音频channels=2的时候，在线视频播放卡顿

[zdw19840929]

我现在有这样一个视频，音频channels是2，这时候在线播放会变得非常卡顿，如果我用ffmpeg -i IMG_3493.MOV -ac 1 IMG_3493Out.MOV命令将他变成1之后就可以正常在线浏览了，大神们知道是这么回事吗？
"streams": [
{
"index": 0,
"codec_name": "aac",
"codec_long_name": "AAC (Advanced Audio Coding)",
"profile": "LC",
"codec_type": "audio",
"codec_tag_string": "mp4a",
"codec_tag": "0x6134706d",
"sample_fmt": "fltp",
"sample_rate": "44100",
"channels": 2,
"channel_layout": "stereo",
"bits_per_sample": 0,
"initial_padding": 0,
"id": "0x1",
"r_frame_rate": "0/0",
"avg_frame_rate": "0/0",
"time_base": "1/44100",
"start_pts": 0,
"start_time": "0.000000",
"duration_ts": 7003136,
"duration": "158.801270",
"bit_rate": "128376",
"nb_frames": "6839",
"extradata_size": 2,
"disposition": {
"default": 1,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0,
"timed_thumbnails": 0,
"non_diegetic": 0,
"captions": 0,
"descriptions": 0,
"metadata": 0,
"dependent": 0,
"still_image": 0
},
"tags": {
"creation_time": "2020-11-24T09:46:40.000000Z",
"language": "und",
"vendor_id": "[0][0][0][0]"
}
},
{
"index": 1,
"codec_name": "h264",
"codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
"profile": "High",
"codec_type": "video",
"codec_tag_string": "avc1",
"codec_tag": "0x31637661",
"width": 640,
"height": 360,
"coded_width": 640,
"coded_height": 360,
"closed_captions": 0,
"film_grain": 0,
"has_b_frames": 2,
"pix_fmt": "yuv420p",
"level": 30,
"chroma_location": "left",
"field_order": "progressive",
"refs": 1,
"is_avc": "true",
"nal_length_size": "4",
"id": "0x2",
"r_frame_rate": "24000/1001",
"avg_frame_rate": "19015/794",
"time_base": "1/90000",
"start_pts": 7516,
"start_time": "0.083511",
"duration_ts": 14292000,
"duration": "158.800000",
"bit_rate": "488310",
"bits_per_raw_sample": "8",
"nb_frames": "3803",
"extradata_size": 40,
"disposition": {
"default": 1,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0,
"timed_thumbnails": 0,
"non_diegetic": 0,
"captions": 0,
"descriptions": 0,
"metadata": 0,
"dependent": 0,
"still_image": 0
},
"tags": {
"creation_time": "2020-11-24T09:46:40.000000Z",
"language": "und",
"vendor_id": "[0][0][0][0]",
"encoder": "JVT/AVC Coding"
}
}
]