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|
// Copyright (C) 2020 Matthew Waters <matthew@centricular.com>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the
// Free Software Foundation, Inc., 51 Franklin Street, Suite 500,
// Boston, MA 02110-1335, USA.
use glib::subclass::prelude::*;
use gst::prelude::*;
use gst::subclass::prelude::*;
use gst::{gst_trace, gst_warning};
use gst_base::subclass::prelude::*;
use crate::ccutils::{extract_cdp, ParseError, ParseErrorCode};
use once_cell::sync::Lazy;
use std::sync::Mutex;
use std::u64;
static CAT: Lazy<gst::DebugCategory> = Lazy::new(|| {
gst::DebugCategory::new(
"ccdetect",
gst::DebugColorFlags::empty(),
Some("Closed Caption Detection"),
)
});
const DEFAULT_WINDOW: u64 = 10 * gst::SECOND_VAL;
const DEFAULT_CC608: bool = false;
const DEFAULT_CC708: bool = false;
#[derive(Debug, Clone, Copy)]
struct Settings {
pub window: u64,
pub cc608: bool,
pub cc708: bool,
}
impl Default for Settings {
fn default() -> Self {
Settings {
window: DEFAULT_WINDOW,
cc608: DEFAULT_CC608,
cc708: DEFAULT_CC708,
}
}
}
#[derive(Debug, Clone, Copy)]
enum CCFormat {
Cc708Cdp,
Cc708CcData,
}
#[derive(Debug, Clone, Copy)]
struct State {
format: CCFormat,
last_cc608_change: gst::ClockTime,
last_cc708_change: gst::ClockTime,
}
#[derive(Default)]
pub struct CCDetect {
settings: Mutex<Settings>,
state: Mutex<Option<State>>,
}
#[derive(Debug, Clone, Copy)]
struct CCPacketContents {
cc608: bool,
cc708: bool,
}
impl CCDetect {
fn detect_cc_data(data: &[u8]) -> Result<CCPacketContents, ParseError> {
if data.len() % 3 != 0 {
gst_warning!(CAT, "cc_data length is not a multiple of 3, truncating");
}
/* logic from ccconverter */
let mut started_ccp = false;
let mut have_cc608 = false;
let mut have_cc708 = false;
for (i, triple) in data.chunks_exact(3).enumerate() {
let cc_valid = (triple[0] & 0x04) == 0x04;
let cc_type = triple[0] & 0x03;
gst_trace!(
CAT,
"triple:{} have ccp:{} 608:{} 708:{} data:{:02x},{:02x},{:02x} cc_valid:{} cc_type:{:02b}",
i * 3,
started_ccp,
have_cc608,
have_cc708,
triple[0],
triple[1],
triple[2],
cc_valid,
cc_type
);
if !started_ccp && cc_valid && (cc_type == 0x00 || cc_type == 0x01) {
if triple[1] != 0x80 || triple[2] != 0x80 {
have_cc608 = true;
}
continue;
}
if cc_type & 0b10 == 0b10 {
started_ccp = true;
}
if !cc_valid {
continue;
}
if cc_type == 0x00 || cc_type == 0x01 {
return Err(ParseError {
code: ParseErrorCode::WrongLayout,
byte: data.len() - i * 3,
msg: String::from("Invalid cc_data. cea608 bytes after cea708"),
});
}
have_cc708 = true;
}
Ok(CCPacketContents {
cc608: have_cc608,
cc708: have_cc708,
})
}
fn detect_cdp(data: &[u8]) -> Result<CCPacketContents, ParseError> {
let data = extract_cdp(data)?;
Self::detect_cc_data(data)
}
fn detect(format: CCFormat, data: &[u8]) -> Result<CCPacketContents, ParseError> {
match format {
CCFormat::Cc708CcData => Self::detect_cc_data(data),
CCFormat::Cc708Cdp => Self::detect_cdp(data),
}
}
fn maybe_update_properties(
&self,
element: &super::CCDetect,
ts: gst::ClockTime,
cc_packet: CCPacketContents,
) -> Result<(), gst::FlowError> {
