|
b.extend_from_slice(&u32b(v));
|
|
}
|
|
stbl_parts.push(full(b"ctts", 0, 0, &b));
|
|
}
|
|
if !syncs.is_empty() && syncs.len() < n {
|
|
let mut b = u32b(syncs.len() as u32).to_vec();
|
|
for s in &syncs {
|
|
b.extend_from_slice(&u32b(*s));
|
|
}
|
|
stbl_parts.push(full(b"stss", 0, 0, &b));
|
|
}
|
|
stbl_parts.push(stsc);
|
|
stbl_parts.push(stsz);
|
|
stbl_parts.push(stco);
|
|
let stbl = bx(b"stbl", &stbl_parts.concat());
|
|
|
|
let url = full(b"url ", 0, 1, &[]);
|
|
let dref = full(b"dref", 0, 0, &[u32b(1).as_slice(), &url].concat());
|
|
let dinf = bx(b"dinf", &dref);
|
|
let vmhd = full(b"vmhd", 0, 1, &[0; 8]);
|
|
let minf = bx(b"minf", &[vmhd, dinf, stbl].concat());
|
|
let mut mdhd_body = vec![];
|
|
mdhd_body.extend_from_slice(&[0; 8]); // creation_time / modification_time
|
|
mdhd_body.extend_from_slice(&u32b(timescale));
|
|
mdhd_body.extend_from_slice(&u32b(media_dur as u32));
|
|
mdhd_body.extend_from_slice(&0x55C4u16.to_be_bytes()); // "und"
|
|
mdhd_body.extend_from_slice(&[0; 2]);
|
|
let mdhd = full(b"mdhd", 0, 0, &mdhd_body);
|
|
let mut hdlr_body = vec![0; 4];
|
|
hdlr_body.extend_from_slice(b"vide");
|
|
hdlr_body.extend_from_slice(&[0; 12]);
|
|
hdlr_body.extend_from_slice(b"Guara\0");
|
|
let hdlr = full(b"hdlr", 0, 0, &hdlr_body);
|
|
let mdia = bx(b"mdia", &[mdhd, hdlr, minf].concat());
|
|
|
|
let matrix: [u32; 9] = [0x10000, 0, 0, 0, 0x10000, 0, 0, 0, 0x4000_0000];
|
|
let mut tkhd_body = vec![];
|
|
tkhd_body.extend_from_slice(&[0; 8]);
|
|
tkhd_body.extend_from_slice(&u32b(1)); // track id
|
|
tkhd_body.extend_from_slice(&[0; 4]);
|
|
tkhd_body.extend_from_slice(&u32b(movie_dur as u32));
|
|
tkhd_body.extend_from_slice(&[0; 8]);
|
|
tkhd_body.extend_from_slice(&[0; 4]); // layer, alternate_group
|
|
tkhd_body.extend_from_slice(&[0; 4]); // volume, reserved
|
|
for m in matrix {
|
|
tkhd_body.extend_from_slice(&u32b(m));
|
|
}
|
|
tkhd_body.extend_from_slice(&u32b(width << 16));
|
|
tkhd_body.extend_from_slice(&u32b(height << 16));
|
|
let tkhd = full(b"tkhd", 0, 3, &tkhd_body);
|
|
let mut trak_parts = vec![tkhd];
|
|
if reorder_delay > 0 {
|
|
let media_time = reorder_delay;
|
|
let mut e = u32b(1).to_vec();
|
|
e.extend_from_slice(&u32b(movie_dur as u32));
|
|
e.extend_from_slice(&u32b(media_time as u32));
|
|
e.extend_from_slice(&0x0001_0000u32.to_be_bytes());
|
|
trak_parts.push(bx(b"edts", &full(b"elst", 0, 0, &e)));
|
|
}
|
|
trak_parts.push(mdia);
|
|
let trak = bx(b"trak", &trak_parts.concat());
|
|
|
|
let mut mvhd_body = vec![];
|
|
mvhd_body.extend_from_slice(&[0; 8]);
|
|
mvhd_body.extend_from_slice(&u32b(movie_ts));
|
|
mvhd_body.extend_from_slice(&u32b(movie_dur as u32));
|
|
mvhd_body.extend_from_slice(&0x0001_0000u32.to_be_bytes());
|
|
mvhd_body.extend_from_slice(&0x0100u16.to_be_bytes());
|
|
mvhd_body.extend_from_slice(&[0; 10]);
|
|
for m in matrix {
|
|
mvhd_body.extend_from_slice(&u32b(m));
|
|
}
|
|
mvhd_body.extend_from_slice(&[0; 24]);
|
|
mvhd_body.extend_from_slice(&u32b(2));
|
|
let mvhd = full(b"mvhd", 0, 0, &mvhd_body);
|
|
bx(b"moov", &[mvhd, trak].concat())
|
|
}
|
|
|
|
/// Checks whether a candidate NAL unit looks structurally valid (slice header, SPS/PPS/AUD sizes).
