如何阻止AWS Elemental MediaConvert截断音频静音部分？

一、AWS Elemental MediaConvert 调整方案 #

核心是强制MediaConvert保留完整的音频轨道时长，需修改以下两处配置：

1. 修正Input配置 #

在Job的Settings.Inputs中，确保AudioSelector的AudioDurationCorrection设为TRACK，同时TimecodeSource设为ZEROBASED（避免依赖嵌入时间码导致的截断），移除不必要的Offset参数：

"Settings": {
    "Inputs": [
        {
            "AudioSelectors": {
                "Audio Selector 1": {
                    "DefaultSelection": "DEFAULT",
                    "SelectorType": "TRACK",
                    "Tracks": [1],
                    "AudioDurationCorrection": "TRACK"
                }
            },
            "VideoSelector": {
                "ColorSpace": "FOLLOW"
            },
            "FilterEnable": "AUTO",
            "PsiControl": "USE_PSI",
            "FilterStrength": 0,
            "DeblockFilter": "DISABLED",
            "DenoiseFilter": "DISABLED",
            "TimecodeSource": "ZEROBASED",
            "FileInput": "my-input-file"
        }
    ]
}

2. 统一模板与Job的Timecode配置 #

确保JobTemplate中的TimecodeConfig.Source保持ZEROBASED，与Input的TimecodeSource一致，避免时间码不匹配：

"TimecodeConfig": {
    "Source": "ZEROBASED"
}

二、对应ffmpeg -af aresample=async=1 的MediaConvert设置 #

ffmpeg的aresample=async=1作用是强制音频流时长严格匹配输入轨道，对应MediaConvert中的AudioDurationCorrection参数：

• 将AudioSelector的AudioDurationCorrection设为TRACK，即可让MediaConvert以原始音频轨道的时长为准，不自动截断静音部分。

三、AWS Elastic Transcoder 替代方案 #

若使用Elastic Transcoder，可创建如下预设并配置Job：

1. 音频转码预设示例（MP3输出） #

{
    "Name": "Preserve-Full-Duration-MP3",
    "Container": "mp3",
    "Audio": {
        "Codec": "mp3",
        "BitRate": 96000,
        "SampleRate": 48000,
        "Channels": 2
    },
    "Thumbnails": {
        "Format": "none"
    }
}

2. Job配置关键项 #

确保TimeSpan设置为完整文件，不做截断：

{
    "PipelineId": "YOUR_PIPELINE_ID",
    "Input": {
        "Key": "my-input-file",
        "FrameRate": "auto",
        "Resolution": "auto",
        "AspectRatio": "auto",
        "Interlaced": "auto",
        "Container": "auto"
    },
    "Output": {
        "Key": "my-output-file.mp3",
        "PresetId": "YOUR_PRESET_ID",
        "TimeSpan": {
            "StartTime": "0",
            "Duration": "auto"
        }
    }
}

内容的提问来源于stack exchange，提问作者fblundun