let mut notify_cc608 = false;
let mut notify_cc708 = false;
{
let mut settings = self.settings.lock().unwrap();
let mut state_guard = self.state.lock().unwrap();
let state = state_guard.as_mut().ok_or(gst::FlowError::NotNegotiated)?;
gst_trace!(
CAT,
"packet contains {:?} current settings {:?} and state {:?}",
cc_packet,
settings,
state
);
if cc_packet.cc608 != settings.cc608 {
if state.last_cc608_change.is_none()
|| ts - state.last_cc608_change > settings.window.into()
{
settings.cc608 = cc_packet.cc608;
state.last_cc608_change = ts;
notify_cc608 = true;
}
} else {
state.last_cc608_change = ts;
}
if cc_packet.cc708 != settings.cc708 {
if state.last_cc708_change.is_none()
|| ts - state.last_cc708_change > settings.window.into()
{
settings.cc708 = cc_packet.cc708;
state.last_cc708_change = ts;
notify_cc708 = true;
}
} else {
state.last_cc708_change = ts;
}
gst_trace!(CAT, "changed to settings {:?} state {:?}", settings, state);
}
if notify_cc608 {
element.notify("cc608");
}
if notify_cc708 {
element.notify("cc708");
}
Ok(())
}
}
#[glib::object_subclass]
impl ObjectSubclass for CCDetect {
const NAME: &'static str = "CCDetect";
type Type = super::CCDetect;
type ParentType = gst_base::BaseTransform;
}
impl ObjectImpl for CCDetect {
fn properties() -> &'static [glib::ParamSpec] {
static PROPERTIES: Lazy<Vec<glib::ParamSpec>> = Lazy::new(|| {
vec![
glib::ParamSpec::new_uint64(
"window",
"Window",
"Window of time (in ns) to determine if captions exist in the stream",
0,
u64::MAX,
DEFAULT_WINDOW,
glib::ParamFlags::READWRITE | gst::PARAM_FLAG_MUTABLE_PLAYING,
),
glib::ParamSpec::new_boolean(
"cc608",
"cc608",
"Whether CEA608 captions (CC1/CC3) have been detected",
DEFAULT_CC608,
glib::ParamFlags::READABLE,
),
glib::ParamSpec::new_boolean(
"cc708",
"cc608",
"Whether CEA708 captions (cc_data) have been detected",
DEFAULT_CC708,
glib::ParamFlags::READABLE,
),
]
});
PROPERTIES.as_ref()
}
fn set_property(
&self,
_obj: &Self::Type,
_id: usize,
value: &glib::Value,
pspec: &glib::ParamSpec,
) {
match pspec.name() {
"window" => {
let mut settings = self.settings.lock().unwrap();
settings.window = value.get_some().expect("type checked upstream");
}
_ => unimplemented!(),
}
}
fn property(&self, _obj: &Self::Type, _id: usize, pspec: &glib::ParamSpec) -> glib::Value {
match pspec.name() {
"window" => {
let settings = self.settings.lock().unwrap();
settings.window.to_value()
}
"cc608" => {
let settings = self.settings.lock().unwrap();
settings.cc608.to_value()
}
"cc708" => {
let settings = self.settings.lock().unwrap();
settings.cc708.to_value()
}
_ => unimplemented!(),
}
}
}
impl ElementImpl for CCDetect {
fn metadata() -> Option<&'static gst::subclass::ElementMetadata> {
static ELEMENT_METADATA: Lazy<gst::subclass::ElementMetadata> = Lazy::new(|| {
gst::subclass::ElementMetadata::new(
"Closed Caption Detect",
"Filter/Video/ClosedCaption/Detect",
"Detect if valid closed captions are present in a stream",
"Matthew Waters <matthew@centricular.com>",
)
});
Some(&*ELEMENT_METADATA)
}
fn pad_templates() -> &'static [gst::PadTemplate] {
