2023-04-25 17:28:03 +04:00

137 lines
3.2 KiB
TypeScript

// @ts-nocheck
/*
* This file is part of the libav.js WebCodecs Polyfill implementation. The
* interface implemented is derived from the W3C standard. No attribution is
* required when using this library.
*
* Copyright (c) 2021 Yahweasel
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
import type * as LibAVJS from '../libav.types';
declare let LibAV: LibAVJS.LibAVWrapper;
// Currently available libav instances
const libavs: LibAVJS.LibAV[] = [];
// Options required to create a LibAV instance
let libavOptions: any = {};
/**
* Supported decoders.
*/
export let decoders: string[] = null;
/**
* libav.js-specific codec request, used to bypass the codec registry and use
* anything your implementation of libav.js supports.
*/
export interface LibAVJSCodec {
codec: string;
ctx?: LibAVJS.AVCodecContextProps;
options?: Record<string, string>;
}
/**
* Set the libav loading options.
*/
export function setLibAVOptions(to: any) {
libavOptions = to;
}
/**
* Get a libav instance.
*/
export async function get(): Promise<LibAVJS.LibAV> {
if (libavs.length) {
return libavs.shift();
}
return LibAV.LibAV(libavOptions);
}
/**
* Free a libav instance for later reuse.
*/
export function free(libav: LibAVJS.LibAV) {
libavs.push(libav);
}
/**
* Get the list of encoders/decoders supported by libav (which are also
* supported by this polyfill)
*/
async function codecs(): Promise<string[]> {
const libav = await get();
const ret: string[] = [];
for (const [avname, codec] of [
['libaom-av1', 'av01'],
['h264', 'avc1'],
['hevc', 'hvc1'],
]) {
if (await libav.avcodec_find_decoder_by_name(avname)) {
ret.push(codec);
}
}
free(libav);
return ret;
}
/**
* Load the lists of supported decoders and encoders.
*/
export async function load() {
decoders = await codecs();
}
/**
* Convert a decoder from the codec registry (or libav.js-specific parameters)
* to libav.js. Returns null if unsupported.
*/
export function decoder(codec: string | { libavjs: LibAVJSCodec }): LibAVJSCodec {
if (typeof codec === 'string') {
codec = codec.replace(/\..*/, '');
let outCodec: string = codec;
switch (codec) {
// Video
case 'av01':
outCodec = 'libaom-av1';
break;
case 'avc1':
outCodec = 'h264';
break;
case 'hvc1':
outCodec = 'hevc';
break;
// Unrecognized
default:
return null;
}
// Check whether we actually support this codec
if (!(decoders.indexOf(codec) >= 0)) {
return null;
}
return { codec: outCodec };
} else {
return codec.libavjs;
}
}