AAC Plugin Tdarr

/* eslint no-plusplus: ["error", { "allowForLoopAfterthoughts": true }] */
const details = () => ({
  id: 'Tdarr_Plugin_Custom_AAC_Only',
  Stage: 'Pre-processing',
  Name: 'Convert Everything to AAC Stereo (Strict)',
  Type: 'Audio',
  Operation: 'Transcode',
  Description: 'Converts all audio streams to AAC stereo with strict stream mapping, preserving subtitles.',
  Version: '1.2',
  Tags: 'pre-processing,ffmpeg,audio only,custom',
});

const plugin = (file, librarySettings, inputs, otherArguments) => {
  const lib = require('../methods/lib')();
  inputs = lib.loadDefaultValues(inputs, details);

  const response = {
    processFile: false,
    container: `.${file.container}`,
    handBrakeMode: false,
    FFmpegMode: true,
    reQueueAfter: true,
    infoLog: '',
  };

  let ffmpegCommandInsert = '';
  let audioIdx = 0;
  let convert = false;

  // Keep video track unchanged
  ffmpegCommandInsert += `-map 0:v -c:v copy `;

  // Loop through each audio stream
  for (let i = 0; i < file.ffProbeData.streams.length; i++) {
    if (file.ffProbeData.streams[i].codec_type.toLowerCase() === 'audio') {
      const codec = file.ffProbeData.streams[i].codec_name;
      const channels = file.ffProbeData.streams[i].channels;
      const bitrate = parseInt(file.ffProbeData.streams[i].bit_rate, 10) || 0;

      let targetBitrate = 96000;
      if (bitrate >= 192000) {
        targetBitrate = 192000;
      } else if (bitrate >= 128000 && bitrate <= 191999) {
        targetBitrate = 128000;
      } else if (bitrate >= 96000 && bitrate <= 127999) {
        targetBitrate = 96000;
      } else {
        targetBitrate = bitrate;
      }

      if (codec === 'aac') {
        if (channels === 1) {
          if (bitrate !== targetBitrate) {
            ffmpegCommandInsert += `-map 0:${i} -c:a:${audioIdx} aac -ac 1 -b:a:${audioIdx} ${targetBitrate} `;
            response.infoLog += `Mono AAC track @ ${bitrate} → ${targetBitrate}bps\n`;
            convert = true;
          } else {
            ffmpegCommandInsert += `-map 0:${i} -c:a:${audioIdx} copy `;
            response.infoLog += `Mono AAC track unchanged @ ${bitrate}bps\n`;
          }
        } else if (channels === 2) {
          if (bitrate !== targetBitrate) {
            ffmpegCommandInsert += `-map 0:${i} -c:a:${audioIdx} aac -ac 2 -b:a:${audioIdx} ${targetBitrate} `;
            response.infoLog += `Stereo AAC track @ ${bitrate} → ${targetBitrate}bps\n`;
            convert = true;
          } else {
            ffmpegCommandInsert += `-map 0:${i} -c:a:${audioIdx} copy `;
            response.infoLog += `Stereo AAC track unchanged @ ${bitrate}bps\n`;
          }
        } else {
          ffmpegCommandInsert += `-map 0:${i} -c:a:${audioIdx} aac -ac 2 -b:a:${audioIdx} ${targetBitrate} `;
          response.infoLog += `Multichannel AAC downmixed to stereo @ ${targetBitrate}bps\n`;
          convert = true;
        }
      } else {
        if (channels === 1) {
          ffmpegCommandInsert += `-map 0:${i} -c:a:${audioIdx} aac -ac 1 -b:a:${audioIdx} ${targetBitrate} `;
          response.infoLog += `Mono ${codec} converted to AAC mono @ ${targetBitrate}bps\n`;
        } else {
          ffmpegCommandInsert += `-map 0:${i} -c:a:${audioIdx} aac -ac 2 -b:a:${audioIdx} ${targetBitrate} `;
          response.infoLog += `${channels}ch ${codec} converted to AAC stereo @ ${targetBitrate}bps\n`;
        }
        convert = true;
      }

      audioIdx++;
    }
  }

  // ✅ Copy all subtitle tracks
  ffmpegCommandInsert += `-map 0:s? -c:s copy `;

  if (convert) {
    response.processFile = true;
    response.preset = `, ${ffmpegCommandInsert} -strict -2 -max_muxing_queue_size 9999 `;
  } else {
    response.infoLog += '☑ File is already in correct format.\n';
  }

  return response;
};

module.exports.details = details;
module.exports.plugin = plugin;