static PAD_TEMPLATES: Lazy<Vec<gst::PadTemplate>> = Lazy::new(|| {
let mut caps = gst::Caps::new_empty();
{
let caps = caps.get_mut().unwrap();
let s = gst::Structure::builder("closedcaption/x-cea-708")
.field("format", &gst::List::new(&[&"cc_data", &"cdp"]))
.build();
caps.append_structure(s);
}
let src_pad_template = gst::PadTemplate::new(
"src",
gst::PadDirection::Src,
gst::PadPresence::Always,
&caps,
)
.unwrap();
let sink_pad_template = gst::PadTemplate::new(
"sink",
gst::PadDirection::Sink,
gst::PadPresence::Always,
&caps,
)
.unwrap();
vec![src_pad_template, sink_pad_template]
});
PAD_TEMPLATES.as_ref()
}
}
impl BaseTransformImpl for CCDetect {
const MODE: gst_base::subclass::BaseTransformMode =
gst_base::subclass::BaseTransformMode::AlwaysInPlace;
const TRANSFORM_IP_ON_PASSTHROUGH: bool = true;
const PASSTHROUGH_ON_SAME_CAPS: bool = true;
fn transform_ip_passthrough(
&self,
element: &Self::Type,
buf: &gst::Buffer,
) -> Result<gst::FlowSuccess, gst::FlowError> {
let map = buf.map_readable().map_err(|_| gst::FlowError::Error)?;
if buf.pts().is_none() {
gst::element_error!(
element,
gst::ResourceError::Read,
["Input buffers must have valid timestamps"]
);
return Err(gst::FlowError::Error);
}
let format = {
let mut state_guard = self.state.lock().unwrap();
let state = state_guard.as_mut().ok_or(gst::FlowError::NotNegotiated)?;
state.format
};
let cc_packet = match Self::detect(format, map.as_slice()) {
Ok(v) => v,
Err(e) => {
gst_warning!(CAT, "{}", &e.to_string());
gst::element_warning!(element, gst::StreamError::Decode, [&e.to_string()]);
CCPacketContents {
cc608: false,
cc708: false,
}
}
};
self.maybe_update_properties(element, buf.pts(), cc_packet)
.map_err(|_| gst::FlowError::Error)?;
Ok(gst::FlowSuccess::Ok)
}
fn sink_event(&self, element: &Self::Type, event: gst::Event) -> bool {
match event.view() {
gst::event::EventView::Gap(gap) => {
let _ = self.maybe_update_properties(
element,
gap.get().0,
CCPacketContents {
cc608: false,
cc708: false,
},
);
self.parent_sink_event(element, event)
}
_ => self.parent_sink_event(element, event),
}
}
fn set_caps(
&self,
_element: &Self::Type,
incaps: &gst::Caps,
outcaps: &gst::Caps,
) -> Result<(), gst::LoggableError> {
if incaps != outcaps {
return Err(gst::loggable_error!(
CAT,
"Input and output caps are not the same"
));
}
let s = incaps
.structure(0)
.ok_or_else(|| gst::loggable_error!(CAT, "Failed to parse input caps"))?;
let format_str = s
.get::<&str>("format")
.map_err(|_| gst::loggable_error!(CAT, "Failed to parse input caps"))?
.ok_or_else(|| gst::loggable_error!(CAT, "Failed to parse input caps"))?;
let cc_format = match format_str {
"cdp" => CCFormat::Cc708Cdp,
"cc_data" => CCFormat::Cc708CcData,
_ => return Err(gst::loggable_error!(CAT, "Failed to parse input caps")),
};
*self.state.lock().unwrap() = Some(State {
format: cc_format,
last_cc608_change: gst::ClockTime::none(),
last_cc708_change: gst::ClockTime::none(),
});
Ok(())
}
fn stop(&self, _element: &Self::Type) -> Result<(), gst::ErrorMessage> {
// Drop state
let _ = self.state.lock().unwrap().take();
Ok(())
}
}
|