|
|
fn nal_plausible(
|
|
codec: Codec,
|
|
head: &[u8],
|
|
len: u64,
|
|
sps: Option<&Sps264>,
|
|
pps_count: usize,
|
|
) -> bool {
|
|
match codec {
|
|
Codec::Avc => {
|
|
let t = head[0] & 0x1F;
|
|
match t {
|
|
1 | 2 | 5 => {
|
|
let rbsp = unescape(&head[1..]);
|
|
let mut b = Bits::new(&rbsp);
|
|
let (Some(first), Some(st), Some(pps)) = (b.ue(), b.ue(), b.ue()) else {
|
|
return false;
|
|
};
|
|
if st > 9
|
|
|| pps > 255
|
|
|| (pps_count > 0 && pps as usize >= pps_count.max(1) && pps > 3)
|
|
{
|
|
return false;
|
|
}
|
|
if t == 5 && !matches!(st, 2 | 4 | 7 | 9) {
|
|
return false;
|
|
}
|
|
if first > 8191 {
|
|
return false;
|
|
}
|
|
if let Some(sp) = sps {
|
|
// IDR slice `frame_num` is always 0
|
|
if t == 5 {
|
|
if let Some(fnum) = b.u(sp.log2_max_frame_num) {
|
|
return fnum == 0;
|
|
}
|
|
}
|
|
}
|
|
true
|
|
}
|
|
9 => len == 2,
|
|
7 => (4..=300).contains(&len),
|
|
8 => (2..=300).contains(&len),
|
|
6 => len >= 2,
|
|
_ => true,
|
|
}
|
|
}
|
|
Codec::Hevc => {
|
|
let t = (head[0] >> 1) & 0x3F;
|
|
match t {
|
|
35 => len <= 4,
|
|
32..=34 => (4..=1000).contains(&len),
|
|
_ => true,
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Counts how many consecutive valid length-prefixed NAL units start at `at` (up to `max`).
|
|
fn chain_len(
|
|
buf: &[u8],
|
|
base: u64,
|
|
at: u64,
|
|
codec: Codec,
|
|
sps: Option<&Sps264>,
|
|
pps_count: usize,
|
|
cap: u64,
|
|
max: usize,
|
|
) -> usize {
|
|
let mut p = (at - base) as usize;
|
|
let mut n = 0;
|
|
while n < max && p + 8 <= buf.len() {
|
|
let l = be32(buf, p) as u64;
|
|
let ok = l >= 1
|
|
&& l <= cap
|
|
&& p as u64 + 4 + l <= buf.len() as u64 + 8
|
|
&& match codec {
|
|
Codec::Avc => avc_nal_ok(buf[p + 4]),
|
|
Codec::Hevc => hevc_nal_ok(buf[p + 4], buf[p + 5]),
|
|
}
|
|
&& nal_plausible(
|
|
codec,
|
|
&buf[p + 4..(p + 4 + (l as usize).min(48)).min(buf.len())],
|
|
l,
|
|
sps,
|
|
pps_count,
|
|
);
|
|
if !ok {
|
|
break;
|
|
}
|
|
n += 1;
|
|
p += 4 + l as usize;
|
|
}
|
|
n
|
|
}
|
|
|
|
/// Finds the next offset in `[from, limit)` where a plausible NAL unit sequence begins.
|
|
/// Prefers an offset with two or more back-to-back valid NALs; falls back to a single valid NAL.
|
|
fn scan_nal(
|
|
src: &dyn Source,
|
|
codec: Codec,
|
|
from: u64,
|
|
limit: u64,
|
|
data_end: u64,
|
|
sps: Option<&Sps264>,
|
|
pps_count: usize,
|
|
cap: u64,
|
|
) -> Option<u64> {
|
|
if limit <= from + 8 {
|
|
return None;
|
|
}
|
|
// Read slightly past `limit` so we can verify the following NAL in the chain.
|
|
let want =
|
|
((limit - from) as usize + (cap as usize).min(4 << 20)).min((data_end - from) as usize);
|
|
let buf = read_vec(src, from, want).ok()?;
|
|
let mut single = None;
|
|
let mut i = 0usize;
|
|
while i + 8 < buf.len() && from + (i as u64) < limit {
|
|
let q = from + i as u64;
|
|
let l2 = be32(&buf, i) as u64;
|
|
if l2 >= 2 && l2 <= cap && q + 4 + l2 <= data_end {
|
|
let nb = buf[i + 4];
|
|
let good_head = match codec {
|
|
// A new access unit starts with parameter sets/AUD/SEI or a slice at macroblock 0.
|
|
Codec::Avc => {
|
|
avc_nal_ok(nb)
|
|
&& (matches!(nb & 0x1F, 6..=9)
|
|
|| (matches!(nb & 0x1F, 1 | 5) && buf[i + 5] & 0x80 != 0))
|
|
}
|
|
Codec::Hevc => hevc_nal_ok(nb, buf[i + 5]),
|
|
};
|
|
if good_head {
|
|
let c = chain_len(&buf, from, q, codec, sps, pps_count, cap, 3);
|
|
if c >= 2 {
|
|
return Some(q);
|
|
}
|
|
if c == 1 && single.is_none() {
|
|
single = Some(q);
|
|
}
|
|
}
|
|
}
|
|
i += 1;
|
|
}
|
|
single
|
|
}
|