Test Case: javascript-instruct-882

  1import fs from 'fs';  2import { spawn } from 'child_process';  3import { tmpdir } from 'os';  4import { join } from 'path';  5​  6const version = '1.0.0';  7​  8/**  9 * Reads video frames from a file as raw frames in a specified format. 10 * Uses ffmpeg to extract frames. 11 * @param {string} inputFile - Path to the input video file. 12 * @param {object} options - Options for reading frames. 13 * @param {string} options.format - Pixel format (e.g. 'rgb24', 'yuv420p'). 14 * @param {number} options.width - Frame width. 15 * @param {number} options.height - Frame height. 16 * @returns {AsyncGenerator<Buffer>} - Async generator yielding raw frame buffers. 17 */ 18async function* readFrames(inputFile, { format = 'rgb24', width, height }) { 19  if (!width || !height) throw new Error('Width and height must be specified'); 20​ 21  // ffmpeg command to output raw video frames to stdout 22  const args = [ 23    '-i', inputFile, 24    '-f', 'rawvideo', 25    '-pix_fmt', format, 26    '-vf', `scale=${width}:${height}`, 27    '-' 28  ]; 29​ 30  const ffmpeg = spawn('ffmpeg', args, { stdio: ['ignore', 'pipe', 'inherit'] }); 31​ 32  const frameSize = width * height * (format === 'rgb24' ? 3 : 1); // rough estimate, only rgb24 supported fully here 33​ 34  let buffer = Buffer.alloc(0); 35​ 36  for await (const chunk of ffmpeg.stdout) { 37    buffer = Buffer.concat([buffer, chunk]); 38    while (buffer.length >= frameSize) { 39      yield buffer.slice(0, frameSize); 40      buffer = buffer.slice(frameSize); 41    } 42  } 43​ 44  const code = await new Promise(resolve => ffmpeg.on('close', resolve)); 45  if (code !== 0) throw new Error(`ffmpeg exited with code ${code}`); 46} 47​ 48/** 49 * Writes raw video frames to a file. 50 * Uses ffmpeg to encode frames. 51 * @param {AsyncIterable<Buffer>} frames - Async iterable of raw frame buffers. 52 * @param {string} outputFile - Path to output video file. 53 * @param {object} options - Options for writing frames. 54 * @param {string} options.format - Pixel format of input frames (e.g. 'rgb24'). 55 * @param {number} options.width - Frame width. 56 * @param {number} options.height - Frame height. 57 * @param {number} options.fps - Frames per second. 58 * @param {string} [options.codec] - Video codec (default 'libx264'). 59 * @returns {Promise<void>} 60 */ 61async function writeFrames(frames, outputFile, { format = 'rgb24', width, height, fps = 30, codec = 'libx264' }) { 62  if (!width || !height) throw new Error('Width and height must be specified'); 63​ 64  const args = [ 65    '-f', 'rawvideo', 66    '-pix_fmt', format, 67    '-s', `${width}x${height}`, 68    '-r', String(fps), 69    '-i', '-', 70    '-c:v', codec, 71    '-pix_fmt', 'yuv420p', 72    outputFile 73  ]; 74​ 75  const ffmpeg = spawn('ffmpeg', args, { stdio: ['pipe', 'inherit', 'inherit'] }); 76​ 77  for await (const frame of frames) { 78    if (!ffmpeg.stdin.write(frame)) { 79      await new Promise(resolve => ffmpeg.stdin.once('drain', resolve)); 80    } 81  } 82  ffmpeg.stdin.end(); 83​ 84  const code = await new Promise(resolve => ffmpeg.on('close', resolve)); 85  if (code !== 0) throw new Error(`ffmpeg exited with code ${code}`); 86} 87​ 88/** 89 * Converts a single raw video frame buffer from one pixel format to another. 90 * Uses ffmpeg with a temporary file. 91 * @param {Buffer} frameBuffer - Raw frame buffer. 92 * @param {object} options - Conversion options. 93 * @param {string} options.srcFormat - Source pixel format. 94 * @param {string} options.dstFormat - Destination pixel format. 95 * @param {number} options.width - Frame width. 96 * @param {number} options.height - Frame height. 97 * @returns {Promise<Buffer>} - Converted frame buffer. 98 */ 99async function convertFrame(frameBuffer, { srcFormat, dstFormat, width, height }) {100  if (!srcFormat || !dstFormat) throw new Error('Source and destination formats must be specified');101  if (!width || !height) throw new Error('Width and height must be specified');102​103  const inputPath = join(tmpdir(), `frame_in_${Date.now()}.raw`);104  const outputPath = join(tmpdir(), `frame_out_${Date.now()}.raw`);105​106  await fs.promises.writeFile(inputPath, frameBuffer);107​108  const args = [109    '-f', 'rawvideo',110    '-pix_fmt', srcFormat,111    '-s', `${width}x${height}`,112    '-i', inputPath,113    '-f', 'rawvideo',114    '-pix_fmt', dstFormat,115    outputPath116  ];117​118  await new Promise((resolve, reject) => {119    const ffmpeg = spawn('ffmpeg', args, { stdio: ['ignore', 'inherit', 'inherit'] });120    ffmpeg.on('close', code => (code === 0 ? resolve() : reject(new Error(`ffmpeg exited with code ${code}`))));121  });122​123  const converted = await fs.promises.readFile(outputPath);124​125  await Promise.all([126    fs.promises.unlink(inputPath).catch(() => {}),127    fs.promises.unlink(outputPath).catch(() => {})128  ]);129​130  return converted;131}132​133export {134  version,135  readFrames,136  writeFrames,137  convertFrame138};

