Error: Output format png is not available

[ljnMeow]

Version information

• fluent-ffmpeg version: 2.1.3
• ffmpeg version: 7.0.2
• OS: macOS Monterey 12.3.1

Code to reproduce

private imageWatermark(file: Express.Multer.File, watermark: string) {
    const { PassThrough } = stream;

    return new Promise(async (resolve, reject) => {
      try {
        const gifStream = new PassThrough();
        gifStream.end(file.buffer);

        const outputStream = new PassThrough();
        const outputBuffers: Buffer[] = [];

        // 转义字符串
        const escapedWatermark = watermark
          .replace(/:/g, '\\:')
          .replace(/\//g, '\\/')
          .replace(/ /g, '\\ ')
          .replace(/@/g, '\\@');

        ffmpeg(gifStream)
          .outputOptions([
            `-vf`,
            `drawtext=text='${escapedWatermark}':x=(w-tw-10):y=(h-th-10):fontsize=12:fontcolor=white@0.6`,
          ])
          .toFormat('png')
          .on('error', (err) => reject(err))
          .pipe(outputStream);

        outputStream.on('data', (chunk: Buffer) => {
          outputBuffers.push(chunk);
        });
        outputStream.on('end', () => resolve(Buffer.concat(outputBuffers)));
      } catch (error) {
        reject(error);
      }
    });
  }

(note: if the problem only happens with some inputs, include a link to such an input file)

Expected results

Get one file buffer

Observed results

Error: Output format png is not available