ya-webadb/libraries/adb/src/commands/framebuffer.ts

import { BufferedStream } from '@yume-chan/stream-extra';
import Struct from '@yume-chan/struct';

import type { Adb } from '../adb.js';

const Version =
    new Struct({ littleEndian: true })
        .uint32('version');

/*
 * ADB uses 8 int32 fields to describe bit depths
 * The only combination I have seen is RGBA8888, which is
 *   red_offset:   0
 *   red_length:   8
 *   blue_offset:  16
 *   blue_length:  8
 *   green_offset: 8
 *   green_length: 8
 *   alpha_offset: 24
 *   alpha_length: 8
 */

export const AdbFrameBufferV1 =
    new Struct({ littleEndian: true })
        .uint32('bpp')
        .uint32('size')
        .uint32('width')
        .uint32('height')
        .uint32('red_offset')
        .uint32('red_length')
        .uint32('blue_offset')
        .uint32('blue_length')
        .uint32('green_offset')
        .uint32('green_length')
        .uint32('alpha_offset')
        .uint32('alpha_length')
        .uint8Array('data', { lengthField: 'size' });

export type AdbFrameBufferV1 = typeof AdbFrameBufferV1['TDeserializeResult'];

export const AdbFrameBufferV2 =
    new Struct({ littleEndian: true })
        .uint32('bpp')
        .uint32('colorSpace')
        .uint32('size')
        .uint32('width')
        .uint32('height')
        .uint32('red_offset')
        .uint32('red_length')
        .uint32('blue_offset')
        .uint32('blue_length')
        .uint32('green_offset')
        .uint32('green_length')
        .uint32('alpha_offset')
        .uint32('alpha_length')
        .uint8Array('data', { lengthField: 'size' });

export type AdbFrameBufferV2 = typeof AdbFrameBufferV2['TDeserializeResult'];

export type AdbFrameBuffer = AdbFrameBufferV1 | AdbFrameBufferV2;

export async function framebuffer(adb: Adb): Promise<AdbFrameBuffer> {
    const socket = await adb.createSocket('framebuffer:');
    const stream = new BufferedStream(socket.readable);
    const { version } = await Version.deserialize(stream);
    switch (version) {
        case 1:
            return AdbFrameBufferV1.deserialize(stream);
        case 2:
            return AdbFrameBufferV2.deserialize(stream);
        default:
            throw new Error('Unknown FrameBuffer version');
    }
}