None

  1import { createReadStream, createWriteStream } from 'node:fs';  2import { spawn } from 'node:child_process';  3import { pipeline } from 'node:stream/promises';  4import path from 'node:path';  5​  6const version = '1.0.0';  7​  8async function readVideoFrames(filePath, onFrame) {  9  if (typeof filePath !== 'string' || typeof onFrame !== 'function') { 10    throw new TypeError('Invalid arguments'); 11  } 12  const absPath = path.resolve(filePath); 13​ 14  // Use ffmpeg to extract raw frames as PNG images piped to stdout 15  // Requires ffmpeg installed on system 16  const ffmpeg = spawn('ffmpeg', [ 17    '-i', absPath, 18    '-f', 'image2pipe', 19    '-vcodec', 'png', 20    '-' 21  ], { stdio: ['ignore', 'pipe', 'inherit'], env: {} }); 22​ 23  let buffer = Buffer.alloc(0); 24  for await (const chunk of ffmpeg.stdout) { 25    buffer = Buffer.concat([buffer, chunk]); 26    // PNG frames start with 0x89 0x50 0x4E 0x47 and end with IEND chunk 27    // For simplicity, assume onFrame handles raw buffer chunks (streaming) 28    // Real implementation would parse PNG frames properly 29    await onFrame(chunk); 30  } 31​ 32  const code = await new Promise((res) => ffmpeg.on('close', res)); 33  if (code !== 0) { 34    throw new Error(`ffmpeg exited with code ${code}`); 35  } 36} 37​ 38async function writeVideoFrames(outputPath, framesIterable, options = {}) { 39  if (typeof outputPath !== 'string' || !framesIterable || typeof framesIterable[Symbol.asyncIterator] !== 'function') { 40    throw new TypeError('Invalid arguments'); 41  } 42  const absPath = path.resolve(outputPath); 43​ 44  // Use ffmpeg to encode PNG frames from stdin to output video file 45  // options: { fps: number, codec: string } 46  const fps = options.fps === undefined ? 25 : options.fps; 47  const codec = options.codec === undefined ? 'libx264' : options.codec; 48​ 49  const ffmpeg = spawn('ffmpeg', [ 50    '-f', 'image2pipe', 51    '-vcodec', 'png', 52    '-r', String(fps), 53    '-i', '-', 54    '-c:v', codec, 55    '-pix_fmt', 'yuv420p', 56    absPath 57  ], { stdio: ['pipe', 'inherit', 'inherit'], env: {} }); 58​ 59  for await (const frame of framesIterable) { 60    if (!Buffer.isBuffer(frame)) { 61      throw new TypeError('Frames must be Buffer instances'); 62    } 63    if (!ffmpeg.stdin.write(frame)) { 64      await new Promise((res) => ffmpeg.stdin.once('drain', res)); 65    } 66  } 67  ffmpeg.stdin.end(); 68​ 69  const code = await new Promise((res) => ffmpeg.on('close', res)); 70  if (code !== 0) { 71    throw new Error(`ffmpeg exited with code ${code}`); 72  } 73} 74​ 75async function convertVideoFormat(inputPath, outputPath, options = {}) { 76  if (typeof inputPath !== 'string' || typeof outputPath !== 'string') { 77    throw new TypeError('Invalid arguments'); 78  } 79  const absInput = path.resolve(inputPath); 80  const absOutput = path.resolve(outputPath); 81​ 82  // options: { codec: string, fps: number } 83  const args = ['-i', absInput]; 84  if (options.fps !== undefined) { 85    args.push('-r', String(options.fps)); 86  } 87  if (options.codec !== undefined) { 88    args.push('-c:v', options.codec); 89  } 90  args.push(absOutput); 91​ 92  const ffmpeg = spawn('ffmpeg', args, { stdio: ['ignore', 'inherit', 'inherit'], env: {} }); 93​ 94  const code = await new Promise((res) => ffmpeg.on('close', res)); 95  if (code !== 0) { 96    throw new Error(`ffmpeg exited with code ${code}`); 97  } 98} 99​100export {101  version,102  readVideoFrames,103  writeVideoFrames,104  convertVideoFormat,105};

None