doc: update README and comments

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Simon Chan 2023-01-20 14:03:09 +08:00
parent 849cb0c7fc
commit 9fc6360032
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7 changed files with 54 additions and 17 deletions

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@ -25,19 +25,19 @@ new ScrcpyOptions1_24({
codecOptions: new CodecOptions({ codecOptions: new CodecOptions({
profile: TinyH264Decoder.maxProfile, profile: TinyH264Decoder.maxProfile,
level: TinyH264Decoder.maxLevel, level: TinyH264Decoder.maxLevel,
}) }),
}) });
``` ```
However, it can fail on some very old devices that doesn't support even Baseline level 4 codec. You can retry without the `codecOptions` option if that happens. However, it can fail on some very old devices that doesn't support even Baseline level 4 codec. You can retry without the `codecOptions` option if that happens.
### Render the video ### Render the video
It draws frames onto `decoder.element` (a `<canvas>` element), you can insert it anywhere you want to display the video. It draws frames onto `decoder.renderer` (a `<canvas>` element), you can insert it anywhere you want to display the video.
```ts ```ts
const decoder = new TinyH264Decoder(); const decoder = new TinyH264Decoder();
document.body.appendChild(decoder.element); document.body.appendChild(decoder.renderer);
videoPacketStream // from `@yume-chan/scrcpy` videoPacketStream // from `@yume-chan/scrcpy`
.pipeTo(decoder.writable) .pipeTo(decoder.writable)

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@ -1,7 +1,7 @@
{ {
"name": "@yume-chan/scrcpy-decoder-tinyh264", "name": "@yume-chan/scrcpy-decoder-tinyh264",
"version": "0.0.17", "version": "0.0.17",
"description": "TypeScript implementation of Scrcpy.", "description": "Raw H.264 stream decoder and renderer wrapping TinyH264 and YUVCanvas packages (software decoding).",
"keywords": [ "keywords": [
"adb", "adb",
"android-phone", "android-phone",

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@ -17,11 +17,11 @@ It has no dependencies and high performance, but is only available on recent ver
## Usage ## Usage
It draws frames onto `decoder.element` (a `<canvas>` element), you can insert it anywhere you want to display the video. It draws frames onto `decoder.renderer` (a `<canvas>` element), you can insert it anywhere you want to display the video.
```ts ```ts
const decoder = new WebCodecsDecoder(); const decoder = new WebCodecsDecoder();
document.body.appendChild(decoder.element); document.body.appendChild(decoder.renderer);
videoPacketStream // from `@yume-chan/scrcpy` videoPacketStream // from `@yume-chan/scrcpy`
.pipeTo(decoder.writable) .pipeTo(decoder.writable)

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@ -1,7 +1,7 @@
{ {
"name": "@yume-chan/scrcpy-decoder-webcodecs", "name": "@yume-chan/scrcpy-decoder-webcodecs",
"version": "0.0.17", "version": "0.0.17",
"description": "TypeScript implementation of Scrcpy.", "description": "Raw H.264 stream decoder and renderer using WebCodecs API (requires modern browser).",
"keywords": [ "keywords": [
"adb", "adb",
"android-phone", "android-phone",

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@ -1,8 +1,40 @@
# @yume-chan/stream-extra # @yume-chan/stream-extra
Some useful extensions for Web Streams API. Some useful extensions for working with binary streams. Conforms to the [Web Streams API](https://streams.spec.whatwg.org/).
Currently it's using [web-streams-polyfill](https://github.com/MattiasBuelens/web-streams-polyfill) because it's hard to load native implementations from both browsers and Node.js. (An experimental implementation using Top Level Await is available in `native.ts`, but not exported). ## Find an implementation
If all of `ReadableStream`, `WritableStream` and `TransformStream` fields are available on `globalThis`, they will be used. Otherwise, the [web-streams-polyfill](https://github.com/MattiasBuelens/web-streams-polyfill) package will be used.
Google Chrome 89 and Mozilla Firefox 102 provide full support for Web Streams API natively.
In Node.js, it's not possible to load the `stream/web` module while keeping the compatibility with both Web and bundlers:
- Webpack has poor support with Top Level Await, for example, Hot Module Replacement doesn't work when any module is using TLA.
- Web doesn't have the `module` module, thus requires a shim in import map.
Assigning `ReadableStream`, `WritableStream` and `TransformStream` from `stream/web` module to `globalThis`, before loading this library, will still work. Other custom polyfill can also be loaded this way.
## Compatibility issue with `ReadableStream#pipeTo` and `ReadableStream#pipeThrough`
The [Web Streams API spec](https://streams.spec.whatwg.org/#readable-stream-pipe-to) specifies that `ReadableStream#pipeTo` must check the argument to be an instance of `WritableStream`, so it can optimize the performance by calling internal methods directly.
Native implementations will perform this check, so `new globalThis.ReadableStream().pipeTo(new Polyfill.WritableStream())` will throw an error.
The `WrapReadableStream` class can be used to bypass this check:
```ts
import { WrapReadableStream } from "@yume-chan/stream-extra";
import { WritableStream as PolyfillWritableStream } from "web-streams-polyfill";
const nativeReadable = new globalThis.ReadableStream();
const wrappedReadable = new WrapReadableStream(new globalThis.ReadableStream());
nativeReadable.pipeTo(new PolyfillWritableStream()); // Error
wrappedReadable.pipeTo(new PolyfillWritableStream()); // OK
```
web-streams-polyfill package's `ReadableStream#pipeTo` only uses public methods, so it can be used with any `WritableStream` implementation.
## `BufferedReadableStream` ## `BufferedReadableStream`

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@ -46,9 +46,9 @@ export class BufferedTransformStream<T>
const value = await transform(buffered); const value = await transform(buffered);
controller.enqueue(value); controller.enqueue(value);
} catch (e) { } catch (e) {
// TODO: BufferedTransformStream: The semantic of stream ending is not clear // Treat `BufferedReadableStreamEndedError` as a normal end.
// If the `transform` started but did not finish, it should really be an error? // If the `transform` method doesn't have enough data to return a value,
// But we can't detect that, unless there is a `peek` method on buffered stream. // it should throw another error to indicate that.
if (e instanceof BufferedReadableStreamEndedError) { if (e instanceof BufferedReadableStreamEndedError) {
controller.close(); controller.close();
return; return;

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@ -50,6 +50,11 @@ export namespace NumberFieldType {
signed: false, signed: false,
size: 2, size: 2,
deserialize(array, littleEndian) { deserialize(array, littleEndian) {
// PERF: Chrome's `DataView#getUint16` uses inefficient operations,
// including branching, bit extending and 32-bit bit swapping.
// The best way should use 16-bit bit rotation and conditional move,
// like LLVM does for code similar to the below one.
// This code is much faster on V8, but the actual generated assembly is unknown.
return ( return (
(((array[1]! << 8) | array[0]!) * (littleEndian as any)) | (((array[1]! << 8) | array[0]!) * (littleEndian as any)) |
(((array[0]! << 8) | array[1]!) * (!littleEndian as any)) (((array[0]! << 8) | array[1]!) * (!littleEndian as any))